Codes of Ptactièe

for Chemicals 11th

Major Hazfrds

Acryloñitñle
r This document
'5b pages
contains J

H
Chemical IndustrySafety & Health Council
ofthe

(hi Chemical Industries Association Limited

The Chemical Industry Safety and Health Council is composed of
directors and senior managersrepresentingmemberfirmsofthe Chemical
Industries Association which provides the secretariat from its staff.

Theobjectives of the Council are to securethehealth, safety and welfare

of persons at work in the industry and to protectothers from the risks
of its products, to maintain the high standards of safe operation already
achieved and to improve and extend them. It coordinates the various
safety and health activities of the Chemical Industries Association.

THE CHEMiCALINDUSTRYSAFETY & HEALTH COUNCIL

OF THE CHEMICALINDUSTRIES ASSOCIATION,
ALEMBIC HOUSE,
93 ALBERT EMBANKMENT,
LONDON,SE1 7TU.
 CONTENTS (Cont'd)
Page
8 TRAINING
8.1 Personnel 12
8.2 Instructions 12
8.3 Emergency Situations 13
8.4 Modifications 13
8.5 Refresher Courses 13

9 TREATMENT FOR EXPOSURE

9.1 Introduction 13
9.2 First Aid 13
9.3 MedicalTreatment 14

10 LEAKS AND SPILLAGES

10.1 Treatment 15
10.2 Disposal 15

11 FIRES
11.1 Burning Acrylonitrile 16
11.2 Mechanical Foam 16
11.3 Water Cooling 16
11.4 Personnel 16
11.5 Liaison 16

12 EMERGENCY PROCEDURES
12.1 Objective 16
12.2 Local Emergency Services 16
12.3 EmergencyProcedures 17
12.4 Responsibility 17
12.5 Provisions 17
12.6 EmergencyEquipment 17

APPENDICES

Propertiesof Acrylonitrile 19
Vapour Pressure/Temperature Relationship 21
III Label 22— For the Guidanceof Medical Officer 22 & 23
 CONTENTS
Page
INTRODUCTION 1

2 DEFINITIONS 1

3 HAZARDS
3.1 Properties 2
3.2 Personal Decontamination 3

4 DESIGN
4.1 Basic Premise 3
4.2 Siting and Layout 4
4.3 Materials of Construction 5
4.4 Pipelines 5
4.5 Pumps 5
4.6 Valves 6
4.7 Relief System 6
4.8 Drainage 6
4.9 Electrical 7

5 LIQUID ACRYLONITRILESTORAGE
5.1 General 7
5.2 Tanks 8
5.3 Venting 8
5.4 Bunding 8
5.5 Alarms 8
5.6 Drum Storage 9

6 HANDLING
6.1 General 9
6.2 Road/Rail Tankers 9
6.3 Drums 10

7 PLANT OPERATION
7.1 Personnel 10
7.2 Safeguards 11
7.3 Procedures 11
7.4 ProtectiveClothing 11
7.5 Maintenance 11
7.6 AttendantPersonnel 12
7.7 Isolation 12
7.8 Safe Systemof Work 12
Codes of Practice
for Chemicals with Major Hazards

The Safe Design, Construction and Use

of Plants Producing or Consuming
ACRYLONITRI LE
 ©Chemical Industries AssociationLimited 1978
No part of this publication may be reproduced, stored in a retrieval system or
transmitted in any form or by any means, electronic, mechanical,photocopying,
recording orotherwise, withoutthe written permissionofthe publisher.

Preparedby a working party set up by the Safety Committee of theChemical

Industry Safety & Health Council of the Chemical Industries Association.
The followingfirms contributed:

Border Chemicals Ltd.

BP Chemicals Ltd.
Courtaulds Ltd.
Du Pont (UK) Ltd.
Monsanto Ltd.

Thanks are also due to the Health & Safety Executive and to the Chemical
Industry Safety & Health Council's Medical Sub-committeeand Acrylonitrile
Health impact Study Team for their advice and help.
 CODE OF PRACTICE
FOR THE SAFE DESIGN, CONSTRUCTION AND USE
OF PLANTS PRODUCINGOR CONSUMING ACRYLONITRILE

INTRODUCTION
This Code sets out the general principles for producing and using
acrylonitrilein a safe manner. Acrylonitrile is a hazardous material
due to its toxicity, flammabilityin air and potential polymeris-
ation capability, yet it can be produced and handled with safety
provided precautionsare taken and observed.
Protection of both the work people and public from the potential
hazards involved in the production and use of acrylonitriledepends
on how plants are designed, built and operated. The design con-
cept for building a plant and the managerial philosophy for running
it are complementary and once builtthe installation has to be run
as intended or in a way that equally well fulfills the safety require-
ments.
The Code is based on sound engineering and the experienceof
companieswho have successfully operated with acrylonitrileover
many years. The Codeaims to presentthis knowledgeand exper-
ience as a guide to the safe design and operation of plants to
produceor use acrylonitrile.
Matters of detail are excluded because these can best be controlled
by the internal administrative systemof each individual company.
It does not cover specific legal requirementswhich must be
observed relating to the construction and operation of installations.
The Code shall be applied to the design of any new installation
and existing onesshould be operated and maintainedas closely to
the Code as practicable. Nevertheless, the Codeshould be used to
check existing installations and if they fail materially to meet its
requirements,consideration must be given as to what alterations
are required.
The Codewill need revision if changes in the hazards or in the
knowledge of the means available for controllingthem make this
necessary.

2 DEFINITIONS
The weight to be attached to particular requirementsis indicated
by the following usages:
i Should — implies a recommendationbased upon the judge-
ment of experienced people but recognises that some
discretion is appropriate.
 ii Shall — implies a strong recommendationbased upon exper-
ience or upon the position adopted by recognised authorities.
iii Must — is a definiterequirement; but is normally limited to
procedures essential to adequate design or sound operation.
The limited degree of discretion expressed in the definitions is
usually permitted in actual technical matters;this is to cater for
abnormal circumstances.

3 HAZARDS
3.1 Properties
3.1.1 Acrylonitrileis a colourless,mobile liquid with a characteristic
odour. The specific gravity of the liquid is 0.81 but it boils at
77°C to form a vapour which is nearly twice as dense as air. It is
soluble in water (7.35%wt) and will dissolve 2.95%wt of water.
Acrylonitrile is flammable and has a low flash-point (-1°C); the
vapoursform explosivemixtures with air over a wide range of con-
centrations (3-17% by volume in air). It can be polymerised
explosively by strong alkalis and peroxides.
Detailed physical propertiesare listed in Appendix I, and
Appendix II gives the vapour pressure/temperature relationship.
3.1.2 The 1976 Threshold Limit Value (TLV) for acrylonitrile is 20 ppm
by volume in air (45 mg acrylonitrileper m3) and the ShortTerm
Exposure Limit (15 mm) is 30 ppm (68 mg acrylonitrileper m3)
TLV is the time-weighted average concentration for an 8-hour
work day and 40-hour work week, to which nearly all workers
may be repeatedlyexposed, day after day, without adverse effect,
the prime objective in the control of vapour should be to reduce
it to the lowest practicable level; in all cases the TWA of acrylo-
nitrile in the atmospheremust be maintainedbelow the TLV*.
In plant operation, detectableamounts of acrylonitrileof the
order of 10 ppm in the atmosphereindicate an abnormality and
breathingapparatus should be worn until the hazard is assessed.
Acrylonitrilecannot be reliably detected by odour at TLV concen-
tration and in any case a tolerance rapidly develops. The usual
method of checking atmosphericconditions is by gas chromato-
graphy. Chemical analysis and infra-red absorption techniquesare
also available.
3.1.3 Acrylonitrile is toxicby ingestion,by inhalation of the vapour or
by absorption of the liquid through the skin. Symptoms of acrylo-
nitrile poisoning by whatever route of entry, are, in order of onset:—
irritation of eyes and nose, limb weakness, laboured breathing,
dizziness and impaired judgement, cyanosis and nausea, collapse,
irregular breathing,convulsions.The pulsebecomes rapid whilstthe
* Particular attentionmust be given to nilnimising atmospheric contamination in viewof
2 3.1.4. Recommendedanalytical methods for atmospheric control are available from the
CIA Publications Department.
 eyes and throat may becomesuffused. When the symptoms include
collapse, irregular breathing, or convulsions,cardiac arrest may
occur without warning. Some patients may display hysteria or
even violence. Liquid on exposed skin can be readily absorbed
and will cause irritation and blistering unless washed off at once.
The vapour affects the eyes mildly, but the liquid in the eye will
result in severe irritation and permanenteye damage may result.
3.1.4 Recentanimal studies have raised the suspicion of carcinognic
activity by acrylonitrile. Epidemiologicalstudies are being carried
out and more detailed advice will be published separatelyas it
becomes available.
Meanwhile every precaution should be taken to minimise exposure.
3.2. Personal Decontamination

3.2.1 Safety showers with freeze protection should be provided at appro-

priate locations. Any affected areas of skin mustbe washed immed-
iately, eyes flushed with water and medical attentionobtained.
(See Section 9)
Contaminated clothing and footwear must be removed immediately.
3.2.2 Contaminated clothing must be exposed to air and laundered
before re-use. Footwear and other leather articles mustbe des-
troyed,since acrylonitrileis easily absorbed by leather.
3.2.3 Any protective clothing that is worn must be washed immediately
after exposure.
3.2.4 In all cases of severe exposure or when this is suspected, medical
attention must be obtained immediately.
3.2.5 First aid and medical treatment should be in accordance with
Section9 and Label 22 for the Guidanceof Medical Officers, issued
by the Chemical IndustriesAssociation Ltd. (See Appendix Ill).

4 DESIGN
4.1 BasicPremise
4.1.1 The plant should be designed for complete containment of liquid
acrylonitrile.
4.1.2 A double safeguard philosophy should be adopted wherever possi-
ble to minimise the escape of acrylonitrilein the event of equip-
ment failure and/or human failure, which may occur in inspection,
maintenanceor in normal operation. (See also 7.2.)
4.1.3 The Area Classificationof a plant shall be determined by the identi-
fication of all sources of hazard and by assessing each hazard. (See
also 4.9.)

3
4.1.4 Potential sources of ignition shall be identifiedand an assessment
made of the risk of exposureto acrylonitrile leaks.
Where the risk is unacceptableconsiderationshall be given to:—

i Eliminating the source of ignition.

ii Protecting the source of ignition from the leak.

4.1.5 Each item or integral section of equipment containing acrylonitrile

shall be provided with means of isolation from the rest of the
systemand with suitable connectionsfor venting, purging, and
washing after the contents have been removed.

4.1.6 Enclosed plant areas where release of acrylonitrilecould result in

the build-up of vapour concentration, should either be regularly
monitored by patrols or be provided with automatic monitoring
devices, placed at appropriate points and connectedto an alarm
system. (See 10.1.1)

4.2 Sitiig and Layout

The potential hazard of acrylonitrilecan be minimised by the care-
ful choice of plantsite, by proper routingof associated pipelines
and by arrangementof the major items on the chosen site.
The factors to be consideredare:
I The distance between potential sources of serious escape and
publi'c places, taking account of the effect of prevailing winds
- and tocal topography.
ii How many peopleare likely to be aboutand how readily they
can get away. The peoplewho may be affected include not
only the general public, but also work peopleon adjoining
sites.
iii What factors could lead to damage and howthe risk of this
may be reducede.g. the relationship with other plants or
equipment on which fire, explosion, or other incidents lead-
ing to damage could possibly occur and with external factors
e.g. roads, railways, and flight paths.
iv Access, both routine and emergency.
v Sources of ignition.
The foregoingguidelinesalso apply to installation of additional
plant or equipment, and to modifications of any such plant. No
work should commenceuntil the appropriate management has
approved the proposals. The Local Planning Authorities, appro-
priate Government Departmentsand the Company's Insurers must
be consulted about major extensions.
4
4.3 Materials of Construction
The importantprocess factors of temperature, pressure and other
chemicals present affect primarily the choice of materials of con-
struction, which have to meet the requirementsfor both mechanical
properties and resistance to corrosion. The most usual material for
acrylonitrileinstallations is carbon steel and for polymerisation
plants, stainless steel. Copper and copper-bearingalloys shall not
be used on plant or auxiliaryequipment, since these can cause con-
tamination which inhibits subsequent polymerisation processes.

4.4 Pipelines
These should be installed:
I Away from high fire riskareas.
ii To be safefrom impact from vehicular traffic.
iii To be accessible for maintenanceand inspection.
iv With due regard to otherequipment in the vicinity, particu-
larly thatcontaining corrosive or flammable materials.
v With means for venting (at highest point) and flushing with
water and draining (at lowest point).
vi With the minimum number of flanges. Screwed fittings should
be avoided.
vii With provision for hydraulic relief. (See 4.7.3)

4.5 Pumps
Operative parts of piston or diaphragm pumps should be of austeni-
tic stainless steel, and a recommended gland packings asbestos
and PTFE composite.
For centrifugal pumps, the following materialsof construction are
satisfactory for acrylonitrileor acrylonitrile/waterstreams:

Casing: Cast Steel

Internals: Cast Iron
Shaft: Chrome molybdenum steel.

Type ofSeal: Where pumps are in open air (particularlyif standby

pumpsare installed) single mechanical sealing is usually adequate.
However, inside buildings or other confined locations, consider-
ation should be given to the use of double mechanical sealing.
Control arrangements should be such, if possible, as to avoid con-
ditionswhich could have adverse effects on centrifugal pumps
(e.g. restricted discharge leading to overheating).Consideration
shall be given to high temperature or low flow cut-off.

5
 4.6 Valves
Carbon steel solid wedge gate valves or ball valves are preferred.
When acrylonitrilecould be released to atmospherethe double
safeguard principle shall be used, e.g. drain valves with cap or
blank.

4.7 Relief System

4.7.1 Any relief systemis a safeguard of the last resort and shall not be
regarded as an alternativeto providing protective systems and
operating instructions which are intended to prevent process con-
ditionsfrom leading to reliefsituations, unless there is an equip-
ment or human failure.
4.7.2 Relief systems must be provided on all closed process vessels unless
their design pressure is higher than any pressure which can conceiv-
ably be generated. (See also 4.7.6 below)
4.7.3 Relief for liquid thermal expansion shall be provided where neces-
sary. The acrylonitrileso relieved shall either be returned to the
systemor be vented to a safe place.
4.7.4 Any relief device shall not be isolated until alternative arrangements
to protectthe vessel have been made.
4.7.5 The sizing and venting of relief systems shall be in accordance with
recognised engineering codes and standards.
4.7.6 Vapour relief devices should relieveto another point in the process
where there is always adequate capacity, or to an expansionvessel,
or to a plant flare or to atmospherein a safearea.
4.7.7 Condensationin the relief line must be consideredwith means for
its disposal.

4.8 Drainage
4.8.1 For drainings of acrylonitrile,and first washings, a closed drain
system is preferred,with the material thus collected being repro-
cessed. It is recommendedthat all vessels,system low points, and
equipment liable to require isolation for maintenancefrom a run-
ning plant, e.g, pumps, level controllerfloat chambers, gauge glasses
etc, should be permanently connectedto a closed drain, with pro-
vision for further flushings to be diverted to a surface drain system.
There must be no possibility of strong alkali or peroxide entering
the closed drain system.
4.8.2 Considerationmust also be given to surface drainage so that it
presents no hazard within the works, and does not exceed the per-
mitted level of chemicals in the Works effluent.
.6
4.9 Electrical
4.9.1 Electrical equipment that is installed in a plantarea shall be entirely
suitable for the classifiedarea concerned. For use in other than
safe areas it should be certifiedor approved by the appropriate
statutoryor test authority for use under the particular conditions.
Sparks from electrical equipment can be sources of ignition and
consideration shall be given to locating the electrical equipment
associated with the plantoutside the plantarea. This will not be
possible with items of equipment such as motors or instruments
and it may be necessary to protect the source of ignition from an
acryldnitrileleak by using equipment constructed in accordance
with suitable design concepts;additional requirementsare neces-
sary for the installation, earthing and maintenanceof such
equipment.

4.9.2 Althoughat normal pumping rates of 3m/sec acrylonitrileshould

not generate electrostatic charges in pipelines,all items of plant
handling acrylonitrileshall be earthed in an approved manner
againststaticdischarges. Structural steelwork shall be effectively
earthed and plantequipment bondedto the structural steelwork.

5 LIQUID ACRYLONITRILESTORAGE
5.1 General
Due to its flammabilityacrylonitrileshould not be stored close to
other materialsthat presenta fire or explosion hazard.
Due to its ability to polymerise rapidly under certain conditions
the followingpoints should be observed:
i Acrylonitrile held in bulk storageshould be stabilised for
example:
a by the methyl ether of hydroquinone (MEHQ) (Para
methoxyphenol) (ca. 40 ppm) when the acrylonitrile
contains dissolved oxygen.
b by ammonia (ca 100 ppm). As ammonia combineswith
acrylonitrileto form stabilising compounds,it will
necessarily decrease in concentration. The best method,
therefore, of determining stabiliser concentration is by
titration value.
c by water, which at 0.2% w/w confers some stabilisation.

ii There must be no possibility of introducing strong alkali or

peroxidesinto a storage vessel or into a bund enclosure.
7
5.2 Tanks
5.2.1 Liquid acrylonitrileshould be stored in above ground carbon steel
fixed roof storage tanks. They should be sufficientlyfar from each
other and from adjoining propertyto minimise the risk of fire
spread and to afford ready access for fire fighting and tank cooling
purposes.
5.2.2 Temperatureindication shafl be provided in each stock tank with
minimum requirement of a local temperature indicator.
5.2.3 Thereshould be provision for the washing out of stock tanks (see
Section 4.8).
5.3 Venting
5.3.1 Venting may be to atmospherethrough a flame arrestor but this
method is dependenton the sitingof the tank becausean explosive
mixture can be presentin the vapour space (5-10% acrylonitrile).
Such vents should be installed at least 3m aboveany working level.
5.3.2 Blanketing with nitrogen is an alternative because it avoids possible
explosivevapour mixtures. To avoid atmosphericpollution,such
nitrogen purges should either be vented to a vent scrubber and the
scrubber liquor returned to process, or be vented back to process
by balance line.

5.4 Bunding
5.4.1 All above-ground stock tanks must be surroundedby a bund. Where
tanks can be bunded individually, the bund should have sufficient
capacity to contain the tank contents above the bund wall level,
plus 10%.
5.4.2 Where more than one tank is surrounded by a single bund the net
capacity of the bund, after making allowances for the volume
occupied by the other tanks, should be sufficientto contain the
contents above bund level of the largest tank, plus 10%.
5.4.3 The ground within the bund should be imperviousto acrylonitrile
and so slopethat minorspillages will not remain beneath or around
vessels. It is recommended that bund walls should be no higher
than 1.5m.
5.4.4 Facilities for emptying the bund must be available.
5.4.5 If a self-drainingbund is used the drain valveshould be closed
except when draining is in progress. (See Section 4.8)
5.5 Alarms
5.5.1 A high level alarm shall be provided in addition to the normal level
indicator, to avoid inadvertent overfilling. Considerationshould be
8
 given to installing a high level cut-outon the charge pump. Tank
filling lines should be bottomentry, but, if top entry, they should
extend to within 75 mm of the base of the tank and be drilled
nearthe tank top to preventsyphoning.

5.6 Drumstorage
5.6.1 For drum storage, a designated area should be provided in the open
air and in a safe location. Drums should be stored with aisles no
less than 3m wide for ease of leak detection and fire fighting.
Considerationshould be given to the provision of a sill to retain
spillages or leaks from the drum storage. (See also Section 6.3)

6 HANDLING
6.1 General
6.1.1 Precautions must be taken to guard againsthealth and fire hazards
wheneveracrylonitrileis handled. If leaks or spillage occuronly
correctly protected personnelshould remain in the area.
6.1.2 Protectiveequipment consistingof neoprene or PVC gloves, boots
and suit, together with compressed air breathingapparatuswith
full face mask must be worn when connecting or disconnecting
pipelines which have contained acrylonitrilebut have not been gas
freed.

6.1.3 Asafety shower should be in the near vicinity of any loading or

unloading area.
6.1.4 Loading and unloadingoperations shall not be undertaken by an
operator on his own.
6.1.5 Adequate washing-down facilities should be provided throughout
the area.
6.1.6 The appropriate hazard identificationlabels should be used.

6.2 Road/Rail Tankers

6.2.1 The transfer point should be in a rail siding capable of being isolated
or in a lay-by to enable a road tanker to draw clear of the roadway.
It is recommended that the ground should be imperviousto acryl-
onitrile and containment be provided for possible spillages.
6.2.2 The engines of any othervehiclesshould be stopped if within 15 m
of transfer operations.
6.2.3 The transfer point shall be level and should include a gantry and
platform to extend over the tanker.
9
6.2.4 If the tanker is not fitted with a dip filling tube a loading arm
extension must be used which extends to the bottom of the tank
to avoid excessivefall and to minimise the generation of static
electricity.
6.2.5 Before any connectionsare made for transfer, adequate precau-
tions shall be taken to preventinadvertent movement of the
tanker.
6.2.6 Earthing connectionsshall be provided for tankers which must be
earthedbefore connectionsare made to the transfer line.
6.2.7 Tanker unloadingshould preferably be by a land pump. If pres-
surisingis used, even for pump priming, an inert gas must be used
(preferably nitrogen).
6.2.8 Means shall be provided to prevent overfilling of the tanker.
6.2.9 Considerationshould be given to venting the tanker back to storage
when loading and unloading.

6.3 Drums

6.3.1 Adequate ventilation must be provided where there is transfer into

or from drums.
6.3.2 Drum filling machines should be provided with an automatic cut-
off allowing ullage for thermal expansion.
6.3.3 When a load of drums is received in an enclosed truck thorough
ventilation should take place before it is entered. Each consign-
ment should be inspected for leaking drums.
6.3.4 Drums must not be emptied by means of air pressure.
6.3.5 Drums must be earth-bondedbefore transfer of liquid.
6.3.6 To remove residual acrylonitrileafter discharging, drums must be
thoroughly steamed or washed out by filling them with water at
leasttwice and completely draining them each time. As an alter-
native, decontaminationby chemical cleaningmay be used, e.g. by
hypochiorite or ammoniasolution. There is a need for control,
possibly by exhaust ventilation to an appropriate place, of the toxic
inhalation risk which might arise from displaced vapour and steam.

7 PLANTOPERATION
7.1 Personnel
No person shall be employed on plant handling acrylonitrileunless
he has received specific training and has been provided with detailed
operating instructions.
10
7.2 Safeguards
A double safeguard philosophy should be adopted whereverpossi-
ble to reduce accidentsdue to human error. Failure of one safe-
guard does not then result in accidentsand the possibility of two
safeguards failing simultaneouslyis remote if properly selected.
Over a complete operation several safeguards may apply but each
operator should ensure that he personally is employing at least two
safeguards during his part of the operation. (See also 4.1.2)

7.3 Procedures
Procedures must be laid down as part of the failsafe philosophy
and to ensure that any failure is promptly identified and rectified.
This calls for:
i Identificationof those items, the correct functioning of which
is critical in emergency (e.g. valves, control systems and relief
systems).
ii Identificationof potential errors with particularly seriouscon-
sequences and the adoption of special precautionsagainst
these particular errors.
iii An administrativesystemto control the regularservicing main-
tenance,inspection and testing of these items as appropriate,
so that a defined reliability is maintained. Adequate super-
vision and checks should be included to ensure that the
intended result is achieved; this can be usefully supplemented
by appropriate permit-to-work arrangements.
iv An administrative systemto control the inspection of vessels
and their protective devices. The maximum intervals between
inspection shall be decided and laid down for a new plant at
the design stage and may be changed in the light of experience
only if specifically authorised by an inspection serviceinde-
pendent of plant management.
v Ignition sources such as the use of spark producing tools,
motor vehicles;torches and communication equipment shall
be identifiedand the necessary procedureto control their use
shall be set up.

7.4 Protective Clothing

When entering a plantarea for normal operations no special pro-
tectiveclothing is required otherthan wearing neopreneor PVC
gloves and boots. Eye protection is desirable.

7.5 Maintenance
For operations and maintenance purposes which require the break-
ing of containment of equipment which has held acrylonitrile,
11
 neopreneor PVC gloves,boots and suittogether with compressed
air breathing apparatus shall be worn by operatorsand craftsmen.

7.6 AttendantPersonnel
Considerationshould be given to the use of a systemwhich requires
that for any operation involving a serious risk of exposureto acryl-
onitrile,e.g. drum sampling,a second fully trained operator,
properly clad, is in attendance.
For maintenancework an operator should see the job started by a
craftsman and be presentwhen containment is broken. He should
remain until the area is proved safeand thereafter visit occasionally.

7.7 Isolation
Isolation prior to maintenancemust involve the removalof acryl-
onitrile, flushing to reprocess tank, washing until the vapour above
the drainings is acrylonitrilefree, followed by complete isolation by
blanking or by physical disconnectionand blanking. Steam or nitro-
gen purging may be used as an alternativeto flushing with water;
the purging must be ventedsafely to an appropriate place.

7.8 Safe System of Work

Due precautions,as part of a safe system of work (H & S Act, S.2)
shall be taken in respect of entry to vessels,whether or not the
circumstances are coveredby Section 30 of the FactoriesAct 1961
(which usefully details specific practical requirements).(See also
Section 7.3 iii above). In particular, before anyone enters a vessel,
duplicate samples of the atmosphereshall be tested for acrylonitrile
and oxygen.

8 TRAINING
8.1 Personnel
Persons handling or working on plant involving acrylonitrileshall
have such training that they can be expected to carry out their job
effectively and knowledgeably.

8.2 Instruction
This training should be supplemented by detailed instructions
covering all scheduled operations in thecommissioning,running,
shutdown and maintenanceof the whole installation. These in-
structions should preserve the design intent and should include
action in the event of possible malfunctions which may occur.
12
8.3 Emergency Situations
In addition adequate instructions shall be given for the handling of
emergency situations. These include:
i Detailed procedures for tackling foreseeable abnormalities.
ii Aide-memo/re of key points, backed by general training which
will provide guidance for the corrective action in emergency
or potential emergency situations which have not been dealt
with as specific cases.

8.4 Modifications
As training should be given from the operating manual the opera-
ting instructions and drawings must be kept up to date to include
modifications to plant or procedure.

8.5 RefresherCourses
Refresher training must be given, particularly when modifications
to the plant have taken place, to ensure that all remain aware of
their own and other people's responsibilitiesand of the actions to
be taken in both normal and emergency situations.

9 TREATMENT FOR EXPOSURE

9.1 Introduction
9.1.1 In viewof the toxic nature of acrylonitrile(Section 3) it is essential
thattreatment should be given as soon as possible.
9.1.2 Equally, it is importantfor the safety of rescuers that they wear
appropriate respiratorswhile giving aid and continue to wear them
until there is no longer any risk of inhalation of vapour, notably
from the patient's clothing.
9.1.3 A doctor must be notified at once and all but the most minor cases
should be referred to hospital, accompaniedby a CIA Label 22,
for the guidance of MedicalOfficers (Appendix Ill).
9.1.4 Employees who are affected by acrylonitrileshould be removed
from the placeof exposure, be kept lying down and warm. In
cases of severe exposure no food or drink must be allowed until
treatment is complete.
9.2 First Aid
9.2.1 Patientsshould be kept at rest and after first aid treatment be seen
by a doctor as quickly as possible on site or transported to hospital.
The necessary equipment and antidotes (see under MedicalTreat-
ment) should be obtained and kept to hand and accompanythe
patient if sent to hospital.
13
 Eye Contact — In case of a splash of acrylonitrileinto an eye, the
eye should be irrigated with water for at least 1 5 minutes. Obtain
medical assistance immediately.

Skin Contact — Clothing that has been contaminated must be

removed immediately and the underlying skin flushed with plenty
of luke-warm, NOT hot water. If soap is available,it should be
used. Contaminatedleather articles must be destroyed since decon-
tamination is uncertain and difficult.

Inhalation — If breathing is weak or has stopped, artificial respir-

ation should be started at the earliest possible moment.
N.B. THE MOUTH-TO-MOUTH METHODIS NOT ADVISED.

9.2.2 The patient may be allowed while recumbent,to inhale pentyl-

nitrite (amyl nitrite). A capsuleshould be broken in a handker-
chief or gauze pad and held about a inch from the patients nose
for 15 to 30 seconds. This should be repeated every 2 to 3 minutes
until the capsule is exhausted. A second capsule may be used;the
number of capsules used should be noted.
9.2.3 NOTE: i Oxygen and amyl nitrite can form an explosive
mixture;naked lights must be avoided.
ii Persons administeringamyl nitrite should avoid
breathing its vapoursas far as possible as it causes
dizziness. Oxygen may be administeredthrough a
face mask.

9.3 Medical Treatment

9.3.1 This must be carried out only by a Medical Officer.
9.3.2 General supportivetherapy is more importantthan the adminis-
tration of specificantidotes.
9.3.3 More severe cases of poisoning by acrylonitrile should be treated as
for hydrogen cyanide and appropriateadvice is given in HSE Cau-
tionary Placard. (SHW 385)
9.3.4 Since some of the toxic effects may be caused by cyanide, the
intravenousadministration of Cobalt EDTA (Kelocyanor)*,
150 mg in lOmI, may prove beneficial in cases of severe poisoning
although this is not normally necessary in the conscious patient.
This dose may be repeated after 10 minutes.

*CobaIt EDTA (K&ocyanor)is obtainable from Boots Pure Drug Co. Limited
and from Rona Laboratories Ltd.

14
9.3.5 Feelings of nausea and dizziness associated with less severe cases
may be treated symptomatically — Prochiorperazine(Stemetil)
25 mg may be effective.

10 LEAKSANDSPILLAGES
10.1 Treatment
10.1.1 All leaks and spillages must be treated with extreme caution,
especially insidea building, since the material is volatile, heavier
than air, highlyflammable and toxic.
10.1.2 The sourceof all leaks should be shut off if this can be done with-
out risk. Any potential sources of ignition in the vicinity should
be removed or switched off, particularly if they are down-wind of
spillage.
10.1.3 The spillageshould be approached from up-wind, wearing self-
contained compressed air breathing apparatus and protective
clothing.(See6.1.2)
10.1.4 The spillage should be contained with sand or earth and covered
with a 1 50 mm layer of mechanicalfoam and an emulsifying agent
or absorbent material supplied prior to disposal.
10.1.5 Water solutions of acrylonitrilemay be treated with calcium or
sodium hypochlorite in the proportions of 5 mols of available
chlorineper mol of acrylonitrile.
10.1.6 Where the abovetreatments are not readily available,surfacespil-
lage and drips from glands and seals may be diluted with copious
quantities of water.

10.2 Disposal
10.2.1 Untreated acrylonitrilemust not be allowed to enter open drains or
sewers. Should this occur inadvertently, flush with copious quanti-
ties of water, check for flammabilityand toxicitydownstream,and
inform the appropriate authority.
10.2.2 Contaminatedearth, sand or absorbent materialsshall be collected
and should be chemically treated over a period until they are safe
for disposal. Alternatively the contaminated materialsmay be
incinerated.
10.2.3 Leaking containersshould be transferred to open ground and the
contents transferred to other containers.Alternatively the contents
may be disposed of via the closed drain system. (See also Sections
6.3.6 and 4.8.1)
15
11 FIRES
11.1 Burning Acrylonitrite
Burning acrylonitrilewill releasecyanide gases, particularly where
the air supply is limited. It burns with a dense black smoke. Fires
should be fought from the up-wind direction if possible and areas
down-wind should be monitored. Fire fighters must be equipped
with self-containedbreathing apparatus and correct protective
clothing. (See 12.6)
11.2 Mechanical Foam
Mechanical foam is an effective extinguishing media used via fixed
installations or hand-held monitoring equipment. (Alkaline type
it
foam must not be used because could initiatepolymerisation).
Small fires can be extinguishedusing dry chemical powder, carbon
dioxide or BCF. Water is usually ineffective in extinguishing an
acrylonitrile fire.
11.3 Water Cooling
Water cooling facilities should be available to protectadjacent
plantand equipment from the effects of a fire.
11.4 Personnel
Personnel responsible for fire-fighting should regularly undergo
specifictrainingto ensure thatthey are aware of the hazards and
can deal with them effectively.

11.5 Liaison
Close liaison with local fire brigades should be maintainedso that
the professional fire-fighters are conversantwith the plant lay-out
and the hazards involved.

12 EMERGENCYPROCEDURES
12.1 Objective
The Code for the design and operation of acrylonitrileplants is
intended to make a major release of acrylonitrileimprobable.
Nevertheless, it cannot be assumed that an incident will not occur
which involvespeople both within and outside the works.

12.2 Local Emergency Services

The local emergency services (Fire Brigade, Ambulance Service,
Hospitals, and Police) should be informed in advance of the poten-
tial hazards of acrylonitrileand be given all information necessary
so that they can deal with any situation that may arise.
16
12.3 EmergencyProcedures
"Emergency Procedures" should be drawn up to define the neces-
sary action should a major incident occur. The procedures should
be agreed with the local emergency servides and periodic practice
drills arranged with them to test the effectiveness of contingency
plans. The type of organisationrequired is dealt with in the book-
let entitled"Recommended Procedures for Handling Major
Emergencies" which is issued by the Chemical Industry Safety and
Health Council of the Chemical IndustriesAssociation Limited.

12.4 Responsibility
It would be the responsibility of the local emergency services to
warn the local population if an incident was one which made this
course of action necessary.

12.5 Provisions

Emergencyprocedures should provide for:

i Prompt recognition of incidents presentingrisk to plant,
personnel and/or the public at large.
ii Immediate alert of the appropriate works emergency service
and those serving the local area.
iii Monitoring down-wind of any large escape.
iv Action to control the incident and mitigate the effects.
v Protect personnel within and outside the Works.
vi Make safe other plants in the affected area.
vii Local availability of additional emergency equipment.

12.6 Emergency Equipment

Appropriate emergency equipment should be provided and readily
available to enable incidents to be dealt with promptly. The actual
equipment should be suited to the local conditions, but typical
items are:
i Self contained breathing apparatus, with full face mask
ii Protective clothing — Neopreneor PVC suits, gloves and boots
iii Resuscitationequipment
iv First aid kit and stretcher
v Emergency tool kit — Non-sparktorches
Valve Key
Portable notices for area/road closed

17
 Spark proof spanners and wrenches
Spark proof shovels
Heavy duty tow rope
Stock of sand and filled sandbags
Stock of vermiculite granules.
vi Fire fightingequipment.—
Dry chemical powder extinguishers,
Foam extinguishers,foam guns,
monitors, hoses, keys etc. Foam con-
centrate, Emulsifying agnt and
applicators.
vii Portablegas monitoring equipment.
It is necessaryto ensure that:
a adequate training is given in the use of emergency equipment,
particularly self-containedbreathing apparatus, and resuscita-
tion equipment;
b there is adequate shift coverage by trained personnel.

18
 APPENDIX I

PROPERTIES OF ACRYLONITRILE

Boiling point at 760 mm Hg 77.3°C

Vapour pressure at 20°C 11.5 kN/m2

(0.115 bar absolute; 1.67 psi a)

Latent heat of vapourisation at

boilingpoint 617 kJ/kg

Heat of polymerisation 1370 kJ/kg

Gas density relative to air 1.83

Liquid density relative to water at 20°C 0.81

Volume expansioncoefficientat 20°C 0.00131

Solubility in waterat 20°C 7.35% by wt

Solubility of water in acrylonitrile 2.95% by wt

Flash point (closed cup) — 1°C

Auto-ignition temperature 480°C

Lower explosivelimit in air 3% by volume

at 25°C
Upper explosive limit in air 17% by volume

Threshold limit value (skin) 20 ppm

Short term exposurelimit 30 ppm

Freezing point — 83.5°C

Viscosity at 20°C 0.34 Cp

Electrical conductivity
MEHQ Stabilised 0.39 mho/cm
Ammonia stabilised 2.7 jimho/cm

Appearance Colourless when pure. The

technical product may have a
slight yellowtinge.
Mild sweet characteristicodour.
19
 APPENDIX II

Vapourpressure/temperaturerelationship

C
U)

I-

0)
I-
6,
U)
.2 0
1

C
U)

0)
U)
U,
0)
0I-

0 20 40 60 80 100 120 140 160

Temperature °C
21
APPENDJX III

Label 22 — For the Guidance of Medical Officer

(Revised August 1977)

Dear Dr

Re: Mr/Mrs/Miss Age

Home Address

Employed by

This patientwasexposed to Acrylonitrile

at am/pm On 19

Degree of exposure )y/ inappropriatesquare)

Slight
Liii
Thissubstance ishighly dangerous and may cause:
a) Faralltis ofthe respiratorycentre
b) Rapidtissueasphyxiaby interference with the normalabsorptionof oxygenfromthe blood.

Theearlywarningsymptoms are:
1 General weakness andheavinessof the arms and legs

2 Increased difficulty in breathing

3 Headache,dizziness, nausea and vomiting

Thesigns of severepoisoning are:

1 Pallor

2 Unconsciousness

3 Cessation of breathing

Poisoning may resultfrominhalationofthegas produced byevaporation ofthe liquid orbyabsorptionthroughtheskin.

A First Aid
It is important for the safety of rescuers that they continue to wearipproptlate respirators while carryingout the
following instructions, until there is no longer any risk of inhalationof vapourfrom the patient'sclothing.Speed Is
essential, A doctor muat be notified at once. See introduction.

)/ indicates action already taken)

1 Remove From exposure

2 Remove all clothing.Leave clothinginopenair, Do not store inclosedcontainer

3 Wash thoroughly )if necessaryunderashower) anyareas ofskin contaminated with liquid

22
4 Applyartificial respirationimmediatelyif breathing has stopped, orshows signs of failing (themouthto-
mouth methodis notadvised)

5 Allowthe patientat the same time, while recumbent, to inhale pentyl nitrite (amyl nitrite). A capsule
should be brokenin a handkerchief orgauze pad and held aboutan inchfrom the patient's nose for 15
to 30 seconds. Repeat every2to 3minutesuntilcapsule exhausted. Asecondcapsule may be used (Note
numberof capsules used)

6 Administeroxygenthrough afacemask

7 Givenothingby mouth 11111

8 Keep at rest and arrange for patientto be seen by adoctor asquickly aspossible onsiteortransportto
hospital.The necessary equipmentand antidotes (see underMedical treatment)should be obtainedand
if
kept to handand accompany the patient sentto hospital
9 FIRSTAIDER MUSTREMAINWITHTHE PATIENTUNTIL MEDICALAID ARRIVES

B MedicalTreatment (To be carriedoutby a Medical Officeronly)

of
General supportivetherapyis moreimportantthan the administration specificantidotes

of
Since some of the toxic effects may be caused by cyanide,the intravenous administration CobaltEOTA (Kelo-
of
cyanor(, 150mg in lOmI, may prove beneficial in cases severe poisoning althoughthis is not normallynecessary in
the conscious patient.Thisdose may be repeated after 10 minutes

Feelings of nausea and dizziness associated with less severe cases may be treated symptomatically— Prochlorperazine
(Stemetill25mg may be effective
CobaltEDTA (Kelocyanorlisobtainablefrom BootsPure Drug Co. Limited and from Rona Laboratories Ltd.
Notes

Signature Doctor/Nurse/FirstAider

Dateand Time am/pm

This information is sentas a matterof routine and is bated on information

compiled by a medical panel of the Chemical Industries Association

23
Some Other Publicationsin this Series
Major Hazards — Memorandum of Guidance on Extensions to Existing
Chemical Plant introducing a Major Hazard.
Recommended Procedures for Handling Major Emergencies.
Safe and Sound Report of a Working Party on US Safety Practices.
Safety Audits — A Guide for the Chemical Industry.
Road Transportof Hazardous Chemicals: PrincipalSafety Requirements.
Exposure to gases and vapours — labels and notes on treatment.
Safety Training — A Guide for the Chemical Industry.
CEFIC Transport Emergency Cards.
Chemsafe — A Manual of the Chemical Industry Scheme forAssistance
in Freight Emergencies.
Codes of Practice for Chemicals with Major Hazards.
Codes of Practice for the Storage, Handling and Transport of Ammonia.

Prices & copiesavailable from

PUBUCATIONSDEPARTMENT,
CHEMICALINDUSTRIES ASSOCIATION LIMITED,
ALEMBIC HOUSE,
93 ALBERT EMBANKMENT,
LONDON,SE1 7TU Published April 1978
-1&yj 11111