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Does DSEAR apply to me?

If your workplace handles flammable gases, liquids, vapours, or dusts, the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) apply to you. A proper risk assessment isn’t just a legal requirement, it’s a crucial part of keeping your team safe and your business running smoothly.

At York Green, we help you make sense of DSEAR without the jargon or the guesswork. Our assessments give you a clear understanding of the risks on site, and practical steps to manage them.

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What is DSEAR?

DSEAR is the law that requires employers to assess and control risks from substances that could ignite or explode. It covers:

  • Flammable liquids like solvents, fuels, and paints

  • Gases such as LPG, hydrogen, or natural gas

  • Combustible dusts from wood, flour, sugar, or plastics

  • Pressurised gases and corrosive substances that can cause harm in the event of a leak or failure

Whether you're running a small workshop or a large manufacturing plant, DSEAR is there to prevent fires, explosions, and chemical incidents before they happen.

What’s included in a DSEAR Risk Assessment?

Our qualified assessors will:

  • Identify hazardous substances and potential explosive atmospheres

  • Review your processes, storage, ventilation, and ignition sources

  • Classify zones where explosive atmospheres may occur

  • Recommend control measures to reduce risk

  • Check whether your equipment meets ATEX requirements

  • Provide a clear, usable report with prioritised actions

We’ll walk you through the findings and support you in taking the next steps. You’ll come away with the confidence that your team and your business is protected.

HAC Drawings - DSEAR

Who needs a DSEAR Assessment?

You likely need one if you:

  • Store or use flammable substances

    If your business handles fuels, solvents, alcohols, or other flammables, DSEAR applies. A risk assessment helps identify ignition risks and keep your team safe.

  • Handle combustible dusts in any process

    If your process creates dust from wood, flour, sugar, plastics or similar materials, there's a risk of explosion. DSEAR assessments help you manage those hazards before they build up.

  • Operate spray booths, fuel storage, or solvent cleaning

    Spray booths, fuel tanks, and solvent-based cleaning all involve flammable substances and vapours. DSEAR ensures the right controls are in place to prevent fires or explosions.

  • Have compressed gases or reactive chemicals on site

    Compressed gases and reactive chemicals can escalate quickly if something goes wrong. A DSEAR assessment helps you understand the risks and keep storage and handling safe.

  • Need to show evidence of compliance to insurers, clients, or the HSE

    Whether it’s your insurer, a client audit, or an HSE visit, you’ll need clear proof of risk control. A DSEAR assessment provides the documented compliance they expect.

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    Not sure if it applies to you?

    We’re happy to talk it through and give honest, practical advice.

Why choose York Green?

We know DSEAR can feel complex. Our job is to make it simple.

With years of experience in high-risk environments, we understand the pressures you’re under, from keeping production on track to meeting legal duties and budget constraints. We offer straight-talking, solution-focused assessments that fit the real world.

  • Fully qualified, experienced assessors

  • No-fuss reports and clear action plans

  • UK-wide service

  • Practical, actionable solutions

  • Competitive pricing with no hidden fees

What is DSEAR?

DSEAR stands for the Dangerous Substances and Explosive Atmospheres Regulations 2002. It’s UK law that requires those responsible for workplaces to control the risks of fire, explosion, or corrosion from dangerous substances.

The idea is: if a substance can ignite, explode, or damage metal under certain conditions, DSEAR demands you manage those risks.

What counts as a “dangerous substance”?

A dangerous substance is anything that, if not managed properly, could cause harm through a fire, explosion, or corrosion. That includes:

  • Flammable liquids, gases, or vapours (e.g. solvents, LPG)

  • Combustible dusts (e.g. wood dust, flour dust)

  • Gases under pressure (even non-flammable gasses)

  • Substances corrosive to metal (which could weaken containers or piping) 

If you use, produce, store, or handle any of those, DSEAR likely applies.

Is DSEAR compliance a legal requirement?

Yes — DSEAR is legally required where dangerous substances are present. Employers and the self-employed have duties under it to:

  • Assess the risks

  • Introduce control or mitigation measures

  • Prepare emergency procedures

  • Train workers about relevant risks and controls

If you ignore it, as well as the potential for fire and explosion, you risk enforcement action, fines, even criminal liability.

Do I need a DSEAR risk assessment (even if I already have a fire risk assessment)?

Yes — a DSEAR risk assessment focuses specifically on dangerous substances, explosive atmospheres, ignition sources, and their control. Having a general fire risk assessment does not automatically cover all DSEAR considerations. 

If your fire risk assessment already flagged chemical, gas, or dust hazards, that’s a good sign you need a DSEAR risk assessment to specifically cover those hazards.

Who can carry out a DSEAR assessment?

It should be done by a competent person, someone with the relevant technical knowledge, experience, and understanding of dangerous substances, explosive atmospheres, and process safety. The level of competence should match the complexity of the risk.

That could be an in-house expert (if suitably experienced) or an external consultant with DSEAR / explosion safety credentials.

What does the assessment process involve?

The steps are:

  1. Identify dangerous substances in your workplace

  2. Evaluate how those substances are used, stored, processed - routes of release, quantity, conditions

  3. Identify potential ignition sources -electrical equipment, mechanical sparks, static, hot surfaces, etc.

  4. Determine whether explosive atmospheres can occur - i.e. mixing of substance + air in flammable proportions

  5. Classify hazardous zones - (if necessary) e.g. Zone 0, 1, 2 for gases/vapours; Zone 20, 21, 22 for dusts.

  6. Decide control measures - to eliminate or reduce risk by substitution, ventilation, containment, explosion protection, safe design

  7. Put in mitigation measures - so that if something goes wrong, consequences are limited

  8. Prepare emergency plans - what to do if an incident occurs

  9. Inform, train, instruct staff about the hazards, risks, and controls

  10. Review and monitor - revisit the assessment when there’s change or regularly over time

How often should a DSEAR assessment be reviewed or redone?

There’s no one fixed interval in the law. Instead:

  • Review it whenever there’s reason to think it’s no longer valid (e.g. changes in process, equipment, substances, layout)

  • In higher risk settings, many choose annual or biannual review

  • In lower risk or stable settings, reviews might be less frequent 

If an incident or near-miss happens, or if new substances are introduced, you should revisit it immediately.

What are zone classifications (Zones 0, 1, 2, 20, 21, 22)?

These are labels for areas where an explosive atmosphere might occur:

Gas / vapour / mist:
 – Zone 0: explosive atmosphere present continuously or for long periods
 – Zone 1: likely to occur in normal operation occasionally
 – Zone 2: unlikely to occur in normal operation, and if it does, will persist only briefly


Dust / powders:
 – Zone 20: dust explosive atmosphere present continuously or long periods
 – Zone 21: likely to occur occasionally during normal operation
 – Zone 22: not likely in normal operation, but if occurs, persists briefly.


Zone classification helps tailor the type of equipment, ignition control, and protective measures you use near to dangerous substances.