A workshop keeps solvent tins in a yellow cabinet and holds the latest safety data sheets. That is useful, but it is not a DSEAR risk assessment. The employer still needs to examine how substances are delivered, decanted, used, released and disposed of; where vapour or dust could accumulate; what could ignite it; and how people would be protected if prevention failed.
Know when DSEAR applies
The Dangerous Substances and Explosive Atmospheres Regulations 2002 apply where work is carried out, a dangerous substance is or could be present, and it could put people at risk through fire, explosion, another energetic event or corrosion of metal. Examples include petrol, LPG, acetylene, paints, solvents, aerosols, combustible wood or flour dust, gases under pressure and substances classified as corrosive to metal.
Do not limit the review to products carrying a flame pictogram. A process can create the dangerous substance: sanding may generate combustible dust, charging may release hydrogen, and heating a liquid may create a flammable vapour even when normal storage presents little risk. Waste, residues, contaminated rags and nominally empty containers also need consideration.
DSEAR addresses safety effects. COSHH addresses risks to health such as inhalation, skin exposure or sensitisation. The same product may require both assessments, but one does not replace the other. Start with labels and safety data sheets, then assess the actual task, quantity, temperature, ventilation, equipment and people exposed.
HSE: DSEAR in detail ↗ · Related guide: a safety data sheet is not a COSHH assessment →
Map the substance through the complete job
Build an inventory that connects each substance with the work. Record where it arrives, its maximum and normal quantity, container size, storage location, transfer method, point of use and waste route. Identify physical-hazard classifications, flash point where relevant, incompatible materials, decomposition hazards and any gas or dust that the process can release.
Then observe normal work and credible departures from it. Consider open pouring, spray application, spills, leaking valves, failed extraction, damaged cylinders, blocked dust collection, hot work, charging, cleaning and maintenance. Identify who could be harmed, including contractors, cleaners, visitors and neighbours—not only the operator holding the container.
The assessment should be suitable and sufficient before the work starts. Where five or more people are employed, the significant findings must be recorded. A product list with SDS links is evidence gathered for the assessment; it is not the assessment itself.
Eliminate first, then control and mitigate
The first question is whether the dangerous substance or process can be removed or replaced. A non-flammable cleaner, ready-mixed product or different transfer method may remove more risk than another sign or item of PPE. If elimination is not reasonably practicable, reduce the quantity and the likelihood of a dangerous release.
Use the DSEAR control order: minimise quantities; prevent or limit releases; control releases at source; prevent a dangerous atmosphere forming; collect and remove releases safely; avoid ignition; avoid unsafe temperatures or other adverse conditions; and separate incompatible substances. Controls may include closed transfer, suitable local ventilation, bonding and earthing, temperature control, suitable electrical equipment, spill containment and disciplined housekeeping.
Mitigation deals with the remaining consequences. It can include limiting the number of people exposed, fire or explosion resistance, suppression or relief, stopping spread, detection, shutdown arrangements and suitable PPE. Training supports these measures, but does not compensate for an avoidable vapour cloud, uncontrolled dust release or ordinary electrical equipment in a hazardous area.
Decide whether hazardous-area zoning is needed
Not every DSEAR assessment produces a zoned area. Zoning is required where an explosive atmosphere may occur in quantities that require special precautions. The classification depends on how likely the atmosphere is to occur and how long it could persist, with different zones for gases, vapours and mists and for combustible dusts.
Where zones are needed, define and document their extent, control ignition sources and select equipment and protective systems suitable for the zone. Mark entry points with the specified EX sign where necessary and consider static electricity, including suitable clothing and footwear. A yellow cabinet or a generic 'no smoking' sign is not a zoning study.
Area classification and equipment selection can require specialist competence. If vapour dispersion, dust explosibility, ventilation reliability or equipment category is uncertain, obtain competent process-safety or hazardous-area advice before commissioning the work—not after buying equipment.
Check the process before selecting equipment.
HR + SAFETY can review the substance inventory, task, releases and existing controls, then identify where specialist DSEAR or hazardous-area input is needed.
Discuss a DSEAR assessmentUse flammable-liquid cabinets for the right purpose
Keep only the minimum quantity needed for current work in the workroom. HSE describes half a day or one shift as the guiding principle. Containers should be closed when not in use, and suitable cabinets or bins should retain spills, sit away from processing where possible and not jeopardise escape routes.
HSE recommends maximum cabinet or bin quantities of 50 litres for extremely and highly flammable liquids and liquids with a flash point below the maximum ambient temperature, and 250 litres for other flammable liquids with a flash point up to 60°C. These are recommended maxima reflecting good practice, not universal statutory limits. The assessment must justify the actual quantity and arrangement.
Cabinet standards can be useful scope-limited benchmarks, but they are not legislation, certificates of DSEAR compliance or substitutes for the assessment. Enhanced cabinets do not remove the need for dedicated storage where stock, empty containers or waste exceed what should remain in the workroom. Separate incompatible materials and keep doors, spill retention and inventory control effective.
Connect DSEAR with emergencies and the fire risk assessment
Prepare proportionate arrangements for foreseeable spills, leaks, fires, pressure releases and loss of ventilation. Define alarms, shutdowns, evacuation, isolation, spill response, emergency-service information and the limited circumstances in which trained people may intervene. Workers need information about the substances, controls and emergency procedures, not simply access to a folder.
Introducing or materially changing a dangerous substance or process means the statutory fire risk assessment must be reviewed and updated. Where the existing FRA cannot adequately assess the process hazard, complete a linked DSEAR assessment and incorporate its findings into the main FRA, emergency arrangements, evacuation strategy, training, maintenance and controls. The DSEAR document supports the FRA; it does not replace it.
Consider consequences as well as likelihood. Sleeping accommodation, care settings, public access, young workers, people with disabilities or restricted mobility, and premises where rapid fire growth could affect large numbers may need tighter quantity limits, stronger separation, earlier detection and more robust assisted-escape arrangements. Avoid calling premises 'higher-risk buildings' unless they meet that separate statutory definition.
GOV.UK: workplace fire risk assessments ↗ · Related guide: workplace fire evacuation planning →
DSEAR risk assessment checklist
Legal requirements and official guidance were checked on 29 September 2026. DSEAR remains in force. Its scope includes fire, explosion, similar energetic events, gases under pressure and substances corrosive to metal; COSHH remains the separate framework for health risks from substances.
- List dangerous substances, process-generated hazards, waste and residues.
- Map delivery, storage, transfer, use, cleaning, maintenance and disposal.
- Use labels and SDS information without treating either as the completed assessment.
- Assess both normal work and credible releases, failures and foreseeable misuse.
- Eliminate or substitute before relying on engineering and procedural controls.
- Minimise quantities and keep incompatible substances separated.
- Check ventilation, containment, ignition control and housekeeping in real use.
- Determine whether explosive-atmosphere zoning and suitable equipment are required.
- Prepare spill, leak, fire, shutdown and evacuation arrangements.
- Inform and train employees, contractors and others where necessary for safety.
- Review the DSEAR assessment after process, substance, quantity or equipment changes.
- Update the statutory fire risk assessment and integrate all linked findings.
A usable DSEAR assessment follows the substance through the real task, removes avoidable hazards, controls releases and ignition, plans for failure and feeds the findings into fire and emergency arrangements. The SDS is evidence—not the finished decision.
This guide provides general information for UK employers. It is not legal advice and should not replace advice based on the facts of a specific matter.