GUIDE TO DSEAR RISK ASSESSMENT
- 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 and the Risk Assessment Form are available and can be downloaded from the University Safety Office website [
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.
Thisguide 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: 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
- 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:
a)measures to reduce the risk and spread of fire;
b)provision of means of detection and giving warning in case of fire;
c)provision of means of escape;
d)means of fighting the fire;
e)avoidance of ignition sources;
f)prevention of leakage of dangerous substances; and
g)providing information, instruction and training about fire precautions and the evacuation plan to employees and all others who may be at risk.
- 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:
Guide to DSEAR Risk AssessmentPage 1 of 26
a)Acetone
b)Acetonitrile
c)Acrylamide monomer
d)Ammonia gas
e)Benzoyl peroxide
f)Butan-1-ol
g)Dioxane
h)Ethanol
i)Ethanolamine
j)Hexane
k)Methanol
l)Methyl ethyl ketone
m)Methyl Propan-1-ol
n)Iso-Butyl alcohol
o)Liquefied petroleum gas (LPG)
p)Octan-1-ol
q)Oxygen gas
r)Toluene
s)Stoddards solution
t)Styrene monomer
u)Varnishes
Guide to DSEAR Risk AssessmentPage 1 of 26
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.
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;
- boiling point,
- flash point,
- auto-ignition temperature, and
- flammability or explosive limits
b)Relevant chemical properties include;
- reactivity,
- heat reaction and self-acceleration temperature
c)For materials that could give rise to dust explosion, factors to be considered would include;
- particle size,
- moisture content,
- maximum explosion pressure,
- 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 –
- used as a means of access for or egress from that place of work, or
- 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.
- 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;
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 andexperience 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 thework 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 thepublic).
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 undertaken must be recorded. It is goodpractice, however, to keep such records in all circumstances. The assessment will prompt decisions on both thegeneral and process precautions that will be required or will need to be improved. Arising from the assessment anaction 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