General Assistance

Environment, Health
& Safety
business hours (510) 6423073

Emergency Phone Numbers

Life-threatening
Emergencies
land line 911
cell phone (510) 642-3333

Hazardous Material
Spills
business hours (510) 642-3073
EH&S off-hours & weekends
(510)
642-6760 UCPD

Facilities Services
24 hour contact (510) 6423073

Department Contacts
Name

Phone Number

Department Safety Coordinator

Building Coordinator
Lab or Shop Emergency Contact

Office of Environment, Health & Safety

ehs.berkeley.edu

Safe
Storage of

Hazardous

Chemicals

Conten
ts

Page

Introduction

1.0 Take Inventory of Your Chemicals

2.0 Label Your Chemicals

Segregate Incompatibles

Common Incompatibles

4.0 Basic Storage Requirements

Chemical Storage Guide: Individual Hazards

and Mixed Hazards
11
Flammables and Combustibles

14

Corrosives

17

Toxics

19

Highly Toxics

20

Oxidizers

22

Compressed Gases

24

Cryogens

26

Pyrophorics (Air Reactives)

Water Reactives

28
29

Explosive and Potentially Explosive

30

Peroxide Forming Chemicals

34

Introduction
The safe storage of hazardous chemicals is an
essential part of an environmental, health, and
safety program. Chemical storage facilities must
meet certain minimum standards to satisfy diverse
regulations, such as those of Cal/OSHA, the local
sanitary district, and the California Fire Code. This
manual provides guidelines to help you meet these
standards.
In addition, laboratories and work areas on campus
must observe several requirements that incorporate
safe storage:
Keeping an up-to-date chemical inventory
Maintaining a chemical hygiene plan and
documenting staff training
Conducting annual self-inspections
EH&S provides more information on the above
programs at its website http://ehs.berkeley.edu.
The five sections of this brochure cover the main
elements of a safe chemical storage program:

Section Information
1

How to Maintain an Accurate

Inventory of Hazardous Chemicals

Proper Chemical Labeling

Segregating Incompatible Chemicals

Providing Basic Storage Needs

Storing Chemicals according to their

Hazardous Characteristic

Illustrations by Oruc
Cakmakli

at a central location.

1.0 Take Inventory of Your Chemicals

Safe storage begins with an up-to-date inventory of
hazardous chemicals that can be used to apprise
personnel of the dangers in a laboratory, shop, or
work area. An accurate inventory
is also necessary if emergency responders are to
respond effectively to a fire or chemical release in the
area. The campus can be fined if it does not provide
an inventory to emergency response personnel and
appropriate regulatory agencies.
The Office of Environment, Health & Safety (EH&S)
coordinates the collection of chemical inventories
for the campus. Submit your inventory to EH&S
annually. Also submit one whenever the maximum
amount listed for a particular chemical changes by
more than 50 percent or you obtain a chemical
that was previously not reported.
Immediately notify EH&S if a laboratory or other area
has been cleaned out or a new laboratory has started
up or moved.
The annual review of your chemical inventory is a
prime opportunity to clean out unwanted chemicals.
Your unwanted chemicals will either be picked up and
disposed of or collected for reuse through the campus
Chemical Exchange Program (CHEX). Visit the EH&S
web site (http://ehs.berkeley.edu) for Fact Sheets
about CHEX and disposal of unwanted hazardous
materials.

Keep an extra copy of

your inventory handy

2.0 Label Your Chemicals

Label your chemicals.

All hazardous chemicals must be clearly labeled for the

benefit of current users, emergency personnel, and
future users. Unknown chemicals can be expensive
to dispose of. Make sure all labels are legible and in
good condition. Repair or replace damaged or
missing labels.

Manufacturers Labels

Cal/OSHA requires that manufacturers provide labels

with the following information:
contents of the container
physical and health hazard information
name, address, and emergency phone
number of the manufacturer or other
responsible party
Original manufacturers labels must not be removed
or defaced. Material Safety Data Sheets (MSDSs)
must be accessible to anyone working with these
chemicals. Electronic format MSDSs are available
from the EH&S web site at http:// ehs.berkeley.edu.
The MSDS may also provide useful storage
information.

Your Own Labels

Hazardous chemicals that are not in the

manufacturers original container (e.g., working
solutions prepared in the lab) must, at a minimum,
be labeled with the contents of the container. If
the contents are
hazardous, attach a label
indicating the hazard to warn
individuals in the work area. It is
not necessary to label
containers that will be used
temporarily (during one work shift)
and are under your immediate
control.
4

Segregate Incompatibles
Chemical Families

Materials should always be segregated and stored

according to their chemical family or hazard
classification. Do not store
chemicals alphabetically unless they are compatible!
The most common hazard classes include:

other chemical families by an approved noncombustible partition or by a distance of twenty feet.

Ideally, each hazard class would be kept in a cabinet or
on a shelf segregated from other hazard

flammables/combustibles
corrosive acids
corrosive bases
toxics
highly toxics
oxidizers
compressed gases
cryogens
pyrophorics
water reactives
explosives

Accidental contact between incompatible chemicals

can result in a fire, an explosion, the formation of
highly toxic and/or
flammable substances, or other potentially harmful
reactions:
Oxidizers mixed with flammable solvents can
cause a fire. Acids mixed with metal dust can
produce flammable hydrogen gas.
Alphabetical storage can bring incompatibles
together. For example, if chromic acid (an oxidizing
acid) and chromium powder (a combustible metal)
were stored together and an accident broke their
containers, the chemicals could mix and react with
explosive violence.

Segregate Families

Each chemical family should be separated from all

6

classes. Incompatible chemicals within the same

hazard class should also be separated from one
another. For example, both nitric and perchloric
acids are incompatible with organic acids (such as
acetic acid) and should not be stored together.

provide information on chemical compatibility.

Most labs have limited space, but the following

priorities may help you decide how to store the
chemicals.
Do not store chemicals alphabetically unless
they are compatible.
Store flammable liquids in approved safety
containers in flammable storage cabinets. Do
not store anything but flammable or
combustible liquids in these cabinets.
Segregate acids from bases.
Segregate most organic acids from oxidizing
mineral acids.
Keep oxidizers away from other chemicals,
especially
flammables, combustibles, and toxic materials.
Keep corrosives away from substances that they
may react
with and release corrosive, toxic, or flammable
vapors.

Multiple Hazard Classes

Many chemicals belong to more than one chemical

family or hazard class. In such cases, all storage
rules must be strictly observed. For example, acetic
acid is both a corrosive acid and a combustible
liquid. It must be stored away from corrosive bases,
such as sodium hydroxide, and also from oxidizing
acids, such as nitric acid.

For More Information

For more specific information, use the storage

guidelines that follow. You can obtain labels and
material safety data sheets (MSDSs) from the
manufacturer, your department, or EH&S. MSDSs
6

Common Incompatibles
Do not store incompatible chemicals in close
proximity to each other. In an earthquake, fire, or
other spill, they could mix and react violently and/or
release poisonous gas.
Laboratory Material
Alkali metals like
calcium, potassium, and
sodium
Acetic Acid

Acetone
Acetylene
Ammonia, Anhydrous
Ammonium Nitrate

Aniline
Bromine

Chlorates

Incompatible with
water, carbon dioxide,
carbon tetrachloride, other
chlorinated hydrocarbons
chromic acid, nitric acid,
hydroxyl-containing
compounds, ethylene
glycol, perchloric acid,
peroxides,
permanganates
concentrated sulfuric or
nitric acid mixtures
copper (tubing), halogens,
silver, mercury, and their
compounds
mercury, halogens, calcium
hypochlorite, hydrogen
fluoride
acids, metal powders,
flammable
liquids,
chlorates, nitrates, sulfur,
finely divided organics or
combustibles
nitric acid, hydrogen
peroxide
ammonia, acetylene,
butadiene, butane,
hydrogen, sodium carbide,
turpentine, finely divided
metals
ammonium salts, acids,
metal
powders,
sulfur,
carbon,
finely
divided
organics, combustibles

Chlorine

Cyanides
Hydrogen Peroxide

Hydrogen Sulfide
Hydrocarbons
(general)
Iodine
Mercury
Nitric Acid

Oxygen
Oxalic Acid
Perchloric Acid
Potassium
Permanganate
Sodium Peroxide
Sulfuric Acid

ammonia, acetylene,
butadiene, benzene, other
petroleum fractions,
hydrogen, sodium carbide,
turpentine, finely divided
powdered
metals
acids
copper, chromium, iron,
most metals or their
respective salts,
flammable liquids or
combustible materials,
aniline,
nitro-methane
nitric acid,
oxidizing gases
halogens, chromic acid,
sodium peroxide
acetylene, ammonia,
chlorine
acetylene, ammonia,
lithium
acetic, chromic, and
hydrocyanic acids, aniline,
carbon, hydrogen sulfide,
flammable material, readily
nitrated substances
oils, grease,
hydrogen;
flammable
silver, mercury,
chlorites, strong
oxidizers
acetic anhydride, bismuth
and its alloys, alcohol,
paper, wood, other organic
materials ethylene glycol,
glycerine,
benzaldehyde, sulfuric acid
any oxidizable substances
chlorates,
perchlorates,
permanganates

Chromic Acid

acetic acid, naphthalene,

camphor, alcohol,
glycerine, turpentine,
other flammable liquids or
combustible materials

Storage Cabinets

4.0 Basic Storage Requirements

The following basic storage requirements apply to all
hazardous chemicals. Refer to the Chemical Storage
Guide sections
of this brochure for additional requirements that
apply to chemicals in a specific hazard class
(e.g., flammables and corrosives).
Label storage areas according to the type of
chemical family or hazard classification found there.
Inspect storage areas at least annually, as required
by Cal/ OSHA.
hallways,

doorways,

Label cabinets with the hazard class of the chemicals.

Storage Shelves

Storage Area Requirements

Keep aisles,
entryways clear.

Use only approved storage cabinets. Never alter a

flammable storage cabinet unless directed to do so by
EH&S.

exits,

and

Shelves should be level, stable, and secured to the

wall or another stable surface.
In case of an earthquake, shelves should have raised
edges or rim guards (minimum height of 2 inches) to
prevent containers from falling. Use bungee cords for
added security.

Keep storage areas well lit, appropriately

ventilated, and at a consistent, cool temperature.

Shelves should be kept free of chemical contamination

and dust.

Eliminate ignition sources such as open flames, heat

sources, or direct sunlight.

Shelves should be located away from direct sun,

flame, and heat sources.

Keep emergency equipment such as fire

extinguishers handy and in good working order.

Containers should not protrude over shelf edges.

Confine chemical storage areas so that leaks or

spills are controlled. Prevent chemicals from running
down sink, floor, or storm water drains. Clean up
spills and drips immediately.

Store large bottles/containers no higher than 2 feet

from the floor. Store corrosives on lower shelves.

Storage Containers
Storage Donts

Dont store chemicals in a sink or fume hood,

except for certain toxic gases that are so
dangerous they can only be stored in a gas
cabinet or fume hood.
Dont store chemicals on dirt or grass, near a creek
or storm drain entrance, where they could
contaminate the environment.
Dont store chemicals on the floor, window
ledges, or balconies.
10

Keep containers closed unless you are dispensing a

chemical or adding to the container. Never store a
container open with a funnel in it.
Provide secondary containment for liquids in
containers larger than 1 gallon in size. Dishpans or
polyethylene trays work well.
Use approved containers for flammable solvents.

11

Chemical Storage Guide:

Individual Hazards and Mixed
Hazards
Sections 5.1 through 5.11 provide basic storage
guidelines for the most common hazard classes.
Each section describes the characteristics of the
hazard class (consistent with California Fire Code). It
includes common examples of laboratory
and non-laboratory chemicals and provides basic
storage requirements and precautions. Note:
These examples do not constitute a full list, and
the laboratory/non-laboratory classifications may
not strictly apply.

NFPA Chemical Hazard Identification

System
Each hazard class section on the following pages
includes two chemical examples illustrated with
National Fire Protection Association (NFPA) diamond
symbols that rate the degree of health, flammability,
reactivity, and special hazards of the

Please note that many chemicals have multiple

hazard classifications. Consequently, you may need
to consult several storage guideline sections to
determine how to store a hazardous chemical safely.
For example, acetic acid is a corrosive acid and also
a combustible liquid. Therefore, you need to follow
section 5.1 (flammables and combustibles) and
section 5.2 (corrosives). You may also call EH&S for
help.
Federal and state regulations may require a Risk
Management Plan for certain highly hazardous
chemicals, depending on the amount stored. EH&S
periodically reviews your chemical inventory and will
notify you if there is a concern. It is a prudent
practice to maintain the lowest possible quantities of
highly hazardous chemicals.
The capital letters in parenthesis used in sections 5.1
5.11 that follow the chemical examples indicate that
the chemical has an additional hazardous
characteristic other than the one being discussed.
Refer to the appropriate storage guideline section in
this brochure for information and follow its directives
as well.
12

13

chemicals discussed. Hazards are rated from 0 for

minimal hazard to 4 for severe hazard.

explosively upon contact with water) and OX (to

indicate an oxidizer that could ignite combustible or
flammable material upon contact).

The degree of hazard is often dependent upon the

physical state of the chemical as well. For
example, a flammable gas will pose a more
significant immediate safety threat upon release
than a liquid that has the same flash point.
The NFPA Health Hazard rates the effect of
short-term exposure to a chemical by physical
contact, eye and skin absorption, or inhalation.
A highly toxic chemical with a health hazard
rating of 4 could be lethal on very short
exposure.
Flammability
(Red)
Health
(Blue)
(Yellow)

Reactivity

Special
(White)

The NFPA Flammability Hazard rates the ease with

which a chemical will ignite from exposure to a
spark, open flame, or high temperature. A
flammable or pyrophoric chemical with a
flammability rating of 4 could readily ignite at
room temperature.
The NFPA Reactivity Hazard rates a chemicals
thermal instability, potential for hazardous reaction
with water, or sensitivity to friction or shock. A highly
unstable chemical, such as an explosive with a
reactivity rating of 4, could readily detonate if
exposed to localized thermal or mechanical shock at
normal temperatures and pressures.
The NFPA Special Hazards include W (to indicate a
water reactive chemical that could react violently or
12

13

Flammables and Combustibles

Non-Laboratory Chemicals

Characteristics

These chemicals are easily

ignited and
may present a serious fire and
explosion hazard. Flammable
liquids have a flash point below
100F. Combustible liquids have a
flash point of 100F to 200F.
Flammable solids have an
ignition temperature below
212F. Flammable solids include
finely divided solid
materials which, when dispersed in air, could ignite.
Other classes of chemicals with a high fire hazard
include oxidizers (section 5.5), pyrophoric chemicals
(section 5.8), and water reactive chemicals (section
5.9).

Laboratory Chemicals

Flammable Solids

Flammable Liquids

moth balls (HT)

(containing
naphthalene)
calcium carbide (WR)

gasoline
lighter fluid
paint
thinner

Flammable Gases

Combustible Liquids

acetylene

antifreeze
diesel
fuel
engine
oil

Additional hazardous characteristics: CACorrosive acid; HT

Highly toxic; PPyrophoric; TToxic; WRWater reactive

Flammable Solids

Flammable Liquids

Storage Limits

naphthalene (HT)
finely divided metal (e.g.,
aluminum, cadmium,
4
chromium, titanium,
zinc)
(P)
1
1

alcohols - methanol,
ethanol
esters - ethyl
acetate ethers diethyl ether
ketones - acetone,
cyclohexane

Flammable Gases

Combustible Liquids

Quantity Limits outside Flammable Storage

Cabinets A maximum of ten (10) gallons of
flammable liquids may be stored outside a
flammable storage cabinet.

hydroge
n
methan
e

ethyl ether

California Fire Code regulations limit the

quantity of flammable liquids stored in
research and teaching
laboratories on the Berkeley campus.

acetic acid (CA) cumene

phenol (CA, T) propionic acid (CA)

1
1

0
glycerine

14

15

Quant
ity
Limits
within
Flam
mable
Stora
ge
Cabin
ets
Flamm
able
liquids
stored
in
approv
ed
cabinet
s
within
laborat
ories
or
classro
oms
shall
not
exceed
sixty
(60)
gallons
.

c
a
p
a
ci
ty
of
gl
a
s
s
c
o
n
ta
in
e
rs
s
h
al
l
n
ot
e
x
c
e
e
d
o
n
e
Maxim (1
)
um
Contai g
al
ner
Capaci lo
n.
ty
The
T
ca
h
pa
e

city of all
other
containers
(including
safety
cans) shall
not exceed
two (2)
gallons.
See the Fact
Sheet on the
storage of
flammable
liquids at
http://ehs.berk
eley.edu. If you
need additional
information,
please contact
the Campus
Fire Marshal at
642-4409.

14

15

Storage Precautions for

Flammables and Combustibles

Corrosives
Characteristics

Keep flammables away from all ignition sources:

open flames, hot surfaces, direct sunlight, spark
sources.

Strong acids and bases can

destroy human tissue and
corrode metals. Acids and bases
are incompatible with one
another and may react with
many other hazard classes.

Store flammables separate from other hazard

classes, especially oxidizers and toxics.
Separate flammable gases from oxidizing gases with
an approved non-combustible partition or by a
distance of 20 feet.
Store flammable liquids in approved safety
containers or cabinets.
In instances where static electricity may
accumulate and ignite flammable vapors, ground
and bond flammable liquid containers.
Keep a fire extinguisher (appropriate for the
hazard) readily available and make sure anyone
who may need to use it is properly trained.
Keep flammable
liquids that require
cold storage
in laboratory-safe
flammable material
refrigerators or
freezers to avoid
ignition of the
materials by sparks
or static electricity.
See the Fact Sheet
about storage of
hazardous materials
in freezers and
refrigerators at

Laboratory Chemicals
Acids

Bases

Organic Acids
acetic acid (C)
citric acid ( C )
WR)
formic acid (C, T)
oxalic acid (T)

ammmonium hydroxide (T)

calcium hydroxide
potassium hydroxide (T,

Inorganic Oxidizing
Acids
chromic acid (O, T)
nitric acid (HT, O)
perchloric acid (O,
PEC) sulfuric acid (O,
T, WR)

http://ehs.berkeley.ed
u.

sodium hydroxide (T, WR)

tri-sodium phosphate (T)

OX

nitric
acid

Retrofitting nonlaboratory safe

refrigerators for use
with flammables is
prohibited.

16

17

sodium hydroxide

Inorganic Non-Oxidizing Acids

hydrochloric
acid
phosphoric
acid

Non-Laboratory Chemicals
Acids

Bases

muriatic acid (contains

drain declogger
(containing hydrochloric acid)
sodium
hydroxide)
wall cleaner (containing trisodium phosphate)
Additional hazardous characteristics: CCombustible
liquid or solid; HTHighly toxic; OOxidizer; PECPotentially
explosive chemical; TToxic; WRWater reactive

16

17

Storage Precautions for Corrosives

Toxics
Characteristics

Segregate acids from bases. Segregate inorganic

oxidizing acids (e.g., nitric acid) from organic acids
(e.g., acetic acid), flammables, and combustibles.

Overexposure to toxic chemicals

can cause injury or death. Toxics
are chemi-cals with a lethal dose
(LD50) of more than 50 and less
than 500 milligrams per
kilogram body weight or a lethal
concentration (LC50) in air of
more than 200 and less than
1,000 parts per million.

Segregate acids from chemicals that could

generate toxic gases upon contact (e.g., sodium
cyanide and iron sulfide).
Segregate acids from water reactive metals such
as sodium, potassium, and magnesium.
Use tight-fitting goggles,
gloves, and closed-toe shoes
while handling corrosives.
Store solutions of inorganic
hydroxides in polyethylene
containers.
Store corrosives on lower shelves,
at least below eye level and in
compatible secondary containers.
Do not store corrosives on metal shelves.
Although ventilation helps, chemicals will still
corrode the shelves. Store containers in plastic
tubs or trays as secondary containment.
If you notice powder deposits, discoloration, and
crystallization around the cap of a container,
particularly an oxidizing acid, contact EH&S
immediately. The material may be potentially
explosive.
Follow the special handling and use procedures for
hydrofluoric acid (See the Fact Sheet about
hydrofluoric acid at http://ehs.berkeley.edu). Keep
calcium gluconate available as an antidote.
18

Laboratory Chemicals
Solids

Liquids

Gases

acrylamide
aniline (C)
ammonia
cadmium chloride
chlordane
hydrogen fluoride
(CA) potassium fluoride (CA)
phenol (C, CA)
vinyl bromide

Non-Laboratory Chemicals
Solids

Liquids

diazinion

copper sulfate

Additional hazardous characteristics:

C - Combustible liquid; CA - Corrosive Acid

Storage Precautions for

Toxics
Segregate toxics from other hazard
classes and store in a cool, well
ventilated area, away from light and
heat.

4
0

hydrogen
sulfide
2
3

phenol

Have spill control pillows or neutralizing agents

available in case of a spill. These may be purchased
from safety supply companies.
19

Containers should be tightly sealed to minimize

exposure to personnel and contamination of other
chemicals.
Manage toxic gases, highly toxic gases, and
pyrophoric gases in accordance with the campus
Toxic Gas Program requirements. Contact EH&S for
specifics, or print out the Fact Sheet about the
campus Toxic Gas Program at
http://ehs.berkeley.edu.

18

19

Highly Toxics
Characteristics

These chemicals can cause

serious injury or death at low
concentrations. Highly toxics
are chemicals with a lethal dose
(LD50) of less than or equal to
50 milligrams per kilogram
body weight or a lethal
concentration (LC50) in air of
less than or equal to 200 parts
per million.

Laboratory Chemicals
Solids

Liquids

Gases

arsenic salts
acrolein
diborane (P, WR)
calium cyanide hydrocyanic acid (CA, F) fluorine (CA,
O, WR) organic mercury nicotine (C) nitrogen dioxide
(O)
compounds

The California Fire Code limits the amount of highly

toxic gases to 20 cubic feet per laboratory or
storage area.
Manage toxic gases, highly toxic gases, or
pyrophoric gases in accordance with the campus
Toxic Gas Program requirements. See the Fact
Sheet about the campus Toxic Gas Program at
http://ehs.berkeley.edu. Contact EH&S for
specifics.
Containers should be tightly sealed to minimize
exposure to personnel and avoid contamination from
other chemicals.
Do not eat, drink, or apply cosmetrics where highly
toxic chemicals are handled.

4
4

The California Fire Code limits the aggregate amount

of highly toxic solids and liquids to 10 pounds per
laboratory or storage area.

3
W

potassium dichromate

diborane
Additional hazardous characteristics: CCombustible; CA
Corrosive acid; FFlammable; OOxidizer; PPyrophoric; WR
Water reactive

Storage Precautions for Highly Toxics

Maintain the lowest possible quantities of highly
toxics.
Segregate highly toxic chemicals from other hazard
classes and store in an area that is cool, well
ventilated, and away from light and heat.
20

21

Use highly toxic chemicals in a designated area or

laboratory. Highly toxic chemicals that produce
fumes or dust should always be handled within a
chemical fume hood.
Handle highly toxic chemicals in a chemical fume hood.

20

21

Oxidizers

Storage Precautions for Oxidizers

Characteristics

Oxidizers are a fire hazard.

They will readily decompose
under certain conditions to yield
oxygen or react to promote or
initiate the combustion of
flammable or combustible
materials.

Laboratory Chemicals
Solids

Liquids

Gases

ammonium nitrate
bromine
chlorine (HT)
calcium nitrate (T)
chromic acid (CA, T)
fluorine (CA, HT,
WR) potassium chlorate
hydrogen peroxide
nitrogen
dioxide (HT) potassium nitrate
nitric
acid
(CA,
HT)
oxygen
sodium dichromate (H, T) perchloric acid
ozone (H,
T) sodium nitrate
(CA, PEC)
sulfuric acid (CA, T, WR)

Non-Laboratory Chemicals
Solids

Liquids

Segregate inorganic oxidizers from organic

peroxides.
Take care not to contaminate oxidizers. Some
oxidizers, such as perchloric acid, can become
explosive mixtures if contaminated with trace
amounts of organic materials or metals. See
Explosive and Potentially Explosive Chemicals
(section 5.10).
Store in a cool, dry place. Do not store under sink.
Remember that perchloric acid, nitric acid, and
hydrogen peroxide are oxidizers and must not be
stored on wooden shelves or in cardboard boxes.

oxygen
chlorine
(T)
0
W
OX

sulfuric
acid

Additional hazardous characteristics: CACorrosive acid; TToxic;

22

Segregate oxidizers from reducing agents (zinc,

alkaline metals, formic acid).

Gases

fertilizers (e.g.,
bleaching agents
ammonium
(e.g.,
nitrate) pool
hyrogen
chemicals
(e.g., bromine tablets) peroxide,
sodium
hypochlorit
0
e)
3
0
1

silver
nitrate

Segregate oxidizers from flammable and

combustible materials (paper, wood). See
Flammables and Combustibles (section 5.1).

Do not store oxidizers on wood shelves. A leak could

start a fire.

23

HTHighly toxic; PECPotentially explosive chemical; WRWater

reactive

22

23

Compressed Gases

Secure cyclinders so they will not fall during an

earthquake.

Characteristics

What all compressed gases

have in common is the large
amount of energy stored in
the cylinder from
the compression of the gas.
Dropping or knocking over a
cylinder can cause the energy
to be rapidly released.
It may even propel a
cylinder like a rocket. Additional hazards can
arise from the toxicity, flammability, corrosivity,
or reactivity of the gas.

Laboratory Chemicals
argon
hydrogen (F)
butane (F)
methane
(F) carbon monoxide (T) nitrogen
chlorine (T,O)
ethylene (F)

Non-Laboratory Chemicals

OX
chlorine

acetylene (F)
compressed
air oxygen
(O)

Additional hazardous
characteristics:
FFlammable; TToxic; OOxidizer

acetylene

An acceptable means includes using two noncombustible restraints, such as chains, one restraint
located approximately one-third of the cylinder
length from the top, and the other restraint one-third
from the bottom.
Keep cylinders away from heat and open flames.
Leave the valve protection cap on the cylinder
unless it is in use.
Never store cylinders in walk-in freezers. The
confined space with no ventilation poses a potential
hazard.
If you suspect that a cylinder is leaking, do not
attempt to sniff the leak out. Apply a soap solution
to the cylinder and locate the leak by noting where
the bubbles appear.
Toxic gases, highly toxic gases, and pyrophoric gases
must be managed in accordance with the campus
toxic gas program requirements. See the Fact Sheet
about the campus Toxic Gas Program at
http://ehs.berkeley.edu. Contact EH&S for details
about ventilation and quantity limitations.

Storage Precautions for Compressed

Gases
Segregate incompatible gases as you would other
24

25

incompatible chemicals.
Limit the quantity of compressed gas cylinders
on site to what will be used within a reasonable
period of time.

Secure gas cylinders adequately.

Store cylinders upright.

24

25

Cryogens
Characteristics

These materials are extremely

cold
(-100C to -270C). Upon
contact with cryogenic
CRYOGENS
materials, living tissue can
freeze and become brittle
enough to shatter. Additional
hazards include rapid pressure
buildup, oxygen enrichment,
and asphyxiation. Rapid
pressure buildup could lead to an explosion if
cryogen is improperly contained. Cryogenic liquids
and gases have many properties and hazardous
characteristics in common with compressed gases.

Laboratory Chemicals

liquid argon
liquid
(F) liquid carbon monoxide (F, T)liquid
(F) liquid ethylene (F)
liquid
liquid fluorine (CA, HT, O, WR) liquid
(O) liquid helium

Use only approved storage vessels (i.e., thermos-like

evacuated, double-walled containers) with pressure
relief mechanisms. Non-approved vessels may
explode.
Secure containers so they will not tip over or
obstruct an aisle, hallway, or corridor during an
earthquake.
Liquid nitrogen and liquid helium are capable of
liquefying oxygen from air. This form of oxygen
enrichment can become a strong fire or explosion
hazard.
Use appropriate protective equipment for handling
cryogens: insulated holders for carrying vessels; eye
protection, goggles, or face shields; and aprons. Use
cryogenic gloves or leather gloves when handling
super cold surfaces.

hydrogen
methane
nitrogen
oxygen

0
0

OX
liquid oxygen

liquid
nitrogen

Additional hazardous characteristics: CACorrosive acid;

FFlammable; HTHighly toxic; OOxidizer; TToxic; WRWater
reactive

Storage Precautions for Cryogens

26

27

Store and handle in a well-ventilated area. When liquid

Wear cryogenic or leather gloves when handling supercold

surfaces.

cryogens are converted to the gaseous phase, they

may create an oxygen deficiency. Do not use
cryogens in small enclosed spaces.

26

27

Pyrophorics (Air Reactives)

Water
Reactives

Characteristics

Substances that ignite

spontaneously upon contact
with air.

SPONTANEOUSLY

DANGEROUS

COMBUSTIBLE

Laboratory Chemicals
Solids

Liquid

Gases

sodium (WR)
aluminum
diborane (HT, WR)
finely divided metal
borohydride (CB,WR) phosphine (HT,
WR)
(e.g., aluminum,
diethylzinc (WR)
silane
(WR) chromium, zinc)

Laboratory Chemicals
Solids

Liquids

aluminum chloride (anhydrous) acetyl chloride (CA, F)

calcium carbide (F)
chlorosulfonic acid (CA,
HT)
magnesium (F)
stannic
chloride
(CA) phosphorus pentatchloride (CA, HT) thionyl
chloride (CA) sodium (P)
2

2
W

silane

WHEN
WET

Characteristics

These substances often react

violently with water and may
ignite or generate toxic,
flammable, or corrosive gases.

zinc

Storage Precautions for

Pyrophorics
Store in a cool, dry place. Prevent contact with air.
Take extreme care to prevent containers of
pyrophorics from leaking or breaking. The use of
corrosion- and shatterresistant secondary containers for storage and
transportation of pyrophoric reagent bottles is
encouraged.

2
W

antimony

potassium hydroxide

Manage pyrophoric gases, toxic gases, and highly

toxic gases, in accordance with the campus Toxic
Gas Program requirements. See the Fact Sheet
about the campus Toxic Gas Program at
http://ehs.berkeley.edu. Contact EH&S for specifics.

Many pyrophorics are also water reactives (section

5.9).
28

29

Additional hazardous characteristics: CACorrosive acid; F

Flammable; HTHighly toxic; PPyrophoric

Storage Precautions for Water

Reactives
Store in a cool, dry
place. Keep away from
water.
In case of fire, do not
use water. Use a dry
chemical extinguisher.

Keep water reactives in a dry

environment.

28

29

Explosive and
Potentially Explosive
Chemicals
Characteristics

Explosive chemicals can

rapidly release tremendous
amounts of destructive
energy. Explosive chemicals
can cause death, serious
EXPLOSIVE
injury, or severe property
damage. Heat, shock,
friction, or even static
electricity can initiate
explosions of these
chemicals.
The family includes pure
chemicals (e.g., TNT) and mixtures (e.g., ammonium
nitrate/ fuel mixtures).
In addition to explosive chemicals, which constitute
a known high hazard, there are chemicals that may
become explosive, depending on how they are
handled. This category is commonly referred to as
potentially explosive chemicals and includes:
pure chemicals or mixtures that may become
explosive through contamination (e.g., perchloric
acid contaminated with organic compounds or
metals); and
pure chemicals or mixtures that may degrade
over time and become explosive (e.g., hydrated
picric acid, which becomes explosive upon
drying). This category also includes certain
alcohols and ethers that may accumulate
explosive levels of peroxides by interacting with
air. See
30

Primary Classes of Explosive

Chemicals (with examples)

Nitrogen-Oxygen
Chemicals (e.g.,
Nitrates, Nitro)
ethylidene dinitrate
picric acid (dry)
thallium aci-phenylnitromethanide
trinitrotoluene (TNT)
Oxides, Peroxides, and Related
Chemicals
(See Peroxide Forming Chemicals)
benzoyl peroxide (97%) (dry)
bis (1-chloroethylthallium chloride)
oxide
Nitrogen-Rich
Chemicals
(e.g., Azo-, Diazo, Triazo, Tetrazole)
aluminum
azide 5aminotetrazol
e 1bromoaziridine
chromyl
azide
chloride
diethyl
diazomalonate
hydrogen
azide
(>17%) lead azide
mercury (I&II) azide
molybdenum diazide tetrachloride
sodium diazomethanide
tetrazole
1,2,3triazole
Perchlorate Chemicals
ammonium
perchlorate

31

4
4

picric acid (dry)

4
4

trinitrotoluene

Peroxide Forming Chemicals (section 5.11).

For more extensive information regarding
potentially explosive chemicals, please see the
Guidelines for Explosive and Potentially Explosive
Chemicals Safe Storage and Handling available
through the EH&S oThce or visit the web site:
http://ehs.berkeley.edu.

30

ethyl perchlorate (the most explosive chemical

known) hexyl perchlorate
Acetylenic Chemicals
n-chloro-3-aminopropyne
propiolic acid
3propynethiol
4sodium hexakis(propynyl)ferrate

31

Examples of Potentially Explosive

Chemicals (which are normally
stable)

Store explosive chemicals in an explosive magazine

and inspect areas weekly to comply with the California
Fire Code. (Contact EH&S for assistance.)

Organic chemicals, such as ethers, that

form peroxides through exposure to air or light
(See Peroxide Forming Chemicals, section
5.11.)

Hydrated picric acid that becomes dry

Sodium amide that reacts with air or moisture

Certain alkyl nitrates (e.g., butyl nitrate or

propyl nitrate) that become contaminated with
nitrogen oxides

Certain normally stable perchlorates (e.g.,

pyridinium
perchlorate
or
tetraethylammonium
perchlorate)
that
become unstable at elevated temperatures

Storage Precautions for Explosive and

Potentially Explosive Chemicals
Identify all explosive and potentially explosive
chemicals in your inventory.
For chemicals that may degrade to become
potentially explosive, record the opening date and
discard date directly onto the container or onto a
potentially explosive chemical warning label
(available from EH&S).
Keep explosive chemicals away from all ignition
sources: open flames, hot surfaces, direct sunlight,
spark sources.
32

33

Consider designating a special area to

store and use potentially explosive
chemicals.
Make sure everyone who uses explosive or
potentially explosive chemicals is thoroughly
trained in safe storage methods, conditions to
PEROXIDE
avoid (e.g.,
contamination), the hazards of the
FORMING
chemical, and disposal procedures.
Contact EH&S immediately if you suspect a material
may have become explosive. Post warning signs so
others do not handle or disturb the material.
Note: Most explosions occur while purifying
or distilling mixtures. Therefore, use
extreme caution before concentrating or
purifying any mixture that may contain an
explosive chemical (e.g., a peroxide forming
chemical or perchlorate).
Contact EH&S to discuss your storage and
handling of explosive and potentially
explosive chemicals.

Peroxide
Forming
Chemicals

t
i
m
e
,
t
h
e
s
e

C
h
a
r
a
c
t
e
r
i
s
t
i
c
s

c
h
e
m
i
c
a
l
s
c
a
n

O
v
e
r

f
o
r
m

p
e
r
o
x
i
d
e
s

p
e
r
i
o
d

32

o
f

33

t
h
a
t
m
a
y

h
e
n
t
h
e
y

e
x
p
l
o
d
e

a
r
e
c
o
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c
e
n
t
r
a
t
e
d

w
h
e
n
t
h
e
c
a
p

d
u
r
i
n
g

i
s
r
e
m
o
v
e
d

l
a
b
o
r
a
t
o
r

o
r
w
32

h
e

a
c
t
i
v
i
t
i
e
s
.

c
o
n
t
a
i
n
e
r
t
h
e

I
t

d
a
t
e

i
s
i
m
p
o
r
t
a
n
t

t
h
e

o
n

c
h
e
m
i
c
a
l
a
r
r
i
v
e
d

t
o
n
o
t
e

33

n
t
h
e

be
tested
for
peroxide
concentration, and
when it should be
discarded. Dispose
of the chemical
before the discard
date indicated on
the container or
follow
the
guidelines below.

l
a
b
o
r
a
t
o
r
y
,
w
h
e
n

D
i
s
p
o
s
e

i
t
w
a
s
o
p
e
n
e
d
,
w
h
e
n

o
f
w
i
t
h
i
n
2
4
H
o
u

i
t
s
32

2
2

h
o
u
l
d

r
s
:

u
n
i
n
h
i
b
i
t
e
d
)

a
c
r
y
l
i
c
a
c
i
d

Test or Dispose of
within 3 Months:

(
u
n
i
n
h
i
b
i
t
e
d
)
b
u
t
a
d
i
e
n
e
(
33

Storage
and
Disposal
of
Peroxid
e
Forming
Chemic
als

tested and show

no detectable
peroxides, or
whose peroxide
concentrations
are less than 100
ppm, may be
retained but
should be tested
at frequent
intervals. Test all
peroxide
forming
chemicals prior
to distillation,
regardless of age.

By the expiration
date, the
owner/user should
either dispose of
the chemical or
test it for peroxide
content. Dispose
of any chemicals
found to have a
peroxide
concentration
greater than or
equal to 100
parts per million.
(Call EH&S for
assistance.)
Materials that
have lasted
beyond the
recommended
shelf life but
have been
b
u
t
a
d
i
e

n
e
(
i
n
h

32

Important note:
Never test
containers of
unknown age or
origin. Old
bottles are likely
to contain
concentrated
peroxides, and
peroxides may
have crystallized
in the cap
threads, which
can present a
serious hazard
when the bottle
is opened for
testing.
ibited)
chloro
prene
divinyl
acetyle
ne
isoprop

yl
e
t
h
e
r
Test or
Dispose of
within 12
Months:
a
c
e
t
a
l
d
e
h
y
d
e
a
c
r
o
l
e
i
n
b
e
n
z
y
l
e

t
h
e
r

t
h
y
l

2
b
u
t
a
n
o
l

v
i
n
y
l
e
t
h
e
r

c
y
c
l
o
h
e
x
a
n
o
l

2
h
e
x
a
n
o
l
3methyl1butanol
tetrahy
drofura
n

d
i
e
t
h
y
l
e
t
h
e
r
e
33

acrylic acid

C
o
n
t
a
c
t

ainers and
for additional
guidelines on the
safe storage and
handling of
peroxide forming
chemicals.

E
H
&
S
diethyl ether

4
1

f
o
r
h
e
l
p
w
i
t
h
m
a
n
a
g
i
n
g
o
l
d
e
r
c
o
n
t
32

33

Storage Precautions for Peroxide

Forming Chemicals
Identify all peroxide forming chemicals in your
inventory.
Write the opening date and discard date on the
containers of chemicals that may degrade to become
potentially explosive.

For more extensive information

regarding potentially explosive
chemicals, please see the Guidelines
for Explosive and Potentially Explosive
Chemicals Safe Storage and Handling
available through the EH&S oThce or
visit the web site: http://
ehs.berkeley.edu.

Store in airtight containers in a dark, cool, and dry

place.
Never store peroxide formers in a freezer because a
change from a solid to a liquid can cause detonation.
Discard or test peroxide forming chemicals before the
expiration date printed on the container label. Contact
EH&S for disposal information.
If precipitate appears in an organic chemical that
may form an explosive peroxide (e.g., crystals
around the neck or cap of bottle), or if an oily layer
appears, do not move it. Contact EH&S
immediately.
Inspect peroxide forming chemicals often for
evidence of contamination, degradation, or any
change from normal physical or chemical
characteristics. Contact EH&S im- mediately if
you suspect a material may have become
explosive. Post warning signs so others do not
handle or disturb the material.
Note: Most explosions occur while purifying or
distilling mixtures. Therefore, use extreme
caution before concentrating or purifying any
mixture that may contain an explosive chemical
(e.g., a peroxide or perchlorate).
36

37

NOTES

36

37