UNIVERSITY OCCUPATIONAL HEALTH AND SAFETY SERVICES
GUIDE TO DSEAR RISK ASSESSMENT
1. Introduction
The Dangerous Substances and Explosive atmospheres Regulations 2002 (DSEAR) are
concerned with the protection of workers and others who may be at risk against risks from
fire, explosion or similar energy releasing events arising from use, handling or storage of
dangerous substances in the workplace. DSEAR sets minimum requirements for the
protection of workers from fire and explosion risks related to dangerous substances and
potentially explosive atmospheres. DSEAR is mainly concerned with dangerous substances
and potentially explosive atmospheres that can create such harmful physical effects as burns
from fires and thermal radiation, blast injuries from explosions or asphyxiation from oxygen
depletion effects. Long term health effects from exposure to such substances or preparations
are not covered under DSEAR, but rather under other more comprehensive health specific
regulations such as those on ionising radiation, asbestos, control of substances hazardous to
health, etc. The key requirements for DSEAR are that the risks, from dangerous substances or
preparations and products thereof, are assessed and eliminated and reduced to as low as is
reasonably practicable.
The DSEAR obliges the employer of a workplace, wherever a dangerous substance is or is
liable to be present, to undertake a suitable and sufficient assessment of the risks which may
arise from use, handling or storage of that substance. This ideally calls for the employer to:
a) carry out a risk assessment of any work activity involving dangerous substances;
b) provide technical and organisational measures to eliminate or reduce risks as far as is
reasonably practicable;
c) provide equipment and procedures to deal with accidents, and emergencies;
d) provide information, instruction and training to employees;
e) classify places where explosive atmospheres may occur into zones and mark the zones
where necessary.
In accordance with the University Health and Safety Policy, ensuring risk assessments are
undertaken for every activity involving dangerous substances in the University’s labs is the
responsibility of the Managers and Principal Investigators. Managers and principal
investigators must ensure that work is not undertaken unless a suitable and sufficient risk
assessment has been carried out and that suitable and adequate measures have been identified
and implemented so as to reduce the risks to the lowest level reasonably practicable. DSEAR
risk assessment must consider normal and abnormal conditions of the work activity and
procedures to deal with accidents and emergencies. All workers including staff and students
must be adequately informed, instructed and trained to enable them to safely carry out the
activities. The manager or principal investigator of the activity is responsible for ensuring the
risks associated with the activity have been adequately assessed and recorded. This guidance
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and the Risk Assessment Form are available and can be downloaded from the University
Safety Office website [http://www.safety.ncl.ac.uk].
In the University, DSEAR risk assessment is considered complementary to that already being
carried out in compliance with the Control of Substances Hazardous to Health Regulations
(COSHH). In this regard there is no need to consider under DSEAR, such issues as, for
example first-aid or personal protective equipment, which are covered under COSHH risk
assessment. It also applies that there is no need to repeat a risk assessment for activities
where dangerous substances are present or used if a DSEAR risk assessment has already been
carried out. The results of both risk assessments under DSEAR and COSHH then form part or
are incorporated into the overall risk assessment required under the MHSW regulations.
This guide is intended to provide a brief practical scope for complying with the requirements
of the Dangerous Substances and Explosive Atmospheres Regulations 2002. It is a snap-shot
and therefore not a comprehensive overview of the law. Detailed guidance for work activities
where dangerous substances and explosive atmospheres may be present is provided by the
HSE Dangerous Substances and Explosive Atmospheres Regulations 2002: Approved Code
of Practice and guidance and a series of other-activity related ACOP and guidance provided
in the following publications:
 Design of plant, equipment and workplaces
 Storage of dangerous substances
 Control and mitigation measures
 Safe maintenance, repair and cleaning procedures
Further information on DSEAR can also be accessed via HSE website: www.hse.gov.uk
which is regularly updated, as well as from other organisational and industry specific
websites such as:
 British Compressed Gases Association (BCGA)
 UKLPG
 Association for Petroleum and Explosives Administration (APEA)
 Fire Protection Association (FPA)
 Petroleum Enforcement Liaison Group (PELG)
Relationship with other health and safety legislation
The requirements of DSEAR apply alongside those under the Health and Safety at Work, etc.
Act 1974 and other regulations made under it, and in particular also legislation on fire
precautions. Key of these legislations and regulations are:
 The Management of Health and Safety at Work Regulations 1999
 The Control of Substances Hazardous to Health Regulations 2002
 The Confined Spaces Regulations 1997
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 The Equipment and Protective Equipment Systems intended for use in Potentially
Explosive Atmospheres Regulations 1996
 The Personal Protective Equipment Regulations 1992
Where does DSEAR apply?
DSEAR applies wherever a dangerous substance is present or could be present, or where an
explosive atmosphere is present or could occur. In our laboratories dangerous substances are
present, as well as explosive atmospheres could occur. DSEAR therefore automatically
applies. In general terms, DSEAR would apply wherever the following activities are
undertaken:
a) storage and use of oxygen
b) storage of liquefied petroleum gas (LPG)
c) handling and storage of flammable waste solvents
d) storage and use of flammable liquid-based paints and inks
e) storage and display of flammable goods, such as paints in shops
f) storage and transport of powders in pharmaceutical and food industries
g) welding or other ‘hot work’ on tanks and drums that have contained flammable
materials
h) deliveries of flammable liquids, gases and bulk powders from road tankers
i) transport of flammable substances in containers around a workplace
j) use of flammable gases, such as acetylene in welding processes
k) chemical manufacturing, processing and warehousing
l) use of flammable solvents in laboratories
Relationship between fires and explosions
In many cases where an explosive atmosphere can occur, any ignition will always cause a fire
other than an explosion. However, both fire and explosion represent a risk to people, plant
and equipment or building. Coincidentally, the precautions required to prevent fires or
explosions are the same. It follows therefore, that when putting in place precautions to
prevent fires or explosions the following considerations taken into account;
a) whether a fire will lead to an explosion;
b) how fast a fire might grow or progress;
c) what other materials might evolve rapidly;
d) any dangers from smoke and toxic emissions;
e) escape routes; and
f) the possible consequences of the fire or explosion.
In summary DSEAR requires the responsible person to carry out and record a suitable and
sufficient fire risk assessment, to implement fire safety precautions and to take special
measures there are dangerous substances present. Fire safety precautions, determined by risk
assessment will include:
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a)
b)
c)
d)
e)
f)
g)
measures to reduce the risk and spread of fire;
provision of means of detection and giving warning in case of fire;
provision of means of escape;
means of fighting the fire;
avoidance of ignition sources;
prevention of leakage of dangerous substances; and
providing information, instruction and training about fire precautions and the
evacuation plan to employees and all others who may be at risk.
2. General definitions
Dangerous substances
While the Dangerous Substances and Explosive Atmospheres Regulations provide a rigorous
definition of a ‘dangerous substance’, it is suffice, in this guidance, to define a dangerous
substance as including any substance, preparation or dust, which because of its properties or
the way it is used could cause harm to people from fires and explosions. Examples of
dangerous substances commonly present or could be present in our laboratories include:
a) Acetone
l) Methyl ethyl ketone
b) Acetonitrile
m) Methyl Propan-1-ol
c) Acrylamide monomer
n) Iso-Butyl alcohol
d) Ammonia gas
o) Liquefied petroleum gas (LPG)
e) Benzoyl peroxide
p) Octan-1-ol
f) Butan-1-ol
q) Oxygen gas
g) Dioxane
r) Toluene
h) Ethanol
s) Stoddards solution
i) Ethanolamine
t) Styrene monomer
j) Hexane
u) Varnishes
k) Methanol
When undertaking a DSEAR risk assessment, the all important thing is to determine if we
have or may have a dangerous substance at work. To determine whether dangerous
substances are present or may be present in the workplace, you need to carry out the
following steps:
Step 1 – check whether the substance or preparation is classified as explosive, oxidising,
extremely flammable, highly flammable or flammable. Any substance or
preparation listed in Part I of the Approved Supply List of substances dangerous for
supply or any substance which is one or more of the categories of danger specified
in Column I of the Chemicals (Hazard Information and Packaging) Regulations
1994 are a dangerous substance. Material Safety Data Sheets (MSDS) provided by
manufacturers or suppliers will also classify substances as explosive, extremely
flammable, highly flammable or flammable, in addition to other relevant
information.
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Step 2 – check whether the work activity has the potential to a fire, explosion or similar
energy releasing event. Usually chemical reaction hazard analysis will provide this
information.
Step 3 – check if the work activity involves the creation or handling of potentially
combustible or explosive dust.
Explosive atmospheres
In the DSEAR an ‘explosive atmosphere’ has been defined as mixture of air and one or
more dangerous substances in the form of gases, vapours, mists or dusts, which under
atmospheric conditions, after ignition has occurred, combustion spreads to the entire
unburned mixture. If there is enough of any of these substances, mixed with air, then all that
is required to cause an explosion is an ignition source.
Hazard
In general terms, a hazard is anything with the potential to cause harm e.g. chemicals,
electricity, working at height on ladders, etc. However, under DSEAR, a hazard is restricted
to a substance or preparation whose physical and chemical properties gives it the potential to
cause a fire or explosion with the potential of causing physical harm to a person at work.
The physical harm to a person considered under DSEAR is only that directly or indirectly
related to fire and explosion such as burns, blast injuries and asphyxiation (oxygen depletion
effect), and not those other injuries such as crushing injuries resulting from storage and
handling containers or cylinders of dangerous substances.
Obviously a hazard is created by the physical and chemical properties of substance or
preparation and the way it is used or present at work. These properties must be taken into
consideration during risk assessment.
a) Relevant physical properties include;
i. boiling point,
ii. flash point,
iii. auto-ignition temperature, and
iv. flammability or explosive limits
b) Relevant chemical properties include;
i. reactivity,
ii. heat reaction and self-acceleration temperature
c) For materials that could give rise to dust explosion, factors to be considered would
include;
i. particle size,
ii. moisture content,
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iii. maximum explosion pressure,
iv. maximum rate of pressure rise.
Most of these properties are provided in material safety data sheets as required under the
CHIP Regulations or from industry specific sources of information.
Risk
Risk is defined under DSEAR as the likelihood of a person’s safety being affected by harmful
physical effects being caused to him from fire, explosion or other events arising from the
hazardous properties of a dangerous substance in connection with work and also the extent of
that harm.
Workplace and work process
DSEAR defines a ‘workplace’ as any premises or part of premises used for or in connection
with work, and includes:
a) any place within the premises to which an employee has access while at work; and
b) any room, lobby, corridor, staircase, road or other place –
i. used as a means of access for or egress from that place of work, or
ii. where facilities are provided for use in connection with that place of work,
other than a public road.
By this definition our laboratories, including outside stores are workplaces under DSEAR.
On the other hand ‘work process’ is defined as including all technical aspects of work
involving dangerous substances, including –
a) appropriate technical means of supervision,
b) connecting devices,
c) protective systems,
d) control and protection systems,
e) engineering controls and solutions,
f) equipment, materials, machinery, plant, and
g) warning and communicating systems.
3. Assessing the risks
Regulation 5 of the Dangerous Substances and Explosive Atmospheres Regulations 2002
requires a suitable and sufficient assessment of risks from fire or explosion that may arise
from the presence of dangerous substances or explosive atmospheres to be carried out before
commencement of any work activity. To ensure a suitable and sufficient assessment of risks,
the following matters need to be taken into consideration:
a) the hazardous properties of the dangerous substances involved;
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b) information on safety provided by the supplier, including information contained in
any relevant safety data sheet;
c) the amount of dangerous substances involved;
d) the work processes, and their interactions, including ignition sources present or which
can be present during any cleaning, repair or maintenance activities being carried out;
e) the containment system and controls provided to prevent liquids, gases, vapours or
dusts escaping into the general atmosphere of the workplace;
f) the arrangements for safe handling, storage and transport of dangerous substances;
g) the temperatures and pressures at which the dangerous substances will be handled;
h) any explosive atmosphere formed within an enclosed plant or storage vessels or any
places which are or can be connected via openings or ducts; and
i) any measures provided to ensure that any explosive atmosphere does not persist for an
extended time, e.g. ventilation.
It important to note that a suitable and sufficient risk assessment is one which assesses the
overall risk presented the dangerous substances together as well as the risk posed a dangerous
substance separately.
Essentials of DSEAR Risk Assessment
DSEAR is concerned with protecting people and buildings from risks associated with
dangerous substances which might cause fire or explosions. Assessing risks arising from the
use, handling or storage of the dangerous substances to protect people and buildings in the
University is the responsibility of managers and principal investigators. Managers and
principal investigators are therefore required to ensure that DSEAR risk assessments are
suitable and sufficient, comprehensive, systematic and appropriate for the level of risk. No
activity should be undertaken without an advance risk assessment and also that they are
undertaken by a person with the necessary competence for the activity (e.g. someone with
sufficient training, knowledge and experience of fire safety in laboratories).
A DSEAR risk assessment is a systematic method of considering risk factors that may lead to
fires or explosions which might occur in the workplace arising from the dangerous substances
or from the work activities and which could cause harm to people (anyone in or in the
immediate vicinity of the premises). The required suitable and sufficient assessment process
may be undertaken in the following five steps:
1) Identification of the fire hazards.
2) Identification of the people who may be at risk (employees, students, visitors,
contractors and members of the public).
3) Evaluation of the risks arising from the hazards in terms of whether or not the existing
precautions are adequate, or whether further action is required to reduce the chance of
fire to an acceptable level.
4) Recording the findings of actions taken as a result of the above and informing
employees of the outcomes.
5) Review of the assessment when the situation changes.
The Management of Health and Safety at Work Regulations categorically require that where
more than five people are employed by an organization then the any risk assessment
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undertaken must be recorded. It is good practice, however, to keep such records in all
circumstances. The assessment will prompt decisions on both the general and process
precautions that will be required or will need to be improved. Arising from the assessment an
action plan should be established for the elimination or further reduction of the fire risks.
Essentially the risk assessment should, among other things;
a) consider the properties of the dangerous substances and the work activity;
b) decide who or what might be harmed and how;
c) decide what control measures are necessary to prevent or adequately control exposure
and minimise the risks;
d) implement the control measures;
e) ensure there are procedures to deal with accidents and emergencies;
f) ensure workers are properly informed, instructed, and trained to enable them to safely
and competently perform the work; and
g) ensure suitable and adequate consultation and communication on risk assessment;
Managers or principal investigators shall ensure the significant findings of the risk
assessment are recorded as soon as is practicable after the assessment is completed. DSEAR
requires risk assessments to be reviewed regularly and the significant findings communicated
to all those who may be at risk or have a duty to implement the measures in place or intended
to put in place in order to eliminate or reduce the identified risks to as low as practicable.
To ensure DSEAR risk assessments in the University are systematic, comprehensive and
appropriate, the University Occupational Health and Safety has developed a standard DSEAR
Risk Assessment Form (Form/Ref) to be used when undertaking DSEAR risk assessments.
The can be downloaded on the link below. The principal investigator or manager may
delegate the preparation of a risk assessment to any competent member of the team but
responsibility for approving the risk assessment remains with the principal investigator or
manager.
Stage 1: Complete a DSEAR Risk Assessment Form
The risk assessment should be completed using a computer. Download the form and then
proceed in the following stages to complete the risk assessment.
 DSEAR Risk Assessment Form
Basic Information
In this section you need to give basic information about the project or work and who is in
responsible for management of the work.
Title of project or activity
You should provide the title of the project or activity in this section. The title should specify
the nature of the work and the hazards.
Principal investigator / Responsible person
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You should provide the name of the principal investigator or the manager who is in charge of
the activity in this section.
School
You should provide the name of your School (e.g. School, Institute or Unit etc).
Date of assessment
You should provide the date on which the assessment was carried out.
Location of work
You should provide the name of the building and room numbers or details of location for
field work.
Section 1 Project or Activity
In this section you need to describe the work that you will be doing.
1.1 Brief description of the project or activity
You should provide a brief but sufficiently detailed description of the work to enable other
people and non-experts to understand the exact nature of the work (e.g. workers, safety
officers or HSE inspectors).
Section 2 Hazards
In this section you need to describe the dangerous substances or preparations or any
potentially explosive atmospheres that may lead to fire, explosion or similar energy releasing
event which could harm people or damage equipment or building(s). Fire or explosion
hazards in laboratories mainly arise from the storage and use of flammable, explosive and
oxidizing substances and fuel gases, and from undertaking experimental activities with these
substances.
It must be taken into consideration that some substances may become a fire or explosion
hazard under certain conditions, for example, flour dust could form an explosive atmosphere
or a high flash point liquid may be raised above their flash point temperature by the work
activity.
When thinking of fire or explosion hazards, you must also consider other substances that
could be given off or arise as a result of maintenance, cleaning or repair works or could be by
products of the work process.
Useful information relating to properties and hazards related to dangerous substances may be
obtained from suppliers in the form of materials safety data sheets or knowledge of the work
processes.
2.1 Dangerous substances or preparations
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You should provide the names of all dangerous substances and preparations which will be
used or could be generated during the activity to which people might be exposed. First you
will have to find out if the substances or preparations to be used or generated have been
classified as explosive, oxidising, extremely flammable, highly flammable or flammable.
Then you will have to enter the name of each substance or preparation together with its
identified chemical property in the relevant box provided (section 2.1.2). If a substance or
preparation has more than one of the five properties, enter all of them in the chemical
property box.
There is a high potential hazard of fire in many laboratories because of the storage and use of
flammable substances, which may be in solid, liquid or gaseous form. The magnitude of
hazard from flammable substances depends both on their physico-chemical properties and the
quantities involved. For a liquid the flashpoint, auto-ignition temperature, explosive limits,
vapour density, and ability to accumulate an electrostatic charge are all important. The
possibility of such hazards being accentuated through oxygen enrichment should also be
considered.
Liquids and solvents in everyday use give off flammable vapour which, when mixed with air,
can ignite and explode. To determine whether an explosive atmosphere may occur, the
following information on properties and classification of flammability must be taken into
consideration.
Flammability
description
Extremely
flammable
Risk
phrase
R12
Highly flammable
R11
flammable
R10
Characteristics
Flash point lower than 0OC,
boiling point lower than or equal
to 35 OC
Liquids with flash point below 21
OC
Liquids with a flash point equal or
greater than 21 OC up to 55 OC
Safety precautionary
specification
Maximum quantity allowed in
workplace 50Lts
Maximum quantity allowed in
workplace 250Lts
Maximum quantity allowed in
workplace 250Lts
Note must be made of the following when evaluate the risks associated with explosive
atmospheres:
a) A risk of fire or explosion is most probable where and when dangerous substances or
processes are present or operate outside the ‘atmospheric conditions’. Atmospheric
conditions refer to conditions within the ambient temperature and pressure range of
between -20 OC to 40 OC, and 0.8 to 1.1 bar respectively.
b) Dangerous substances or mixtures of such substances, that are explosive with an oxidant
other than air, for example pure oxygen or chlorine, are not considered as contributing an
explosive atmosphere under DSEAR.
c) Where a gas or dust is present in the atmosphere in concentration below the lower
flammable or explosive limit, the atmosphere is not considered explosive.
2.2 Explosive atmospheres
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Here you will have to make note if there is a possibility of an explosive atmosphere being
formed during the activity. If the activity may create or release flammable gases or vapours at
ambient temperature and pressure then an explosive atmosphere is likely to be formed.
Fire or explosion can occur when flammable vapours are mixed with oxygen or air in
proportions within critical values known as the Lower and Upper Explosive Limits (LEL and
UEL, respectively). For most solvents the LEL lies within the range 1-5% in air and therefore
good ventilation is essential in order to eliminate the risk of forming a flammable or
explosive atmosphere when such substances are used. However, it is significant that the LEL
is usually considerably greater than the occupational (workplace) exposure limit for the
concentration of vapour in the workroom air.
Vapours from flammable liquids are denser than air and thus tend to sink to ground level
where they can spread over a large area. Care should be taken to minimise the production of
such vapours and the associated risk of ignition by flashback from a remote source.
Flammable, pyrophoric or combustible solids that are often encountered in laboratories
include alkali metals, metallic hydrides, some organometallic compounds, phosphorus and
sulphur.
Section 3 Risks
You need to identify and decide on the level of risk of a fire or explosion arising from use,
handling, storage or disposal of the dangerous substances or explosive atmosphere present or
that may occur. This should be an estimate of the level of risk without the use of controls. In
the controls section you will specify the necessary control measures which are required to
reduce the level of the risk to the lowest level that is reasonably practicable and in any case to
a level which is adequate to protect the people and buildings, equipment or plant.
3.1 The risk of fire, explosion or similar energy releasing event
Here you must consider and detail risks that may arise from the release of dangerous
substances into the working environment during use, handling, storage and disposal. The
risks to be considered must include those that may arise from, broadly;
a) Unavoidable releases, such as from cylinder filling and dispensing;
b) Intentional releases, such as the activity or work processes themselves; and
c) Foreseeable releases, for example, leaks from process equipment or storage containers
or spills during dispensing.
In addition to hazards associated with the handling of these substances it should be
remembered that unstable substances may be formed during chemical operations or
prolonged storage and appropriate measures should be taken to avoid this happening. For
example, certain ethers, alcohols and aldehydes can form peroxides that may detonate during
distillation. For this reason bottles of substances prone to peroxidation should not be kept for
prolonged periods once they have been opened. Some substances are inherently unstable and
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can detonate under certain conditions of pressure and temperature (e.g. acetylene, carbon
disulphide and substances prone to autopolymerisation).
3.2 Ignition sources
Here you are required to identify all possible sources of ignition in the areas where dangerous
substances may be present. You are also expected to assess and identify where ignition
sources have the potential to cause a fire or explosion including chemical decomposition
which adversely affect the safety of those at risk. DSEAR recognises that certain ignition
sources are necessary as they are part the work activity thus the emphasis on the need for
consideration of risks from both intentional and unintentional ignition sources. It must also be
noted that some substances can create a fire or explosion hazard on heating, for example, as a
result of auto-ignition, self decomposition or exothermic reaction, such cases you must also
be considered in the risk assessment. In such cases you must include consideration of
possible effects of heat from sources such as steam pipes, heaters, processing and possible
ignition of combustible materials. In general ignition sources would include;
a) heat energy, from heating installations, open and naked flames, internal combustion
engines, hot surfaces, hot-work, laser or other intense radiation sources;
b) electrical energy e.g. electrical lighting devices such as lamps, electromagnetic
radiation, short circuit, lightening or discharges of static electricity;
c) mechanical energy e.g. overheating as a result of friction, impacts and grinding
processes; or
d) chemical energy e.g. from self-heating, impact and heat sensitive materials such as
pyrophoric substances or runaway exothermic reactions.
3.3 Who might be at risk?
DSEAR is intended to protect not only employees but also other persons whether at work or
not who may be at risk of a fire or explosion. You should provide details of who will be
doing the work and if any other people will be affected by the work. Specify which persons
might be directly at risk of fire or explosion hazards (e.g. staff, students) and who might be
indirectly at risk (e.g. porters, cleaners, maintenance workers or the public).
3.4 Assessment of risk
Where dangerous substances or explosive atmospheres are present or may occur, DSEAR
requires a suitable and sufficient risk assessment to be undertaken before commencing any
activity. The purpose of the risk assessment is to enable you decide on measures to be taken
in order to eliminate or reduce the risks of fire, explosion or similar energy releasing event.
You need to decide on the overall level of risk of fire or explosion arising from the dangerous
substances and explosive atmospheres for any activity. Please note that this is the level of risk
without the use of controls. In the controls section you will specify the necessary control
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measures which are required to reduce the level of exposure to the lowest level that is
reasonably practicable and in any case to a level which is adequate to protect the safety of
employees or any other persons at risk. To help you estimate the level of risk you should use
the information below and the risk estimation matrix. This will give you an estimate of the
potential risks to human health of the work. Select only one of the following terms:
Effectively zero, Low, Medium or High.
The risk of an activity is normally the product of the severity of harm if it were to occur and
the likelihood of that harm occurring, mathematically presented as:
Risk = Severity of harm X likelihood of harm occurring, where
• severity of harm if it were to occur can be denoted as severe, moderate, minor or
negligible; and
• likelihood of harm occurring can be denoted as high, medium, low or negligible.
In practice an estimate of the level of risk is obtained in a number of different ways. In this
case you are encouraged to use the risk estimation matrix provided below.
Risk Estimation Matrix
Severity of harm
Severe
Moderate
Minor
Negligible
Likelihood of harm
High
Medium
High
High
High
Medium
Medium
Low
Low
Effectively zero
Low
Medium
Low
Low
Effectively zero
Negligible
Low
Effectively zero
Effectively zero
Effectively zero
Section 4 Controls to eliminate or reduce risks to as low as possible
DSEAR requires a hierarchical approach for the elimination or reduction of the risks from
dangerous substances. This means you should first consider how to eliminate or reduce the
risk by replacing the dangerous substance with another substance, or using a different work
process.
4.1 Elimination or reduction of risks from dangerous substances
The most effective control to avoid the risk from dangerous substances is to remove them
from the workplace, and DSEAR requires that efforts are made to avoid using dangerous
substances where this is possible. Elimination is the best solution and must be considered
first. This involves replacing a dangerous substance with a substance or process that totally
eliminates the risk. However, the nature of the work may mean that this is simply not possible
- often the properties that make a substance useful or needed in a work activity or process
also make it dangerous.
Substitution
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Where elimination of the risks is not practicable as usually the case is, substitution becomes
the second best option. Substitution entails replacing the dangerous substance with one that is
less dangerous one (e.g. by replacing a low flashpoint solvent with a high flashpoint one) or
to design the process so that it is less dangerous - for example, by reducing quantities of
substances in the process. Care must be taken, however, whilst carrying out these steps so as
to ensure that no other new safety or health risks are created or increased. DSEAR specifies
that the measures taken to achieve the required reduction of the risks may also include:
a) design, construction and maintenance of the workplace (e.g. fire-resistance, explosion
relief);
b) design, assembly, construction, installation, provision, use and maintenance of
suitable work processes, including all relevant plant, equipment, control and
protection systems; and
c) the application of appropriate systems of work including: written instructions, permits
to work and other procedural systems of organising work.
Control measures
Where this is not reasonably practicable, you should consider what control measures to take
to prevent a fire, explosion occurring. DSEAR specifies the following control measures to be
considered, in order of priority:
a) reducing the quantity of dangerous substances to a minimum;
b) avoiding or minimising releases;
c) controlling of releases at source;
d) preventing the formation of an explosive atmosphere;
e) collecting, containing and removing any releases to a safe place (e.g. by ventilation)
f) avoiding ignition sources;
g) avoiding adverse conditions e.g. exceeding the limits of temperature or control
settings, that could lead to danger; and
h) separate storage of incompatible substances apart.
Mitigation measures
Where the implementation of the control measures are still deemed inadequate or reasonably
not practicable, mitigation measures to reduce the detrimental effects of a fire, explosion or
similar incident must be considered. The mitigation measures to be considered should
include:
a) reducing the numbers of employees exposed
b) providing plant which is explosion resistant
c) providing explosion suppression or explosion relief equipment
d) taking measures to control or minimise the spread of fires or explosions
e) providing suitable personal protective equipment (PPE), of course, not as a substitute
for providing appropriate protective measures on the plant, equipment or workplace
itself.
The control and mitigation measures you implement should be consistent with the findings of
the risk assessment and appropriate to the nature of the activity or operation.
4.2 Places where explosive atmospheres may occur
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The correct implementation of control measures aims to prevent the formation of potentially
explosive atmospheres, or limit their extent. However, due to the way dangerous substances
are stored, handled and used, you cannot fully avoid the risk of potentially explosive
atmospheres occurring. The areas where hazardous explosive atmospheres may occur should
be identified and classified into zones, based on their likelihood and persistence. This is
known as Hazardous Area Classification. DSEAR recommends the following measures to be
taken for all areas identified as being potentially hazardous:
a) exclude all potential ignition sources, including sparks, hot surfaces, smoking
materials, naked flames, unsuitable equipment etc are excluded;
b) used and install only equipment and protective systems, including portable equipment
that meets the requirements of the Equipment and Protective Systems Intended for
Use in Potentially Explosive Atmospheres Regulations 1996 (Such equipment will be
CE marked and carry the Ɛx symbol in a hexagon);
c) before bringing them into operation for the first time, as part of the commissioning
procedure, a person competent to do so should verify that the equipment and
protective systems provided are suitable and sufficient to make sure the fire and
explosion risks are properly controlled;
d) people who provide, maintain or verify electrical installations and equipment in, or
associated with, the hazardous areas are competent to undertake the task (e.g.
CompEx trained);
e) where necessary, a warning sign is posted at the entry points of places that have been
classified as hazardous areas to warn those entering those areas that special
precautions are required;
f) employees working in these areas are provided with appropriate clothing that does not
create a risk of an electrostatic discharge capable of igniting the explosive
atmosphere.
4.3 Identification of hazardous content of containers and pipes
DSEAR requires the identification of the contents of pipes and containers in order to alert
employees and others to the presence of dangerous substances. If the contents have already
been identified in order to meet the requirements of other law, this does not need to be done
again under DSEAR. Many will already be marked or lebelled under existing EC legislation.
For those that are not already identified, marking or provision of warning signs will be
required, together with provision of adequate information, instruction and training.
The contents of gas cylinders are easily identifiable from the colour of the cylinder shoulder
and the label on the cylinders shoulder. Common gases have specified colours while others
are coloured according to their hazards (see examples below):
Example of specific gas colour codes
Name of gas
Colour code
Oxygen
White
Acetylene
Maroon
Guide to DSEAR Risk Assessment
Example of colour codes by hazard
Name of gas
Colour code
Toxic and corrosive
Yellow
Flammable
Red
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Nitrogen
Argon
Carbon dioxide
Nitrous oxide
Black
Dark green
Grey
Blue
Oxidising
Inert
Light blue
Bright green
Further details of the colour coding system, can be obtained from the British Standard BS EN
1089-3
4.4 Handling, storage and disposal of dangerous substances
Here you must consider and provide details of measures to reduce risks that may arise from
the release of dangerous substances into the working environment during use, handling,
storage and disposal. It is expected under DSEAR that the measures to be put in place will
consider in broad terms such issues as;
a)
b)
c)
d)
e)
f)
access – both authorised and unauthorised;
ventilation;
extreme temperatures, including weather protection;
drainage and duct openings, including floor conditions;
space, lighting and cleanliness;
emergency actions – fire fighting, evacuation, etc., and emergency equipment.
4.5 Arrangements for dealing with accidents or emergencies
In this section you need to describe the emergency control measures and procedures which
will be used to protect people from fire and explosion risks. You should provide details of the
procedures that will be required to deal with accidents, incidents and emergencies that could
cause any employee or other person to be exposed. DSEAR recommends that measures to be
considered must include:
a) procedures, including the provision of appropriate first-aid facilities and relevant
safety drills (which shall be tested at regular intervals), have been prepared which can
be put into effect when such an event occurs;
b) information on emergency arrangements, including details of relevant work hazards
and hazard identification arrangements, and specific hazards likely to arise at the time
of an accident, incident or emergency, is available;
c) suitable warning and other communication systems are established to enable an
appropriate response, including remedial actions and rescue operations, to be made
immediately when such an event occurs;
d) where necessary, before any explosion conditions are reached, visual, or audible,
warnings are given and employees withdrawn; and
e) where the risk assessment indicates it is necessary, escape facilities are provided and
maintained to ensure that, in the event of danger, employees can leave endangered
places promptly and safely.
f) equipment and personal protective equipment for essential personnel appointed to
deal with emergencies.
While DSEAR is concerned with the protection of employees and all others who may be at
risk, consideration for arrangements to deal with accidents, incidents and emergencies and the
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provision of information, instruction and training is necessarily limited to persons at the
workplace.
4.6 Information, instruction and training
Employers are required to provide and other people at the workplace who might be at risk
with suitable information, instructions and training on precautions actions they need to ensure
their own safety and that of others. DSEAR specifies this duty to include as a minimum the
provision of:
the names of dangerous substances present in the workplace and the risks they present
including access to any relevant safety data sheets and information on any other
legislation that applies to the dangerous substance;
b) the findings of the risk assessment and the control measures put in place as a result
(including their purpose and how to follow and use them); and
c) emergency procedures.
a)
Information, instruction and training need only be provided to other people (non-employees)
where it is required to ensure their safety. It should be in proportion to the level and type of
risk.
Section 5 Emergency Procedures
In this section you need to describe the emergency control measures and procedures which
will be used to protect people in the work in an emergency. You should provide details of the
procedures that will be required to deal with accidents, incidents and emergencies that could
cause any employee or other person to be at risk. The manager, principal investigator and
workers are responsible for ensuring that accidents and emergencies are properly dealt with
since these are the experts in the dangerous substances and the work. You need to assess the
potential for accidental exposure and implementing emergency procedures for your work.
Emergency procedures and plans must be prepared in advance and must include:
a) details of the procedure that will be used to deal with spillage or release. Specify the
contents of any spillage kit. Where there is a risk that an electrical ignition could
cause an explosion then the building should be evacuated without sounding the alarm.
b) details of how you would deal with a fire affecting the dangerous substances in the
work. Specify the best types of fire fighting methods and appropriate personal
protective equipment which can be used to deal with an emergency.
c) details of training programs for emergency procedures.
You should provide the names and contact details of people to contact in case of an accident
or emergency. This must include the name of the principal investigator or manager who is in
charge of and understands the work together with details of other relevant persons including
the workers doing the work and colleagues involved in the work. The information and
contract details of managers, safety officers, security, and emergency services etc are also
provided separately in emergency arrangements posters and websites etc.
Section 6 Approval
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In this section the assessor and principal investigator or manager must sign and date the form
to state that they have assessed the risks and reviewed and approved the risk assessment. The
manager, principal investigator or person in charge of the work is responsible for ensuring the
risks associated with their work are properly assessed and recorded. The principal
investigator or manager may delegate the work of preparing a risk assessment to any
competent member of the team but responsibility for approving the risk assessment remains
with the principal investigator or manager.
6.1: Assessor
The person who carries the risk assessment on behalf of the principal investigator or person
responsible for the work must sign this part of the form. The assessment must be carried out a
competent person to ensure it is a suitable and sufficient for the type of work. Guidance on
risk assessment can be obtained from School Safety Officers.
6.2: Principal investigator / Responsible person
The principal investigator or person responsible for the work (e.g. manager, supervisor or course
leader) must sign this part of the form to confirm that they have reviewed and approved the risk
assessment. You must check that the assessment has been carried out correctly and to a suitable and
sufficient level and that appropriate control measures for the work have been identified. Guidance on
risk assessment can be obtained from School Safety Officers. You should consult with other people
who might be adversely affected by the dangerous substances in your work where necessary (e.g.
colleagues, other groups or workers).
Stage 2: Monitor the Work
The principal investigator or manager must carefully monitor the work. Monitoring is
necessary to meet two main objectives. The first is to ensure compliance in the
implementation of all the control measures identified as necessary through the COSHH risk
assessment. If your risk assessment is suitable and sufficient for the work then each identified
control measure is necessary to prevent or control exposure to risk. Compliance is therefore
both necessary and a legal requirement. The second objective is to ensure that the control
measures and procedures continue to be appropriate. The review process, discussed below,
will provide a point of reference to decide if the risk assessment remains valid, but regular
monitoring can identify problems in the interim period. You should regularly check what
people are doing and the activities to ensure that the work is done safely. The type of
monitoring needed is proportional to the risks, with higher risk work requiring a higher level
of monitoring than lower risk work. Where problems are identified such as with the risk
assessment, controls or the need for additional training or supervision then action must be
taken and the necessary changes or improvements must be to the risk assessment, procedures,
instructions, training or supervision.
Stage 3: Review the DSEAR Risk Assessment
DSEAR requires the risk assessment be regularly reviewed so as to keep it up to date and
particularly if a) there is reason to suspect that the risk assessment is no longer valid; or
b) there has been a significant change in the matters to which the risk assessment relates
including when the workplace, work processes, or organisation of the work undergoes
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significant changes, extensions or conversions; and where, as a result of the review,
changes to the risk assessment are required, those changes shall be made.
The changes in the workplace for which DSEAR has specified as require a risk assessment to
be reviewed include:
a) changes to the substances used;
b) replacement or modification to the plant and/or equipment used;
c) changes in processes or methods of work which could effect the nature of hazards and
risks; and
d) changes in the workforce - such as reductions in numbers or experience of employees
involved in a work activity.
Also DSEAR requires a review of a risk assessment following an accident or dangerous
occurrence.
Stage 4: Record the DSEAR Risk Assessment
It is a requirement under DSEAR that the significant findings of the risk assessment be
recorded as soon as is practicable after that assessment is made. This record is necessary as it
serves to provide information regarding;
a) the measures which are in place or will be taken in order to ensure that risks arising
from dangerous substances or explosive atmosphere that may be present at the work
place have been identified and control measures put in place to eliminate or reduce
them to as low as practicable; and
b) to show that the workplace and work processes are designed, operated and
maintained with due regard for safety and that adequate arrangements have been
made for the safe use of work equipment.
References
Bayliss, D (2009) Compressed & Cryogenic Gas Safety: Laboratory Gas Safety. Seminar
Notes Gas Safety UK
BCGA (2005) Guidance for the Storage of Gas Cylinders in the Workplace. British
Compressed Gases Association (2005) Guidance Note GN2 ISSN 0260 – 4809
Control and mitigation measures. Dangerous Substances and Explosive Atmospheres
Regulations 2002. Approved Code of Practice and guidance, L136 HSE Books ISBN 0
7176 2201 0
FPA (2005) Recommendations for the storage, use and handling of common industrial gas
cylinders including LPG. Fire Protection Association, Loss Prevention Recommendation
RC8, Gloucestershire, UK
RISCAuthority (1992) Risk Control: Fire protection of laboratories. RISCAuthority
Recommendation RC5(version 02) (1992)
Guide to DSEAR Risk Assessment
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Storage of dangerous substances. Dangerous Substances and Explosive Atmospheres
Regulations 2002. Approved Code of Practice and guidance, L135 HSE Books 2003
ISBN 0 7176 2199 5
The Dangerous Substances and Explosive Atmospheres Regulations 2002. SI 2002/2776 The
Stationery Office 2002 ISBN 0 11 042957 5
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Appendices
Recommendations for storage, use and handling gas cylinders including LPG.
Introduction
Gases contained in cylinders are used for many different purposes such as in research work, for
soldering, welding and flame cutting, and for extinguishing fires. They are safe when adequate risk
control is in place but users and others sometimes suffer accidents if careful risk assessment has not
been carried out. The main causes of accidents with gas cylinders are:
a) inadequate training and supervision of users
b) poor installation;
c) poor examination and maintenance;
d) faulty equipment and/or design (e.g. badly fitted valves and regulators);
e) poor handling;
f) poor storage; or
g) inadequately ventilated working conditions.
The following recommendations address the fire and explosion hazards of common industrial gases in
cylinders and of liquefied petroleum gas (LPG) bottles and are applicable to their storage, use and
handling.
General recommendations
Appendix 1: General recommendations for storage, use and handling
 Users should know and understand the properties of the gas they are using and the correct
procedures for the equipment being used with the gas. Safety data and operating instructions
should be obtained from the suppliers of cylinders and equipment. Adequate training, including
actions in the event of an emergency, is essential for all users before equipment is deployed.
 Cylinders should be treated with care. They should be prevented from falling during use, in store
and when being transported. They should never be rolled along the floor or ground.
 Always make sure that cylinder outlet is clean and undamaged and check for dirt or moisture.
Reject the connection if there are any hydrocarbon deposits (oil, grease, etc) in the valve outlet.
 Only cylinders that are properly labelled and colour-coded should be accepted from the supplier.
The label should be checked against requirements. Prior to use the label and the colour code
should again be checked to ensure that the correct cylinder has been selected.
 Any damage or contamination of the cylinders should be immediately reported to the suppliers and
repainting of cylinders involved in a fire or other damaging incident should never be undertaken.
No attempt to repair cylinders or their valves should be made.
 Smoking should be prohibited in all areas where cylinders are used or stored and suitable notices
displayed.
 An explosion risk assessment should be carried out to comply with the DSEAR. The gases should
be assessed for safety hazards and in relation to COSHH.
 Operators using or handling cylinders should wear appropriate low-flammability clothing, safety
shoes and suitable eye protection.
 Where loading or unloading is involved, employers should be aware of their responsibilities under
the Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations
2004.
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Appendix 2: Storage recommendations
Appendix 2A: General storage
 Good natural ventilation is essential, particularly where storage is within a building.
a) Ventilation should be provided at high and low levels.
b) It is preferable for cylinders to be stored in the open but with some protection from the
weather.
 Storage should not be below ground level. In large areas where cylinders of different classes of
gases are stored consideration should be given to the provision of radiation barriers. Such barriers
should have a fire resistance of at least 30min and have a height not less than that of the tallest
cylinder.
 Storage areas should be readily accessible but secure to prevent access by unauthorised persons.
 Permanent warning notices should be prominently displayed at the storage areas, identifying the
gases stored and prohibiting smoking and the use of naked lights or motor vehicles (except for
loading and unloading of cylinders).
 Designated storage areas should be used solely for the storage of gas cylinders. They should not
contain any other products, particularly not oil, paint or corrosive liquids.
 Cylinders should be stored with their valves uppermost. Protective valve covers should be used
when cylinders are not in service.
 Full cylinders should be stored separately from nominally empty cylinders and cylinders of different
gases should be segregated from each other.
 Storage arrangements should ensure adequate turnaround of stock. Nominally empty cylinders
should not be stored longer than absolutely necessary and a check should be made to ensure their
valves are closed.
 Gas cylinders should at all times be securely supported either on trolleys, within racks or fixed to
structural features using welded steel chain.
 Within the storage area, oxygen cylinders should not be stored within 3m of any flammable gas
cylinder.
 Compressed gas cylinders and acetylene cylinders should not be stored within 3m of any LPG
cylinder in excess of 50kg capacity.
Appendix 2B: Storage in the open
 Cylinders stored in the open should be enclosed within a compound, which should be sited as far
from buildings as possible, and where practicable, at least 4m from boundary fences. The
compound should not be close to roadways or motor vehicle movements (other than for loading
and unloading cylinders).
 Storage should be on a compacted, level, load-bearing surface, preferably concrete or paved.
There should be no drains, manholes or openings to basement areas in or near storage areas.
 The compound should be securely fenced with, for example, 1.8 high wire mesh on metal or
concrete posts. Gates to the compound should be secured by a good quality chain and padlock.
 To shade cylinders from direct sunlight, a light, open-sided weather covering of non combustible
construction should be used. Storage should not be under tarpaulins.
 The compound and adjacent areas should be kept clear of combustible materials and vegetation. If
weed killers are employed only those of the non-chlorate type should be used.
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Appendix 2C: Storage within a building
 If it is essential that gas cylinders are stored in a building used for processes other than cylinder
storage, then the numbers should be kept to an absolute minimum.
 Where possible the store should be a detached building constructed of non-combustible materials
and located as far as practicable from other buildings.
 Good natural ventilation is essential. Ventilation should be provided at high and low levels.
 If cylinders are stored within part of a building used for some other purpose then the following
conditions should be satisfied:
a) the store should be on the ground floor of the building in a room having at least one wall
constituting or being contiguous with an external wall with a door or doors leading directly to
the open,
b) the store should be separated from the rest of the building by walls and floors built to fire
break standards (as specified in the LPG Design Guide for Fire Protection of Buildings
2000), and
c) the store should be of non-combustible construction.
 Cylinders should be stored in a cool area. They should not be stored adjacent to steam or hot
water pipes or radiators.
 Where possible, electrical equipment and wiring should be located outside areas where flammable
gases are stored.
 Areas where flammable gases are stored should be subject to a risk assessment to comply with
DSEAR.
Appendix 3: Use and handling recommendations
Appendix 3A: Cylinders
 If the cylinder valve is key-operated check that you have enough spindle keys – one for each
cylinder in use. Cylinder valves should only be opened with proper keys. If the valve is thought to
be damaged no attempt should be made to open it. Cylinder valves should always be carefully
closed whenever equipment is not in use.
 Never open a valve fully in case the spindle gets stuck on its back-stop and cannot then be closed.
Always open and close valves using moderate torque and with the correct key. Never hit a key
with a mallet or similar implement.
 In the case of a pressure regulator failure, consider fitting an additional fail-safe device such as an
excess flow valve to detect the effect of a leak and automatically isolate the supply.
 There should never be a transfer of gas to another cylinder for mixing of gases or for any other
reason. An individual cylinder should never be removed from a manifolded cylinder pallet.
 Cylinders in use should be kept well clear of all heat sources, especially oxy-fuel gas torches and
electrical welding tools.
 Grease or oil should never be allowed to come in contact with cylinders, their valves or equipment.
This is particularly important with cylinders containing oxygen as this gas will react dangerously
with grease or oil. White or red lead, jointing compounds or jointing tape should never be applied
to any cylinders, valves or equipment.
 Before assembling regulators and fittings, care should be taken that there is no particles of dirt in
the cylinder outlet.
 Where a cylinder is connected to a laboratory or manufacturing process in which the process
pressure can exceed the cylinder supply pressure, adequate precautions should be taken to
prevent back flow of contaminated gases or liquids. An empty cylinder should never be left
connected to a process.
 Where many cylinders are in use simultaneously, a pipeline supply from a manifolded system of
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cylinders located safely outside a building should be considered. Cylinders inside a building can
cause severe fire-fighting difficulties.
 Acetylene and LPG cylinders should be used and stored in the upright position apart from LPG
cylinders specially designed for use on fork lift trucks where the internal tubing is arranged for
horizontal use.
 When not in use oxy/acetylene sets should be returned to an appropriate, well ventilated storage
location within the workroom well away from any combustible materials or wherever possible a
separate and suitable store.
 Consider fitting an alarm indicator to alert when the cylinder supply is almost exhausted and needs
to be changed.
Appendix 3B: Equipment
 Equipment (regulators, hoses, blowpipes) should be disconnected prior to storage or
transportation of cylinders. Where cylinders are fitted to a purpose-made cylinder trolley for
moving to a place of work, then the equipment may be left connected but the valves must be
closed before moving.
 Before connecting any cylinders to a system ensure it is suitable for the pressure involved.
 Constant and thorough ventilation should be provided wherever cylinder gases are used. This
particularly important in confined spaces.
 Only the regulator designed for the gas should be used. In particular, propane and butane need
different regulators.
 For welding and similar applications, flashback arrestors should be fitted downstream of pressure
regulators to all fuel gas supply hoses/lines and oxygen supply hose/lines where used in
conjunction with fuel gases, to prevent flames travelling back into cylinders.
 Only purpose-made hoses in good condition should be used. The condition of hose connections
should be regularly checked. Hoses should be secured by clips that are approved by the
equipment manufacturer. Worm-driven clips are not suitable for this purpose.
 Joint fittings or piping made of copper should on no account be used in conjunction with
acetylene.
 Hoses should not be coiled around cylinders or their regulators. The use of hoses which are either
too long or too short for their purpose should be avoided. The latter could lead to operations being
carried out too close to cylinders. Hoses should be sited well clear of sparks and where they will
not be subjected to damage by being walked on or by contact with sharp metal. Fires in coiled
hoses are especially difficult to deal with.
 With oxy-fuel equipment, use hose check valves to prevent backfeeding, to prevent the mixing of
oxygen and fuel gas in a hose and subsequently a fire within the hose.
 Cylinder valves, including those in store and assembled equipment should be checked for leaks
as a matter of routine and not only when a leak is heard or smelt. Particular attention should be
given to all joints, pressure regulators and equipment valves. Naked flames should never be used
when looking for a leak, only a leak-testing fluid approved by the gas cylinder supplier should be
used for testing. Particular caution should be observed when testing for oxygen leaks since any
residue could result in a reaction with the gas leading to spontaneous ignition.
 Permanent welding and other hot work areas should be considered as high fire hazard areas. The
risks from fire will be mitigated by ensuring that combustible items and other hazards are
segregated from the hot work by non-combustible/fire-resistant partitions or screens and that no
combustible building components are likely to be ignited by the operations.
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Appendix 3C: Maintenance of equipment
 All cylinders and equipment should be maintained in a clean condition. Special care is required in
the storage oxygen regulators. The nozzles of blowpipes should be regularly examined and, if
clogged, cleaned in accordance with the manufacturer’s instructions.
 All equipment for use with cylinders should be returned to the supplier for routine examination
and/or servicing at intervals recommended by the supplier. Repairs when required should always
be arranged with the equipment supplier. Faulty or leaking regulator gauges should always be
dealt with by returning the complete regulator assembly.
 Cylinders owned by the gas supplier are automatically submitted for maintenance and testing
when returned to the gas supplier for filling. This is not the case when the cylinders are owned by
the user, who must then be aware of the statutory obligations with regard to these functions.
Appendix 4: Fire protection
Appendix 4A: General fire precautions
 No attempt should be made to extinguish an outbreak of a fire involving burning flammable gases
until the gas supply has been shut off. Untrained personnel should not attempt to tackle a fire
involving flammable gases. The area should be evacuated and the fire brigade should be called
immediately.
 Provision should be made for an adequate supply of water for fire brigade use to provide hose
streams for cooling cylinders that might become exposed to heat from a fire. Suitable access
should also be provided for fire-fighting.
 Fire extinguishers, approved and certified by an independent, third-party certification body, of a
type suitable for extinguishing fires in nearby materials should be provided in the vicinity of all
areas in which gases are used or stored. These should be provided in easily accessible positions
and maintained in accordance with BS 5306: Parts 3 and 8.
 Consideration should be given to water spray or automatic sprinkler protection in situations where
significant numbers of cylinders of flammable gases are stored.
 All practical steps, including the installation and maintenance of an adequate exhaust ventilation
system, must be taken to prevent vapours from highly flammable liquids escape into the general
atmosphere of a workroom.
 All dusts, trunks and casing used in connection with an exhaust ventilation system must be fireresisting structures.
 Electric motors used to power exhaust ventilation systems must not be sited in the path of highly
flammable vapours.
Appendix 4B: Precautions for Safe Storage of highly flammable liquids
 Unless the amount of highly flammable liquids present is small, in other words the minimum
amount needed to support the work process or activity, all highly flammable liquids must be stored:
a) in suitable fixed storage tanks in safe positions; or
b) in suitable closed vessels kept in a safe position in the open and, where necessary protected
against direct sunlight; or
c) in suitable closed vessels kept in a storeroom that is either in a safe position or is a fireresisting structure; or
d) in the case of a workroom, where the aggregate quantity stored does not exceed 50L, in
suitably closed vessels kept in a fire-resisting cupboard or bin.
 All openings, other than air vents, in cupboards, bins, tanks and vessels used for the storage of
highly flammable liquids must be kept closed except for access.
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 All reasonably practicable steps must be taken to ensure that leakages and spills of highly
flammable liquids are either neutralised and made safe, or drained off to a suitable container.
Appendix 4C: Precautions for preventing escape of vapours
 Storerooms, workrooms, cabinets or enclosures necessarily provided for the storage or use of
highly flammable liquids must not only be fire-resisting and constructed of non combustible
materials, but must also, incorporate suitable explosion pressure reliefs or venting in the form of
non-combustible lightweight roofing or walling, so arranged as to ensure that the pressure
released by an explosion is vented to a safe place.
 Every storeroom, cupboard, bin, tank and vessel used for storage of highly flammable liquids must
be clearly marked so.
 Highly flammable liquids should be conveyed at work through a leak-proof and totally-enclosed
system, such as a pipeline.
 All drums and containers used to transport highly flammable liquids must be so designed and
constructed as to avoid the risk of spilling.
 Accidental spillages and leakages of highly flammable liquids must be contained or made safe
without delay, or be drained off to a suitable container or safe area.
 Empty tanks and drums or similar containers must be returned to their original storage area (fireproof cupboard or bin) and, unless made free of vapour, must be kept closed.
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