DSEAR Regulations
DSEAR, which stands for Dangerous Substances and Explosive Atmospheres Regulations 2002, is a set of regulations in the United Kingdom that aims to protect workers and others from the risks posed by dangerous substances and explosive atmospheres. DSEAR places legal responsibilities on employers and duty holders to assess and manage these risks effectively.
The primary goal of DSEAR is to prevent fires and explosions that could cause harm to your people. It covers a wide range of industries and workplaces where dangerous substances are present or created, including manufacturing plants, food and drink factories, chemical facilities, laboratories, energy centres, warehouses, and more.
Learn more about the regulations below.
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In DSEAR, a ‘dangerous substance’ includes any substance or preparation which, because of its properties or the way it is used, could cause harm to people from fires and explosions. Dangerous substances include those with potential energy releasing events similar to fire and explosion such as exothermic reactions.
Wherever a dangerous substance is present in the workplace, it must be considered under DSEAR to determine if it is capable of creating an explosive atmosphere so that appropriate measures and safeguards can be implemented to mitigate the hazard being released.
Examples include: petrol; liquefied petroleum gas (LPG); paints; varnishes; solvents; and dusts which when mixed with air could cause an explosive atmosphere (e.g. dusts from milling and sanding operations).
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It is a duty of the employer to assess whether an explosive atmosphere is likely to form and for how long it is likely to remain under Regulation 7 of DSEAR - this process is called Hazardous Area Classification (HAC), sometimes referred to as ATEX zoning.
Gases, vapours, mists and dusts can cause explosive atmospheres when dispersed within certain concentrations in air. These concentrations are called the Lower Explosive Limit (LEL) or Lower Flammable Limit (LFL) for vapours and gases, and the Minimum Explosible Concentration (MEC) for combustible dusts.
The presence of a combustible material does not necessarily mean a hazardous zone will need to be classified - a HAC will typically consider the properties of the substance, the quantity of substance and how it is being used, process conditions, specific containment measures (e.g. tank bunds, pipe-in-pipe and double-walled tanks, flange guards, etc.), and ventilation.
If an area is identified to be hazardous, (i.e. a zoned area), then equipment and work activities in the area must be controlled to prevent ignition occurring. Common examples of these control measures include ATEX rated equipment, electrostatic discharge (ESD) controls, and lightning protection.
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A DSEAR Risk Assessment is a systematic evaluation of the risks posed by dangerous substances and explosive atmospheres within your workplace. It involves identifying potential hazards, assessing the likelihood and severity of incidents, and implementing effective control measures to mitigate risks.
Regulation 5 of DSEAR prescribes criteria that must be considered, which include: the physical properties and safety information of the substances, the circumstances of the work, activities where there is a high level of risk (e.g. maintenance, start-up, shut-down), the likelihood of an explosive atmosphere forming and its subsequent effective ignition, and the severity of anticipated effects.
The risk assessment should be considered as a live document and updated if it is felt it is no longer valid. This may be as a result of changes to the materials being used, process conditions, equipment, and other factors.
The purpose of the risk assessment is to allow employers make informed decisions on how best to eliminate or reduce the risks to as low as reasonably practicable (ALARP) and demonstrate that a structured approach has been followed when considering the safety of personnel and the control measures required.
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Regulation 6 of DSEAR places a duty on employers to ensure that risk is either eliminated or reduced as far as is reasonably practicable. The regulation provide a prioritised list of measures to achieve this, which aligns with the engineering hierarchy of controls (Elimination, Substitution, Engineering Controls, Procedural Controls, PPE).
The regulations split these control measures into two lists - control measures (i.e. measures to stop the hazard being realised) and mitigation measures (i.e. measures to mitigate the harm caused by the event after it has occurred). The measures in these lists are to be applied so far as is reasonably practicable in the order in which they appear.
A common mistake that is made is procurement of ATEX rated equipment without first trying to prevent an explosive atmosphere from forming in the first place. It is not only against the regulations, but can add significant capital and operational expense that could be avoided!
Control Measures:
Eliminate the dangerous substance or substitute it with a less hazardous substance
Reduce the quantity of substances to a minimum
Avoid or minimise release of the substance
Control the release of a substance at source
Prevent the formation of an explosive atmosphere (e.g. through effective ventilation)
Avoid ignition sources
Avoid adverse conditions that could give rise to harmful effects
Segregate incompatible substances
Mitigation Measures:
Minimise the number of personnel exposed
Avoid propagation of fires and explosions
Pressure relief
Explosion suppression
Explosion containment
PPE
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Before a workplace containing hazardous areas is used for the first time, its overall explosion safety must be verified by someone who is competent in the field of explosion protection as a result of their experience and/or professional training. It should be noted that this is only required for when then workplace is brought into use for the first time, so does not apply to existing workplaces.
The purpose of this requirement is to confirm that the workplace can operate in compliance with DSEAR. If the verification deems that the workplace is not safe, then it should not be brought into use.
Typically the verification of explosion safety will take place around the commissioning stage of a project, after the equipment has been installed. If a DSEAR expert has been involved in the project from the conceptual design stage, no major issues should be identified at this stage. However, special care should be taken at the interface between different vendor packages, as it is sometimes not clear what is within the scope and important safety considerations these areas can often be overlooked!
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Personnel are required to receive information, instruction and training which is appropriate to their level of understanding and experience. This training should include being made aware of how and where dangerous substances are being used at their workplace, the safeguards that are in place (including procedures), the reasoning behind the actions they are being instructed to perform, emergency response procedures, and any other relevant information identified in the risk assessment.
Some of the aspects of training required by DSEAR will be covered in forums such as site visitor and contractor inductions, fire drills and other courses. However, it is unlikely that this will be of sufficient depth and detail to provide the knowledge required so that personnel can effectively mitigate the explosion hazards in their workplace.
FAQs
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There is no prescribed frequency at which a DSEAR assessment should be updated - the regulations state that it should be reviewed ‘regularly’.
We advise that a DSEAR assessment should be reviewed whenever there is a change to the process - such as the materials being used, process conditions, or equipment.
If there are no major changes, then we recommend the DSEAR assessment is reviewed every 3-5 years to capture any creeping changes.
A DSEAR assessment should also be reviewed if there has been an incident or a near-miss in your workplace. This is to make sure that the process has been accurately captured, and that any additional safeguard requirements are highlighted and actioned.
If you need a DSEAR assessment to be updated or reviewed, get in touch and we’ll be happy to help.
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It is a legal requirement to have a DSEAR assessment if your workplace handles dangerous substances.
If you are making modifications to your workplace (e.g. expanding production, changing equipment) then we recommend you engage with a DSEAR expert at the start of this process - typically during the conceptual design stage before any equipment is ordered. One of the biggest mistakes we see is the DSEAR assessment being conducted after equipment has been ordered, which can result in significant project delays and overspend.
If you are not sure when you should conduct a DSEAR assessment, get in touch and we’ll be happy to help.
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Although it can be complex, there is no qualification required for you to conduct a DSEAR assessment. All that is required is for the assessor to be ‘competent’ - this can be demonstrated through their experience and/or training.
If you have questions about conducting a DSEAR assessment, or would like to have your DSEAR assessment peer reviewed, please get in touch and we’ll be happy to help.
