Analysis of Refinery

Chemical Emissions and

Health Effects
March 2019

Office of Environmental Health

Hazard Assessment

California Environmental Protection Agency

Jared Blumenfeld
Secretary, California Environmental Protection Agency

Lauren Zeise, Ph.D.

Director, Office of Environmental Health Hazard Assessment
 LIST OF CONTRIBUTORS

Office of Environmental Health Hazard Assessment

California Environmental Protection Agency

Authors1
Karen Riveles, PhD MPH
Alyssa Nagai

Reviewers
Kenneth Kloc, PhD
James F. Collins, PhD
John Faust, PhD
Melanie A. Marty, PhD
Allan Hirsch
Lauren Zeise, PhD

1The authors would like to acknowledge the contributions of Ms. Lilian Polsky in editing this document.
 CONTENTS
PREFACE ........................................................................................................................ i

EXECUTIVE SUMMARY .................................................................................................. i

I. INTRODUCTION ..................................................................................................... 1

II. LIST OF CHEMICALS EMITTED FROM CALIFORNIA REFINERIES .................... 2

III. HEALTH GUIDANCE AND EMERGENCY EXPOSURE VALUES .......................... 6

A. OEHHA and US EPA Health Guidance Values ................................................. 6

B. US EPA and NIOSH Emergency Exposure Levels .......................................... 15

IV. HEALTH EFFECTS OF SELECT CALIFORNIA REFINERY CHEMICALS........... 20

V. MOST HIGHLY EMITTED CHEMICALS AND OTHER SUPPORTING

INFORMATION ..................................................................................................... 27

A. California Refinery Incident History .................................................................. 28

B. California Refinery Process Units, Emission Points, and Equipment ............... 29

C. Chemical Analysis Categories for Air Monitoring ............................................. 30

D. Most Highly Emitted Routine Emissions of Toxic Air Contaminants from ........ 31

California Refineries......................................................................................... 31

E. Routine and Non-routine Chemical Emissions by California Refineries ........... 34

F. Refinery Emissions in the US and Fuel-Burning Experiments ......................... 36

VI. CONCLUSIONS .................................................................................................... 37

REFERENCES .............................................................................................................. 38
APPENDIX A: SUPPLEMENTARY INFORMATION ON HEALTH EFFECTS OF
SELECT REFINERY CHEMICALS ...................................................... A-1

APPENDIX B: CALIFORNIA REFINERY PROCESS UNITS AND EMISSION

POINTS WITH ASSOCIATED CHEMICAL EMISSIONS ..................... B-1

APPENDIX C: CALIFORNIA REFINERY CHEMICALS SORTED BY CHEMICAL

ANALYSIS CATEGORY ..................................................................... C-1

APPENDIX D: ROUTINE TOXIC AIR CONTAMINANT EMISSIONS FROM

CALIFORNIA REFINERIES ................................................................. D-1

APPENDIX E: NON-ROUTINE AND ROUTINE EMISSIONS...................................... E-1

APPENDIX F: REFINERY EMISSIONS IN THE US AND FUEL-BURNING

EXPERIMENTS .................................................................................... F-1

APPENDIX G: DATA ANALYSIS OF REFINERY CHEMICALS ACROSS

CATEGORIES ..................................................................................... G-1

APPENDIX H: TOXICITY WEIGHTED TOTALS FOR CHEMICALS RELEASED

FROM CALIFORNIA REFINERIES .................................................... H-1

APPENDIX I: LIST OF ABBREVIATIONS .................................................................. I-1

LIST OF TABLES
Table 1. List of Chemicals Emitted from California Refineries......................................... 3

Table 2. OEHHA and US EPA Health Guidance Values and Descriptions ..................... 7

Table 3. Health Guidance Values for Chemicals Emitted from California Refineries ...... 8

Table 4. US EPA and NIOSH Emergency Exposure Levels and Descriptions .............. 16

Table 5. Emergency Exposure Levels for Chemicals Emitted from California Refineries
...................................................................................................................................... 17

Table 6. Health Effects of Select California Refinery Chemicals ................................... 21

Table 7. Process Units, Emission Points, and Equipment Reported to be Associated

with California Refinery Incidents ..................................................................... 29

Table 8. California Refinery Process Units, Emission Points, and Equipment Sorted by
Release Type ................................................................................................... 30

Table 9. Chemical Analysis Categories for Air Monitoring............................................. 30

Table 10. Toxic Air Contaminants with the Ten Highest Routine Emissions from
California Refineries ...................................................................................... 33

Table 11: Ten Highest Routine Chemical Emissions by California Refineries ............... 34

Table 12. Ten Highest Non-routine Chemical Emissions by California Refineries ........ 35

Table B1. California Refinery Process Units and Emission Points with Associated
Chemical Emissions.................................................................................... B-2

Table C1. California Refinery Chemicals Sorted by Chemical Analysis Category ........ E-1

Table D1. Average Annual Routine Toxic Air Contaminant Emissions for California
Refineries ................................................................................................... C-1

Table E1. Annual Routine and Non-routine Chemical Emissions by California

Refineries .................................................................................................... E-1

Table F1. Refinery Emissions in the US and Fuel-Burning Experiments..................... F-1

Table G1. Comparison of Chemicals with High Routine Emissions and Health
Guidance Values ......................................................................................... G-3
Table G2. OEHHA REL Values for Chemicals with High Routine Emissions .............. G-3

Table G3. Chemicals Sorted by Chemical Analysis Category ..................................... G-4

Table H1. Toxicity Weighted Totals for Chemicals Released from California
Refineries .................................................................................................... H-1
LIST OF FIGURES
Figure 1. Relative Occurrence of Chemical Analysis Categories in Routine Toxic Air
Contaminant Emissions from California Refineries ........................................ 33

Figure 2. Relative Occurrence of Chemical Analysis Categories in Routine Toxic Air

Contaminant Emissions from California Refineries ........................................ 35

Figure 3. Relative Occurrence of Chemical Analysis Categories in Non-routine Chemical

Emissions by California Refineries ................................................................. 36
 i

PREFACE

The Office of Environmental Health Hazard Assessment (OEHHA) has collaborated with
the California Air Resources Board (CARB) and the Interagency Refinery Task Force to
develop information on chemicals emitted from refineries and their health effects. This
information can support CARB and other groups in developing plans for air monitoring
in the vicinity of refineries in California. In the event of a refinery emergency, knowledge
of health guidance values and emissions of chemicals can also help emergency
responders characterize potential health effects that may occur following a chemical
release.

In August 2012, there was a serious fire at the Chevron Refinery in Richmond, CA.
During that event, an estimated 15,000 people from the nearby community sought care
at local emergency departments and clinics. Follow-up investigations of the incident
revealed a number of refinery safety issues. In July 2013, CARB released a report
entitled “Air Monitoring for Accidental Refinery Releases: Assessment of Capabilities
and Potential Improvements Project Plan.” This report laid out a stepwise plan to
improve California’s refinery air monitoring and emergency response system.

In February 2014, Governor Brown issued a report titled “Improving Public and Worker
Safety at Oil Refineries,” which echoed the importance of monitoring air quality near
refineries and resulted in the establishment of the Interagency Refinery Task Force
coordinated by the California Environmental Protection Agency (CalEPA). In public
meetings following the release of the governor’s report, community members asked if a
complete list of chemicals that could be released from refineries existed, and if those
chemicals had been prioritized for monitoring to ensure that monitoring systems would
be tailored—insofar as feasible—to measure the most important chemicals.

As a result of these questions from the public, OEHHA compiled the information in this
report. The report presents as comprehensive a list of chemicals as possible using
existing data sources, and then prioritizes the chemicals according to their emissions
and toxicity. This report does not attempt to estimate exposure or risk in communities.

OEHHA released a draft of this report in September 2017, while CARB concurrently
released a draft report titled Refinery Emergency Air Monitoring Assessment Report.
Objective 2: Evaluation of Air Monitoring Capabilities, Gaps and Potential
Enhancements. OEHHA, CARB, and CalEPA participated in a series of workshops
throughout California in 2018 to receive feedback on the reports. During the
workshops, OEHHA did not receive any comments on its report that necessitated any
changes or additions. The final OEHHA report is now being released. This report offers
a useful compendium of information to assist local air districts and communities as they
make decisions about air monitoring, emergency response, and other efforts related to
refinery chemicals and public health.

EXECUTIVE SUMMARY

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Introduction

The Office of Environmental Health Hazard Assessment (OEHHA), in collaboration with

the California Air Resources Board (CARB) and the California Environmental Protection
Agency’s (CalEPA) Interagency Refinery Task Force, has developed information on
chemicals emitted from refineries, and their health effects. This information may assist
CARB, local air districts, and communities in developing plans for air monitoring at
refineries in California. In the event of a refinery emergency, this information may also
help emergency responders characterize the potential health effects that may occur
following a chemical release.

OEHHA has compiled a list of 188 chemicals that have been reported to be emitted
from California refineries. This list can assist the CARB in identifying candidate
chemicals for potential air monitoring near refineries.

OEHHA created this list of chemicals based on:

 Data on routine releases of toxic air contaminants from California refineries

reported to CARB during the years 2009-2012 and 2014.
 Data on routine and non-routine emissions from California refineries reported to
the US Environmental Protection Agency (US EPA) as part of a data call-in in
2010.
 Publicly available data in government reports, internet databases, and peer-
reviewed journal articles.

The presence of a chemical on this list does not necessarily mean it is released from all
refineries, at all times, or in significant quantities. Nor does it indicate the chemical’s
degree of toxicity.

For these reasons, OEHHA took steps to screen the list of 188 chemicals, based on
exposure and toxicity potential.

Comparisons between high routine emissions of chemicals and health guidance values
or emergency exposure levels that measure the toxicity of those chemicals may help
determine which chemicals are appropriate for air monitoring, and may ultimately help
protect communities surrounding these refineries by limiting exposures to those
chemicals. To that end, OEHHA has performed some preliminary analyses of the
compiled data. Measures of toxicity of individual chemicals included OEHHA’s
Reference Exposure Levels (RELs), Cancer Potency Factors (CPFs) and Unit Risk
Values, No Significant Risk Levels and Maximum Allowable Dose Levels for chemicals
on California’s Proposition 65 list, and the US Environmental Protection Agency’s
(US EPA) Reference Concentrations (RfCs). In addition, OEHHA looked at US EPA’s
Acute Emergency Exposure Guidelines (AEGLs) and the National Institute for
Occupational Safety and Health’s (NIOSH) Immediately Dangerous to Life and Health
(IDLH) values.

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These health guidance values and toxicity designations were compared to routine and
non-routine (including accidental) emissions from refineries, chemicals involved in
previous incidents, and chemicals with involvement in the most refinery equipment or
processes. Finally, US EPA toxicity-weighting factors were used in conjunction with
routine emissions data to calculate toxicity-weighted emissions scores. The report also
provides health and safety information for select candidate chemicals known to be
emitted in high quantities from refineries in California, with the understanding that
potential health effects are dependent on the extent and duration of exposure.

Toxicity: Health Guidance Values and Toxicity Designations for the General
Population

OEHHA and other agencies develop health guidance values for cancer and noncancer
endpoints, to guide regulatory agencies like CARB in taking actions that protect the
general public from the effects of possible toxic chemical exposures. In general, the
health guidance value for an airborne pollutant is the air concentration of the chemical
that is not likely to cause adverse health outcomes in humans, including sensitive
subgroups, for the specified exposure duration.

After compiling the list of chemicals emitted from California refineries, OEHHA
determined which chemicals had health guidance values. Specific types of health
guidance values included in our analysis are described below. Any one chemical may
have multiple types of health guidance values.

OEHHA determines Reference Exposure Levels (RELs) for airborne chemicals as

required by California’s Air Toxics ‘Hot Spots’ Program. The REL assessments identify
human systems (e.g. the respiratory system) or organs that could be affected by the
noncancer effects of the chemicals. These RELs can cover three types of exposure
durations: acute (for infrequent 1-hour exposure), 8-hour (for repeated 8-hour
exposures), and chronic (for continuous long-term exposure). OEHHA determined
which refinery chemicals from the list of 188 had each of these RELs. OEHHA found
that 67 chemicals have at least one REL and some of these have more than one REL.
Forty chemicals have an acute REL, 10 have an 8-hour REL, and 62 have a chronic
REL. OEHHA found that there are RELs for all the listed chemicals with combined
releases of greater than 10,000 pounds per year across all refineries in California.

US EPA also establishes noncancer health guidance values referred to as Reference

Concentrations (RfCs) for air contaminants. US EPA RfCs are developed using a
different risk assessment methodology, and therefore may be different from OEHHA’s
RELs. OEHHA identified 48 chemicals found in refinery emissions with RfC values, of
which nine do not have RELs. Overall, 109 of the 188 chemicals reported to be
released from California refineries were determined to have at least one REL or RfC.

OEHHA develops Cancer Potency Factors (CPF) and Unit Risk Factors (URF) for the
Air Toxics ‘Hot Spots’ program to address the carcinogenic effects of chemicals. These
values are applied to measured or modeled airborne chemical concentrations to

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estimate the cancer risks to an exposed population. Of the 188 refinery chemicals on
the list, OEHHA identified 70 chemicals that have CPFs, and 57 that have URFs.

For each chemical in the refinery chemical list, OEHHA noted whether it was also on the
Proposition 65 list for cancer or reproductive toxicity. Of the 188 chemicals on the list,
54 are listed under Proposition 65 as carcinogens with No Significant Risk Levels, 21
are listed for developmental effects, and 13 are listed for effects on the male or female
reproductive system with a Maximum Allowable Dose Level.

Overall, 46 of the listed chemicals have none of the types of health guidance values
described here; however, the absence of health guidance values does not necessarily
mean that the chemicals are not hazardous.

Refinery accidents, if they occur, may release high concentrations of chemicals into the
air. Therefore, in accident scenarios where high concentrations of chemicals are
measured or estimated in the air, it can be appropriate to reference emergency
exposure levels. These levels are designed to evaluate risks during emergencies
related to emergency-response worker exposure. They are not applicable in evaluating
exposures for the general public or sensitive populations such as children and the
elderly.

Emergency exposure levels can help emergency responders evaluate the immediate
dangers from such chemical releases. OEHHA identified which chemicals from the list
have emergency exposure levels using Acute Exposure Guideline Levels (AEGL) and
Immediately Dangerous to Life and Health (IDLH) values. AEGLs are developed by
US EPA, and IDLH values are developed by the National Institute for Occupational
Safety and Health. Of the 188 chemicals on the list, 94 chemicals have at least one of
these two emergency exposure levels. The absence of emergency exposure levels
does not necessarily mean that these chemicals are not hazardous.

Most Highly Emitted Chemicals and Other Supporting Information

OEHHA investigated publicly available data on California’s refinery incident history and
the process units or equipment associated with such incidents. For the years 2001-
2012, OEHHA found reports on 127 incidents. Flares were the most common
category/source of incidents that resulted in emissions to outdoor air. The term “smoke”
(from explosion, fire, or flares) was associated with the highest number of incidents (63)
reported during that period. The most frequently cited chemicals are included on the
candidate list for air monitoring provided below: benzene, 1,3-butadiene, hydrogen
fluoride, hydrogen sulfide, particulate matter (PM), sulfur dioxide, sulfuric acid, toluene,
and hydrocarbons (not otherwise specified).

All California refineries active during the year 2010 were required to measure air
emissions from each of their process or emission points for a certain amount of time,
and to submit this data to US EPA. OEHHA used these emissions inventories to
identify the most commonly occurring processes along with their associated chemical

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emissions. A total of 20 processes were examined and chemicals involved in the most
processes or equipment were considered for the candidate chemical list. The candidate
chemicals released in the majority of processes were benzene, naphthalene, and
toluene.

OEHHA collected information on routine and non-routine emissions from California

refineries. One source of data on routine emissions came from the Assembly Bill 2588
Air Toxics ‘Hot Spots’ Program reported in the California Emission Inventory
Development and Reporting System database (CEIDARS) for 2009-2012 and 2014.

The ten most frequently reported routine toxic air contaminant emissions from California
refineries from 2009-2012 (starting with the highest) were:

 ammonia  toluene
 formaldehyde  xylene
 methanol  benzene
 sulfuric acid  hexane
 hydrogen sulfide  hydrogen chloride

The average routine emissions for all chemicals reported in CEIDARS for California
refineries for 2009-2012 in pounds per year are compiled in this report.

OEHHA also used additional data for routine and non-routine emissions of all pollutants
(not just TACs) that California refineries reported to the US EPA for the year 2010 only.
Using these data, OEHHA determined the most frequently emitted chemicals (starting
with the highest) were:

 sulfur dioxide  butane

 carbon monoxide  nitrogen dioxide
 nitrogen oxides  propylene
 PM10 and PM2.5  hexane

OEHHA totaled the amount of routine and non-routine emissions for all chemicals
reported in this data set in the report.

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Conclusions

Of the 188 chemicals identified as emitted from California refineries, the chemicals
listed below are the top candidates for air monitoring, based on their toxicity, average
levels of emissions from refineries statewide, and involvement in multiple refinery
processes and incidences. OEHHA also derived a “toxicity-weighted” emissions score
for each chemical for which emissions data were available for all refineries across
California. OEHHA calculated the toxicity-weighted emissions scores using emissions
data (pounds emitted per year) obtained from the Air Toxics ‘Hot Spots’ Emissions
Inventory database (CEIDARS) for 2014, and a toxicity weight derived from US EPA’s
Inhalation Toxicity Scores for individual chemicals. The candidate chemicals that had
high calculated toxicity-weighted emissions are noted in the candidate list below with an
asterisk (in alphabetical order).

These candidates for air monitoring were not further ranked or prioritized.

 acetaldehyde*  naphthalene*
 ammonia*  nickel*
 benzene*  nitrogen oxide
 1,3-butadiene*  polycyclic aromatic hydrocarbons
 cadmium* (PAH)*
 diethanolamine*  particulate matter (PM)
 formaldehyde*  sulfur dioxide
 hydrogen fluoride  sulfuric acid
 hydrogen sulfide*  toluene
 manganese*

An important consideration for air monitoring at individual refineries is that the candidate
chemicals will differ based on location as well as year. Some top-candidate chemicals
are only released in small amounts from individual refineries.

Finally, the release of these chemicals from refineries does not necessarily mean that
local communities face substantial exposures or significant health risks. However, it
does increase their likelihood of exposure. Air monitoring of these chemicals may
inform decisions that could reduce exposure.

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I. INTRODUCTION
This report may assist the California Air Resources Board (CARB) in making decisions
for the air monitoring of communities near refineries, and assist local air districts in
selecting the most appropriate monitoring methods and tools when responding to future
emergency releases. This report may inform statewide guidance and recommendations
being developed by CARB and the California Air Pollution Control Officers Association
(CAPCOA) as part of their joint effort to improve air monitoring near California’s
refineries.

CARB and CAPCOA initiated a statewide assessment of emergency air monitoring

capabilities at California oil refineries in an effort to improve employee and public safety.
CARB is collaborating with other members of the California Environmental Protection
Agency’s (CalEPA) Interagency Refinery Task Force (IRTF) to develop findings,
recommendations, and proposed implementation measures for improving emergency
air monitoring at refineries.

As part of this interagency collaboration, the Interagency Refinery Task Force asked the
Office of Environmental Health Hazard Assessment (OEHHA) to assess the potential
health effects of chemicals commonly emitted from California refineries and to provide
specific regulatory and advisory health values for these chemicals. To this end, OEHHA
first compiled an initial list of chemicals emitted from California refineries based on data
for Toxic Air Contaminants (TACs)1 reported in the California Emission Inventory
Development and Reporting System (CEIDARS) database for all California refineries
active from 2009 to 2012. Further data on California refinery chemicals, not limited to
TACs, were provided by internet databases, publicly available data, government
reports, and peer-reviewed journal articles. Upon completion of the refinery chemicals
list, OEHHA researched chemical-specific information regarding health effects and
advisory health standards. Information on chemical health effects was obtained from
the OEHHA Reference Exposure Level (REL) web page, the US Environmental
Protection Agency (US EPA) Integrated Risk Information System (IRIS) web page, and
the Agency for Toxic Substances and Disease Registry (ATSDR) Toxic Substances
Portal. Additional sources include the web pages for the National Institutes of Health
(NIH) Hazardous Substances Data Bank (HSDB) and Toxicology Data Network
(TOXNET), the Centers for Disease Control and Prevention (CDC) Emergency
Preparedness and Response web page, the NIOSH Pocket Guide to Chemical
Hazards, and the National Oceanic and Atmospheric Administration’s (NOAA)
Computer-Aided Management of Emergency Operations (CAMEO) Chemicals.

1“Toxic air contaminants” are defined in California law as air pollutants which may cause or contribute to
an increase in mortality or in serious illness, or which may pose a present or potential hazard to human
health (Health and Safety Code section 39655)
URL to current list: https://www.arb.ca.gov/toxics/quickref.htm#TAC

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II. LIST OF CHEMICALS EMITTED FROM CALIFORNIA REFINERIES

To create an initial list of chemicals that have been reported as emitted from California
oil refineries, OEHHA obtained a list of TACs reported in the CEIDARS database from
CARB for all California refineries active at any point during 2009 to 2012. These
emissions data were reported in accordance with the Air Toxics Hot Spots Information
and Assessment Act (AB 2588) and served as the foundation of OEHHA’s list of
refinery-emitted chemicals. Chemicals other than TACs were added to the list based on
California refinery emissions data provided by US EPA. To identify other chemicals not
included in the CEIDARS or US EPA datasets, OEHHA also performed a literature
search and compiled information on refinery air monitoring and incidents in California.
This search resulted in additional sources such as peer-reviewed journal articles,
government reports such as Bay Area Air Quality Management District (BAAQMD)
incident reports, and online databases such as the US Chemical Safety Board (CSB)
Industrial Chemical Incident Screening Database and the list of major accidents at
refineries reported by Contra Costa Health Services (CCHS). After the later release of
CEIDARs data for 2014, OEHHA also examined and analyzed this dataset

The name and Chemical Abstracts Service Registry Number (CAS RN) of each
chemical included in the initial list of California refinery chemicals are shown in Table 1
below. Some chemicals on this list are routinely emitted from refineries, others may be
emitted only during incidents, and others may rarely be emitted.

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Table 1. List of Chemicals Emitted from California Refineries

Chemical CAS RN Source1 Chemical CAS RN Source
Acenaphthene 83329 [1] Carbon monoxide 630080 [2]
Acenaphthylene 208968 [1] Carbon tetrachloride 56235 [1]
Acetaldehyde 75070 [1] Carbonyl sulfide 463581 [2]
Acetone 67641 [2] Chlorine 7782505 [1]
Acetylene 74862 [2] Chlorobenzene 108907 [2]
Acrolein 107028 [1] Chlorodifluoromethane 75456 [2]
Aluminum 7429905 [1] Chloroform 67663 [1]
Ammonia 7664417 [1] 2-Chloronaphthalene 91587 [2]
Aniline 62533 [2] Chromium 7440473 [2]
Anthracene 120127 [1] Chromium (hexavalent & compounds) 18540299 [1]
Antimony 7440360 [2] Chromium III (& compounds) 16065831 [2]
Arsenic 7440382 [2] Chrysene 218019 [2]
Asbestos 1332214 [1] Cobalt 7440484 [2]
Barium 7440393 [2] Copper 7440508 [1]
Benz[a]anthracene 56553 [1] Cresols (mixtures of) 1319773 [2]
Benzene 71432 [1] m-Cresol 108394 [2]
Benzo[b]fluoranthene 205992 [1] o-Cresol 95487 [2]
Benzo[j]fluoranthene 205823 [1] p-Cresol 106445 [2]
Benzo[k]fluoranthene 207089 [1] Cumene 98828 [2]
Benzo[g,h,i]perylene 191242 [1] Cyclohexane 110827 [2]
Benzo[a]pyrene 50328 [1] Cyclopentadiene 542927 [2]
Benzo[e]pyrene 192972 [1] Cyclopentane 287923 [2]
Beryllium 7440417 [1] Dibenz[a,h]anthracene 53703 [1]
Biphenyl 92524 [2] Dibenzo-p-dioxins (chlorinated) ― [1]
1,2-Butadiene 590192 [2] 1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin 35822469 [2]
1,3-Butadiene 106990 [2] 1,2,3,4,7,8-Hexachlorodibenzo-p-dioxin 39227286 [2]
Butane 106978 [2] 1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin 57653857 [2]
1-Butene 106989 [2] 1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin 19408743 [2]
2-Butene 107017 [2] 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin 3268879 [1]
Cadmium 7440439 [1] 1,2,3,7,8-Pentachlorodibenzo-p-dioxin 40321764 [2]

1 Sources: 1 Air Resources Board; 2 US EPA, 2012a; US EPA, 2012b; 3 Chemical Safety Board (CSB)

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Chemical CAS RN Source1 Chemical CAS RN Source

Carbon disulfide 75150 [2] 2,3,7,8-Tetrachlorodibenzo-p-dioxin 1746016 [2]
Dibenzofuran 132649 [2] Ethylene glycol monoethyl ether acetate 111159 [2]
Dibenzofurans (chlorinated) 1080 [1] Fluoranthene 206440 [2]
1,2,3,4,6,7,8-Heptachlorodibenzofuran 67562394 [2] Fluorene 86737 [2]
1,2,3,4,7,8,9-Heptachlorodibenzofuran 55673897 [2] Formaldehyde 50000 [1]
1,2,3,4,7,8-Hexachlorodibenzofuran 70648269 [2] Glutaraldehyde 111308 [2]
1,2,3,6,7,8-Hexachlorodibenzofuran 57117449 [2] Glycol ethers (& acetates) 1115 [1]
1,2,3,7,8,9-Hexachlorodibenzofuran 72918219 [2] Heptane 142825 [2]
2,3,4,6,7,8-Hexachlorodibenzofuran 60851345 [2] Hexachloroethane 67721 [2]
1,2,3,4,6,7,8,9-Octachlorodibenzofuran 39001020 [2] Hexane 110543 [2]
1,2,3,7,8-Pentachlorodibenzofuran 57117416 [2] Hydrogen 1333740 [3]
2,3,4,7,8-Pentachlorodibenzofuran 57117314 [2] Hydrogen chloride 7647010 [1]
2,3,7,8-Tetrachlorodibenzofuran 51207319 [2] Hydrogen cyanide 74908 [2]
Dibutyl phthalate 84742 [2] Hydrogen fluoride 7664393 [1]
1,4-Dichlorobenzene 106467 [2] Hydrogen sulfide 7783064 [1]
1,1-Dichloroethane 75343 [2] Indeno[1,2,3-c,d]pyrene 193395 [2]
1,1-Dichloroethylene 75354 [2] Isobutane 75285 [3]
1,2-Dichloropropane 78875 [1] Isobutene 115117 [2]
1,3-Dichloropropene 542756 [1] Isopentane 78784 [2]
Diesel engine exhaust 9901 [1] Isoprene 78795 [2]
Diethanolamine 111422 [2] Isopropanol 67630 [1]
Diethyl phthalate 84662 [2] Lead 7439921 [2]
Di(2-ethylhexyl)phthalate 117817 [2] Manganese 7439965 [2]
1,1-Dimethylallene 598254 [2] Mercury 7439976 [2]
7,12-Dimethylbenz[a]anthracene 57976 [1] Methane 74828 [2]
1,4-Dioxane 123911 [1] Methanol 67561 [1]
Ethane 74840 [2] Methyl bromide 74839 [2]
Ethyl chloride 75003 [2] Methyl chloride 74873 [2]
Ethylbenzene 100414 [2] Methyl chloroform 71556 [1]
Ethylene 74851 [1] Methyl ethyl ketone 78933 [2]
Ethylene dibromide 106934 [2] Methyl isobutyl ketone 108101 [2]
Ethylene dichloride 107062 [2] Methyl tert-butyl ether 1634044 [2]
Ethylene glycol monoethyl ether 110805 [2] 3-Methylcholanthrene 56495 [2]

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Chemical CAS RN Source1 Chemical CAS RN Source

Methylcyclohexane 108872 [2] Propane 74986 [2]
Methylene chloride 75092 [2] Propylene 115071 [2]
2-Methylnaphthalene 91576 [1] Propylene glycol monomethyl ether 107982 [2]
Molybdenum 7439987 [2] Propylene glycol monomethyl ether acetate 108656 [2]
Naphthalene 91203 [2] Propylene glycol mono-t-butyl ether 57018527 [2]
Nickel 7440020 [2] Propylene oxide 75569 [2]
Nitrogen dioxide 10102440 [2] Pyrene 129000 [2]
Nitrogen oxides ― [2] Selenium (& compounds) 7782492 [1]
Nitrous oxide 10024972 [1] Selenium sulfide 7488564 [2]
Octane 111659 [2] Styrene 100425 [2]
PAHs, total, w/ individ. components
reported 1150 [1] Sulfur dioxide 7446095 [2]
PAHs, total, w/o individ. components
reported 1151 [1] Sulfur monoxide 13827322 [3]
1,2-Pentadiene 591957 [2] Sulfur trioxide 744619 [3]
cis-1,3-Pentadiene 1574410 [2] Sulfuric acid 766439 [1]
trans-1,3-Pentadiene 2004708 [2] 1,1,2,2-Tetrachloroethane 79345 [1]
1,4-Pentadiene 591935 [2] Toluene 108883 [2]
2,3-Pentadiene 591968 [2] 1,1,2-Trichloroethane 79005 [1]
Pentane 109660 [2] Trichloroethylene 79016 [2]
Perchloroethylene 127184 [2] Trichlorofluoromethane 75694 [2]
Perylene 198550 [2] 1,1,2-Trichloro-1,2,2-trifluoroethane 76131 [2]
Phenanthrene 85018 [2] Triethylamine 121448 [2]
Phenol 108952 [2] Trimethylbenzene 25551137 [2]
Phosphoric acid 7664382 [1] 1,2,4-Trimethylbenzene 95636 [1]
Phosphorus 7723140 [1] 2,2,4-Trimethylpentane 540841 [2]
PM (condensable) ― [2] Vanadium 7440622 [1]
PM10 ― [2] Vinyl chloride 75014 [2]
PM10 (filterable) ― [2] Xylenes (mixed) 1330207 [2]
PM2.5 ― [2] m-Xylene 108383 [2]
PM2.5 (filterable) ― [2] o-Xylene 95476 [2]
Polychlorinated biphenyls 1336363 [2] p-Xylene 106423 [2]
Propadiene 463490 [2] Zinc 7440666 [1]
1 Air Resources Board; 2 US EPA, 2012a; US EPA, 2012b; 3 Chemical Safety Board (CSB)

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III. HEALTH GUIDANCE AND EMERGENCY EXPOSURE VALUES

A. OEHHA and US EPA Health Guidance Values

The release of chemicals from refineries may potentially result in exposure to workers,
bystanders (persons proximate to the refinery), and nearby communities. In the event
of a refinery emergency, health guidance values can help responders characterize
potential health effects that may result following a chemical release. OEHHA
determines Reference Exposure Levels (RELs) associated with physiological systems
that are could be affected (for example, respiratory system) for the noncancer effects of
airborne chemicals as part of the Air Toxics Hot Spots program. US EPA also
establishes noncancer health guidance values referred to as Reference Concentrations
(RfCs) for air contaminants. It can be reasonably anticipated that no adverse health
effects will occur in exposed populations, including sensitive subpopulations for
exposures to concentrations at or below the OEHHA RELs, including the acute REL for
short-term exposures (one-hour), the eight-hour REL for repeated eight-hour exposures,
and the chronic REL for continuous long-term exposures. The US EPA RfCs are similar
to OEHHA’s chronic RELs for long-term exposures, but are developed using a different
risk assessment methodology than OEHHA employs and therefore may be different.

Cancer Potency Factors (CPF), also referred to as Cancer Slope Factors (CSF), and
unit risk values are calculated for chemicals known to be carcinogenic. These values
are developed under several OEHHA’s programs: the Air Toxics Hot Spots Program;
Public Health Goals (PHG) for drinking water; Toxic Air Contaminant Program; and
Proposition 65. In addition, CPFs are obtained from US EPA’s Integrated Risk
Information System (IRIS). These factors are used in combination with measured or
modeled airborne concentrations to estimate lifetime cancer risks to an exposed
population.

The health guidance values shown in Table 2 below have been developed to protect the
general public from the cancer and noncancer endpoints that may result from toxic
chemical exposures.

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Table 2. OEHHA and US EPA Health Guidance Values and Descriptions

Guidance Value1 Source Description
Reference Exposure OEHHA Airborne concentration level at or below
Level (REL) (µg/m3 which no adverse health effects are
inhalation, µg/kg-day anticipated for a specified exposure
oral) duration. OEHHA has acute RELs for an
exposure lasting one hour2, eight-hour
RELs for long-term, repeated (up to daily)
exposures of eight hours, and chronic RELs
for continuous exposures lasting ≥12% of a
lifetime. A few RELs are based on an oral
exposure.
Reference US EPA (IRIS) Estimate of continuous inhalation exposure
Concentration (RfC) to the human population (including
(mg/m3) sensitive subgroups) lasting ≥12% of an
individual’s lifetime that is likely to be
without an appreciable risk of deleterious
effects during a lifetime.
Cancer Slope Factor OEHHA (Air Toxics Upper 95% confidence limit of the slope of
(CSF) (mg/kg-day)-1 Hot Spots, TAC, the extrapolated dose-response curve; this
Proposition 65), US is equivalent to the probability of developing
EPA (IRIS) cancer from continuous lifetime exposure to
a substance (in units of milligram per
kilogram of body weight per day).
Unit Risk (µg/m3)-1 OEHHA (Air Toxics Upper 95% confidence limit of the slope of
Hot Spots, TAC, the extrapolated dose-response curve; this
Proposition 65), US is equivalent to the probability of developing
EPA (IRIS) cancer from continuous lifetime exposure to
a substance (in units of microgram per
cubic meter of air).

1 micrograms per meter cubed, micrograms per kilogram-day

2 A few acute RELs are for slightly longer durations – see OEHHA (2008).

This section does not include all potential health guidance values. Regional Screening
Levels (RSLs), for instance, are developed by US EPA and can be used to determine
chemical-specific concentrations for contaminants found in air, drinking water, and soil
that warrant hazardous waste site cleanup. Additionally, OEHHA develops California
Human Health Screening Levels (CHHSLs) to enable property owners and government
officials to determine the degree of effort that may be required to remediate
contaminated soil. CHHSLs include Soil-Screening Numbers for nonvolatile chemicals
based on total exposure to contaminated soil (inhalation, ingestion, and dermal
absorption), and Soil-Gas Screening Numbers for volatile chemicals below buildings
constructed with and without engineered fill below sub-slab gravel. For further
information on RSLs and CHHSLs, see the US EPA regional screening levels web page
or the OEHHA soil and soil gas risk assessment web page (URLs in References
section).

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Table 3 lists the refinery-emitted chemicals from Table 1 that have one or more of the health guidance values described
above, or that are included on the Proposition 65 list of carcinogens and reproductive or developmental toxicants.

Table 3. Health Guidance Values for Chemicals Emitted from California Refineries
OEHHA OEHHA Cancer Slope Unit Risk
US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1
Eyes; respiratory system
― A 470 ― C 0.01a 2.7x10-6
(sensory irritation)
Acetaldehyde
― 8 300 ― Respiratory system ― ― ―
9 C 140 ― Respiratory system ― ― ―
Eyes, respiratory system
― A 2.5 ― ― ― ―
(sensory irritation)
Acrolein
― 8 0.7 ― Respiratory system ― ― ―
0.02 C 0.35 ― Respiratory system ― ― ―
― A 3,200 ― Respiratory system; eyes ― ― ―
Ammonia
100 C 200 ― Respiratory system ― ― ―
Aniline 1 ― ― ― ― C 5.7x10-3 b 1.6x10-6
Development; cardiovascular
― A 0.2 ― C 12a 3.0x10-3
system; nervous system
Development; cardiovascular
― 8 0.015 ― system; nervous system; ― 1.5b (oral) ―
Arsenic respiratory system; skin
Inhalation and Oral:
Development; cardiovascular
― C 0.015 3.5x10-3 ― ― ―
system; nervous system;
respiratory system; skin
Asbestos ― ― ― ― ― C 220a 0.063

1 US EPA Inhalation Reference Concentrations (RfC). http://www2.epa.gov/iris.

2 OEHHA acute, eight-hour, and chronic Reference Exposure Levels (REL) with corresponding hazard index target organs.
https://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary
3 Proposition 65 status, Chemicals denoted with a C are classified as carcinogens; those with a D are classified as developmental toxicants; those

with Rm, Rf, or Rm/f are reproductive toxicants in males, females or both.
4 OEHHA Cancer Potency Factors (CPF), also known as Cancer Slope Factors (CSF) and Unit Risk Factors, from Appendix A (updated 2011) of

the Technical Support Document for Cancer Potency Factors. http://oehha.ca.gov/media/downloads/crnr/appendixa.pdf. Sources of values: (a)
Toxic Air Contaminant (TAC); (b) Integrated Risk Information System (IRIS); (c) Proposition 65; (d) Public Health Goal (PHG) document.

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OEHHA OEHHA Cancer Slope Unit Risk

US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1
― ― ― ― ― C 0.39a 1.1x10-4
Benz[a]anthracene
― ― ― ― ― ― 1.2 (oral) ―
Development; immune system;
― A 27 ― C 0.1a 2.9x10-5
hematologic system
Benzene
― 8 3 ― Hematologic system D, Rm ― ―
30 C 3 ― Hematologic system ― ― ―
― ― ― ― ― C 3.9a 1.1x10-3
Benzo[a]pyrene
― ― ― ― ― ― 12 (oral) ―
― ― ― ― ― C 0.39a 1.1x10-4
Benzo[b]fluoranthene
― ― ― ― ― ― 1.2 (oral) ―
― ― ― ― ― C 0.39a 1.1x10-4
Benzo[j]fluoranthene
― ― ― ― ― ― 1.2 (oral) ―
― ― ― ― ― C 0.39a 1.1x10-4
Benzo[k]fluoranthene
― ― ― ― ― ― 1.2 (oral) ―
Inhalation: Respiratory system,
immune system; Oral:
Beryllium 0.02 C 7.0x10-3 2 C 8.4b 2.4x10-3
Alimentary system
(gastrointestinal tract)
― A 660 ― Development C 0.6a 1.7x10-4
1,3-Butadiene ― 8 9 ― Reproductive system D, Rm/f ― ―
2 C 2 ― Reproductive system ― ― ―
Inhalation: Kidney, respiratory
― C 0.02 0.5 C 15a 4.2x10-3
Cadmium system; Oral: Kidney
― ― ― ― ― D, Rm ― ―
Reproductive/development;
― A 6,200 ― D, Rm/f ― ―
nervous system
Carbon disulfide
Nervous system; reproductive
700 C 800 ― ― ― ―
system
Carbon monoxide ― A 2.3x104 ― Cardiovascular system D ― ―
Alimentary system (liver);
― A 1,900 ― reproductive/development; C 0.15a 4.2x10-5
Carbon tetrachloride nervous system
Alimentary and nervous
100 C 40 ― ― ― ―
systems; development

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OEHHA OEHHA Cancer Slope Unit Risk

US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1
A 660 Nervous system ― ― ―
Carbonyl sulfide 8 10 Nervous system ― ― ―
C 10 Nervous system ― ― ―
― A 210 ― Respiratory system; eyes ― ― ―
Chlorine
― C 0.2 ― Respiratory system ― ― ―
Alimentary system (liver);
Chlorobenzene ― C 1,000 ― ― ― ―
kidney; reproductive system
Chlorodifluoromethane 5.0x104 ― ― ― ― ― ― ―
Reproductive/development;
― A 150 ― respiratory system; nervous C 0.019a 5.3x10-6
Chloroform system
Alimentary system; kidney;
― C 300 ― D ― ―
development
8.0x10-3 Inhalation: Respiratory system;
C 0.2 20 C 510a 0.15
Chromium (hexavalent)& (aerosols) Oral: Hematologic system
compounds) 0.1 ― ― ― ― D, Rm/f 0.42c (oral) ―
(particulates)
― ― ― ― ― C 0.039a 1.1x10-5
Chrysene
― ― ― ― ― ― 0.12 (oral) ―
Cobalt ― ― ― ― ― C ― ―
Copper ― A 100 ― Respiratory system ― ― ―
Cresols (mixtures of) ― C 600 ― Nervous system ― ― ―
Cumene 400 ― ― ― ― C ― ―
Cyclohexane 6,000 ― ― ― ― ― ― ―
Dibenz[a,h]anthracene ― ― ― ― ― C 4.1c 1.2x10-3
Inhalation and Oral: Alimentary
Dibenzo-p-dioxins5 (liver), reproductive, endocrine,
― C 4.0x10-5 1.0x10-5 C ― ―
(chlorinated) respiratory, hematologic
systems; development
1,2,3,4,6,7,8-
Heptachlorodibenzo-p- ― ― ― ― ― ― 1,300a 0.38
dioxin5
1,2,3,4,7,8-
Hexachlorodibenzo-p- ― ― ― ― ― ― 1.3x104 a 3.8
dioxin5

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OEHHA OEHHA Cancer Slope Unit Risk

US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1
1,2,3,6,7,8-
Hexachlorodibenzo-p- ― ― ― ― ― ― 1.3x104 a 3.8
dioxin5
1,2,3,7,8,9-
Hexachlorodibenzo-p- ― ― ― ― ― ― 1.3x104 a 3.8
dioxin5
1,2,3,7,8-
Pentachlorodibenzo-p- ― ― ― ― ― ― 1.3x105 a 38
dioxin5
Inhalation and Oral: Alimentary
2,3,7,8-
(liver), reproductive, endocrine,
Tetrachlorodibenzo-p- ― C 4.0x10-5 1.0x10-5 C 1.3x105 a 38
respiratory, hematologic
dioxin5
systems; development
1,2,3,4,6,7,8-
― ― ― ― ― ― 1,300a 0.38
Heptachlorodibenzofuran
1,2,3,4,7,8,9-
― ― ― ― ― ― 1,300a 0.38
Heptachlorodibenzofuran
1,2,3,4,7,8-
― ― ― ― ― ― 1.3x104 a 3.8
Hexachlorodibenzofuran
1,2,3,6,7,8-
― ― ― ― ― ― 1.3x104 a 3.8
Hexachlorodibenzofuran
1,2,3,7,8,9-
― ― ― ― ― ― 1.3x104 a 3.8
Hexachlorodibenzofuran
2,3,4,6,7,8-
― ― ― ― ― ― 1.3x104 a 3.8
Hexachlorodibenzofuran
1,2,3,7,8-
― ― ― ― ― ― 6,500a 1.9
Pentachlorodibenzofuran
2,3,4,7,8-
― ― ― ― ― ― 6.5x104 a 19
Pentachlorodibenzofuran
2,3,7,8-
― ― ― ― ― C 1.3x104 a 3.8
Tetrachlorodibenzofuran

5Polychlorinated biphenyls individual congeners evaluated using toxic equivalent factor (TEF) methodology, relative to 2,3,7,8-tetrachlorodibenzo-
p-dioxin. No specific value

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OEHHA OEHHA Cancer Slope Unit Risk

US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1
Nervous and respiratory;
1,4-Dichlorobenzene 800 C 800 ― alimentary system (liver); C 0.04c 1.1x10-5
kidney
1,1-Dichloroethane ― ― ― ― ― C 5.7x10-3 c 1.6x10-6
1,1-Dichloroethylene 200 C 70 ― Alimentary system (liver) ― ― ―
1,2-Dichloropropane 4 ― ― ― ― C ― ―
1,3-Dichloropropene 20 ― ― ― ― C ― ―
― A 0.6 ― Nervous system; development D
Nervous system; development;
― 8 0.06 ― ― ― ―
Mercury kidney
Inhalation & Oral: Nervous
0.3 C 0.03 0.16 ― ― ―
system; development; kidney
― A 2.8x104 ― Nervous system D ― ―
Methanol
2.0x104 C 4,000 ― Development ― ― ―
Nervous system; respiratory
― A 3,900 ― system; reproductive/ D ― ―
Methyl bromide development
Respiratory system; nervous
5 C 5 ― ― ― ―
system; development
Methyl chloride 90 ― ― ― ― D, Rm ― ―
― A 6.8x104 ― Nervous system ― ― ―
Methyl chloroform
5,000 C 1,000 ― Nervous system ― ― ―
Methyl ethyl ketone 5,000 A 1.3x104 ― Respiratory system; eyes ― ― ―
3,000 ― ― ― ― C ― ―
Methyl isobutyl ketone
― ― ― ― ― D ― ―
Kidney; eyes; alimentary
Methyl tert-butyl ether 3,000 C 8,000 ― ― 1.8x10-3 a 2.6x10-7
system (liver)
3-Methylcholanthrene ― ― ― ― ― C 22c 6.3x10-3
Cardiovascular system;
― A 1.4x104 ― C 3.5x10-3 a 1.0x10-6
nervous system
Methylene chloride
Cardiovascular system;
600 C 400 ― ― ― ―
nervous system

Naphthalene 3 C 9 ― Respiratory system C 0.12a 3.4x10-5

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OEHHA OEHHA Cancer Slope Unit Risk

US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1
― A 0.2 ― Immune system C 0.91a 2.6x10-4
― 8 0.06 ― Respiratory, immune systems ― ― ―
Nickel Inhalation: Respiratory system;
― C 0.014 11 hematologic system; Oral: ― ― ―
Development
Nitrogen dioxide ― A 470 ― Respiratory system ― ― ―
Nitrous oxide ― ― ― ― ― D, Rf ― ―
Nervous system; respiratory
― A 2.0x104 ― C 0.21a 5.9x10-6
system; eyes
Perchloroethylene
Kidney; alimentary system
40 C 35 ― ― 0.051c (oral) ―
(liver)
― A 5,800 ― Respiratory system; eyes ― ― ―
Alimentary system;
Phenol
― C 200 ― cardiovascular system; kidney; ― ― ―
nervous system
Phosphoric acid 10 C 7 ― Respiratory system ― ― ―
Inhalation and Oral: Alimentary
(liver), reproductive, endocrine,
Polychlorinated ― C5 ― ― C 2b 5.7x10-4
respiratory, hematologic
biphenyls
systems; development
― ― ― ― ― D ― ―
Propylene ― C 3,000 ― Respiratory system ― ― ―
Propylene glycol
2,000 C 7,000 ― Alimentary system (liver) ― ― ―
monomethyl ether
Propylene glycol mono-t-
― ― ― ― ― C ― ―
butyl ether
Respiratory system; eyes;
― A 3,100 ― C 0.013b 3.7x10-6
Propylene oxide reproductive/development
30 C 30 ― Respiratory system ― 0.24 (oral) ―
Inhalation and Oral: Alimentary
Selenium (& compounds) ― C 20 5 system (liver); cardiovascular ― ― ―
system; nervous system

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OEHHA OEHHA Cancer Slope Unit Risk

US EPA
Chemical Inhalation Oral REL2 Hazard Index Target Organs2 Proposition 653 Factor4 Factor4
RfC1 (µg/m3)
REL2 (µg/m3) (µg/kg-day) (mg/kg-day)-1 (µg/m3)-1

Inhalation and Oral: Alimentary

5
Selenium sulfide ― C 20 system (liver); cardiovascular C ― ―
system; nervous system

Respiratory system; eyes;

― A 2.1x104 ― ― ― ―
Styrene reproductive/development
1,000 C 900 ― Nervous system ― ― ―
Sulfur dioxide ― A 660 ― Respiratory system D ― ―
― A 120 ― Respiratory system C (mist) ― ―
Sulfuric acid
― C 1 ― Respiratory system ― ― ―
1,1,2,2-
― ― ― ― ― C 0.2b 5.8x10-5
Tetrachloroethane
Respiratory, nervous systems;
― A 3.7x104 ― eyes; D ― ―
Toluene reproductive/development
Nervous system; respiratory
5,000 C 300 ― ― ― ―
system; development
1,1,2-Trichloroethane ― ― ― ― ― C 0.057b 1.6x10-5
2 C 600 ― Nervous system; eyes C 7.0x10-3 a 2.0x10-6
Trichloroethylene
― ― ― ― ― D, Rm 0.015c (oral) ―
― A 2,800 ― Nervous system; eyes ― ― ―
Triethylamine
7 C 200 ― Eyes ― ― ―
Nervous system; respiratory
Vinyl chloride 100 A 1.8x105 ― C 0.27a 7.8x10-5
system; eyes
Nervous and respiratory
Xylenes (mixed and m- ― A 2.2x104 ― ― ― ―
systems; eyes
xylene, o-xylene, and p-
Nervous and respiratory
xylene isomers) 100 C 700 ― ― ― ―
systems; eyes

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For information on the development of Reference Exposure Levels, see OEHHA (2008),
and to access the complete list of existing OEHHA RELs, see OEHHA’s Acute, 8-hour
and Chronic Reference Exposure Level (REL) Summary. For US EPA RfCs, see the
US EPA IRIS website. Additional information regarding chemical-specific cancer
studies and the development of CSFs can be found in OEHHA (2009) and on OEHHA’s
Proposition 65 web page. The International Agency for Research on Cancer (IARC)
Monographs on Evaluation of Carcinogenic Risks to Humans provides information on
studies related to carcinogenicity in animals and humans. These Monographs can be
accessed on the IARC web page (URLs in References section).

B. US EPA and NIOSH Emergency Exposure Levels

Refinery accidents are unpredictable and may release high concentrations of chemicals
into the air. Emergency exposure levels can help emergency responders evaluate the
immediate dangers from such chemical releases. While health guidance values can be
used to anticipate the health risks associated with exposure to low chemical
concentrations, emergency exposure levels may be applied in scenarios in which high
concentrations of chemicals are measured or estimated in the air. For this reason,
OEHHA has compiled information on the emergency exposure levels for chemicals in
Table 1 including: US EPA’s Acute Exposure Guideline Levels (AEGL), and the National
Institute for Occupational Safety and Health’s (NIOSH) Immediately Dangerous to Life
and Health (IDLH) values In addition, OEHHA notes which chemicals have Lower
Explosive Limits (LEL).

AEGLs and IDLHs are used to protect workers and emergency responders. Based on
the severity of toxic effects resulting from exposure, chemicals can have up to three
AEGLs and an IDLH. AEGLs are used to make informed decisions on shelter-in-place
orders or emergency evacuations. The US EPA Office of Pollution Prevention and
Toxics’ (OPPT) National Advisory Committee for the Development of Acute Exposure
Guideline Levels for Hazardous Substances (NAC/AEGL Committee) and NIOSH,
respectively develop AEGLs and IDLHs for chemical exposures.

LELs and Upper Explosive Limits (UEL) establish a range of concentrations in which a
flash will occur or a flame will travel if flammable vapor or gas in air is ignited. Thus,
LELs are calculated for flammable chemicals and may be used as guidelines to avoid
accidental chemical explosions.

AEGLs are established for varying durations of exposure. The 10-minute AEGLs listed
can be used in acute exposure scenarios such as those which may occur in a refinery
emergency. There are additional emergency exposure levels which are also used to
plan for and respond to uncontrolled chemical releases. Chemicals can have up to
three AEGLs, Emergency Response Planning Guidelines (ERPG), Temporary
Emergency Exposure Limits (TEEL), and Protective Action Criteria (PAC) depending on
the severity of toxic effects resulting from inhalation exposure. The American Industrial
Hygiene Association (AIHA) Emergency Response Planning Committee develops

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ERPGs to assist emergency responders in evaluating the potential spread and airborne
concentration in the event of a release, particularly for chemicals that have high
potential for uncontrolled releases and those that may pose hazards due to their
volatility and toxicity. Because AEGLs and ERPGs exist only for a limited number of
chemicals, the US Department of Energy Subcommittee on Consequence Assessment
and Protective Actions (SCAPA) also develops Temporary Emergency Exposure Levels
(TEELs), which serve as temporary limits for chemicals until AEGLs or ERPGs are
developed. TEELs are used in similar situations as one-hour AEGLs and ERPGs.
TEELs estimate the concentrations at which most people will begin to experience health
effects from exposure in air. In combination, AEGLs, ERPGs, and TEELs are referred
to as PACs. During an emergency, these criteria may be used to assess the severity of
the event and its health consequences, identify potential outcomes, and determine what
protective actions should be taken.

Further information about the development, application, and current list of ERPGs can
be found on the AIHA web page. For additional information on the PAC dataset and
TEEL development, visit the SCAPA PAC/TEEL web page.

The definitions of AEGLs, IDLHs, and LELs are shown in Table 4 below.

Table 4. US EPA and NIOSH Emergency Exposure Levels and Descriptions

Exposure Level Source Description
Acute Exposure US EPA 1: Airborne concentration above which the
Guideline Level (NAC/AEGL general population, including susceptible
(AEGL) (mg/m3) Committee) individuals, could experience notable
discomfort, irritation, or certain
asymptomatic nonsensory effects after an
exposure duration of 10 minutes, 30
minutes, 1 hour, 4 hours, or 8 hours. Effects
are not disabling and are transient and
reversible upon cessation of exposure.
2: Airborne concentration above which the
general population, including susceptible
individuals, could experience irreversible or
other serious, long-lasting adverse health
effects or impaired ability to escape after an
exposure duration of 10 minutes, 30
minutes, 1 hour, 4 hours, or 8 hours.
Immediately NIOSH Airborne concentration likely to cause death
Dangerous to Life or immediate or delayed permanent adverse
and Health (IDLH) health effects or prevent escape from such
(mg/m3) an environment as a consequence of a 30-
minute exposure.

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Table 5 displays the chemicals from OEHHA’s list of refinery chemical emissions
(Table 1) that have 10-minute AEGLs, IDLHs, or LELs.

Table 5. Emergency Exposure Levels for Chemicals Emitted from California

Refineries

AEGL-11 AEGL-21 IDLH2

Chemical LEL3 (%)
(µg/m3) (µg/m3) (µg/m3)

Acenaphthene ― ― ― 0.6
Acetaldehyde 8.11 × 104 6.13 × 105 3.60 × 106 4
Acetone 4.75 × 105 2.21 × 107 5.95 × 106 2.5
Acetylene ― ― ― 2.5
Acrolein 69 1,009 4,580 2.8
Ammonia 2.09 × 104 1.53 × 105 2.09 × 105 15
Aniline 1.83 × 105 2.74 × 105 3.81 × 105 1.3
Anthracene ― ― ― 0.6
Antimony ― ― 5.00 × 104 ―
Arsenic ― ― 5,000 ―
Barium ― ― 5.00 × 104 ―
Benzene 4.15 × 105 6.39 × 106 1.60 × 106 1.2
Beryllium ― ― 4,000 ―
Biphenyl ― 7.57 × 104 1.00 × 105 0.6 (232˚F)
1,3-Butadiene 1.48 × 106 1.48 × 107 4.43 × 106 2
Butane 2.38 × 107 5.71 × 107 ― 1.6
1-Butene ― ― ― 1.6
Cadmium 130 1,400 9,000 ―
Carbon disulfide 5.30 × 104 6.23 × 105 1.56 × 106 1.3
Carbon monoxide ― 4.81 × 105 1.37 × 106 12.5
Carbon tetrachloride ― 1.70 × 105 1.26 × 106 ―
Carbonyl sulfide ― 1.70 × 105 ― ―
Chlorine 1,450 8,120 2.90 × 104 ―
Chlorobenzene 4.60 × 104 1.98 × 106 4.60 × 106 1.3
Chloroform ― 5.86 × 105 2.44 × 106 ―
Chromium (hexavalent & compounds) ― ― 2.50 × 105 ―
Chromium III ― ― 2.50 × 104 ―
Cobalt ― ― 2.00 × 104 ―
Copper ― ― 1.00 × 105 ―
m-Cresol ― ― 1.11 × 106 1.1 (300˚F)
o-Cresol ― ― 1.11 × 106 1.4 (300˚F)
p-Cresol ― ― 1.11 × 106 1.1 (300˚F)
Cumene 2.46 × 105 2.70 × 106 4.42 × 106 0.9

1 US EPA 10-minute Acute Exposure Guideline Levels (AEGL) from OPPT.

2 NIOSH Immediately Dangerous to Life and Health (IDLH) values.
3 Lower Explosive Limits (LEL) for flammable chemicals, expressed as percent in air from NIOSH.

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AEGL-11 AEGL-21 IDLH2

Chemical LEL3 (%)
(µg/m3) (µg/m3) (µg/m3)

Cyclohexane ― ― 4.47 × 106 1.3

Cyclopentadiene ― ― 2.03 × 106 ―
Cyclopentane ― ― ― 1.1
Dibutyl phthalate ― ― 4.00 × 106 0.5
1,4-Dichlorobenzene ― ― 9.02 × 105 2.5
1,1-Dichloroethane ― ― 1.22 × 107 5.4
1,1-Dichloroethylene ― ― ― 6.5
1,2-Dichloropropane ― ― 1.85 × 106 3.4
1,3-Dichloropropene ― ― ― 5.3
Diethanolamine ― ― ― 1.6
Diethyl phthalate ― ― ― 0.7 (368˚F)
Di(2-ethylhexyl)phthalate ― ― 5.00 × 106 0.3 (473˚F)
1,4-Dioxane 6.13 × 104 2.09 × 106 1.80 × 106 2
Ethane ― ― ― 2.9
Ethyl chloride ― ― 1.00 × 107 3.8
Ethylbenzene 1.43 × 105 1.26 × 107 3.47 × 106 0.8
Ethylene ― ― ― 2.75
Ethylene dibromide 4.00 × 105 5.61 × 105 7.68 × 105 ―
Ethylene dichloride ― ― 2.02 × 105 6.2
Ethylene glycol monoethyl ether ― ― 1.85 × 106 1.8
Ethylene glycol monoethyl ether
― ― 2.71 × 106 1.7
acetate
Formaldehyde 1,105 1.72 × 104 2.46 × 104 7
Heptane ― ― 3.07 × 106 1.05
Hexachloroethane ― ― 2.90 × 106 ―
Hexane ― 1.41 × 107 3.88 × 106 1.1
Hydrogen ― ― ― 4
Hydrogen chloride 2,687 1.49 × 105 7.46 × 104 ―
Hydrogen cyanide 2,761 1.88 × 104 5.52 × 104 5.6
Hydrogen fluoride 818 7.77 × 104 2.45 × 104 ―
Hydrogen sulfide 1,045 5.71 × 104 1.39 × 105 4
Isobutane ― ― ― 1.6
Isopropanol ― ― 4.92 × 106 2
Lead ― ― 1.00 × 105 ―
Manganese ― ― 5.00 × 105 ―
Mercury ― 3,100 1.00 × 104 ―
Methane ― ― ― 5
Methanol 8.78 × 105 1.44 × 107 7.86 × 106 6
Methyl bromide ― 3.65 × 106 9.73 × 105 10

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AEGL-11 AEGL-21 IDLH2

Chemical LEL3 (%)
(µg/m3) (µg/m3) (µg/m3)

Methyl chloride ― 2.27 × 106 4.13 × 106 8.1

Methyl chloroform 1.25 × 106 5.08 × 106 3.82 × 106 7.5
Methyl ethyl ketone 5.90 × 105 1.45 × 107 8.85 × 106 1.8
Methyl isobutyl ketone ― ― 2.05 × 106 1.4
Methyl tert-butyl ether 1.80 × 105 5.05 × 106 ― ―
Methylcyclohexane ― ― 4.82 × 106 1.2
Methylene chloride 1.01 × 106 5.91 × 106 7.99 × 106 13
Molybdenum ― ― 5.00 × 106 ―
Naphthalene ― ― 1.31 × 106 0.9
Nickel ― ― 1.00 × 104 ―
Nitrogen dioxide 941 3.76 × 104 3.76 × 104 ―
Octane ― ― 4.67 × 106 1
Pentane ― ― 4.43 × 106 1.5
Perchloroethylene 2.37 × 105 1.56 × 106 1.02 × 106 ―
Phenol 7.31 × 104 1.12 × 105 9.62 × 105 1.8
Phosphoric acid ― ― 1.00 × 106 ―
Phosphorus ― ― 5,000 ―
Propane ― ― 3.79 × 106 2.1
Propylene ― ― ― 2
Propylene glycol monomethyl ether ― ― ― 1.6
Propylene oxide 1.73 × 105 1.06 × 106 9.50 × 105 2.3
Selenium (& compounds) ― ― 1,000 ―
Styrene 8.52 × 104 9.80 × 105 2.98 × 106 0.9
Sulfur dioxide 524 1,965 2.62 × 105 ―
Sulfur trioxide 200 8,700 ― ―
Sulfuric acid 200 8,700 1.50 × 104 ―
1,1,2,2-Tetrachloroethane ― ― 6.87 × 105 ―
Toluene 2.52 × 105 5.28 × 106 1.88 × 106 1.1
1,1,2-Trichloroethane ― ― 5.46 × 105 6
Trichloroethylene 1.40 × 106 5.16 × 106 5.37 × 106 12.5
1,1,2-Trichloro-1,2,2-trifluoroethane ― ― 1.53 × 107 ―
Triethylamine ― ― 8.28 × 105 1.2
1,2,4-Trimethylbenzene 8.85 × 105 2.26 × 106 ― 0.9
Vanadium (fume or dust) ― ― 3.50 × 104 ―
Vinyl chloride 1.16 × 106 7.17 × 106 ― 3.6
Xylenes (mixed) 5.64 × 105 1.09 × 107 ― ―
m-Xylene ― ― 3.91 × 106 1.1
o-Xylene ― ― 3.91 × 106 0.9
p-Xylene ― ― 3.97 × 106 1.1

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To learn more about the AEGLs, IDLHs, and LELs described in this section, visit the US
EPA AEGL web page or the NIOSH Pocket Guide to Chemical Hazards web page
(URLs in References section).

IV. HEALTH EFFECTS OF SELECT CALIFORNIA REFINERY CHEMICALS

This section provides further information for select California refinery chemicals on
various health and safety risks to exposed populations. These include noncancer
health effects, carcinogenic effects, and effects on development or reproduction.
Appendix A provides an expanded description of the acute and chronic health effects for
a number of refinery chemicals. The chemicals described below are only a few of many
chemicals that may have adverse effects on human health. OEHHA selected these
chemicals based on their high emissions, low health guidance values, emissions from
multiple processes and equipment, involvement in incident history, or level of toxicity-
weighted emissions.

Table 6 presents health effects for select California refinery chemicals including
information on the physical/chemical properties, acute health effects, and chronic health
effects of each chemical. These effects are dependent on level and duration of
exposure. Web sources for the health summaries are also included below.

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Table 6. Health Effects of Select California Refinery Chemicals

Chemical Health Effects
Physical/Chemical Properties: Colorless liquid with distinct,
pungent odor. Flammable.
Acute Health Effects: bronchoconstriction; irritation of the eye,
upper respiratory tract, nose, throat, and lung; decreased
Acetaldehyde
pulmonary function
Chronic Health Effects: degeneration, inflammation, and
hyperplasia of nasal airways; in animals: changes in nasal
mucosa, respiratory distress, growth retardation, early mortality
Physical/Chemical Properties: Colorless gas with pungent and
irritating odor. Corrosive at high concentrations. Slight fire
hazard.

Acute Health Effects: irritation of the eyes, nose, throat, and skin;
corrosive injury to the skin and mucus membranes of the eyes,
Ammonia
lungs, and gastrointestinal tract; eye redness and lacrimation;
cough, choking sensation; dyspnea; death from pulmonary edema

Chronic Health Effects: decreased pulmonary function; irritation of

the eyes, skin, and respiratory tract; chronic cough; asthma; lung
fibrosis; chronic irritation of the eye membranes and skin
Physical/Chemical Properties: Grey metallic solid with no
characteristic taste or smell. Noncombustible in large amounts,
but a slight fire hazard if dust is exposed to flame.
Acute Health Effects: decreased fetal weight (mice); respiratory
tract irritation, cough, dyspnea, chest pain, sore throat, dermatitis,
Arsenic laryngitis, mild bronchitis, conjunctivitis, death if ingested
Chronic Health Effects: impairment of intellectual function and
neurobehavioral development; malaise; peripheral sensorimotor
neuropathy; anemia; jaundice; gastrointestinal discomfort;
darkened skin with warts on the palms, soles, and torso; irritation
of the throat and respiratory tract; perforation of the nasal septum

Physical/Chemical Properties: Colorless liquid with a petroleum-

like smell. Highly flammable.

Acute Health Effects: developmental damage in blood cells

(mice); irritation of the eyes, nose, and throat; central nervous
system depression; drowsiness; dizziness; rapid heart rate;
Benzene headache; tremor; confusion; unconsciousness; death from
respiratory failure

Chronic Health Effects: increases and decreases in blood cell

count, aplastic anemia, excessive bleeding, damage to the
immune system

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Chemical Health Effects

Physical/Chemical Properties: Pale yellow solid with a faint
aromatic odor. Nonflammable.
Benzo[a]pyrene
Acute Health Effects: irritation and burning sensation of the eyes
and skin

Physical/Chemical Properties: Colorless gas with a mild gasoline-

like odor. Highly flammable.

Acute Health Effects: decreased male fetal weight (mice); irritation

of the eyes, nose, throat, and lungs; blurred vision; nausea;
paresthesia; dryness of the mouth, throat, and nose; fatigue;
1,3-Butadiene headache; vertigo; hypotension; unconsciousness; central
nervous system depression

Chronic Health Effects: ovarian atrophy (mice); exacerbation of

asthmatic symptoms, increased incidence of respiratory tract
infections, cardiovascular diseases, effects on the blood and
female reproductive organs

Physical/Chemical Properties: Colorless crystals. Nonflammable.

Acute Health Effects: chloracne, gastrointestinal upsets,

Dibenzofurans
increased levels of serum enzymes and triglycerides, numbness
(PCDF), Dibenzo-p-
of the extremities
dioxins (PCDD)

Chronic Health Effects: increased mortality; decreased weight

gain; changes in the liver, lungs, and lymphoid and vascular
tissues (rats)

Physical/Chemical Properties: Colorless powder or liquid with

ammonia-like odor. Combustible.

Acute Health Effects: cough, nausea, headache, lacrimation,

sneezing, smothering sensation, eye and skin burns, corneal
Diethanolamine necrosis

Chronic Health Effects: asthmatic airway obstruction

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Chemical Health Effects

Physical/Chemical Properties: Colorless liquid with a gasoline-like

odor. Highly flammable.

Acute Health Effects: chest constriction, irritation of the eyes and

throat, dizziness, vertigo; in animals: eye irritation, central nervous
Ethylbenzene system toxicity, effects on the liver and kidney, pulmonary effects

Chronic Health Effects: cellular alterations and necrosis in the

liver, nephrotoxicity, pituitary gland hyperplasia (mice, rats);
developmental toxicity (rats, rabbits); other effects in animals:
effects on the blood, irreversible damage to the inner ear and
hearing

Physical/Chemical Properties: Colorless gas with distinct, pungent

odor. Flammable.

Acute Health Effects: mild and moderate eye irritation, headache,

rhinitis, dyspnea, lacrimation, mucous membrane irritation,
burning, difficulty breathing, bronchitis, pulmonary edema,
Formaldehyde
pneumonia

Chronic Health Effects: nasal obstruction and discomfort, lower

airway discomfort, allergic sensitization, cough, running nose,
lacrimation, cellular changes in airway membranes, decreased
lung function, headache, depression, mood changes, insomnia,
attention deficit, impairment of dexterity and memory

Physical/Chemical Properties: Colorless fuming liquid or gas with

a strong, pungent odor. Emits highly irritating and poisonous
fumes that are corrosive to metals and body tissues when heated.
Nonflammable.

Acute Health Effects: eye, nose, and throat irritation; lacrimation;

Hydrogen Fluoride
sore throat; cough; chest tightness; wheezing; pulmonary edema

Chronic Health Effects: dental fluorosis; congestion and irritation

of the nose, throat, and bronchi; liver and kidney damage

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Chemical Health Effects

Physical/Chemical Properties: Colorless gas with a pungent rotten

egg odor. Corrosive and highly flammable.

Acute Health Effects: headache; nausea; irritation of the skin,

eyes, mucus membranes, and respiratory tract; conjunctivitis with
Hydrogen Sulfide ocular pain, lacrimation, and photophobia; death from respiratory
arrest

Chronic Health Effects: nasal inflammation (mice); low blood

pressure, headache, nausea, loss of appetite, weight loss, ataxia,
eye membrane inflammation, chronic cough

Physical/Chemical Properties: Silver solid. Combustible.

Acute Health Effects: impaired function, nonspecific pulmonary

edema, brain damage
Manganese

Chronic Health Effects: impaired visual reaction time, hand-eye

coordination, and hand steadiness; manganism; changes in
neurobehavioral and cognitive abilities; increased incidence of
cough, bronchitis, and dyspnea during exercise; increased
susceptibility to infectious lung disease

Physical/Chemical Properties: Volatile white crystalline volatile

solid. Flammable in the presence of an ignition source.

Acute Health Effects: headache, nausea, vomiting, diarrhea,

Naphthalene malaise, confusion, anemia, jaundice, convulsions, neurological
damage in infants, hemolytic anemia, liver damage, coma

Chronic Health Effects: nasal inflammation, olfactory epithelia

metaplasia, respiratory epithelial hyperplasia (mice); hemolytic
anemia, cataracts, retinal hemorrhage; in animals: chronic
inflammation of the lung, chronic nasal inflammation, hyperplasia
of nasal respiratory epithelium, metaplasia of the olfactory
epithelium

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Chemical Health Effects

Physical/Chemical Properties: Yellow-brown liquid or reddish

brown gas with a strong odor. Corrosive. Noncombustible, but
will accelerate burning of combustible materials.

Acute Health Effects: increased airway reactivity in asthmatics,

Nitrogen Oxides cough, fatigue, nausea, choking, headache, abdominal pain,
(Nitrogen Dioxide) strained breathing, anxiety, mental confusion, lethargy, loss of
consciousness, pneumonitis, bronchitis, death from pulmonary
edema and inflammatory changes

Chronic Health Effects: permanent and obstructive lung disease,

increased risk of respiratory infections in children

Physical/Chemical Properties: Mixture of liquid droplets and solids

such as dust, dirt, soot, and smoke. Nonflammable.

Acute Health Effects: irritation of the eyes, nose, and throat;

Particulate Matter reduced lung function; asthma attacks; irregular heartbeat; cough;
(PM10, PM2.5) wheezing; increased risk of heart attack, stroke, cardiac arrest,
and/or congestive heart failure; premature death

Chronic Health Effects: increased incidence of heart and lung

problems

Physical/Chemical Properties: Colorless, irritating gas with a

choking or suffocating odor. Nonflammable.

Acute Health Effects: impairment of airway function; irritation of

the eyes, mucous membrane, skin, and respiratory tract; airway
Sulfur Dioxide
obstruction from reflex laryngeal spasm and edema,
bronchospasm, pneumonitis, pulmonary edema; death

Chronic Health Effects: altered sense of smell, increased

susceptibility to respiratory infections, symptoms of chronic
bronchitis, accelerated decline in pulmonary function

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Chemical Health Effects

Physical/Chemical Properties: Colorless, oily liquid. Corrosive to

metals and all body tissues. Noncombustible, but may be
explosive or incompatible with other substances.

Acute Health Effects: small changes in airway function, dental

Sulfuric Acid erosion, respiratory tract irritation, bronchoconstriction, altered
lung function

Chronic Health Effects: hyperplasia of bronchial cells in lungs

(monkeys); decreased lung function, tracheobronchitis, stomatitis,
conjunctivitis, gastritis

Physical/Chemical Properties: Clear, volatile liquid with an

aromatic odor. Flammable.

Acute Health Effects: irritation of the eyes, skin, and respiratory

tract; impaired reaction time; headache; dizziness; feeling of
intoxication; fatigue; sleepiness; nausea; central nervous system
Toluene depression; ataxia; euphoria; hallucinations; tremors; seizures;
coma; death
Chronic Health Effects: decreased brain weight and altered
dopamine receptor binding (rats); nausea, fatigue, eye and upper
respiratory tract irritation, dizziness, headache, difficulty with
sleep, disorders of the optic nerve, central nervous system
depression, permanent neuropsychiatric effects, muscle
disorders, cardiovascular effects, renal tube damage, death

Physical/Chemical Properties: Colorless, volatile liquid with an

aromatic odor. Flammable.

Acute Health Effects: irritation of the eyes, skin, and respiratory

tract; headache; decreased muscle coordination; dizziness;
confusion; lung function, liver, and memory impairment; delayed
Xylene response to visual stimuli; stomach discomfort; ventricular
arrhythmias; acute pulmonary edema; death
Chronic Health Effects: eye irritation; sore throat; floating
sensation; lack of appetite; headache; fatigue; dizziness; tremors;
loss of coordination; anxiety; impairment of short-term memory;
inability to concentrate; cardiovascular, renal, and gastrointestinal
effects; permanent neuropsychiatric manifestations; chronic toxic
encephalopathy

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Health effects described should not be considered a complete profile of the toxicity of
the listed chemicals. For more information about the health effects of specific
chemicals, see the OEHHA REL web page, the US EPA IRIS web page, or the Agency
for Toxic Substances and Disease Registry (ATSDR) Toxic Substances Portal.
Additional information can be obtained from sources such as the web pages for the
National Institutes of Health (NIH) Hazardous Substances Data Bank (HSDB) and
Toxicology Data Network (TOXNET), the Centers for Disease Control and Prevention
(CDC) Emergency Preparedness and Response web page, the NIOSH Pocket Guide to
Chemical Hazards, or the National Oceanic and Atmospheric Administration’s (NOAA)
Computer-Aided Management of Emergency Operations (CAMEO) Chemicals.

V. MOST HIGHLY EMITTED CHEMICALS AND OTHER SUPPORTING

INFORMATION

High emissions increase a person’s risk of exposure. Refinery incident history, common
processes, chemical emission rates, and knowledge of health guidance values and
emergency exposure levels can help to judge whether air monitoring is needed and
guide decisions that may reduce adverse health effects caused by chemical exposures.
Refinery incident history and knowledge of common refinery processes can provide
responders with information about which processes have had non-routine emissions in
the past, and chemicals that may be released in the event of a refinery emergency.
Chemical emissions can be useful in assessing the acute and chronic health effects that
are anticipated based on the degree of chemical exposure. OEHHA has collected
further information on these factors and summarized the findings below.

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A. California Refinery Incident History

Refinery incidents are unanticipated conditions at facilities that allow chemicals to be

released into the ambient air. These events can include situations in which chemical
emissions exceed typical emissions in an accidental release, normal controls are
bypassed, or the effectiveness of the normal controls is reduced. During refinery
emergencies, large amounts of chemical-rich emissions may be carried to populated
areas and cause exposure to a number of compounds. The extent of exposure
depends on factors such as the quantity released, chemical properties, and
meteorological conditions. In addition to these factors, understanding the chemicals
present in a release, the amount emitted, the acute and chronic health effects of
exposure, and the air monitoring capabilities for chemicals can help responders
characterize the risk associated with a refinery incident or emergency event.
Furthermore, members of nearby communities may experience cumulative exposure
from multiple events over time and may be more susceptible to pollution-related health
problems.

To compile data on recent refinery incidents in California, OEHHA performed searches

using the Google search engine. Searches on individual web pages included: CalEPA
IRTF, the Chemical Safety Board (CSB), the Bay Area Air Quality Management
District’s (BAAQMD), various other California Air Quality Management District (AQMD)
and Air Pollution Control District (APCD) web pages, and the Contra Costa Health
Services web page. OEHHA performed these searches between August and
December of 2015.

Based on this research, sulfur dioxide, hydrogen sulfide, and hydrocarbons were the
most commonly reported chemicals emitted during refinery incidents. In many
instances, adverse health effects were reported following the release of sulfur
compounds. Symptoms were consistent with those associated with acute sulfur dioxide
and/or hydrogen sulfide exposure: nausea; dizziness; irritation of the eyes, nose, throat,
and skin; and unconsciousness.

OEHHA also looked for information on the process units, emission points, and
equipment linked to refinery incidents since knowledge of individual refinery processes
involved in incidents can provide information on which chemicals are likely to be
released into the air. Of the process units, emission points, and equipment identified,
flares were the most common sources involved in incidents resulting in emissions to
outdoor air. Flares are used at refineries for the combustion and disposal of
combustible gases and hydrocarbons to prevent release directly into the atmosphere.
Flare events can be planned or unplanned, and usually occur due to emergency relief,
overpressure, process upsets, startups, shutdowns, power outages, and other
operational safety reasons. Certain chemicals such as sulfur dioxide, hydrogen sulfide,
and carbon monoxide are commonly associated with such events. Because they
involve the release of smoke, flaring events also result in the release of particulate
matter.

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Other process units, emission points, and equipment associated with emissions
commonly identified in the literature include heaters, storage tanks, cokers, sulfur
recovery units, boilers, gas compressors, fluid catalytic cracking units (FCCU), and
crude units. Table 7 below displays the process units, emission points, and equipment
reported to be associated with refinery incidents based on data for 2001-2012 for
California.

Table 7. Process Units, Emission Points, and Equipment Reported to be

Associated with California Refinery Incidents3
Ammonia recovery unit FCCU4 Oxidizer
Boiler Flares Sonic meter system
Cogeneration unit Gas compressor Storage tank
Coker Heater/furnace Sulfur recovery unit
Cooling unit Hydrogen plant Vacuum distillation unit
Crude unit Hydrotreater Vapor recovery unit
Diesel unit Jet fuel unit

3 Process units reported to be associated with refinery incidents are listed in alphabetical order based on
California data for 2001-2012 reported by Chemical Safety Board, Bay Area Air Quality Management
District, and Contra Costa Health Services web pages. Note that the process units listed above may
not constitute all equipment or processes involved in refinery incidents in the state.
4 Fluid catalytic cracking unit (FCCU)

Findings discussed in this section refer to the frequency of refinery incidents with
identified chemical releases in California from 2001-2012. They are based on limited
data and do not represent all of the refinery incidents during this period. The majority of
incidents included in this search was self-reported by personnel from California
refineries and community residents and were not the result of air monitoring efforts.
The occurrence of refinery incidents varies from refinery to refinery and may reflect site-
specific equipment failure and equipment maintenance and upkeep.

B. California Refinery Process Units, Emission Points, and Equipment

To expand OEHHA’s list of refinery chemical emissions, chemicals associated with

specific refinery areas, equipment, or processes were identified using data provided by
US EPA (2012a, 2012b). In response to a request from US EPA, all refineries active
during the year 2010 were asked to measure air emissions from each process, emission
point, or piece of equipment for a specified period and submit the data to that agency.
This request resulted in a list of chemicals routinely emitted and measured for each
process unit, emission point, or equipment. OEHHA used these emissions inventories
to identify the most commonly occurring processes and their associated chemical
emissions.

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Appendix B displays a list of chemical emissions associated with each process unit or
emission point based on these 2010 California data. The process data and chemicals
shown in Appendix B are those most commonly found based on OEHHA’s research and
do not represent a complete list of all refinery processes or chemicals emitted from each
process.

Table 8 shows a sample of process units and release types (fugitive and point
emissions) selected based on comparison of data obtained from California refineries
active during the year 2010.

Table 8. California Refinery Process Units, Emission Points, and Equipment

Sorted by Release Type
Fugitive Emissions Point Emissions Fugitive and Point Emissions
Hydrogen plant Boiler Alkylation unit
Product loading Flare Cogeneration unit
Wastewater treatment Heater Coker
Hydrotreater Cooling tower
Sulfur recovery unit Crude unit
Thermal oxidizer Fluid catalytic cracking unit
Vent Hydrocracker
Incinerator
Stack
Storage tank

C. Chemical Analysis Categories for Air Monitoring

Upon completion of OEHHA’s compilation of California refinery chemicals (Table 1),

chemicals were sorted by CARB (Appendix C) into chemical analysis categories based
upon air monitoring capabilities and methodology for collecting air samples. This
classification scheme allowed for the consideration of emissions, health effects, and
health guidance values of chemicals that require similar procedures for air monitoring.
Table 9 is an overview of the chemical analysis categories provided by CARB.

Table 9. Chemical Analysis Categories for Air Monitoring

Acid Metal
Aldehyde Microscopy (for asbestos)
Dioxin/Dibenzofuran Mass/Particulate Matter (PM)
Extractable Polycyclic Aromatic Hydrocarbons (PAH)
Gas Volatile Organic Compounds (VOC)
Glycol

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D. Most Highly Emitted Routine Emissions of Toxic Air Contaminants from

California Refineries

Since high emissions increase a person’s risk of exposure, consideration of chemical

emission rates can help CARB make judgements about air monitoring. Routine
emissions data from California refineries for 2009-2012 were obtained from the
CEIDARS database facility search tool. The emissions data were submitted to CARB
under the AB 2588 Air Toxics Hot Spots Program requirements and reflect TAC
releases that occurred during routine facility operations. The Hot Spots program
requires facilities to report emission inventory updates every four years. Therefore, not
all facilities update emission inventories in the same year. As a result, some chemicals
may not be reported each year. Based on this quadrennial method of updating
emission inventories in the Hot Spots Program, the information that the CEIDARS
database provides on the TACs emitted from refineries may underestimate total routine
emissions across refineries in any given year.

US EPA’s Toxics Release Inventory (TRI) Program is an additional resource for learning
about toxic chemical releases into the air, as well as into land and water. The TRI
Program requires certain industrial facilities in the US to report annual release data in
accordance to the Emergency Planning and Community Right-to-Know Act (EPCRA).
The TRI database contains data by facility and by year. The focus of this report is the
potential health effects of chemicals emitted from refineries. This is not an assessment
of the potential health effects of all emissions. However, OEHHA found it useful to
understand the relative routine and non-routine emissions to compare with the health
effects of those chemicals to assist CARB in prioritizing chemicals for air monitoring.

Appendix D provides the complete list of average routine TAC emissions obtained from
CEIDARS from 2009-2012. A four-year average was calculated for each chemical. The
10 pollutants routinely released from refineries in California in the greatest quantities per
year based on 2009-2012 data are displayed in Table 10.

In evaluating the emissions, the toxic potency of the chemical emitted can also be taken
into account. Summing emissions of a chemical for all California refineries and
weighting it by a value related to its toxic potency results in a “toxicity-weighted”
emissions score. The toxicity-weighted emissions score was calculated using
emissions data (pounds emitted per year) obtained from the Air Toxics “Hot Spots’
Emissions Inventory” (2014) multiplied by a toxicity-weight derived from US EPA’s
Inhalation Toxicity Scores for individual chemicals. (https://www.epa.gov/rsei/rsei-
toxicity-data-and-calculations).

In terms of toxicity, by applying toxicity weights to the total pounds released, the top
toxicity-weighted releases, starting with the highest are: formaldehyde, nickel, arsenic,
cadmium, and benzene followed by polycyclic aromatic hydrocarbons (PAHs) (total),
hexavalent chromium, benzo(a)pyrene, phenanthrene, beryllium, ammonia, 1,3-
butadiene, naphthalene, hydrogen sulfide, acetaldehyde, manganese, and
diethanolamine. However, it should be noted that the amount released of hexavalent

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chromium, arsenic, and beryllium are minimal, all less than 100 lbs annually. Appendix
H provides more information on TAC emissions for the 2014 CEIDARs data and the
toxicity-weighted emissions scores.

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Table 10. Toxic Air Contaminants with the Ten Highest Routine Emissions from
California Refineries
Chemical Emissions (lb/year)5
Ammonia 2,085,824
Formaldehyde 288,412
Methanol 122,611
Sulfuric acid 104,573
Hydrogen sulfide 103,385
Toluene 87,945
Xylenes 79,177
Benzene 43,308
Hexane 39,646
Hydrogen chloride 21,450

5Average annual routine TAC emissions from 28 California refineries based on data from the Air
Resources Board CEIDARS database for 2009-2012.

Routine TAC emissions from California refineries during 2009-2012 were examined
based on the chemical analysis categories provided by CARB. Gases made up the
majority of the routine TAC emissions. The VOC, aldehyde, and acid categories also
had notable amounts. Figure 1 below displays the relative occurrence of CARB’s
chemical analysis categories for air monitoring (Table 9) among the routine TAC
emissions from the refineries during this period.

Figure 1. Relative Occurrence of Chemical Analysis Categories in Routine

Toxic Air Contaminant Emissions from California Refineries

PAH

Extractable
VOC
Glycol
Other
Gas Acid
Metal
Aldehyde

Microscopy

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E. Routine and Non-routine Chemical Emissions by California Refineries

OEHHA compiled data on routine and non-routine chemical emissions, not limited to
TACs, from the California refineries active during 2010 using data provided by US EPA
(2012a, 2012b). Routine emissions represent chemical releases that occur during
normal facility operations, while non-routine releases reflect emissions during any non-
routine refinery operation. Non-routine operations include startups, shutdowns, and
malfunction operations such as refinery-wide power loss, maintenance, and flaring
events.

The refinery emissions shown in this section were measured or calculated at various
process units, emission points, and equipment and reported by refineries to US EPA;
however, these data were limited to a single reporting year of 2010, and therefore may
not be representative of all non-routine emissions from California refineries. Appendix E
includes the complete list of routine and non-routine emissions data reported by
California refineries for 2010. In some instances, non-routine emissions exceeded
routine emissions during this period. The 10 pollutants routinely released from
refineries in California in the greatest quantities in 2010 based on data from US EPA are
displayed in Table 11 below.

Table 11: Ten Highest Routine Chemical Emissions by California Refineries1

Chemical Emissions (lb)
Sulfur dioxide 21,158,748
Carbon monoxide 16,972,733
Nitrogen oxides 16,415,674
Volatile organic compounds (VOC) 13,562,963
PM10 6,617,952
Butane 5,881,551
PM10 (filterable) 2,805,076
PM2.5 2,004,663
Nitrogen dioxide 1,971,085
PM (condensable) 1,677,433

1 Annual routine chemical emissions from California refineries based on data for
2010 (US EPA, 2012a; US EPA, 2012b).

Routine emissions from California refineries were composed primarily of chemicals in

the gas, VOCs, and particulate matter categories. Although data for routine emissions
is limited to 2010, OEHHA included this dataset because it provides information about
the chemicals other than TACs that are present in refinery emissions. Figure 2 shows
the relative occurrence of CARB’s categories for air monitoring (Table 9) found in
routine refinery emissions during 2010.

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Figure 2. Relative Occurrence of Chemical Analysis Categories in Routine

Toxic Air Contaminant Emissions from California Refineries1

PM

VOC Acid

Aldehyde
Other
Extractable
Metal

PAH
Gas

1 PM is Particulate Matter and includes PM10 and PM2.5. The chemical analysis category is also referred
to as “mass”.

Table 12 displays the ten highest non-routine chemical emissions from refineries in
California in the greatest quantities in 2010 based on data from US EPA.

Table 12. Ten Highest Non-routine Chemical Emissions by California Refineries1

Chemical Emissions (lb)
Volatile organic compounds (VOC) 1,123,158
Sulfur dioxide 553,834
Carbon monoxide 418,331
Nitrogen oxides 223,792
PM10 89,572
PM2.5 26,306
PM10 (filterable) 22,802
Nitrogen dioxide 12,397
Propylene 7,799
Hexane 7,625

1Annual non-routine emissions from California refineries based on data for 2010 (US EPA, 2012a; US
EPA, 2012b).

While these emissions appeared to have a similar profile of chemical analysis

categories to that of routine emissions, non-routine emissions from California refineries

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were composed of a greater fraction of VOC releases than releases of gases and
particulate matter. The relative occurrence of CARB’s chemical analysis categories for
air monitoring (Table 9) found in non-routine refinery emissions during 2010 are shown
in Figure 3 below.

Figure 3. Relative Occurrence of Chemical Analysis Categories in Non-routine

Chemical Emissions by California Refineries

VOC Acid
Aldehyde

PM Other Extractable

Metal
PAH
Gas

F. Refinery Emissions in the US and Fuel-Burning Experiments

Because refineries are only required to report emissions of regulated chemicals,

knowledge of unregulated chemicals also released can provide information on chemical
speciation or characteristics that can ultimately be used by officials for air monitoring or
risk assessment purposes. To this end, OEHHA conducted a literature search in peer-
reviewed journal articles to find additional chemicals associated with refinery emissions
in the US. Appendix F lists the chemicals and CAS RNs found in literature describing
refinery air monitoring in the US or controlled burning experiments during 1979-2007.

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VI. CONCLUSIONS

OEHHA has compiled a list of chemicals emitted from petroleum refineries in California.
This list identifies possible acute and chronic health effects resulting from exposure to
these chemicals, including cancer and effects on development or reproduction. OEHHA
has compiled a list of health guidance values and emergency exposure levels for
refinery chemicals that can be referenced during or after emergencies to evaluate the
potential for health risks associated with unanticipated chemical releases into the air.
Health effects were summarized for a selection of chemicals based on the availability of
health guidance values and emergency exposure levels, the quantities emitted in
routine and non-routine emissions, and the frequency of occurrence of these chemical
emissions in refinery processes and emissions. The refinery chemicals were sorted by
chemical analysis categories based on current air monitoring capabilities.

The list of California refinery chemicals, processes, and routine and non-routine
emissions included in this report represent data obtained from sources that represent
different periods and durations of time in different levels of detail. The data does not
encompass all of the refinery chemicals, processes, and emissions points occurring in
California. OEHHA has compiled this information to assist CARB and local air districts
in making decisions and recommendations for air monitoring of chemicals in
communities near refineries, especially during emergencies.

The top candidates for air monitoring based on amounts of emission and toxicity
considerations include acetaldehyde, ammonia, benzene, 1,3-butadiene, cadmium,
diethanolamine, formaldehyde, hydrogen sulfide, manganese, naphthalene, nickel,
PAHs, PM, sulfur dioxide, sulfuric acid, and toluene. The release of these chemicals
from refineries does not necessarily mean that local communities face a significant
health risk or substantial exposures, but it does increase the likelihood of exposure for
nearby communities. Air monitoring of these chemicals may inform decisions that could
reduce exposure.

The top toxicity-weighted releases, starting with the highest, are: formaldehyde, nickel,
arsenic, cadmium, and benzene followed by polycyclic aromatic hydrocarbons (PAHs)
(total), hexavalent chromium, the individual PAHs benzo(a)pyrene and phenanthrene,
beryllium, ammonia, 1,3-butadiene, naphthalene, hydrogen sulfide, acetaldehyde,
manganese, and diethanolamine. However, it should be noted that the total amount
released of hexavalent chromium, arsenic, and beryllium from all California refineries is
minimal, less than 100 lbs annually, so these would be unlikely candidates for air
monitoring. This data was obtained from CEIDARS for 2014.

The top candidates for air monitoring are not ranked or prioritized further, as this report
identifies the top candidates based on their average emissions across all California
refineries. An important consideration for air monitoring at individual refineries is that
the candidate chemicals will differ based on location as well as year. Some top-
candidate chemicals are only released in small amounts from individual refineries.

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REFERENCES
Abdo KM, Grumbein S, Chou BJ and Herbert R (2001). Toxicity and carcinogenicity
study in F344 rats following 2 years of whole-body exposure to naphthalene vapors.
Inhal Toxicol 13: 931-950.

Agency for Toxic Substances and Disease Registry (ATSDR). Toxic Substances Portal.
Substances A-Z. Centers for Disease Control and Prevention.
http://www.atsdr.cdc.gov/substances/indexAZ.asp. Last updated March 3, 2011.
Accessed September 3, 2015.

American Industrial Hygiene Association (AIHA). Emergency Response Planning

Guidelines. https://www.aiha.org/get-involved/AIHAGuidelineFoundation/
EmergencyResponsePlanningGuidelines/Pages/default.aspx. Accessed March 15,
2016.

Arisawa K, Takeda H and Mikasa H (2005). Background exposure to

PCDDs/PCDFs/PCBs and its potential health effects: A review of epidemiologic studies.
J Med Invest 52: 10-21.

ATSDR. (2000). Medical Management Guidelines (MMGs) for Acute Chemical

Exposures. In: Managing Hazardous Materials Incidents. Vol. 3. Agency for Toxic
Substances and Disease Registry, Centers for Disease Control and Prevention.
http://www.atsdr.cdc.gov/MHMI/mhmi_v1_2_3.pdf. Accessed January 13, 2016.

Bay Area Air Quality Management District (BAAQMD). Incidents and Advisories.
http://www.baaqmd.gov/about-air-quality/incidents-and-advisories. Last updated
June 9, 2015. Accessed September 3, 2015.

Booher LE and Janke B (1997). Air Emissions from Petroleum Hydrocarbon Fires
During Controlled Burning. Am Ind Hyg Assoc J 58: 359-365.

Bord N, Cretier G, Rocca JL, Bailly C and Souchez JP (2004). Determination of

diethanolamine or N-methyldiethanolamine in high ammonium concentration matrices
by capillary electrophoresis with indirect UV detection: Application to the analysis of
refinery process waters. Anal Bioanal Chem 380: 325-332.

California Air Resources Board (CARB). California Emission Inventory Development

and Reporting System. California Environmental Protection Agency.
http://www.arb.ca.gov/app/emsinv/emssumcat.php. Last updated June 9, 2014.
Accessed September 3, 2015.

CARB and CAPCOA. (2015). Refinery Emergency Air Monitoring Assessment Report.
Objective 1: Delineation of Existing Capabilities. Air Resources Board, California
Environmental Protection Agency. California Air Pollution Control Officers Association
Air Monitoring Committee. http://www.arb.ca.gov/fuels/carefinery/crseam/crseam.htm.
Accessed August 28, 2015.

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 39

CARB and OEHHA. (2002). Chapter 7: Health Effects of Particulate Matter. In: Public
Hearing to Consider Amendments to the Ambient Air Quality Standards for Particulate
Matter and Sulfates. Air Resources Board and Office of Environmental Health Hazard
Assessment, California Environmental Protection Agency.
http://www.arb.ca.gov/carbis/research/aaqs/std-rs/pm-final/ch7-9.pdf. Last updated
May 16, 2005. Accessed December 21, 2015.

Catoggio JA, Succar SD and Roca AE (1989). Polynuclear aromatic hydrocarbon

content of particulate matter suspended in the atmosphere of La Plata, Argentina. Sci
Total Environ 79: 43-58.

California Environmental Protection Agency (CalEPA). Interagency Refinery Task

Force. http://www.calepa.ca.gov/Refinery/. Accessed March 15, 2016.

Centers for Disease Control and Prevention (CDC). Emergency Preparedness and
Response: Chemical Agents. http://emergency.cdc.gov/agent/agentlistchem.asp. Last
updated April 8, 2013. Accessed September 3, 2015.

Chemical Safety Board (CSB). (2013). Industrial Chemical Incident Screening

Database. United States Chemical Safety and Hazard Investigation Board.

CSB. US Chemical Safety Board. United States Chemical Safety and Hazard
Investigation Board. http://www.csb.gov/. Accessed September 3, 2015.

Contra Costa Health Services (CCHS). Major Accidents at Chemical/Refinery Plants.

http://cchealth.org/hazmat/accident-history.php. Accessed September 3, 2015.

Fingas MF, Lambert P, Li K, Wang Z, Ackerman F, Whiticar S and Goldthorp M (2001).

Studies of Emissions from Oil Fires. Int Oil Spill Conf 2001(1): 539-544.

IARC. Monographs and Supplements Available Online. International Agency for

Research on Cancer, World Health Organization.
http://monographs.iarc.fr/ENG/Monographs/PDFs/index.php. Accessed September 3,
2015.

Kulkarni P, Chellam S and Fraser MP (2007). Tracking Petroleum Refinery Emission

Events Using Lanthanum and Lanthanides as Environmental Markers for PM2.5.
Environ Sci Technol 41: 6748-6754.

Lewis RC, Gaffney SH, Le MH, Unice KM and Parstenbach DJ (2012). Airborne
concentrations of metals and total dust during solid catalyst loading and unloading
operations at a petroleum refinery. Int J Hyg Environ Health 215: 514-521.

Lucas R (2002). Petroleum Refinery Source Characterization and Emission Model for
Residual Risk Assessment. Office of Air Quality Planning and Standards, United States

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 40

Environmental Protection Agency.

http://www3.epa.gov/ttnchie1/efpac/protocol/refinery_RR_model_documentation_Final.p
df. Accessed January 13, 2016.

National Institutes of Health (NIH). Hazardous Substances Data Bank (HSDB). United
States National Library of Medicine. http://toxnet.nlm.nih.gov/newtoxnet/hsdb.htm.
Accessed March 15, 2016.

National Institute for Occupational Safety and Health (NIOSH). Chemical Listing and
Documentation of Revised IDLH Values (as of 3/1/95). Centers for Disease Control and
Prevention. http://www.cdc.gov/niosh/idlh/intridl4.html. Last updated December 4,
2014. Accessed September 3, 2015.

Nelson TP (2013). An Examination of Historical Air Pollutant Emissions from US

Petroleum Refineries. Environ Progr Sustain Energy 32(2): 425-432.

NIH. Toxicology Literature Online (TOXLINE). National Institutes of Health, United

States National Library of Medicine. http://toxnet.nlm.nih.gov/newtoxnet/toxline.htm.
Accessed March 15, 2016.

NIOSH. Occupational Safety and Health Guideline for Ammonia. National Institute for
Occupational Safety and Health, Centers for Disease Control and Prevention.
http://www.cdc.gov/niosh/topics/ammonia/. Last updated February 4, 2014. Accessed
September 2, 2015.

NIOSH. NIOSH Pocket Guide to Chemical Hazards. National Institute for Occupational
Safety and Health, Centers for Disease Control and Prevention.
http://www.cdc.gov/niosh/npg/. Last updated February 13, 2015. Accessed September
3, 2015.

NOAA. CAMEO Chemicals. Database of Hazardous Materials. National Oceanic and

Atmospheric Administration, United States Department of Commerce.
http://cameochemicals.noaa.gov/. Accessed September 9, 2015.

NOAA. Immediately Dangerous to Life and Health Limits (IDLHs). National Oceanic
and Atmospheric Administration, United States Department of Commerce.
http://response.restoration.noaa.gov/idlhs. Last updated September 18, 2015.
Accessed September 21, 2015.

OEHHA. (2008). Technical Support Document for the Derivation of Noncancer

Reference Exposure Levels. Office of Environmental Health Hazard Assessment,
California Environmental Protection Agency.
http://oehha.ca.gov/media/downloads/crnr/noncancertsdfinal.pdf.

OEHHA. (2009). Technical Support Document for Cancer Potency Factors:

Methodologies for derivation, listing of available values, and adjustments to allow for

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 41

early life stage exposures. Office of Environmental Health Hazard Assessment,

California Environmental Protection Agency.
http://oehha.ca.gov/media/downloads/crnr/tsdcancerpotency.pdf.

OEHHA. Appendix A. Hot Spots Unit Risk and Cancer Potency Values. In: Technical
Support Document for Cancer Potency Factors: Methodologies for derivation, listing of
available values, and adjustments to allow for early life stage exposures. Office of
Environmental Health Hazard Assessment, California Environmental Protection Agency.
http://oehha.ca.gov/media/downloads/crnr/appendixa.pdf. Accessed January 13, 2016.

OEHHA. Appendix B. Chemical-specific summaries of the information used to derive

unit risk and cancer potency values. In: Technical Support Document for Cancer
Potency Factors: Methodologies for derivation, listing of available values, and
adjustments to allow for early life stage exposures. Office of Environmental Health
Hazard Assessment, California Environmental Protection Agency.
http://oehha.ca.gov/media/downloads/crnr/appendixb.pdf. Accessed January 13, 2016.

OEHHA. OEHHA Acute, 8-hour and Chronic Reference Exposure Level (REL)
Summary. Office of Environmental Health Hazard Assessment, California
Environmental Protection Agency. http://oehha.ca.gov/air/general-info/oehha-acute-8-
hour-and-chronic-reference-exposure-level-rel-summary. Accessed September 3,
2015.

OEHHA. Chemicals Known to the State to Cause Cancer or Reproductive Toxicity.

Office of Environmental Health Hazard Assessment, California Environmental
Protection Agency. http://oehha.ca.gov/media/downloads/proposition-
65//p65single04222016.pdf. Accessed September 3, 2015.

OEHHA. California Human Health Screening Levels (CHHSLs). Office of

Environmental Health Hazard Assessment, California Environmental Protection Agency.
http://oehha.ca.gov/risk-assessment/california-human-health-screening-levels-chhsls.
Accessed March 15, 2016.

OEHHA. About Proposition 65. Office of Environmental Health Hazard Assessment,

California Environmental Protection Agency. http://oehha.ca.gov/proposition-65/about-
proposition-65. Accessed March 15, 2016.

OPPT. Acute Exposure Guideline Levels (AEGLs). Office of Pollution Prevention and
Toxics, United States Environmental Protection Agency.
http://www.epa.gov/oppt/aegl/pubs/chemlist.htm. Last updated June 15, 2015.
Accessed September 3, 2015.

SCAPA. Protective Action Criteria for Chemicals - Including AEGLs, ERPGs, & TEELs.
Subcommittee on Consequence Assessment and Protective Actions, United States
Department of Energy. http://orise.orau.gov/emi/scapa/chem-pacs-teels/. Accessed
March 15, 2016.

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 42

SCAQMD. Special Monitoring and Emissions Studies. South Coast Air Quality
Management District. http://www.aqmd.gov/home/library/air-quality-data-
studies/special-monitoring. Accessed September 4, 2015.

Sexton K and Westberg H (1979). Ambient Air Measurements of Petroleum Refinery

Emissions. J Air Poll Control Assoc 29(11): 1149-1152.

Shaw SD, Berger ML, Harris JH, Yun SH, Wu Q, Liao C, Blum A, Stefani A and Kannan
K (2013). Persistent organic pollutants including polychlorinated and polybrominated
dibenzo- p-dioxins and dibenzofurans in firefighters from Northern California.
Chemosphere 91: 1386-1394.

Skrtic L (2006). Hydrogen Sulfide, Oil and Gas, and People’s Health. University of
California, Berkeley.
http://www.bouldercounty.org/doc/landuse/hydrogensulfidestudy.pdf. Accessed
January 13, 2016.

Stigter JB, de Haan HPM, Guicherit R, Dekkers CPA and Daane ML (2000).
Determination of cadmium, zinc, copper, chromium and arsenic in crude oil cargoes.
Environ Pollut 107: 451-464.

Strosher MT (2000). Characterization of Emissions from Diffusion Flare Systems. J Air

& Waste Manage Assoc 50: 1723-1733.

Thompson TS, Clement RE, Thornton N and Luyt J (1990). Formation and Emission of
PCDDs/PCDFs in the Petroleum Refining Industry. Chemosphere 20: 1525-1532.

US EPA. (2012a). Petroleum Refinery ICR Responses. DVD 1 of 6: Facilities

AK5A0040 – CA5A0260. United States Environmental Protection Agency.

US EPA. (2012b). Petroleum Refinery ICR Responses. DVD 2 of 6: Facilities

CA5A0270 – LA3C0580. United States Environmental Protection Agency.

US EPA. Integrated Risk Information System (IRIS). United States Environmental

Protection Agency. http://www.epa.gov/iris/. Last updated March 15, 2016. Accessed
October 6, 2015.
US EPA. Acute Exposure Guideline Levels for Airborne Chemicals. United States
Environmental Protection Agency. https://www.epa.gov/aegl. Last updated October 5,
2015. Accessed October 6, 2015.

US EPA. TTNWeb - Technology Transfer Network. United States Environmental

Protection Agency. https://www3.epa.gov/ttn/. Last updated September 10, 2015.
Accessed October 6, 2015.
US EPA. Regional Screening Levels (RSLs) - Generic Tables (November 2015).
United States Environmental Protection Agency. https://www.epa.gov/risk/regional-

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 43

screening-levels-rsls-generic-tables-november-2015. Last updated March 7, 2016.

Accessed March 15, 2016.

US EPA. Toxics Release Inventory (TRI) Program. United States Environmental

Protection Agency. https://www.epa.gov/toxics-release-inventory-tri-program. Last
updated April 19, 2016. Accessed April 28, 2016.

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 A-1

APPENDIX A: SUPPLEMENTARY INFORMATION ON HEALTH EFFECTS OF

SELECT REFINERY CHEMICALS

Appendix A provides further information on select California refinery chemicals based

on various factors that may pose health and safety risks to exposed populations, such
as noncancer health effects, carcinogenic effects, effects on development or
reproduction, and flammability. OEHHA selected these specific chemicals for inclusion
here based on their high emissions, low health guidance values, emissions from
multiple processes and equipment, involvement in incident history, or based on their
toxicity-weighted emissions.

The health summaries included in Appendix A expand upon the basic acute and chronic
health effects of the refinery-associated chemicals in California shown in Table 6, but
should not be considered a complete list of health effects of the chemicals. The health
and exposure summaries described in this section are derived primarily from the
OEHHA web page for REL documents, the US EPA IRIS and Technology Transfer
Network web pages, the ATSDR Medical Management Guidelines for Acute Chemical
Exposures, or the NIOSH Pocket Guide to Chemical Hazards. Additional information on
chemical toxicity profiles can be obtained from sources such as the web pages for NIH’s
Hazardous Substances Database (HSDB) and Toxicology Data Network (TOXNET),
CDC’s Emergency Preparedness and Response, or CAMEO Chemicals (URLs in
References section).

Information regarding CPFs and the Proposition 65 status of carcinogens and

developmental or reproductive toxicants was obtained from publically available OEHHA
documents. To learn more about chemical-specific cancer studies, the development of
CSFs, and Proposition 65 status, see OEHHA (2009) and visit the OEHHA air toxics
and Proposition 65 web pages, or the IARC web page (URLs in References section).

Descriptions of California refinery incidents occurring in 2001-2012 were derived from

data provided by CSB, BAAQMD, and CCHS. In addition, California refinery process
and air emissions data were provided by US EPA (2012a, 2012b) and CARB unless
otherwise noted.

The following chemicals are discussed in Appendix A:

i. Acetaldehyde
ii. Ammonia
iii. Arsenic
iv. Benzo[a]pyrene
v. Benzene, Toluene, Ethylbenzene, and Xylene (BTEX)
vi. 1,3-Butadiene
vii. Dibenzofurans/Dibenzo-p-dioxins
viii. Diethanolamine
ix. Formaldehyde
x. Hydrogen Fluoride

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xi. Hydrogen Sulfide

xii. Manganese
xiii. Naphthalene
xiv. Nitrogen Oxides
xv. Particulate Matter (PM10 and PM2.5)
xvi. Sulfur Dioxide
xvii. Sulfuric Acid

i. Acetaldehyde

At room temperature, acetaldehyde is a colorless liquid with a distinct, pungent odor

detectable even at low concentrations. Acetaldehyde is found in air in the vapor, water
vapor, and particulate phases. It is flammable with an LEL of 4%, and combustion may
generate carbon monoxide. Emissions of acetaldehyde into the environment commonly
occur during combustion processes, making inhalation the primary route of exposure.

Acetaldehyde has been detected in both ambient air emissions and at several refinery
process units such as boilers, cokers, crude units, FCCUs, heaters, and incinerators
(Lucas, 2002). Vapors of acetaldehyde are heavier than air and can cause asphyxiation
in low-lying, enclosed, or poorly ventilated areas. In addition, it has been shown that
this respiratory irritant has a more severe impact on infants and children.

In acute and chronic inhalation studies, the respiratory system has been the hazard
index target tissue for acetaldehyde. Acute exposure to acetaldehyde has been linked
to eye redness and swelling, sensory (eye, nose, throat) irritation, and
bronchoconstriction in asthmatics. Asthmatics are more sensitive to the adverse effects
of acetaldehyde and may be more likely to show symptoms such as shortness of
breath, bronchoconstriction, wheezing, and decreased pulmonary function. Because
children are more likely to be diagnosed with asthma than adults and their asthma
episodes can be more severe, they are particularly vulnerable to the effects of
acetaldehyde exposure. In a study conducted on adult human volunteers, asthmatics
exhibited bronchoconstriction after inhalation of 142 mg/m3 acetaldehyde for two to four
minutes. In a supporting study, eye irritation, followed by upper respiratory tract, nose,
throat, and lung irritation, was observed following whole-body exposure to 45 mg/m3 for
15 minutes. At high concentrations, the temporary onset of transient conjunctivitis
(inflammation or infection of the eye) was also noted. The OEHHA acute REL for
acetaldehyde was determined to be 470 µg/m3 after time and dose adjustments and
consideration of uncertainties in these studies.
Inflammation and injury to the respiratory tract occurs following prolonged exposure to
acetaldehyde. In animals, acetaldehyde exposure targets the nasal cavity and has
been shown to lead to effects such as changes in the nasal mucosa, respiratory
distress, growth retardation, and early mortality in rats. OEHHA used an inhalation
study on rats exposed to various concentrations of acetaldehyde as the basis for the
OEHHA chronic REL. The degenerative, inflammatory, and hyperplastic (increased cell
proliferation) effects on the nasal airways observed in this study at 270 mg/m3 were

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used as the point of departure to derive the OEHHA chronic REL and US EPA RfC for
acetaldehyde of 140 µg/m3 and 9 µg/m3, respectively.

Acetaldehyde is a carcinogenic TAC with CPFs derived by OEHHA based on the nasal
tumors observed in rats following exposure. In hamsters, laryngeal tumors have also
been reported. Acetaldehyde has a CSF of 1.0x10-2 (mg/kg-day)-1 and a unit risk value
of 2.7x10-6 (µg/m3)-1. In addition, this chemical has been shown to cause
developmental and teratogenic effects in rats and mice and may have a role in the
manifestation of fetal alcohol syndrome. It has also been shown to cross the placenta in
animals.

ii. Ammonia

At room temperature, ammonia is a colorless gas that is typically found in air in the form
of water vapor or particulates. Ammonia is corrosive at high concentrations. Although
the odor of ammonia is pungent and irritating, it provides precautionary warning of its
presence in most cases. However, after prolonged exposure to this chemical, it is more
difficult to detect due to olfactory fatigue or adaptation. Ammonia has been categorized
as a slight fire hazard by the National Fire Protection Association (LEL = 15%), but this
hazard is increased in the presence of oil or other combustible materials. The majority
of exposures occur by way of inhalation, and accidental releases of ammonia can form
toxic, dense vapor clouds that travel downwind and put nearby residents at risk.

In California refineries, ammonia emissions have been detected at several process

units. Major emissions are primarily from the FCCU process. Ammonia is the most
commonly released routine facility emission of all the chemicals examined in this report.
In addition, two nonfire incidents during 2001-2012 have been reported in the CSB
Chemical Incident Screening Database. Ammonia is listed as the worst-case-scenario
toxic release in the Risk Management Plans (RMP) of multiple California refineries
evaluated in the 2015 Refinery Emergency Air Monitoring Assessment Report prepared
by CARB OER and CAPCOA (CARB and CAPCOA, 2015). It is also listed in the RMPs
of many refineries as an alternative release scenario, indicating that it is considered to
be more likely than the worst-case-scenario.

Acute inhalation of ammonia may lead to corrosive injury to the skin and mucus
membranes of the eyes, lungs, and gastrointestinal tract. Exposure to very high
concentrations may result in eye redness and lacrimation (tearing), nose and throat
irritation, cough, choking sensation, dyspnea (labored breathing or shortness of breath),
lung damage, or death. Fatalities from ammonia exposure are most commonly caused
by pulmonary edema (fluid accumulation in the lung). People with asthma and other
respiratory conditions such as cardiopulmonary disease or with no tolerance developed
from recent exposure may be more sensitive to the toxic effects of ammonia. In
addition, blood ammonia levels are increased by chronic high dose aspirin therapy and
therapy with valproic acid. Several studies, including one in which human volunteers
were exposed to ammonia for 10 minutes, have demonstrated effects of exposure such

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as the urge to cough and irritation of the eyes, nose, and throat beginning at
concentrations around 36 mg/m3. These critical effects were used as the point of
departure for the ammonia OEHHA acute REL of 3.2 mg/m3.

Chronic exposure to ammonia may impact pulmonary function tests or lead to

subjective symptomatology in workers. Chronic cough, asthma, lung fibrosis, and
chronic irritation of the eye membranes and skin have also been reported. The most
sensitive endpoints of chronic ammonia exposure are decreased pulmonary function,
and eye, skin, and respiratory irritation, which were reported in an occupational
inhalation study at a concentration of 6.5 mg/m3. After time and dose adjustments and
consideration of uncertainties, a chronic OEHHA REL of 200 µg/m3 and US EPA RfC of
100 µg/m3 for ammonia have been developed.

iii. Arsenic

In its elemental form, arsenic is a grey metallic solid with no characteristic taste or smell.
Inorganic arsenic compounds are respiratory irritants and may vary in relative toxicity.
Arsenic exists in air in the particulate phase. Contact with acid or acid vapors produces
arsine, the most dangerous form of arsenic. While ingestion is the most important route
of exposure for arsenic trioxide, exposure to other arsenic compounds sufficient to
cause toxicity may be more likely to occur via inhalation.

Arsenic likely originates as an impurity in crude oil (Stigter et al., 2000), and it has been
detected at many of the process units such as boilers, crude units, heaters, storage
tanks, cokers, FCCUs, and incinerators. Arsenic has also been detected in routine and
non-routine refinery emissions.

Acute exposure to arsenic has been associated with severe irritation of the mucus
membranes of the respiratory tract and symptoms of cough, dyspnea (labored breathing
or shortness of breath), and chest pain. Breathing high levels of arsenic may lead to a
sore throat and lung irritation. Ingestion may result in symptoms characteristic of severe
gastritis or gastroenteritis (inflammation, irritation, or erosion of the stomach) and even
death due to severe inflammation of the mucus membranes and increased capillary
permeability. Signs of acute arsenic poisoning include dermatitis, nasal mucosal
irritation, laryngitis, mild bronchitis, and conjunctivitis (inflammation or infection of the
eye). In an inhalation study of pregnant mice, decreased fetal weight was reported at
concentrations starting at 0.2 mg/m3. After time and dose adjustments and
consideration of uncertainties, OEHHA derived an acute REL for arsenic of 0.2 µg/m3.

Chronic exposure to arsenic has been associated with symptoms such as malaise
(general feeling of discomfort), peripheral sensorimotor neuropathy (nerve damage),
anemia, jaundice, and gastrointestinal discomfort. Prolonged exposure to arsenic also
targets the lungs and skin and can cause darkened skin and the appearance of small
“corns” or “warts” on the palms, soles, and torso. Conjunctivitis (inflammation or
infection of the eye), irritation of the throat and respiratory tract, and perforation of the

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nasal septum have also been reported. Additionally, literature suggests that arsenic
exposure during childhood may impart greater toxicity than adult exposure. In a study
conducted on 10-year-old children exposed to 0.23 µg/m3 of arsenic by drinking water,
the impairment of intellectual function and neurobehavioral development was observed.
After time and dose adjustments and consideration of uncertainties, OEHHA developed
a chronic inhalation REL of 0.015 µg/m3 and a chronic oral REL of 0.035 µg/kg-day.

Arsenic is listed by IARC as a known human carcinogen of the lung, urinary bladder,
and skin. Some studies have also observed carcinogenesis in several other organs.
Arsenic is on the Proposition 65 list for both cancer and developmental toxicity. Arsenic
has an inhalation and oral CSF of 12 (mg/kg-day)-1 and 1.5 (mg/kg-day)-1, respectively,
based on the incidence of lung tumors in workers occupationally exposed via inhalation
and the incidence of skin cancer in individuals exposed via drinking water. The unit risk
for arsenic is 0.003 (µg/m3)-1. Arsenic ions originating from arsenic trioxide have been
shown to cross the placenta and can also be excreted in breast milk. In animals
exposed to arsenic compounds, embryonic lethality, fetal malformations, decreased
fetal weight, delayed bone maturation, skeletal malformations, and increased risk of
chromosome aberrations in liver cells have been reported. A decrease in spermatozoa
motility has also been observed following exposure.

iv. Benzo[a]pyrene

In pure form, benzo[a]pyrene is a pale yellow solid with a faint aromatic odor. Most
benzo[a]pyrene in air is bound to particulates and is formed as a by-product of
incomplete combustion from sources like volcanoes, automobile exhaust, cigarette
smoke, and burning coal. Although it is considered to be nonflammable,
benzo[a]pyrene emits acrid smoke and toxic carbon monoxide and carbon dioxide
fumes or vapors when it is heated to decomposition. Due to its consistent association
with the presence of smoke, benzo[a]pyrene may serve as an air monitoring surrogate
for other polycyclic aromatic hydrocarbons (PAH) and smoke itself in addition to
particulate matter in the event of a refinery emergency.

The general population is exposed to benzo[a]pyrene primarily by breathing air

containing PAHs attached to particles and by consumption of PAHs in food. Once in
the environment, PAHs are of concern due to their ability to travel long distances in the
air, persist in the environment for extended periods of time, and bioaccumulate up the
food chain. Benzo[a]pyrene has been detected in routine refinery emissions and
around many areas of petroleum refineries such as separators, boilers, cooling towers,
crude units, heaters, storage tanks, cokers, FCCUs, wastewater treatment, incinerators,
and vents.

Benzo[a]pyrene generally occurs in conjunction with other PAHs, therefore most

available information on its relevant health effects is in reference to the chemical as part
of a mixture containing benzo[a]pyrene, chrysene, benz[a]anthracene,
benzo[b]fluoranthene, dibenz[a,h]anthracene, and other carcinogenic or potentially

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carcinogenic compounds. Acute exposure can cause irritation and a burning sensation
of the eyes and skin.

Benzo[a]pyrene is currently classified as a known carcinogen by OEHHA and US EPA,

and has additionally been classified as a human carcinogen by IARC, based on the
increased incidence of tumors observed in animals on the skin, in lymphoid and
hematopoietic tissues, and in various organs such as the lung, forestomach, liver,
oesophagus, and tongue. Benzo[a]pyrene has an inhalation CSF of 3.9 (mg/kg-day)-1
based on the occurrence of respiratory tract tumors in male hamsters exposed via
inhalation and an oral CSF of 12 (mg/kg-day)-1 based on the occurrence of gastric
tumors in male and female mice exposed via diet. The unit risk for benzo[a]pyrene is
0.0011 (µg/m3)-1.

Benzo[a]pyrene has also been shown to cause reproductive effects in humans such as
decreased sperm quality and fertility in males. In animals, decrements in sperm quality,
changes in testicular histology, and hormone alterations in males and decreased fertility
and ovotoxic effects in females have been reported. In addition, adverse effects on fetal
survival, postnatal growth, and development have been associated with human
exposure during gestation. Changes in fetal survival, pup weight, blood pressure,
fertility, reproductive organ weight and histology, and neurological function have also
been observed in animals exposed during gestation and/or early life.

v. Benzene, Toluene, Ethylbenzene, and Xylene (BTEX)

Benzene, toluene, ethylene, and xylene, collectively called BTEX, are volatile and well-
absorbed chemicals that are found in petroleum products such as gasoline, jet fuels,
and kerosene. BTEX chemicals often occur simultaneously at hazardous waste sites
and emissions of each have been widely detected in similar areas within California
refineries. BTEX is both an environmental and health concern because it can
contaminate all media (air, water, and soil) and cause neurological impairment with
exposure.

Benzene

Benzene is an aromatic hydrocarbon emitted into the air during the production and
combustion of diesel and petroleum fuels. It is highly volatile and primarily found in the
vapor phase. At room temperature, benzene is a colorless and highly flammable liquid
(LEL = 1.2%) with a petroleum-like smell. Benzene vapor is heavier than air and can
cause asphyxiation in enclosed, poorly ventilated, or low-lying areas. Benzene is of
concern because it is emitted from numerous routine refinery operations (sulfuric acid
loading, separators, boilers, cooling towers, crude units, heaters, storage tanks, cokers,
FCCUs, wastewater treatment, incinerators, and vents) and is commonly found in
refinery emissions.

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In humans, acute inhalation of benzene may lead to eye, nose, and throat irritation, and
central nervous system depression. Acute hazard index targets include developmental
effects and potential damage to the immune and hematologic systems. Drowsiness,
dizziness, rapid heart rate, headaches, tremors, confusion, and unconsciousness may
result from breathing high levels of benzene. Acute exposure can also increase cardiac
sensitivity to epinephrine-induced arrhythmias. Brief exposure to very high levels in air
can lead to death through respiratory failure. People with existing hematologic
disorders and cellular anemias or heart conditions may be at increased risk for bone
marrow toxicity and cardiac arrhythmias, respectively. In addition, intake of epinephrine
and ethanol has been shown to increase the cardiac toxicity of benzene in humans and
the bone marrow toxicity of benzene in mice, respectively. In mice, acute benzene
exposure has been shown to cause developmental damage in the blood cells of fetal
and neonatal mice. This is the basis of OEHHA’s acute benzene REL of 27 µg/m3.

The hematologic system is the main hazard index target for chronic benzene exposure.
Long-term or repeated benzene exposure may cause noncancer detrimental health
effects, including decreases in blood cell count, as well as leukemia. Chronic exposure
to benzene can also lead to aplastic anemia, excessive bleeding, and damage to the
immune system. Metabolic breakdown products of benzene have been shown to cause
chromosomal changes that are consistent with those occurring in cases of
hematopoietic cancer. Both the OEHHA chronic REL (3 µg/m3) and the US EPA RfC
(30 µg/m3) for benzene are derived from human occupational inhalation studies finding
decreased blood cells counts in workers exposed to an average concentration of 0.61
mg/m3 for durations lasting 1 to 21 years.

Any benzene exposure is a concern regardless of exposure length. Benzene is

currently listed under Proposition 65 as a carcinogen, a developmental toxicant, and a
male reproductive toxicant. It has also been classified as a known human carcinogen of
the hematopoietic system, primarily leukemia, by IARC. At benzene exposures
between 0.13 – 0.45 µg/m3, US EPA estimates that 1 in 1,000,000 individuals will be at
risk of benzene-induced cancer. Children are at particular risk to the carcinogenic
effects of benzene due to the high level of cell growth and turnover in their developing
systems. Based on both animal and human data, the benzene CSF is 0.1 (mg/kg-
day)-1. The unit risk for benzene is 2.9x10-5 (µg/m3)-1.

Benzene has been shown to cross the placenta and, in animals exposed to benzene via
inhalation, developmental effects such as low birth weight, bone marrow toxicity, and
delayed bone formation have been observed. At very high levels of exposure, benzene
has also been associated with adverse effects on the reproductive organs of animals.

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Ethylbenzene

Ethylbenzene is a colorless, highly flammable liquid (LEL = 0.8%) with an odor similar to
that of gasoline. Ethylbenzene vapor is formed in air during the combustion of oil, gas,
and coal, and breaks down within a few days by reaction with sunlight. The general
population is exposed to ethylbenzene by breathing air, especially in cities with multiple
factories or busy highways. Residential drinking water wells near landfills, waste sites,
or leaking underground storage tanks can also lead to high levels of exposure.
Because it occurs naturally in oil, ethylbenzene vapors can additionally be released into
the environment during the production, transport, and refining of petroleum.
Ethylbenzene emissions have been detected at many refinery process units including:
separators, cooling towers, crude units, heaters, storage tanks, cokers, FCCUs,
wastewater treatment, incinerators, and vents, and in routine and non-routine refinery
emissions.

Acute exposure to ethylbenzene can cause chest constriction, irritation of the eyes and
throat, and neurological effects such as dizziness and vertigo in humans. In animals
acutely exposed to ethylbenzene by inhalation, eye irritation, central nervous system
toxicity, effects on the liver and kidney, and pulmonary effects have been observed.

Studies on long-term occupational exposure to ethylbenzene have provided limited

information regarding its effects on the blood, likely due to the presence of other
chemicals such as xylenes in the same environment. In animals chronically exposed to
ethylbenzene, effects on the blood, liver, and kidneys have been reported. Irreversible
damage to the inner ear and hearing has also been noted. Based on the adverse
effects on the liver (cellular alterations and necrosis), kidney (nephrotoxicity), and
pituitary gland (hyperplasia) appearing in mice and rats discontinuously exposed to 1.1
µg/m3 ethylbenzene via inhalation, OEHHA developed a chronic REL of 2 mg/m3. A US
EPA RfC for ethylbenzene of 1 mg/m3 has also been established due to the
developmental toxicity observed in rats and rabbits following chronic exposure.

Because inhalation exposure has been associated with an increase in tumors of the
kidney in rats and of the lung and liver in mice, ethylbenzene was classified by IARC in
2010 as a possible human carcinogen. In 2004, it was also listed as a carcinogen by
OEHHA under Proposition 65. The inhalation and oral CSFs for ethylbenzene are
8.7x10-3 (mg/kg-day)-1 and 1.1x10-2 (mg/kg-day)-1, respectively, and are based on the
incidence of kidney cancer in male rats. Ethylbenzene also has a unit risk value of
2.5x10-6 (µg/m3)-1.

Toluene

Toluene is a clear, volatile liquid with an aromatic odor that generally serves as an
adequate warning of acutely toxic concentrations. It can be ignited under almost all
ambient temperature conditions (LEL = 1.1%). While toluene may give rise to toxic
effects by inhalation, ingestion, or dermal contact, the general population is primarily
exposed to toluene by way of inhalation. Because its vapors are heavier than air,

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caution should be taken to avoid possible asphyxiation in enclosed, poorly ventilated, or

low-lying areas. Toluene is a natural constituent in crude oil and is produced in large
quantities by distillation during petroleum refining, serving as a sentinel chemical for
benzene exposure. As with the rest of the BTEX chemicals, toluene vapors have been
widely detected at various refinery emission points (sulfuric acid loading, separators,
boilers, cooling towers, crude units, heaters, storage tanks, cokers, FCCUs, wastewater
treatment, incinerators, and vents) and in outdoor refinery emissions.

Both acute and chronic exposures to toluene are a serious concern because they target
the nervous system. Symptoms such as fatigue, sleepiness, headaches, nausea, and
irritation of the eyes, skin, and respiratory tract may be experienced in people acutely
exposed to low or moderate levels in air. Central nervous system depression, ataxia
(lack of muscle control during voluntary movements), euphoria, hallucinations, tremors,
seizures, coma, and death may occur at higher levels of exposure. Some people with
liver, neurological, or heart disease may be at increased risk for adverse effects
resulting from exposure. Concurrent use of salicylates, alcohol, or over-the-counter
bronchial dilators containing epinephrine may also increase an individual’s susceptibility
to toluene. A human acute inhalation study demonstrated eye and nose irritation,
impaired reaction time, headache, dizziness, and a feeling of intoxication. This study of
toluene exposure was used in OEHHA’s development of the acute REL (37 mg/m3).

Most studies regarding the effects of chronic toluene exposure involve deliberate
sniffing of toluene-containing solvents or workplace exposures and have reported a
range of neurotoxic effects such as brain damage and decreased performance on
psychometric tests. Prolonged exposure has also been associated with nausea,
fatigue, eye and upper respiratory tract irritation, sore throat, dizziness, headache, and
difficulty with sleep. In cases of occupational exposure, disorders of the optic nerve and
neurobehavioral effects such as loss of coordination, memory loss, and loss of appetite
have been reported. Chronic toluene abuse can lead to symptoms indicative of central
nervous system depression including: drowsiness, ataxia (lack of muscle control during
voluntary movements), tremors, cerebral atrophy (loss of neurons), involuntary eye
movements, and impairment of speech, hearing, and vision. Permanent
neuropsychiatric effects, muscle disorders, cardiovascular effects, renal tube damage,
and sudden death can also occur. OEHHA derived the chronic REL (300 µg/m3) for
toluene based on an inhalation study on rats that began showing neurotoxic effects
(decreased brain weight and altered dopamine receptor binding) at a concentration of
300 µg/m3 following exposure to an average of 26.3 mg/m3. Neurological effects in
occupationally-exposed workers were also observed in multiple studies, serving as the
basis for the US EPA inhalation RfC of 5 mg/m3.

Toluene is listed under Proposition 65 as a developmental toxicant and has been shown
to cross the placenta and be excreted in breast milk. Children whose mothers were
toluene abusers during pregnancy were born with small heads and have head, face,
and limb abnormalities, attention deficits, hyperactivity, and developmental delay with
language impairment. Preterm delivery, perinatal death, and growth retardation have
also been reported.

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Xylene

Xylene exists in three forms (m-xylene, o-xylene, and p-xylene) that are commonly
combined to form what is known as mixed or technical xylene. An entry for each
constituent of technical xylene, as well as the mixture itself, is included in Table 1. For
the purposes of this section, the term “xylene” will refer to technical xylene, which is
richest in m-xylene and usually also contains ethylbenzene and traces of toluene.

Xylene is a colorless, volatile, flammable liquid (LEL = 1.1%) with an aromatic odor. In
air, xylene exists as vapor and may be an explosion hazard. Combustion of this
chemical will produce irritating gases that are corrosive and/or toxic. Xylene can be
found in drinking water, but because it easily evaporates into the air, exposure typically
occurs via inhalation. Exposure to high concentrations of xylene vapors can result in
asphyxiation in low-lying or poorly ventilated areas. Xylenes occur naturally in
petroleum and coal and are additionally used as solvents and gasoline additives in the
petroleum industry. Data from US EPA show that xylene vapors have been detected in
refinery emissions and around separation, conversion, product handling, and auxiliary
processes carried out in refineries.

Both short-term and long-term exposure to high levels of xylene may cause eye, skin,
and respiratory tract irritation, but the central nervous system is the primary target of
such encounters. Headaches, decreased muscle coordination, dizziness, confusion,
and altered sense of balance may be experienced following acute exposure. Short-term
exposure to elevated levels in air have also been associated with symptoms such as
strained breathing, lung function impairment, delayed response to visual stimuli,
impaired memory, stomach discomfort, ventricular arrhythmias, acute pulmonary edema
(fluid accumulation in the lung), and hepatic impairment. Very high levels may be fatal.
In addition, studies have shown that xylene may increase the rate of metabolism of
other chemicals; however, the presence of other solvents inhibits the breakdown of
xylene itself and may thus lead to increased toxicity. OEHHA used acute exposure
studies demonstrating eye, nose, and throat irritation in humans exposed to xylene to
develop the acute REL of 22 mg/m3.

Chronic exposure to xylene in occupational settings has led to neurological effects such
as headache, fatigue, dizziness, tremors, loss of coordination, anxiety, impairment of
short-term memory, and inability to concentrate. Cardiovascular effects (labored
breathing, impairment of pulmonary function, heart palpitations, chest pain, and
abnormal electrocardiogram) and effects on the gastrointestinal system (nausea,
vomiting, and gastric discomfort) have also been associated with prolonged exposure.
Some studies also report effects on the kidneys. Xylene exposure from solvent abuse
has also been shown to lead to permanent neuropsychiatric manifestations, which can
progress to become chronic toxic encephalopathy (malfunction or degradation of brain
function). In workers occupationally exposed to xylene, eye irritation, sore throat,
floating sensation, and lack of appetite were observed at a concentration of 61.6 ng/m3
and used as the basis for the OEHHA chronic REL of 700 µg/m3. A US EPA RfC of

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100 µg/m3 was also established for this chemical based on the impaired motor
coordination seen in rats following subchronic inhalation exposure.

Xylene has been reported to cross the placenta in humans and high doses may be
fetotoxic in animals. Animal inhalation studies have shown developmental effects such
as skeletal variations in fetuses, delayed bone formation, fetal resorptions, decreased
body weight, and decreased motor performance during adolescence. Maternal toxicity
has also been observed. The isomers with the greatest fetotoxicity and maternal
toxicity are p-xylene and m-xylene, respectively.

vi. 1,3-Butadiene

1,3-Butadiene is a colorless gas with a mild gasoline-like odor that is usually an

adequate warning to protect individuals against acutely hazardous levels. Although this
gas is noncorrosive, it is highly flammable (LEL = 2%) and forms explosive peroxides
upon prolonged exposure to air. The primary route of exposure to 1,3-butadiene is
inhalation. While motor vehicle exhaust contributes to ambient levels of 1,3-butadiene,
exposure to higher levels of the chemical primarily occurs in occupational settings since
it is produced through the processing of petroleum, and used in making other products.
1,3-Butadiene is heavier than air and at high concentrations can cause asphyxiation in
enclosed, poorly ventilated, or low-lying areas.

In refineries 1,3-butadiene emissions have been detected in many different areas:

sulfuric acid loading, separators, cooling towers, crude units, heaters, storage tanks,
cokers, FCCUs, and wastewater treatment. Boilers, internal combustion engines, and
turbines may be additional sources of release. 1,3-Butadiene has been detected in
routine and non-routine refinery emissions and has been identified in a refinery fire
incident linked to the coking unit.

At low concentrations, acute inhalation of 1,3-butadiene vapors may be irritating to the

eyes, nose, throat, and lungs. OEHHA reports that blurred vision, nausea, paresthesia
(tingling or pricking sensation), and mouth, throat, and nose dryness are the initial signs
of acute exposure to high concentrations, and may be followed by fatigue, headache,
vertigo, hypotension, decreased heart rate, and unconsciousness. At very high
concentrations, central nervous system depression can occur. A whole-body inhalation
study of pregnant mice leading to decreased male fetal weight was the basis of the
OEHHA acute REL (660 µg/m3) for 1,3-butadiene chemical because it addressed the
most sensitive endpoint of 1,3-butadiene exposure, developmental effects.

Chronic exposure to 1,3-butadiene, in the presence of other pollutants, has been found
to exacerbate symptoms of asthma and increase incidence of respiratory tract
infections. While long-term exposure to the gas has been linked to cardiovascular
diseases and effects on the blood, female reproductive organs are considered the
critical target of chronic exposure for noncancer effects. In addition, animal studies
have shown that chronic exposure to 1,3-butadiene can lead to bone marrow

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depression and DNA repair deficiencies. The chronic OEHHA REL and US EPA RfC of
2 µg/m3 are the same for 1,3-butadiene and were derived based on the increased
occurrence of ovarian atrophy (degeneration of cells) observed during an inhalation
study conducted on mice exposed daily for 6 hours, 5 days per week, for a duration of 9
to 24 months.

1,3-Butadiene is a carcinogen and a male and female developmental toxicant under

Proposition 65. It has also been classified as a human carcinogen by IARC based on
evidence that it causes cancer of the hematolymphatic organs. The CSF and unit risk
for 1,3-butadiene are 0.6 (mg/kg-day)-1 and 1.7x10-4 (µg/m3)-1, respectively, and were
derived by OEHHA based on the incidence of lung tumors reported in inhalation studies
of female mice. Although information regarding the developmental or reproductive
effects of 1,3-butadiene is limited, animal studies have reported developmental effects
such as skeletal malformations and decreased fetal weights, and reproductive effects
such as damage to the ovaries and testes following inhalation exposure.

vii. Dibenzo-p-dioxins/Dibenzofurans

Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) make up a group

of 210 closely related halogenated aromatic compounds collectively referred to as
“dioxins.” In pure form, many dioxins are colorless crystals. Polyhalogenated
compounds like dioxins are one of eight major categories of polycyclic organic matter, a
broad class of compounds that is present in the atmosphere. Dioxins released into the
air are deposited on land or water, where they persist for long periods of time and can
build up in the fatty tissues of animals that ingest it (bioaccumulation). In refineries,
dioxins are formed during catalyst regeneration and during the combustion of organic
materials in the presence of chlorine and have been detected at process units such as
heaters, incinerators, and wastewater (Thompson et al., 1990; Shaw et al., 2013).

Dioxins are a major concern due to the wide range of severe health effects induced by
chronic exposure to low doses. In humans, exposure to dioxins has been shown to lead
to the development of a skin condition resembling severe acne (chloracne),
gastrointestinal upset, increased levels of serum enzymes and triglycerides, and
numbness of the extremities. Although the toxic responses observed in animals treated
with various members of this group are generally similar, those chlorinated at the 2, 3,
7, and 8 positions are particularly toxic. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is
considered the most potent congener of the dioxin family and is thus the most widely
studied of the group. The most sensitive targets of chronic dioxin exposure include the
alimentary system (liver), reproductive system, development, endocrine system (pineal,
pituitary, thyroid, parathyroid, and adrenal glands, pancreas, ovaries, testes,
hypothalamus, and gastrointestinal tract), respiratory system, and hematopoietic system
(bone marrow, spleen, tonsils, and lymph nodes). In a study on rats continuously
exposed to TCDD for two years via diet, effects such as increased mortality, decreased
weight gain, and changes in the liver, lungs, and lymphoid and vascular tissues were
noted at a dose of 0.001 µg/kg/day, which served as the point of departure for the

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chronic REL for dioxins (4x10-5 µg/m3). Because of the ability of dioxins to
bioaccumulate, a chronic oral REL of 1x10-5 µg/kg-day has also been developed. There
is no acute REL or RfC for this group of chemicals. US EPA developed a Reference
Dose (RfD) for 2,3,7,8-tetrachlorodibenzo-p-dioxin of 7x10-10 mg/kg-d based on
decreased sperm count in men exposed as boys and decreased thyroid stimulating
hormone (TSH) in neonates.

Both PCDDs and PCDFs are carcinogenic TACs with CPFs derived by OEHHA based
on the occurrence of liver tumors in male mice after exposure. Dioxin-related cancer
mortality following an accidental release of TCDD from a 1,2,3-trichloropropane-
producing plant in Seveso, Italy included conditions such as digestive cancer, stomach
cancer, lymphatic and hemopoietic cancer, multiple myeloma, rectal cancer, leukemia,
ovarian cancer, and thyroid cancer. TCDD has a CSF and a unit risk value of 1.3x105
(mg/kg-day)-1 and 38 (µg/m3)-1, respectively. PCDDs and PCDFs have been classified
as carcinogens by OEHHA under Proposition 65 and by US EPA. PCDDs including
TCDD have also been classified as multi-site carcinogens in animals by IARC.
Immunotoxicity, particularly from perinatal exposure, and developmental toxicity are key
endpoints of concern for infants and children. In addition, dioxins have been shown to
cross the placenta and can be transferred from mother to infant during breastfeeding.
Effects on thyroid development and infant neurodevelopment and an increased risk of
diabetes and endometriosis from dietary intake have also been reported (Arisawa et al.,
2005).

viii. Diethanolamine

Diethanolamine is a hydrocarbon found in air in the water vapor and particulate phases.
It is a colorless powder or liquid in pure form and has an odor resembling that of
ammonia. Diethanolamine produces acrid vapors when heated that are slightly heavier
than air. It has been classified as a slight fire hazard by the National Fire Protection
Association, but must be preheated prior to ignition. In petroleum refineries,
diethanolamine is used in desulfurization processes and may contaminate wastewater
(Bord et al., 2004). This chemical has been detected at multiple refinery process units
included in this report (crude units, storage tanks, cokers, and wastewater treatment)
and may also be found in amine scrubbers used for natural gas purification (Nelson,
2013).

In humans, acute inhalation exposure to diethanolamine may cause nose and throat
irritation. Coughing, nausea, headache, and a smothering sensation may result from
breathing its vapors. Other effects of acute exposure may include eye burns, corneal
necrosis (death of corneal cells), skin burns, lacrimation (tearing), and sneezing.

Currently, there is inadequate information on the chronic effects of diethanolamine in

humans. The respiratory and cardiovascular systems are the targets for chronic
exposure. In one occupational case report, the handling of diethanolamine-containing
cutting fluid caused asthmatic airway obstruction. Diethanolamine may exacerbate

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asthma; thus, children may be more vulnerable to its irritant effects. The chronic REL of
3 µg/m3 was derived based on an inhalation study in rats that showed chronic
inflammation and abnormal cellular changes (squamous hyperplasia, metaplasia) of the
larynx at a concentration of 15 mg/m3. Diethanolamine has been shown to cause liver
tumors in rats by IARC and has been classified as a carcinogen by OEHHA under
Proposition 65.

ix. Formaldehyde

At room temperature, formaldehyde is a colorless gas with a distinct, pungent odor

detectable even at low concentrations. Formaldehyde is found in air in the vapor, water
vapor, and particulate phases. Formaldehyde is flammable with an LEL of 7%, and its
combustion may generate carbon monoxide. Emissions of this chemical into the
environment commonly occurs during combustion processes; thus, inhalation is the
primary route of exposure. Formaldehyde has been detected in both ambient air
emissions and at several refinery process units such as boilers, cokers, crude units,
FCCUs, heaters, and incinerators (Lucas, 2002). Vapors of formaldehyde are heavier
than air and high concentrations can cause asphyxiation in low-lying, enclosed, or
poorly ventilated areas. In addition, this respiratory irritant may have a more severe
impact on infants and children.

Acute exposure to low concentrations of formaldehyde can result in eye irritation,

headache, rhinitis (irritation or inflammation of mucous membrane in the nose), and
dyspnea (labored breathing or shortness of breath). Some people may be more
sensitive to the effects of formaldehyde exposure and experience exacerbation of
asthma and dermatitis at low doses. Higher doses may cause lacrimation (tearing),
severe mucous membrane irritation, burning, difficulty breathing, and effects on the
lower respiratory system such as bronchitis, pulmonary edema (fluid accumulation in
the lung), or pneumonia. Asthmatics and individuals previously sensitized to
formaldehyde may be more vulnerable to the adverse respiratory effects resulting from
exposure. Because studies have shown that asthma is more common and may be
more severe in children than adults, formaldehyde exposure is also a concern for
infants and children. An acute REL was derived for formaldehyde based on a study in
which non-asthmatic, nonsmoking individuals were exposed to the chemical for three
hours and began experiencing mild and moderate eye irritation at an airborne
concentration of 0.9 mg/m3. The OEHHA acute REL is 55 µg/m3 after adjustments for
dose, time, and uncertainties.

Long-term exposure to formaldehyde primarily targets the respiratory system and may
lead to allergic sensitization, respiratory symptoms such as coughing and wheezing,
nasal symptoms such as running nose and crusting, lacrimation (tearing), cellular
changes in airway membranes, and decreased lung function. Effects on the nervous
system such as headaches, depression, mood changes, insomnia, attention deficit, and
dexterity and memory impairment have also been reported. OEHHA used an
occupational study in which workers experienced nasal obstruction and discomfort and

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lower airway discomfort at an average concentration of 0.09 mg/m3 to derive the chronic
REL of 9 µg/m3 for formaldehyde.

Formaldehyde is a carcinogenic TAC with CPFs derived by OEHHA based on the

incidence of nasal tumors in male and female rats and male mice resulting from
exposure. In humans, formaldehyde exposure has additionally been associated with
cancers of the upper respiratory tract, specifically buccal cancer, pharyngeal cancer,
and nasopharyngeal cancer. Formaldehyde has also been associated with an elevated
risk of leukemia and sinonasal cancer. The CSF for formaldehyde is 2.1x10-2 (mg/kg-
day)-1 and the unit risk value is 6.0x10-6 (µg/m3)-1. Formaldehyde has been classified as
a carcinogen by OEHHA, US EPA, and IARC.

x. Hydrogen Fluoride

Hydrogen fluoride is a colorless fuming liquid or gas with a strong, pungent odor.
Dissolution in water forms corrosive hydrofluoric acid, a systemic poison. Although it
will not burn under typical fire conditions, this acid emits highly irritating and poisonous
vapors that are corrosive to metals and body tissues when heated. Because it is
corrosive to metals, hydrogen fluoride may yield hydrogen and may thus indirectly
create a fire hazard. Hydrogen fluoride in air is normally found in the water vapor and
particulate phases. The general population may be exposed to hydrogen fluoride in the
ambient environment from industrial process emissions and coal combustion. In
refineries, this chemical is used as a catalyst during alkylation or cracking and has been
detected in refinery emissions and around crude units and cokers.

Short-term inhalation of hydrogen fluoride can lead to severe respiratory damage

(irritation and fluid accumulation in the lung), lacrimation (tearing), sore throat, cough,
chest tightness, and wheezing. Due to the ability of the fluoride ion to penetrate tissues,
some health effects may be delayed for one to two days after exposure. Breathing high
levels of the gas or in combination with dermal exposure may be fatal due to pulmonary
edema (fluid accumulation in the lung) and bronchial pneumonia. People with
cardiopulmonary disease may be particularly vulnerable to lower airway irritation at high
concentrations. The most sensitive endpoint for short-term inhalation exposure to
hydrogen fluoride is eye, nose, and throat irritation, which was observed in an inhalation
study of healthy, male volunteers after one hour of exposure to concentrations of 0.2-
0.6 mg/m3. After time and dose adjustments and consideration of uncertainties,
OEHHA established an acute REL of 240 µg/m3 to protect individuals from these effects.

Long-term exposure to low levels of hydrogen fluoride has been linked to congestion
and irritation of the nose, throat, and bronchi. Liver and kidney damage has also been
noted. Exposure to higher levels has been associated with increased bone density
(skeletal fluorosis). This was observed in a study on fertilizer plant workers chronically
exposed to an average of 0.14 mg/m3 hydrogen fluoride. In this study, OEHHA
determined the point of departure for increased bone density to be 1.13 mg/m3, which
served as the basis of the chronic REL of 14 µg/m3. Because fluorides may

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contaminate food and drinking water, OEHHA has also developed a chronic oral REL
for hydrogen fluoride, based on the dental fluorosis observed in the inhabitants of
several US cities exposed via drinking water. A point of departure of 0.82 mg/m3 at
which the incidence of moderate to severe dental fluorosis was considered to be rare
among the population was used to calculate the chronic oral REL of 40 µg/kg-day.
Dental fluorosis has additionally been noted in children after maternal exposure to high
levels during pregnancy.

xi. Hydrogen Sulfide

Found in air in the water vapor and particulate phases, hydrogen sulfide is a corrosive
gas with a pungent rotten egg odor. For this chemical, odor is not a reliable indicator of
its presence due to the olfactory fatigue that occurs at both high concentrations and
continuous low concentrations. Hydrogen sulfide is highly flammable (LEL = 4%) and
may produce an explosion at levels above 4.5% in air. When heated, highly toxic sulfur
oxide fumes or vapors are emitted. Hydrogen sulfide is slightly heavier than air and
may be present at higher levels in enclosed, poorly ventilated, and low-lying areas.
Because it is released naturally as a product of decaying organic matter, hydrogen
sulfide is a natural component and the predominant impurity of crude oil and natural gas
(Skrtic, 2006).

In oil refineries, hydrogen sulfide is formed during the removal of sulfur compounds from
petroleum products and has been detected at various process units such as boilers,
crude units, heaters, storage tanks, cokers, FCCUs, wastewater treatment, and
incinerators. Hydrogen sulfide is one of the most routinely emitted refinery pollutants
included in this report and its distinct smell made it one of the most frequently
mentioned chemicals in refinery incident reports during 2001-2012. As with ammonia, it
appears in many refineries’ RMPs as the worst-case-scenario toxic release and
alternate release scenario (CARB and CAPCOA, 2015).

Hydrogen sulfide is very toxic by inhalation. Because exposure to this chemical affects
most organ systems, hydrogen sulfide is considered to be a broad spectrum toxicant
and may pose a significant health risk to those exposed. Acute exposure to hydrogen
sulfide targets the central nervous system and leads to symptoms such as headache,
nausea, and irritation of the skin, eyes, mucus membranes, and respiratory tract. Acute
exposure to higher levels of hydrogen sulfide can cause conjunctivitis (inflammation or
infection of the eye) with ocular pain, lacrimation (tearing), and photophobia.
Concentrations in air high enough to exceed the body’s detoxification threshold lead to
cellular respiratory poisoning and asphyxiation (Skrtic, 2006). Death due to hydrogen
sulfide exposure is typically caused by respiratory arrest. In addition, ethanol has been
shown to decrease the average time-to-unconsciousness in mice exposed to the gas
and may thus potentiate its effects.

The most sensitive endpoints for acute hydrogen sulfide exposure are headache and
nausea in human volunteers, which were reported at levels below the odor threshold

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after exposure to doses ranging from 16.8 to 96.6 µg/m3. After time and dose
adjustments and consideration of uncertainties, an acute REL of 42 µg/m3 was
developed by OEHHA.

Chronic effects of hydrogen sulfide include: low blood pressure, headache, nausea, loss
of appetite, weight loss, ataxia (lack of muscle control during voluntary movements), eye
membrane inflammation, and chronic cough. In mice, prolonged exposure to hydrogen
sulfide targets the respiratory system and causes nasal inflammation (chronic REL = 10
µg/m3). The inhalation RfC of 2 µg/m3 was derived based on a study showing olfactory
loss and nasal lesions in rats following subchronic exposure to 42.5 mg/m3 of the
chemical. Individuals living in close proximity to oil refineries may be at risk of chronic
exposure to hydrogen sulfide. Hydrogen sulfide is not listed as a carcinogen under
Proposition 65, but the literature indicates that this chemical may be a reproductive
toxicant that increases risk of spontaneous abortion.

xii. Manganese

Naturally-occurring manganese compounds are often associated with organic materials

or metals. The general public is exposed to manganese through inhalation, particularly
in areas where it is used in manufacturing and through consumption of food and water.
Manganese is of concern because of the amount of routine refinery emissions and the
many process units with which it is associated (boilers, cooling towers, crude units,
heaters, storage tanks, cokers, FCCUs, and incinerators). Manganese may be ignited
by friction, heat, sparks, or flames. It may also react violently or explosively with water,
and dusts or vapors may yield explosive mixtures in air.

Both short-term and long-term inhalation exposures to manganese have the potential to
cause adverse health effects and appear to target the nervous system. While small
amounts of manganese are beneficial to human health, exposure to higher levels may
cause brain damage. Acute manganese exposure may lead to impaired function and
nonspecific pulmonary edema (fluid accumulation in the lung).

Chronic manganese exposure may lead to more serious health effects, including
“manganism” neurotoxicity. The symptoms of “manganism” appear similar to those of
Parkinson’s disease, with affected individuals suffering from dystonia (involuntary
muscle contractions), altered gait, generalized rigidity, and fine tremor. Some
individuals may also suffer from psychiatric disturbances. Lower levels of prolonged
manganese exposure can lead to changes in neurobehavioral and cognitive abilities
such as slower visual reaction time, poorer hand steadiness, and impaired hand-eye
coordination in both adults and children. Chronic exposure may also cause respiratory
effects such as increased incidence of cough, bronchitis, dyspnea (labored breathing or
shortness of breath) during exercise, and increased susceptibility to infectious lung
disease. Manganese exposure in early life may affect behavioral and intellectual
capabilities. The manganese OEHHA chronic REL of 0.09 µg/m3 was derived based on
the impaired human neurobehavioral functioning (impaired visual reaction time, hand-

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eye coordination, and hand steadiness) reported in a study of battery plant workers
occupationally exposed to 0.04 to 4.43 mg manganese/m3 per year via inhalation of
respirable dust. US EPA’s RfC for manganese is 0.05 µg/m3, and is similarly based on
impairment of neurobehavioral functioning seen in individuals occupationally exposed to
manganese.

Animal studies have shown decreased dopamine in the striatum and poorer
performance on behavioral tests in rats orally exposed to manganese. Decreased
activity levels and average pup weights have been noted in mice exposed via inhalation.
High levels of exposure may also lead to accumulation of the metal in brain regions
such as the striatum and the midbrain.

xiii. Naphthalene

Naphthalene is a volatile white crystalline solid that exists in air in the form of vapor or
adsorbed to particulates. It is released into the atmosphere from coal and oil
combustion and from the use of mothballs. The primary route of human exposure to
naphthalene is inhalation. Naphthalene emissions have been detected at several
refinery process units (separators, boilers, cooling towers, crude units, heaters, storage
tanks, cokers, FCCUs, wastewater treatment, incinerators, and vents) and naphthalene
has been detected in both routine and non-routine emissions. Naphthalene is of
particular concern due to its flammability in the presence of an ignition source (LEL =
0.9%). Fire may yield irritating or toxic gases, and powders, dusts, and shavings may
be explosive.

People who are acutely exposed to naphthalene may experience headache, nausea,
vomiting, diarrhea, malaise (general feeling of discomfort), confusion, anemia, jaundice,
convulsions, and coma. Short-term exposure has also been associated with
neurological damage in infants, hemolytic anemia, and liver damage.

Prolonged exposure to large amounts of naphthalene may damage or destroy red blood
cells, leading to hemolytic anemia, and has been reported to cause cataracts and retinal
hemorrhage in humans. In mice chronically exposed to naphthalene via inhalation,
chronic inflammation of the lung, chronic nasal inflammation, hyperplasia of nasal
respiratory epithelium, and metaplasia of the olfactory epithelium has been noted. The
OEHHA chronic REL of 9 µg/m3 for naphthalene was derived (after time and dose
adjustments and consideration of uncertainties) on the noncancer respiratory effects
observed in mice chronically exposed to a concentration of 52.6 ng/m3 including: nasal
inflammation, olfactory epithelia metaplasia, and respiratory epithelial hyperplasia (Abdo
et al., 2001). Such symptoms are indicative of the carcinogenic potential of
naphthalene. An RfC of 3,000 µg/m3 has also been developed by US EPA based on
this study.

Naphthalene is listed as a carcinogen on the Proposition 65 list and has been classified
as a possible human carcinogen by IARC based on the nasal tumors seen in rats and

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the lung tumors seen in female mice exposed by inhalation. Naphthalene has a CSF of
0.12 (mg/kg-day)-1, which is based on data for incidence of nasal tumors, specifically
nasal respiratory epithelial adenoma and nasal olfactory epithelial neuroblastoma, in
male rats. In mice, inhalation exposure to naphthalene has also been shown to
increase the incidence of lung tumors. The unit risk for naphthalene is 3.4x10-5
(µg/m3)-1.

Because their bodies have not fully developed detoxification mechanisms, newborns
and infants are thought to be especially vulnerable to the effects to naphthalene
exposure. In infants born to mothers who were exposed by inhalation and ingestion
during pregnancy, hemolytic anemia has been reported. Oral exposure in mice has
also been shown to cause maternal toxicity (increased mortality and decreased weight
gain) and fetotoxicity.

xiv. Nitrogen Oxides (NOx)

Nitrogen oxides (NOx) represent a group of highly reactive gasses including nitric oxide,
nitrogen dioxide, nitrogen trioxide, nitrogen tetroxide, and nitrogen pentoxide that are
released into the air from combustion sources. Because nitrogen dioxide is considered
to be one of the most toxicologically significant of the nitrogen oxides and is used by
both the US EPA and CalEPA as the indicator for the group, it will be the focus of this
subsection. Nitrogen dioxide is a yellow-brown liquid at room temperature that takes
the form of a reddish brown gas at temperatures above 70oF. It is a corrosive gas with
a strong odor that generally provides adequate warning of acute exposure to high
levels. Although it is nonflammable, nitrogen dioxide will accelerate the burning of
combustible materials and may react violently with cyclohexane, fluorine, formaldehyde
and alcohol, nitrobenzene, petroleum, and toluene. In the environment, nitrogen dioxide
can form nitric acid, a major constituent of acid rain, and contributes to the formation of
ozone and fine particle pollution. Gaseous nitrogen dioxide is also heavier than air and
at high concentrations can lead to asphyxiation in poorly ventilated, enclosed, or low-
lying areas.

NOx has been detected in non-routine refinery emissions and around many refinery
process units such as boilers, crude units, heaters, storage tanks, cokers, FCCUs,
incinerators, and flares. It has also been associated with multiple fire incidents reported
during 2001-2012.

Coughing, fatigue, nausea, choking, headache, abdominal pain, and strained breathing
may be experienced immediately following acute exposure to nitrogen dioxide. Short-
term exposure to nitrogen dioxide may also have delayed health effects such as
pulmonary edema (fluid accumulation in the lung) with anxiety, mental confusion,
lethargy, loss of consciousness, pneumonitis (inflammation of lung tissue), and
bronchitis. Exposure to high concentrations of nitrogen dioxide may lead to pulmonary
edema (fluid accumulation in the lung) and delayed inflammatory changes, which can
be life-threatening. Burns, spasms, swelling of tissues in the throat, and upper airway

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obstruction may also occur. In addition to children and the elderly, individuals with
asthma and other preexisting pulmonary diseases, especially RADS, may be more
sensitive to the toxic effects of nitrogen dioxide. OEHHA developed an acute REL of
470 µg/m3 for nitrogen dioxide based on the increased airway reactivity observed in
asthmatics following a one-hour exposure at this concentration. Since that time, the
CARB has promulgated a one-hour AAQS of 340 µg/m3 based on OEHHA’s health-
based recommendation.

Chronic exposure to nitrogen oxides can cause permanent and obstructive lung disease
from bronchiolar damage. Increased risk of respiratory infections in children has also
been associated with long-term exposure. While NOx has not been classified as
carcinogens or developmental or reproductive toxicants under Proposition 65, they have
mutagenic, clastogenic (inducing disruption or breakage of chromosomes), and fetotoxic
effects in rats. In one study exposing pregnant rats to nitrogen dioxide, an increased
occurrence of intrauterine deaths, stillbirths, developmental abnormalities, and low birth
weights was observed.

xv. Particulate Matter (PM10 and PM2.5)

Particulate matter (PM) is a mixture of liquid droplets and solids such as dust, dirt, soot,
and smoke in the air. These particles exist in a large variety of shapes, sizes, and
chemical compositions. In addition to the well-characterized health effects of PM,
particle pollution reduces visibility and damages welfare such as crops and buildings.
Two size categories of PM are regulated at the state and federal levels. Respirable
particles (PM10) are those with a mass mean aerodynamic diameter of 10 micrometers
or less, and pose a health concern due to their ability to pass through the nose and
throat and into the deeper portions of the respiratory system. Fine particles (PM2.5) are
those with a diameter of 2.5 micrometers or smaller and are considered to be a
significant health risk due to their ability to travel into deep areas of the lungs and
smaller ultrafine particles (generally less than 100 nanometers) may even enter the
bloodstream.

The composition of PM largely depends on particle size and origin. Fine particles
commonly contain ionic species (e.g. sulfate, nitrate, and ammonium), acid (e.g.,
hydrogen ion, H+), organic and elemental carbon, and trace elements (e.g. aluminum,
silicon, sulfur, chlorine, potassium, calcium, titanium, vanadium, chromium, manganese,
nickel, copper, zinc, selenium, bromine, arsenic, cadmium, and lead). PM2.5 can also
contain larger amounts of PAHs such as naphthalene, chrysene, phenanthrene, and
anthracene than PM10 (Catoggio et al., 1989).

Particulates have been detected at many emissions points in petroleum refineries

(abrasive blasting, asbestos abatement, boilers, cooling towers, crude units, heaters,
cokers, FCCUs, incinerators, and flares) and in non-routine emissions outdoors.
Because of the ubiquitous nature of particulates in smoke, all fire events reported in the
2001-2012 data also involved the unintentional release of particulate matter.

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Short-term exposure to PM2.5 has been linked to increased hospitalizations and

emergency room visits for heart and lung-related illnesses and premature death.
Inhalation of fine particles can be harmful to the heart and blood vessels, and may
increase risk of heart attack, stroke, cardiac arrest, and/or congestive heart failure.
Other symptoms of exposure include eye, nose, and throat irritation, reduced lung
function, asthma attacks, irregular heartbeat, and increased respiratory symptoms such
as coughing, wheezing, and shortness of breath.

Chronic exposure to fine particle pollution also leads to increased incidence of heart and
lung problems, and some studies further suggest its possible association with cancer
and reproductive and developmental toxicity. Population-based epidemiological studies
have found associations between ambient particulate pollution and lung cancer. While
healthy individuals may experience temporary symptoms, the elderly, children, people
with heart or lung conditions, and people exposed to unusually high levels of pollution
are considered to be more susceptible to the adverse health effects of particulate matter
exposure. Pregnant women, newborns, and individuals with certain health conditions
such as obesity and diabetes may also be at increased risk. For further information on
the health effects of PM, see CARB and OEHHA (2002).

xvi. Sulfur Dioxide

At room temperature, the criteria air pollutant sulfur dioxide is a colorless, irritating gas
with a choking or suffocating odor that generally provides adequate warning of exposure
at high levels of exposure. Found in the vapor and particulate phases, sulfur dioxide in
the atmosphere is formed both endogenously from volcanic eruptions and marine and
terrestrial biogenic emissions and exogenously from the combustion of coal and oil. It
may be converted to sulfuric acid, sulfur trioxide, and sulfates in air, and its dissolution
in water can yield corrosive sulfurous acid. Gaseous sulfur dioxide will not burn under
typical fire conditions. Exposure to sulfur dioxide occurs mainly via inhalation. Sulfur
dioxide is heavier than air and asphyxiation may result from exposure to high
concentrations in poorly ventilated, enclosed, or low-lying areas.

Sulfur dioxide and its vapors have been detected at various refinery emission points
including boilers, crude units, heaters, cokers, FCCUs, and incinerators. Sulfur dioxide
has been detected in non-routine refinery emissions and was noted in incident reports
more frequently than any other chemical included in this report, often during or after
flaring events.

Acute inhalation exposure to sulfur dioxide has been associated with eye, mucous
membrane, skin, and respiratory tract irritation. Symptoms of respiratory irritation
include sneezing, sore throat, wheezing, shortness of breath, chest tightness, and a
feeling of suffocation. Breathing very high levels can be life-threatening. Airway
obstruction from reflex laryngeal spasm and edema, bronchospasm, pneumonitis
(inflammation of lung tissue), and pulmonary edema (fluid accumulation in the lung)

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after exposure has been reported. Asthmatics, especially when exercising or when in
cold, dry air, and some individuals that are atopic (predisposed toward developing
certain allergic hypersensitivity reactions) or have RADS are more sensitive to the
irritant properties of sulfur dioxide. Since the occurrence of asthma is most common in
African Americans, children ages 8-11 years, and people living in cities, African
American children in urban areas are also expected to have increased vulnerability to
this chemical. Further, adverse effects on pulmonary function may be more severe in
asthmatics and those with cardiopulmonary disease dually exposed to sulfur dioxide
and other irritants such as sulfuric acid, nitrogen dioxide, and ozone. OEHHA used
multiple inhalation studies of healthy, asthmatic, and atopic (predisposed toward
developing certain allergic hypersensitivity reactions) volunteers for the derivation of the
acute REL for sulfur dioxide (660 µg/m3). This value is identical to the California AAQS
for one-hour exposure. The most sensitive endpoint observed at this concentration was
impairment of airway function, particularly in asthmatics.

Chronic exposure to sulfur dioxide may lead to an altered sense of smell, increased
susceptibility to respiratory infections, symptoms of chronic bronchitis, and accelerated
decline in pulmonary function. The California AAQS for 24-hour averaging is 0.04 ppm
(105 µg/m3) for sulfur dioxide. In 2011, sulfur dioxide was added to the Proposition 65
list as a developmental toxicant based on studies showing increased incidence of
preterm birth and indicators of fetal growth retardation such as low birth weight.
Evidence that air pollution containing sulfur dioxide induces DNA damage in human
sperm has also been reported.

xvii. Sulfuric Acid

Sulfuric acid is a colorless, oily liquid that exists in air in water vapor and particulates. It
is corrosive to metals and organic materials and emits toxic sulfur trioxide-containing
fumes or vapors when heated. While it will not burn under typical fire conditions,
sulfuric acid in high concentrations is explosive or incompatible with a variety of
substances including organic materials, chlorates, carbides, fulminates, water, and
powdered metals. The general population is exposed to this chemical by breathing
ambient air where oil, gas, or coal is burned. In petroleum refineries, sulfuric acid is
used as a catalyst during alkylation and in various treatment processes (Lewis, 2012).
This chemical has also been detected in large amounts in refinery air emissions and
reported in multiple fire and non-fire incidents.

Both acute and chronic exposures to sulfuric acid target the respiratory system.
Breathing sulfuric acid mists for short periods of time in occupational settings has been
associated with dental erosion and respiratory tract irritation, which leads to
bronchoconstriction and altered lung function. Multiple exposures to other pollutants
also common to industrial areas may increase the irritant effects of sulfuric acid,
particularly for individuals with asthma. In addition, animal studies suggest that the
young may be more sensitive to adverse effects than adults. The most sensitive
endpoint of acute exposure was observed in a human study that showed small changes

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in airway function, particularly in asthmatics, following a 16-minute exposure to 450

µg/m3 of sulfuric acid. After time and dose adjustments and consideration of
uncertainties, an OEHHA acute REL of 120 µg/m3 was established.

Long-term exposure to sulfuric acid has been associated with decreased lung function.
Chronic exposure may also lead to tracheobronchitis (inflammation of the windpipe and
bronchioles), stomatitis (inflamed or sore mouth), conjunctivitis (inflammation or
infection of the eye), and gastritis (inflammation, irritation, or erosion of the stomach).
The chronic REL for sulfuric acid was derived from a continuous inhalation study that
led to abnormal changes in bronchial cells in the lungs of monkeys (increased cell
reproduction and organ/tissue enlargement) at a concentration of 380 µg/m3. OEHHA
determined the chronic REL for sulfuric acid to be 1 µg/m3.

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 B-1

APPENDIX B: CALIFORNIA REFINERY PROCESS UNITS AND EMISSION POINTS

WITH ASSOCIATED CHEMICAL EMISSIONS

In response to a request by US EPA, all refineries active during 2010 measured air
emissions from each process and emission point for a specified time period and
submitted the data to US EPA. This request resulted in a list of chemicals measured to
be routinely emitted in each process, and OEHHA used these emissions inventories to
identify the most commonly occurring processes in California refineries (Table 8) and
their reported chemical emissions. Since some refinery processes are associated with
a particular chemical profile, such information can be used to help anticipate the types
of chemicals that may be released during a refinery accident and characterize the
potential health effects of chemical exposure. Thus, consideration of common
processes and characteristic emissions, in addition to knowledge of health guidance
values and emergency exposure levels, can be used to help CARB make judgements
about air monitoring.

Appendix B displays a list of chemical emissions associated with each process based
on California data for 2010. The processes and chemicals shown in Appendix B reflect
a sample of those most commonly found in our research based on California data for
2010 provided by US EPA but are not intended to be a complete list of all refinery
processes or chemicals emitted from each process.

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Table B1. California Refinery Process Units and Emissions Points Associated with Chemical Emissions
Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

Acenaphthene X X X X X X X X X X X X X

Acenaphthylene X X X X X X X X X X X X X X X
Acetaldehyde X X X X X X X X X X X X X
Acetylene X X X X X
Acrolein X X X X X X X X X X
Ammonia X X X X X X X X X X X X X X X

Analine X X X X X X X X X X X X X

Anthracene X X X X X X X X X X X X X X X
Antimony X X X X X X X X X X X
Arsenic X X X X X X X X X X X X
Barium X X X X X X X X X X X
Benz[a]anthracene X X X X X X X X X X X X X X X
Benzene X X X X X X X X X X X X X X X

Benzo[b]fluoranthene X X X X X X X X X X X X X X X
Benzo[k]fluoranthene X X X X X X X X X X X X X X X
Benzo[g,h,i]perylene X X X X X X X X X X X X X X X
Benzo[a]pyrene X X X X X X X X X X X X X X X
Benzo[e]pyrene X X X X X X X X X X X X X X

Beryllium X X X X X X X X X X X X

Biphenyl X X X X X X X X X X X X X X X
1,2-Butadiene X X X X X X

1 Abbreviations for the fluid catalytic cracking unit (FCCU), the sulfur recovery unit (SRU), and wastewater treatment (WWT) have been used.
2 Chemical emissions detected at California refinery process units and emission points in 2010 (US EPA, 2012a; US EPA, 2012b).

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Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

1,3-Butadiene X X X X X X X X X X X X X

Butane X X X X X X X X X X X X X
1-Butene X X X X X X X X X
2-Butene X X X X X X X X
Cadmium X X X X X X X X X X X X
Carbon disulfide X X X X X X X X X X X X X

Carbon monoxide X X X X X X X X X X X

Carbonyl sulfide X X X X X X X X X X X X X X
Chlorine X X X X
Chloroform X X X X X X X X X
Chloromethane X X X X X X
2-Chloronaphthalene X X X X X X X X X X X X X X X

Chromium (hexavalent) X X X X X X X X X X X
Chromium (total) X X X X X X X X X X X X
Chrysene X X X X X X X X X X X X X X X
Cobalt X X X X X X X X X X X
Copper X X X X X X X X X X X X
Cresols (total) X X X X X X X X X X X X X X

m-Cresol X X X X X X X X X X X X X X X

o-Cresol X X X X X X X X X X X X X X X
p-Cresol X X X X X X X X X X X X X X X
Cumene X X X X X X X X X X X X X X
Cyclohexane X X X X X X X X X X X X X X
Cyclopentadiene X X X X X

Cyclopentane X X X X

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 B-4

Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

Dibenz[a,h]anthracene X X X X X X X X X X X X X X X
1,2,3,4,6,7,8-
Heptachlorodibenzo-p-dioxin
X
1,2,3,4,7,8-
Hexachlorodibenzo-p-dioxin
X
1,2,3,6,7,8-
Hexachlorodibenzo-p-dioxin
X
1,2,3,7,8,9-
Hexachlorodibenzo-p-dioxin
X
1,2,3,4,6,7,8,9-
Octachlorodibenzo-p-dioxin
X
1,2,3,7,8-Pentachlorodibenzo-
p-dioxin
X
2,3,7,8-Tetrachlorodibenzo-p-
dioxin
X X X X

Dibenzofuran(s) X X X X X X X X X
1,2,3,4,6,7,8-
Heptachlorodibenzofuran
X
1,2,3,4,7,8,9-
Heptachlorodibenzofuran
X
1,2,3,6,7,8-
Hexachlorodibenzofuran
X
1,2,3,7,8,9-
Hexachlorodibenzofuran
X
2,3,4,6,7,8-
Hexachlorodibenzofuran
X
1,2,3,4,6,7,8,9-
Octachlorodibenzofuran
X
1,2,3,7,8-
Pentachlorodibenzofuran
X X
2,3,4,7,8-
Pentachlorodibenzofuran
X
2,3,7,8-
Tetrachlorodibenzofuran
X X

Dibutyl phthalate X

1,4-Dichlorobenzene X X X X X X X X X
1,1-Dichloroethane X
Di(2-ethylhexyl)phthalate X X

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 B-5

Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

1,1-Dichloroethylene X X X

1,2-Dichloropropane X
1,3-Dichloropropene X
Diethanolamine X X X X X X X X X X X
Diethyl phthalate X
7,12-
Dimethylbenz[a]anthracene
X X X X X X X X X X X X X X X

Ethane X X X X X X X X X X

Ethylbenzene X X X X X X X X X X X X X X
Ethylene X X X X X X X X X X X X
Ethylene dibromide X X X X X
Ethylene dichloride X X X X X X X
Fluoranthene X X X X X X X X X X X X X X X
Fluorene X X X X X X X X X X X X X X X

Formaldehyde X X X X X X X X X X X
Heptane (& isomers) X X X X
Hexachloroethane X
Hexane X X X X X X X X X X X X X X X
Hydrogen chloride X X X X X X X X X
Hydrogen cyanide (&
compounds)
X X X X X X X X X X

Hydrogen fluoride X X X X X X
Hydrogen sulfide X X X X X X X X X X X X X X X
Indeno[1,2,3-cd]pyrene X X X X X X X X X X X X X X X
Isobutane X X X X X X
Isobutene X X X X X X X X X X

Isopentane X X X X X

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 B-6

Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

Isoprene X X X X

Lead X X X X X X X X X X X X X
Manganese X X X X X X X X X X X X
Mercury X X X X X X X X X X X X
Methanol X X X X X X X X X X X X
Methyl bromide X

3-Methyl-1,2-butadiene X X X

Methyl ethyl ketone X X X X X X X X X X X X X

Methyl isobutyl ketone X X X X X X X X X X X X X X
Methyl tert-butyl ether X X X X X X X X X X X X X X
3-Methylchloranthrene X X X X X X X X X X X X X X X
Methylcylcohexane X X X X

2-Methylnaphthalene X X X X X X X X X X X X X X X
Molybdenum X X X X X X X X
Naphthalene X X X X X X X X X X X X X X X
Nickel X X X X X X X X X X X X
Nitrogen dioxide X X X X X X X X X
Nitrogen oxides X X X X X X X X X X X X

Octane (& isomers) X X X X X

1,2-Pentadiene X X X X
cis-1,3-Pentadiene X X X X
trans-1,3-Pentadiene X X X X
1,4-Pentadiene X X X X
2,3-Pentadiene X X X X

Pentane X X X X X X X X X X X

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 B-7

Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

Perchloroethylene X X X X X X

Perylene X X X X X X X X X X X X X X
Phenanthrene X X X X X X X X X X X X X X X
Phenol X X X X X X X X X X X X X X X
Phosphorus X X X X X X
PM (condensable) X X X X X X X X X X X

PM10 X X X X X X X X X X X

PM10 (filterable) X X X X X X X X X X
PM2.5 X X X X X X X X X X X
PM2.5 (filterable) X X X X X X X X X X
Polychlorinated biphenyls X X X X X X
Propadiene X X X X X

Propane X X X X X X X X X X X
Propylene X X X X X X X X X X X X X X
Pyrene X X X X X X X X X X X X X X X
Selenium X X X X X X X X X X X X
Styrene X X X X X X X X X X X X X X
Sulfur dioxide X X X X X X X X X X X X

1,1,2,2-Tetrachloroethane X X

Tetrachloroethylene X X X X
Toluene X X X X X X X X X X X X X X X
1,1,2-Trichloroethane X X X X X
Trichloroethylene X X X X
Triethylamine X X X X X X X X X X

Trimethylbenzene(s) X X X X X X X X X X X X X X

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 B-8

Process1
Alkylation Cooling Crude Product Storage
Coker FCCU SRU
Unit Cogeneration Tower Unit Loading Tank Thermal
Boiler (Fugitive (Fugitive Flare Heater (Fugitive Vent WWT
(Fugitive Unit (Fugitive (Fugitive (Fugitive (Fugitive (Fugitive Oxidizer
(Point) and and (Point) (Point) and (Point) (Fugitive)
and and Point) and and and and (Point)
Point) Point) Point)
Chemical 2 Point) Point) Point) Point) Point)

2,2,4-Trimethylpentane X X X X X X X X X X X X X X X

Vanadium X X X X X X X X X X X
Vinyl chloride X X
Volatile organic compounds X X X X X X X X X X X X X X
Xylenes (total) X X X X X X X X X X X X X X
m-Xylene X X X X X X X X X X X X X X X

o-Xylene X X X X X X X X X X X X X X X

p-Xylene X X X X X X X X X X X X X X X
Zinc X X X X X X X X X X X

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

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This page intentionally left blank.
 C-1

APPENDIX C: CALIFORNIA REFINERY CHEMICALS SORTED BY CHEMICAL

ANALYSIS CATEGORY

OEHHA used a classification scheme provided by CARB by assigning specific chemical

analysis categories, shown in Table 9, to chemicals included in OEHHA’s list of
California refinery chemicals (Table 1). The classification of chemicals by air monitoring
capability allowed for the consideration of emissions, health effects, and health
guidance values of chemicals with similar properties. Appendix C displays the
chemicals included in each chemical analysis category. The analysis categories and
chemicals within them are sorted in alphabetical order.

Table C1. California Refinery Chemicals Sorted by Chemical Analysis Category

Chemical Analysis Category Chemical
Acid Hydrogen chloride
Acid Hydrogen cyanide
Acid Hydrogen fluoride
Acid Phosphoric acid
Acid Sulfuric acid
Aldehyde Acetaldehyde
Aldehyde Formaldehyde
Aldehyde Glutaraldehyde
Dioxins, Dibenzofurans Dibenzo-p-dioxins (chlorinated)
Dioxins, Dibenzofurans 1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans 1,2,3,4,7,8-Hexachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans 1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans 1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans 1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans 1,2,3,7,8-Pentachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans 2,3,7,8-Tetrachlorodibenzo-p-dioxin
Dioxins, Dibenzofurans Dibenzofurans (chlorinated)
Dioxins, Dibenzofurans 1,2,3,4,6,7,8-Heptachlorodibenzofuran
Dioxins, Dibenzofurans 1,2,3,4,7,8,9-Heptachlorodibenzofuran
Dioxins, Dibenzofurans 1,2,3,4,7,8-Hexachlorodibenzofuran
Dioxins, Dibenzofurans 1,2,3,6,7,8-Hexachlorodibenzofuran
Dioxins, Dibenzofurans 1,2,3,7,8,9-Hexachlorodibenzofuran
Dioxins, Dibenzofurans 2,3,4,6,7,8-Hexachlorodibenzofuran
Dioxins, Dibenzofurans 1,2,3,4,6,7,8,9-Octachlorodibenzofuran
Dioxins, Dibenzofurans 1,2,3,7,8-Pentachlorodibenzofuran
Dioxins, Dibenzofurans 2,3,7,8-Tetrachlorodibenzofuran
Extractable Phenol
Extractable Aromatic Biphenyl

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 C-2

Chemical Analysis Category Chemical

Extractable Aromatic Cresols (mixtures of)
Extractable Aromatic Dibutyl phthalate
Extractable Aromatic Di(2-ethylhexyl)phthalate
Extractable Hetero Aromatic Aniline
Extractable Hetero Aromatic Polychlorinated biphenyls
Extractable Hetero Hydrocarbon Diethanolamine
Gas Ammonia
Gas Methane
Gas Nitrous oxide
Gas Propylene oxide
Gas, CEM Nitrogen oxides
Gas, CEM Sulfur dioxide
Gas, Colorimetric, CEM Carbonyl sulfide
Gas, Colorimetric, CEM Chlorine
Gas, Colorimetric, CEM Hydrogen sulfide
Gas, Colorimetric, VOC, CEM Carbon monoxide
Glycol Ethylene glycol monoethyl ether
Glycol Propylene glycol monomethyl ether
Glycol Acid Ethylene glycol monoethyl ether acetate
Glycol Acid Propylene glycol monomethyl ether acetate
Glycol Ether Propylene glycol mono-t-butyl ether
Glycol, Glycol Acid Glycol ethers (& acetates)
Mass PM10
Mass PM2.5
Metal Aluminum
Metal Antimony
Metal Arsenic
Metal Barium
Metal Beryllium
Metal Cadmium
Metal Chromium III
Metal Chromium (hexavalent & compounds)
Metal Cobalt
Metal Copper
Metal Lead
Metal Manganese
Metal Mercury
Metal Nickel
Metal Particulate divalent mercury

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 C-3

Chemical Analysis Category Chemical

Metal Selenium (& compounds)
Metal Selenium sulfide
Metal Vanadium (fume or dust)
Metal Zinc
Metal Spectrophotometric Elemental gaseous mercury
Metal Spectrophotometric Gaseous divalent mercury
Metal, Acid Phosphorus
Microscopy Asbestos
PAH Acenaphthene
PAH Acenaphthylene
PAH Anthracene
PAH Benz[a]anthracene
PAH Benzo[b]fluoranthene
PAH Benzo[j]fluoranthene
PAH Benzo[k]fluoranthene
PAH Benzo[g,h,i]perylene
PAH Benzo[a]pyrene
PAH Benzo[e]pyrene
PAH 2-Chloronaphthalene
PAH Chrysene
PAH Dibenz[a,h]anthracene
PAH 7,12-Dimethylbenz[a]anthracene
PAH Fluoranthene
PAH Fluorene
PAH Indeno[1,2,3-c,d]pyrene
PAH 3-Methylcholanthrene
PAH 2-Methylnaphthalene
PAH Naphthalene
PAH PAHs, total, w/ individ. components reported
PAH PAHs, total, w/o individ. components reported
PAH Perylene
PAH Phenanthrene
PAH Pyrene
VOC Canister Acetylene
VOC Canister Acrolein
VOC Canister 1,3-Butadiene
VOC Canister Butane
VOC Canister 1-Butene
VOC Canister 2-Butene

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 C-4

Chemical Analysis Category Chemical

VOC Canister Carbon disulfide
VOC Canister Chlorodifluoromethane
VOC Canister Ethylene
VOC Canister Isopropanol
VOC Canister Methyl bromide
VOC Canister Methyl chloride
VOC Canister Methylene chloride
VOC Canister cis-1,3-Pentadiene
VOC Canister Propylene
VOC Canister Trichlorofluoromethane
VOC Canister 1,1,2-Trichloro-1,2,2-trifluoroethane
VOC Canister Vinyl chloride
VOC Canister, Sorbent Benzene
VOC Canister, Sorbent Carbon tetrachloride
VOC Canister, Sorbent Chlorobenzene
VOC Canister, Sorbent Chloroform
VOC Canister, Sorbent Cumene
VOC Canister, Sorbent Cyclohexane
VOC Canister, Sorbent Cyclopentadiene
VOC Canister, Sorbent Cyclopentane
VOC Canister, Sorbent 1,4-Dichlorobenzene
VOC Canister, Sorbent 1,2-Dichloropropane
VOC Canister, Sorbent 1,3-Dichloropropene
VOC Canister, Sorbent Ethylbenzene
VOC Canister, Sorbent Ethylene dibromide
VOC Canister, Sorbent Ethylene dichloride
VOC Canister, Sorbent Hexane
VOC Canister, Sorbent Methyl chloroform
VOC Canister, Sorbent Methyl ethyl ketone
VOC Canister, Sorbent Methyl isobutyl ketone
VOC Canister, Sorbent Methyl tert-butyl ether
VOC Canister, Sorbent Perchloroethylene
VOC Canister, Sorbent Propylene dichloride
VOC Canister, Sorbent Styrene
VOC Canister, Sorbent 1,1,2,2-Tetrachloroethane
VOC Canister, Sorbent Toluene
VOC Canister, Sorbent 1,1,2-Trichloroethane
VOC Canister, Sorbent Trichloroethylene
VOC Canister, Sorbent 1,2,4-Trimethylbenzene
VOC Canister, Sorbent 2,2,4-Trimethylpentane

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 C-5

Chemical Analysis Category Chemical

VOC Canister, Sorbent Xylenes (mixed)
VOC Canister, Sorbent m-Xylene
VOC Canister, Sorbent o-Xylene
VOC Canister, Sorbent p-Xylene
VOC Sorbent Methanol

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 D-1

This page intentionally left blank

APPENDIX D: ROUTINE TOXIC AIR CONTAMINANT EMISSIONS FROM

CALIFORNIA REFINERIES
OEHHA obtained a list of TACs reported in the California Emission Inventory
Development and Reporting System (CEIDARS) database for all California refineries
active during 2009-2012. The emissions data obtained from CEIDARS were submitted
to CalEPA in accordance with the AB 2588 Air Toxics Hot Spots Program requirements,
and reflect TAC releases that occurred during routine facility operations. The Hot Spots
program requires facilities to report emission inventory updates every four years.
Therefore, not all facilities update emission inventories in the same year. As a result,
some chemicals may not be reported each year. Based on this quadrennial method of
updating emission inventories in the Hot Spots Program, the information that the
CEIDARS database provides on the TACs emitted from refineries are likely
underestimates of total routine emissions across refineries in any given year.

Appendix D is an expanded version of Table 10 and displays the average annual

routine TAC emissions for California refineries during 2009-2012 based on data
provided by CARB. Emissions data are reported in pounds per year and listed in
descending order.

Table D1. Average Annual Routine Toxic Air Contaminant Emissions for
California Refineries
Chemical Routine Emissions (lb/year)1
Ammonia 2,085,824
Formaldehyde 288,412
Methanol 122,611
Sulfuric acid 104,573
Hydrogen sulfide 103,385
Toluene 87,945
Xylenes (mixed) 79,177
Benzene 43,308
Hexane 39,646
Hydrochloric acid 21,450
Naphthalene 17,836
Acetaldehyde 16,136
Carbonyl sulfide 15,111
Ethyl benzene 11,960
1,2,4-Trimethylbenzene 9,815
Propylene 6,022
Diethanolamine 3,511

1Average annual routine Toxic Air Contaminant (TAC) emissions for California refineries during 2009-
2012, listed in descending order.
 D-2

Chemical Routine Emissions (lb/year)1

Hydrogen fluoride 3,463
1,3-Butadiene 3,156
Acrolein 2,804
Perchloroethylene 2,742
PAHs, total, w/o individ. components reported 2,666
o-Xylene 2,662
Manganese 2,587
Chloroform 2,048
Nickel 1,720
Copper 1,145
m-Xylene 1,000
Selenium 826
Phenanthrene 817
Methane 790
Benzo[a]pyrene 735
Methyl chloroform 720
p-Xylene 677
Chlorodifluoromethane 621
Phenol 598
Lead 431
Mercury 415
Cadmium 283
Phosphorus 275
Styrene 249
Chlorine 228
Glutaraldehyde 168
Fluorene 156
Arsenic 145
Diesel engine exhaust 123
Methyl ethyl ketone 111
PAHs, total, w/ individ. components reported 103
Trichloroethylene 86
Methyl tert-butyl ether 74
1,1,2-Trichloro-1,2,2-trifluoroethane 65
Glycol ethers (& acetates) 50
Asbestos 45
Isopropanol 45
Trichlorofluoromethane 36
Nitrous oxide 31

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 D-3

Chemical Routine Emissions (lb/year)1

Chromium (hexavalent & compounds) 24
Beryllium 23
Methylene chloride 21
Chrysene 14
Propylene oxide 13
Cresols (mixtures of) 11
Phosphoric acid 10
Ethylene dichloride 7
Ethylene dibromide 6
Propylene glycol monomethyl ether 3
Fluoranthene 3
Pyrene 3
Vanadium (fume or dust) 2
Indeno[1,2,3-cd]pyrene 2
Methyl isobutyl ketone 2
Acenaphthylene 2
Benzo[b]fluoranthene 2
Anthracene 1
2-Methyl naphthalene 1
Benz[a]anthracene 1
Carbon tetrachloride 1
Carbon disulfide 1
Benzo[k]fluoranthene 1
Acenaphthene 1
Zinc 1
Benzo[e]pyrene 0.4
Vinyl chloride 0.3
1,1,2,2-Tetrachloroethane 0.3
Dibenz[a,h]anthracene 0.2
1,1,2-Trichloroethane 0.2
1,2-Dichloropropane 0.2
1,3-Dichloropropene 0.2
Benzo[g,h,i]perylene 0.2
Methyl chloride 0.1
Aluminum 0.1
Propylene glycol monomethyl ether acetate 0.06
Perylene 0.03
7,12-Dimethylbenz[a]anthracene 0.01
Benzo[j]fluoranthene 0.006

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 D-4

Chemical Routine Emissions (lb/year)1

Chlorobenzene 0.005
1,4-Dioxane 0.004
Dibenzofurans (chlorinated) 0.002
1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin 9x10-6

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 E-1

APPENDIX E: NON-ROUTINE AND ROUTINE EMISSIONS

OEHHA has compiled data on routine and non-routine emissions, not limited to TACs,
from the California refineries active during 2010 using data provided by US EPA (Tables
11 and 12). While routine emissions represent chemical releases that occur during
normal facility operations, non-routine releases reflect emissions during any non-routine
refinery operation, including startups, shutdowns, and malfunction operations such as
refinery-wide power loss, maintenance, and flaring events.

The refinery emissions shown in Appendix E were measured or calculated at various

processes and emission points and self-reported by refineries to US EPA; however,
these data were limited to 2010, and therefore may not be representative of all chemical
emissions based on reporting requirements.

Table E1. Annual Routine and Non-routine Chemical Emissions by California

Refineries
Routine Non-routine Emissions
Chemical
Emissions (lb)1 (lb)1
Acenaphthene 855 0.03
Acenaphthylene 129 0.02
Acetaldehyde 14,613 60
Acrolein 85,112 22
Ammonia 1,457,960 1,735
Aniline 462 ―
Anthracene 959 1
Antimony 348 0.5
Arsenic 129 0.2
Barium 1,248 4
Benz[a]anthracene 242 0.02
Benzene 91,584 6,755
Benzo[b]fluoranthene 118 0.02
Benzo[k]fluoranthene 78 0.01
Benzo[g,h,i]perylene 146 0.002
Benzo[a]pyrene 225 0.04
Benzo[e]pyrene 41 ―
Beryllium 62 0.09
Biphenyl 22,021 681
1,2-Butadiene 16 ―
1,3-Butadiene 7,781 5,374

1Routine and non-routine emissions as reported by California refineries for 2010, listed in alphabetical
order (US EPA, 2012a; US EPA, 2012b).

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 E-2

Routine Non-routine Emissions

Chemical
Emissions (lb)1 (lb)1
Butane 5,881,551 4,446
1-Butene 179 155
2-Butene 165 ―
Cadmium 5,781 1
Carbon disulfide 21,240 27
Carbon monoxide 16,972,733 418,331
Carbonyl sulfide 68,329 90
Chlorine 3,040 ―
Chloroform 690 0.02
2-Chloronaphthalene 3 ―
Chromium 1,291 2
Chromium (hexavalent & compounds) 226 0.2
Chrysene 285 0.01
Cobalt 167 0.07
Copper 1,062 1
Cresols (mixtures of) 3,265 417
m-Cresol 351 1
o-Cresol 364 ―
p-Cresol 364 ―
Cumene 21,988 237
Cyclohexane 22,567 204
Cyclopentadiene ― 3,190
Cyclopentane 23 ―
Dibenz[a,h]anthracene 134 0.001
1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin 0.03 ―

1,2,3,4,7,8-Hexachlorodibenzo-p-dioxin 6x10-6 ―

1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin 8x10-6 ―

1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin 8x10-6 ―

1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin 0.001 ―
1,2,3,7,8-Pentachlorodibenzo-p-dioxin 5x10-6 ―
2,3,7,8-Tetrachlorodibenzo-p-dioxin 5x10-4
―
Dibenzofuran 0.03 ―
1,2,3,4,6,7,8-Heptachlorodibenzofuran 7x10-4 ―

1,2,3,4,7,8,9-Heptachlorodibenzofuran 1x10-5 ―
1,2,3,4,7,8-Hexachlorodibenzofuran 2x10-4 ―

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 E-3

Routine Non-routine Emissions

Chemical
Emissions (lb)1 (lb)1
1,2,3,6,7,8-Hexachlorodibenzofuran 0.04 ―
1,2,3,7,8,9-Hexachlorodibenzofuran 5x10-6 ―
2,3,4,6,7,8-Hexachlorodibenzofuran 2x10-4
―
1,2,3,4,6,7,8,9-Octachlorodibenzofuran 3x10-4 ―
1,2,3,7,8-Pentachlorodibenzofuran 2x10-5 ―
2,3,4,7,8-Pentachlorodibenzofuran 0.02 ―
2,3,7,8-Tetrachlorodibenzofuran 5x10-5 ―
Dibutyl phthalate 0.03 ―
1,4-Dichlorobenzene 129 0.03
1,1-Dichloroethane 2 ―
1,2-Dichloropropane 2 ―
1,3-Dichloropropene 2 ―
Diethanolamine 3,496 321
Diethyl phthalate 0.3 ―
Di(2-ethylhexyl)phthalate 5 ―
7,12-Dimethylbenz[a]anthracene 8 0.01
Ethane 502,829 3,029
Ethyl chloride 0.2 ―
Ethylbenzene 75,917 1,317
Ethylene 15,450 2,184
Ethylene dibromide 5 ―
Ethylene dichloride 3 ―
Fluoranthene 181 0.02
Fluorene 1,228 0.2
Formaldehyde 78,370 923
Heptane 243 ―
Hexane 809,803 7,625
Hydrogen chloride 37,893 121
Hydrogen cyanide 34,445 3
Hydrogen fluoride 62 ―
Hydrogen sulfide 79,310 2,981
Indeno[1,2,3-c,d]pyrene 124 0.05
Isobutane 794 2,437
Isobutene 168 167
Isopentane 803 ―
Lead 1,084 1
Manganese 3,238 0.4

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 E-4

Routine Non-routine Emissions

Chemical
Emissions (lb)1 (lb)1
Mercury 519 0.2
Methanol 308,640 0.02
Methyl bromide 51 ―
Methyl chloride 1 ―
Methyl ethyl ketone 157 ―
Methyl isobutyl ketone 123 ―
Methyl tert-butyl ether 23,558 1,980
3-Methylcholanthrene 3 0.002
Methylcyclohexane 111 ―
2-Methylnaphthalene 23,387 0.02
Molybdenum 6,629 1
Naphthalene 33,216 1,192
Nickel 3,509 2
Nitrogen dioxide 1,971,085 12,397
Nitrogen oxides 16,415,674 223,792
Octane 35 ―
Pentane 433,457 2,457
Perchloroethylene 1,354 4x10-6
Perylene 41 ―
Phenanthrene 2,979 3
Phenol 6,509 1,171
Phosphorus 602 0.1
PM (condensable) 1,677,433 3,855
PM10 (filterable) 2,805,076 22,802
PM10 (primary) 6,617,951 89,572
PM2.5 (filterable) 1,088,791 1,303
PM2.5 (primary) 2,004,663 26,306
Polychlorinated biphenyls 0.1 ―
Propadiene ― 0.1
Propane 332,004 5,012
Propylene 71,931 7,799
Pyrene 465 0.01
Selenium (& compounds) 1,583 1
Styrene 58,849 1
Sulfur dioxide 21,158,748 553,834
1,1,2,2-Tetrachloroethane 6x10-5 ―
Toluene 273,000 4,530
1,1,2-Trichloroethane 2 ―

Analysis of Refinery Chemical Emissions and Health Effects OEHHA

March 2019
 E-5

Routine Non-routine Emissions

Chemical
Emissions (lb)1 (lb)1
Triethylamine 111 ―
Trimethylbenzene 31,177 21
2,2,4-Trimethylpentane 501,931 84
Vanadium (fume or dust) 8,455 2
Volatile organic compounds 13,562,963 1,123,158
Xylenes (mixed) 274,547 4,700
m-Xylene 1,209 ―
o-Xylene 1,096 ―
p-Xylene 1,151 ―
Zinc 20,726 26

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 F-1

APPENDIX F: REFINERY EMISSIONS IN THE US AND FUEL-BURNING EXPERIMENTS

Based on research in peer-reviewed journal articles, OEHHA has provided a list of
additional chemicals measured in US refinery emissions or oil-burning experiments during
1979-2007. Because refineries are only required to report emissions of regulated
chemicals, knowledge of unregulated chemicals also released can provide information on
chemical speciation or characteristics that may ultimately be used by officials for air
monitoring or risk assessment purposes. The chemicals found in the literature describing
controlled burning experiments or refinery air monitoring in the US are listed in Appendix F.

Table F1. Additional Chemicals Found in the Literature on Refinery Emissions in the
US and Fuel-Burning Experiments
Chemical CAS RN Source
Benzaldehyde 100527 [2]
Benzo[a]fluorine 238846 [3]
Benzo[b]fluorine 30777196 [2]
Benzo[b]thiophene 55712602 [3]
Benzo[def]fluorine 203645 [3]
Benzoic acid 65850 [3]
2-Benzylnaphthalene 613592 [3]
Biphenylene 259790 [3]
Butyraldehyde 123728 [4]
Cerium 7440451 [5]
cis-1,3-Dimethyl cyclohexane 638040 [3]
Crotonaldehyde 123739 [2]
Cymene 99876 [3]
Decane 124185 [2]
1,3-Diethyl-5-methylbenzene 2050240 [3]
Diethylbenzene 25340174 [3]
2,2-Dimethyl-1-hexene 6975924 [3]
2,5-Dimethylbenzaldehyde 93027 [2]
1,2-Dimethylcyclopentane 2452995 [3]
4,4’-Dimethyldiphenylmethane 4957146 [3]
2,3-Dimethylfluorene 4612639 [3]
3,4-Dimethylheptane 922281 [3]
1,2-Dimethylindane 17057828 [3]
1,4-Dimethylnaphthalene 571584 [3]
1,5-Dimethylnaphthalene 571619 [3]
1,7-Dimethylnaphthalene 575371 [3]
2,3-Dimethylnaphthalene 581408 [3]
2,6-Dimethylnaphthalene 1123564 [4]
4,5-Dimethylnonane 17302237 [3]
2,6-Dimethyloctane 2051301 [3]
 F-2

Chemical CAS RN Source

3,3-Dimethylpentane 562492 [3]
2,3-Dimethylphenanthrene 3674655 [3]
2,5-Dimethylphenanthrene 3674666 [3]
3,6-Dimethylphenanthrene 1576676 [3]
2,5-Dimethylphenol 95874 [3]
3,4-Dimethylphenol 95658 [3]
3,5-Dimethylphenol 108689 [3]
1,1-Dimethylpropylbenzene 2049958 [3]
1,2-Diphenoxybenzene 3379371 [3]
1,4-Diphenoxybenzene 3061367 [3]
2,5-Diphenyl-1,4-benzoquinone 844519 [3]
Diphenylbutadiyne 886668 [3]
Dodecane 112403 [2]
Dysprosium 7429916 [5]
1-Ethenyl-2-methylbenzene 611154 [3]
1-Ethenyl-3-methylenecyclopentene 61142072 [3]
1-Ethyl-2,3-dimethylbenzene 933982 [3]
1-Ethyl-2-methylbenzene 611143 [3]
2-Ethyl-1,1’-biphenyl 1812517 [3]
2-Ethyl-4-methylphenol 3855263 [3]
Ethylcyclohexane 1678917 [3]
3-Ethylhexane 619998 [3]
2-Ethylnaphthalene 939275 [3]
2-Ethylphenol 90006 [3]
1-Ethylpropylbenzene 1196583 [3]
m-Ethyltoluene 620144 [3]
o-Ethyltoluene 611143 [3]
p-Ethyltoluene 622968 [3]
Ethynylbenzene 536743 [3]
Europium 7440531 [5]
Gadolinium 744542 [5]
Hexadecane 544763 [2]
Hexanal 66251 [2]
Iron 7439896 [6]
1-Isobutyl-3-methylcyclopentane 29053041 [3]
Isohexane 107835 [1]
Isopentane 78784 [2]
Isovaleraldehyde 590863 [2]
Lanthanum 7439910 [5]
1-Methyl-2-[2-phenylethenylbenzene] 74685420 [3]
1-Methyl-2-[3-methylphenyl-methylbenzene] 21895136 [3]
 F-3

Chemical CAS RN Source

1-Methyl-3-[4-methylphenyl-methylbenzene] 21895169 [3]
1-Methyl-3-[2-phenylethenylbenzene] 14064483 [3]
1-Methyl-2-phenylmethylbenzene 713360 [3]
1-Methyl-4-phenylmethylbenzene 620837 [3]
1-Methyl-2-propylbenzene 1074175 [3]
3-Methyl-1,1’-biphenyl 643936 [3]
3-Methyl-2-butenylbenzene 4489843 [3]
2-Methylanthracene 613127 [3]
4-Methylbenzaldehyde 104870 [3]
3-Methyldecane 13151343 [3]
9-Methylenefluorene 4425825 [3]
9-Methylene-fluorene 4425825 [3]
1-Methylethenyl-1,1’-biphenyl ― [3]
1-Methylfluorene 730376 [2]
1-Methylfluorene 1730376 [3]
2-Methylfluorene 1430973 [3]
5-Methylhexan-5-olide 2610959 [3]
3-Methylhexane 589344 [3]
1-Methylnaphthalene 90120 [4]
3-Methylnonane 5911046 [3]
2-Methylpentane 107835 [3]
3-Methylpentane 96140 [1]
1-Methylphenanthrene 832699 [4]
2-Methylphenanthrene 2531842 [3]
3-Methylphenanthrene 832713 [3]
2-Methylpropylcyclohexane 1678984 [3]
2-Methylpyrene 3442782 [3]
Naphtho[2,1-b]furan 232951 [3]
Neodymium 7440008 [5]
Nonane 111842 [2]
Pentamethylbenzene 700129 [3]
Propyne 74997 [2]
3-Penten-1-yne 2206237 [3]
1-Pentene 109671 [1]
Platinum 7440064 [6]
Praseodymium 7440100 [5]
Propionaldehyde 123386 [2]
Propylbenzene 103651 [3]
Samarium 7440199 [5]
Silicon 7440213 [6]
Silver 7440224 [6]
 F-4

Chemical CAS RN Source

Tetradecane 629594 [2]
1,2,3,4-Tetramethylbenzene 488233 [3]
1,2,3,5-Tetramethylbenzene 527537 [3]
1,2,4,5-Tetramethylbenzene 95932 [3]
p-Tolualdehyde 104870 [2]
1,3,5-Trimethylbenzene 108678 [3]
1,2,4-Trimethylcyclohexane 2234755 [3]
1,3,5-Trimethylcyclohexane 1839630 [3]
1,4,5-Trimethylnaphthalene 2131411 [3]
1,4,6-Trimethylnaphthalene 2131422 [3]
2,3,5-Trimethylnaphthalene 2245387 [4]
2,3,5-Trimethylphenanthrene 3674735 [3]
Triphenylene 217594 [3]
Undecane 1120214 [2]
Valeraldehyde 110623 [2]

[1] Sexton and Westberg, 1979. [4] Fingas et al., 2001.

[2] Booher and Janke, 1997. [5] Kulkarni et al., 2007.
[3] Strosher, 2000. [6] Lewis et al., 2012.
 G-1

APPENDIX G: DATA ANALYSIS OF REFINERY CHEMICALS ACROSS CATEGORIES

Comparisons between high routine emissions and health guidance values or emergency exposure
levels may help determine chemicals for air monitoring and may help protect the community
surrounding these refineries by limiting exposure. To that end, OEHHA has performed some
preliminary analysis of the compiled data to offer comparisons between various categories of
information and to note which chemicals are most common in the comparisons. Table G-1 uses
information already in the report to make these assessments.

The analysis in Table G-1 compares chemicals with health guidance values with chemicals that have
high routine emissions. The footnotes to the table explain each comparison in detail.
 G-2

Table G1. Comparison of Chemicals with High Routine Emissions and Other Health Guidance Values
High Routine High Routine High Routine High Routine High High Routine High Routine Incident High Routine
Emissions and Emissions and Emissions and Emissions and Routine Emissions Emissions and History8 Emissions and
OEHHA Noncancer US EPA RfC2 OEHHA OEHHA Emissions and Emergency Processes9
REL1 Proposition 65 (D Proposition 65 and Noncancer Exposure
or R)3 (C)4 OEHHA and Cancer Levels7
CPF5 Effects6
Ammonia (A, C) Ammonia Ammonia Ammonia

Benzene (A,8,C) Benzene Benzene (D, Rm) Benzene Benzene Benzene Benzene Benzene

Butane
Carbon Monoxide
Carbon Monoxide (A) (D) Carbon Monoxide
Formaldehyd Formaldehyd Formaldehyd
Formaldehyde (A,8,C) Formaldehyde Formaldehyde
e e e
Hexane (C) Hexane Hexane
Hydrocarbons
Hydrogen Chloride Hydrogen Hydrogen
(A,C) Chloride Chloride
Hydrogen Sulfide Hydrogen Hydrogen
(A,C) Hydrogen Sulfide Hydrogen Sulfide
Sulfide Sulfide
Methanol (A,C) Methanol Methanol (D) Methanol
(A)
Nitrogen Dioxide Nitrogen Dioxide Nitrogen Dioxide

Sulfur Dioxide (A) Sulfur Dioxide Sulfur Dioxide (D) Sulfur Dioxide Sulfur Dioxide

Sulfuric Acid (A,C) Sulfuric Acid Sulfuric Acid Sulfuric Acid Sulfuric Acid

Toluene (A,C) Toluene Toluene (D) Toluene Toluene

Xylenes (mixed) (A,C) Xylenes (mixed) Xylenes (mixed) Xylenes (mixed)

1 Have Acute (A), 8-hour (8), or Chronic (C) OEHHA noncancer RELs (Table 3) and high routine emissions (Table 10, 11)
2 Have US EPA RfC (Table 3) and high routine emissions (Table 10, 11)
3 Have Proposition 65 status for Reproductive (R) or Developmental (D) harm (Table 3) and high routine emissions (Table 10, 11)
4 Have Proposition 65 status as Carcinogenic (C) (Table 3) and high routine emissions (Table 10, 11)
5 Have OEHHA CPF (Table 3) and high routine emissions (Table 10, 11)
6 Have OEHHA RELs and/or US EPA RfCs and Proposition 65 status as carcinogenic and/or CPFs (Table 3) and high routine emissions (Table 10, 11)
7 Have US EPA AEGL 1 or AEGL 2, NIOSH IDLH, or LEL (Table 5) and high routine emissions (Table 10, 11)
8 Involved in incidents mentioned in Section V-4: California Refinery Incident History
9 Involved in the most processes (15 of 15 total processes) (Table D-1)
 G-3

To complement Table G-1, OEHHA expanded on the analysis in column 1 of Table I-1 comparing
chemicals with high routine emissions to specific values of OEHHA noncancer RELs for acute, 8-
hour, and chronic exposure in Table 1-2.

Table G2. OEHHA REL Values for Chemicals with High Routine Emissions

Acute 8-Hour Chronic

Chemical
(µg/m3) (µg/m3) (µg/m3)
Ammonia 3,200 200
Benzene 27 3 3
Carbon Monoxide 2.3x104
Formaldehyde 55 9 9
Hexane 7x103
Hydrogen Chloride 2,100 9
Hydrogen Sulfide 42 10
Methanol 2.8x104 4,000
Nitrogen Dioxide 470
Sulfur Dioxide 660
Sulfuric Acid 120 1
Toluene 3.7x104 300
 G-4

In Table G3, OEHHA prioritized chemicals by chemical analysis category based on presence in all the tables in the report. In
addition to total number of categories, some chemicals were prioritized based on considerations of toxicity, volatility, and
highest or lowest values in particular categories (highest routine or non-routine emissions or lowest RELs/RfCs). The top
chemicals for each chemical analysis category are noted.

Table G3. Chemicals Sorted by Chemical Analysis Category

Non- Incident
Chemical Analysis Avg Routine Prop
routine REL RfC Processes History AEGLs IDLH TOTAL
Category emissions 65
2010 2001-12

ACIDS
Sulfuric acid X X X X X 5
Hydrogen fluoride X X X X X 5
Hydrogen Cyanide X X X X X 5

ALDEHYDES
Acetaldehyde* X X X X X X X 7
Formaldehyde* X X X X X X 6
DIOXINS,
DIBENZOFURANS
Dibenzofurans (chlorinated)
{PCDFs} X X X X 4
Tetrachlorodibenzo-p-Dioxin
(2,3,7,8) ** X X X 3
Hexachlorodibenzofuran
(1,2,3,7,8,9) X X 2
Hexachlorodibenzofuran
(2,3,4,6,7,8) X X 2
EXTRACTABLES
(PHENOLS, AROMATICS,
HYDROCARBONS)
Phenol X X X X X 5
Aniline X X X X 4
Cresols (mixtures of)
{Cresylic acid} X X X 3

GASES
 G-5

Non- Incident
Chemical Analysis Avg Routine Prop
routine REL RfC Processes History AEGLs IDLH TOTAL
Category emissions 65
2010 2001-12
Hydrogen sulfide {H2S} X X X X X 5
Chlorine X X X X 4
Carbon monoxide X X X X 4
Propylene oxide X X X 3
Sulfur dioxide X X X X 3
Ammonia {NH3} X X X 3
Carbonyl sulfide X X X

GLYCOLS
Propylene glycol
monomethyl ether X X X 3
ethylene glycol monoethyl
ether X X X 3
Glycol ethers (and their
acetates) X X 2
MASS
Diesel engine exhaust,
particulate matter (Diesel
PM) X X X X 4
PM10 X 1
PM2.5 X 1

METALS
Cadmium X X X X 4
Beryllium X X X X 4
Manganese X X X X 4
Arsenic X X X X 4
Mercury X X X 3
Lead X X X 3

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March 2019
 G-6

Non- Incident
Chemical Analysis Avg Routine Prop
routine REL RfC Processes History AEGLs IDLH TOTAL
Category emissions 65
2010 2001-12

PAH
Naphthalene X X X X X X X 7
Anthracene X X 2
Benz[a]Anthracene X X 2
Benzo[a]pyrene X X 2
Benzo[k]fluoranthene X X 2
Dibenz[a,h]anthracene X X 2
PAHs, total, w/o individ.
components reported
[Treated as B(a)P for HRA] X X 2

VOC CANISTER
Butadiene (1,3) ** X X X X X 5
Methyl Bromide X X X X X 5
Acrolein X X X X 4
Carbon disulfide X X X X 4
Propylene X X X X 4
Methylene chloride
{Dichloromethane} ** X X 2
Vinyl chloride X X 2

VOC CANISTER,
SORBENT
Benzene X X X X X 5
Styrene X X X 3
Carbon tetrachloride ** X X X 3
Ethylene dichloride {EDC} X X X 3
Hexane (listed as n-Hexane
in CA refinery) X X X 3
Ethyl benzene ** X X X 3
Toluene X X X 3
Xylenes (mixed) X X X 3
Chlorobenzene X X 2

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 H-1

APPENDIX H: TOXICITY WEIGHTED TOTALS FOR CHEMICALS RELEASED FROM

CALIFORNIA REFINERIES

OEHHA reviewed recent data from CEIDARs on Toxic Air Contaminants (TACs)
routinely released from California refineries in 2014. OEHHA used the average annual
routine TAC emissions for California refineries during 2014 to derive a “toxicity-
weighted” emission score for each chemical across all refineries in California for which
emissions data were available. The toxicity-weighted emissions score was calculated
using emissions data (pounds emitted per year) obtained from the Air Toxics “Hot
Spots’ Emissions Inventory and a toxicity-weight derived from US EPA’s Inhalation
Toxicity Scores for individual chemicals. For more information on toxicity weights see:
https://www.epa.gov/rsei/rsei-toxicity-data-and-calculations.

Chemicals listed in Table H1 have the highest calculated overall toxicity-weighted

pounds emitted. Table H1 shows the sum of emissions by chemical for all California
refineries included in this analysis. The calculated toxicity-weighted pounds emitted for
each chemical across all California refineries are the product of total pounds released
and their corresponding chemical specific toxicity-weights.

Table 1. Toxicity Weighted Totals for Chemicals Released From California

Refineries (2014)
Toxicity-weighted lbs.
Chemical Total lbs. released1 Toxicity weights2 released3
Formaldehyde 91682 46,000 4,217,368,613
Nickel 1338 930,000 1,244,140,036
Arsenic 65 17,000,000 1,101,338,814
Cadmium 155 6,400,000 992,557,509
Benzene 20313 28,000 568,775,348
PAHs 711 710,000 504,822,625
Hexavalent chromium 10 43,000,000 426,073,431
Benzo[a]pyrene 500 710,000 355,219,396
Phenanthrene 280 710,000 198,694,330
Beryllium 12 8,600,000 106,826,366
Ammonia 2,517,005 35 88,095,180
1,3-Butadiene 740 110,000 81,404,664
Naphthalene 6,313 12,000 75,756,270
Hydrogen Sulfide 12,321 1,800 22,178,439
Acetaldehyde 1,392 7,900 10,997,059
Manganese 474 12,000 5,691,981
Diethanolamine 1,778 1,200 2,133,390

1 Total amount of chemical released across California refineries

2 Proportional numerical weight given to each chemical based on chronic adverse health outcomes
3 Total chemical release multiplied by the toxicity weight

Analysis of Refinery Chemical Emissions and Health

Effects OEHHA
March 2019
 I-1

APPENDIX I: LIST OF ABBREVIATIONS

AAQS Ambient Air Quality Standards

AEGL Acute Exposure Guideline Levels
AIHA American Industrial Hygiene Association
APCD Air Pollution Control District
AQMD Air Quality Management District
ATSDR Agency for Toxic Substances and Disease Registry
BAAQMD Bay Area Air Quality Management District
BTEX Benzene, toluene, ethylene, and xylene
CAD Coronary Artery Disease
CalEPA California Environmental Protection Agency
CAMEO Computer-Aided Management of Emergency Operations
CAPCOA California Air Pollution Control Officers Association
CARB California Air Resources Board
CAS RN Chemical Abstracts Service Registry Number
CCHS Contra Costa Health Services
CDC Centers for Disease Control and Prevention
CEIDARS California Emission Inventory Development and Reporting System
CHHSL California Human Health Screening Level
COPD Chronic Obstructive Pulmonary Disease
CPF Cancer Potency Factor
CSB Chemical Safety Board
CSF Cancer Slope Factor
EPCRA Emergency Planning and Community Right-to-Know Act
ERPG Emergency Response Planning Guidelines
FCCU Fluid Catalytic Cracking Unit
HSDB Hazardous Substances Data Bank
IARC International Agency for Research on Cancer
ICR Information Collection Request
IDLH Immediately Dangerous to Life and Health
IRIS Integrated Risk Information System
IRTF Interagency Refinery Task Force
LEL Lower Explosive Limit
NAAQS National Ambient Air Quality Standard
NAC/AEGL National Advisory Committee for the Development of Acute
Exposure Guideline Levels for Hazardous Substances
NIH National Institutes of Health
NIOSH National Institute for Occupational Safety and Health
NOAA National Oceanic and Atmospheric Administration
NOx Nitrogen oxides
OEHHA Office of Environmental Health Hazard Assessment
OER Office of Emergency Response
OPPT Office of Pollution Prevention and Toxics
PAC Protective Action Criteria
PAH Polycyclic Aromatic Hydrocarbon
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Effects OEHHA
March 2019
 I-2

PCDD Polychlorinated dibenzo-p-dioxin

PCDF Polychlorinated dibenzofuran
PHG Public Health Goal
PM Particulate matter
PM10 Particulate matter ≤10 µm in diameter
PM2.5 Particulate matter ≤2.5 µm in diameter
RADS Reactive Airway Dysfunction Syndrome
REL Reference Exposure Level
RfC Reference Concentration
RfD Reference Dose
RMP Risk Management Plan
RSL Regional Screening Level
SCAPA Subcommittee on Consequence Assessment and Protective
Actions
SCAQMD South Coast Air Quality Management District
SRU Sulfur Recovery Unit
TAC Toxic Air Contaminant
TCDD 2,3,7,8-Tetrachlorodibenzo-p-dioxin
TEEL Temporary Emergency Exposure Limit
TOXNET Toxicology Data Network
TRI Toxics Release Inventory
TSH Thyroid stimulating hormone
US EPA United States Environmental Protection Agency
UEL Upper Explosive Limit
VOC Volatile Organic Compound
WWT Wastewater treatment

Analysis of Refinery Chemical Emissions and Health

Effects OEHHA
March 2019