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EXPERTISE · DSEAR

DSEAR

Workplace requirements for managing dangerous substances and explosive atmospheres.

Managing dangerous substances and explosive atmospheres safely.

DSEAR (the Dangerous Substances and Explosive Atmospheres Regulations) requires employers to assess and control the risks from dangerous substances that could create fires, explosions or similar energetic events in the workplace. It sits alongside, rather than within, the chemical-registration regulations, focusing on workplace risk assessment, classification of hazardous areas and control measures.
We support DSEAR risk assessments and help align them with wider product and hazard compliance obligations, so classification and workplace controls tell a single, consistent story.
✓DSEAR risk assessment support
✓Hazardous area classification input
✓Alignment with product hazard classification
✓Practical, proportionate control recommendations
HAZARDOUS AREA ZONES

Six zones, defined by likelihood and duration.

DSEAR requires areas where an explosive atmosphere could occur to be classified into zones, based on how likely that atmosphere is and how long it could last. Gas and vapour atmospheres use one set of zones; combustible dust uses another.

Zone 0
A place where an explosive gas atmosphere is present continuously, for long periods, or frequently.
Zone 1
A place where an explosive gas atmosphere is likely to occur in normal operation occasionally.
Zone 2
A place where an explosive gas atmosphere is not likely to occur in normal operation, and if it does, only briefly.
Zone 20
A place where an explosive dust atmosphere, as a cloud of combustible dust in air, is present continuously, for long periods, or frequently.
Zone 21
A place where an explosive dust atmosphere is likely to occur occasionally in normal operation.
Zone 22
A place where an explosive dust atmosphere is not likely to occur in normal operation, and if it does, only briefly.
EQUIPMENT & DOCUMENTATION

Matching equipment to the zone, and writing it down.

Each hazardous area zone sets the minimum equipment category that can be installed within it, under the UKEX / ATEX equipment framework: Category 1 equipment for Zones 0 and 20, Category 2 for Zones 1 and 21, and Category 3 for Zones 2 and 22. The higher the likelihood of an explosive atmosphere persisting, the higher the integrity the equipment needs.

DSEAR also requires the outcome of the risk assessment and zoning exercise to be captured in a formal Explosion Protection Document, covering the hazards identified, the zones assigned, the control measures in place and the arrangements for reviewing them.

✓Hazardous area classification and zone assignment
✓Equipment category verification against assigned zones (UKEX / ATEX)
✓Explosion Protection Document preparation and review
✓Control measure and ignition source assessment
RISK REDUCTION HIERARCHY

The order DSEAR expects you to work through.

DSEAR does not treat every control measure as equally acceptable. It expects risks to be worked through in a set order, starting with removing the hazard altogether and only relying on emergency arrangements as a last line of defence.

Eliminate or substitute
Remove the dangerous substance from the process entirely, or replace it with one that presents a lower risk, wherever that is reasonably practicable.
Control the risk
Where the substance cannot be eliminated, reduce the likelihood of an explosive atmosphere forming and control ignition sources through engineering and procedural measures.
Mitigate the effects
Where a risk cannot be fully controlled, reduce the harm an incident could cause through measures such as explosion relief, suppression or containment.
Plan for emergencies
Prepare and rehearse plans and procedures for dealing with accidents, incidents and emergencies involving dangerous substances.
HOW WE HELP

Turning a DSEAR assessment into a defensible position.

A DSEAR position touches process safety, equipment specification, documentation and training all at once, and it needs to stay current as processes, substances and equipment change.
We help identify dangerous substances and assess the risks they present, classify hazardous areas into zones, verify that installed and specified equipment matches those zones, and build the Explosion Protection Document and supporting evidence the assessment depends on.
✓Dangerous substance identification and risk assessment
✓Hazardous area classification and zone assignment
✓Equipment specification checks against UKEX / ATEX categories
✓Explosion Protection Document development and review
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