DSEAR for Small Businesses: What Every Business Owner and Office Manager Needs to Know

If your business uses flammable liquids, produces combustible dust, stores gas cylinders, or carries out hot work of any kind, DSEAR applies to you. This is not a regulation reserved for chemical plants and oil refineries. It covers thousands of ordinary small businesses in Surrey and across the UK.

Most small business owners and office managers have heard of fire safety law.

They know they need a fire risk assessment, fire extinguishers, and a means of escape.

What many do not realise is that there is a separate, legally distinct set of obligations that sits alongside general fire safety: the Dangerous Substances and Explosive Atmospheres Regulations 2002, known as DSEAR.

DSEAR is enforced by the Health and Safety Executive and applies to any business where dangerous substances are present, used, or produced.

In practice, that covers a very wide range of everyday businesses. If your workshop uses solvents, your garage stores petrol, your print shop uses cleaning chemicals, or your carpentry business generates wood dust, DSEAR is relevant to your operations.

This guide has been written specifically for business owners and office managers in light industrial and commercial settings.

We will explain what DSEAR requires, walk through how it applies to different types of business, and set out what you need to do to get and stay compliant.

ESI: Fire Safety works with small and medium-sized businesses across Surrey, covering Guildford, Woking, Reigate, Redhill, Epsom, Farnham, Dorking, Leatherhead, and the surrounding area.

What is DSEAR and Why Does it Exist?

DSEAR stands for the Dangerous Substances and Explosive Atmospheres Regulations 2002.

It came into force on 9 December 2002 and was updated in 2015 to extend its scope to gases under pressure and substances corrosive to metals. It implements two EU directives into UK law and, following Brexit, has been retained as part of UK legislation.

The regulations exist for a straightforward reason: fires and explosions involving dangerous substances kill people and destroy businesses.

The Health and Safety Executive (HSE) is clear that these incidents are preventable with proper risk assessment and control measures in place. DSEAR sets out the legal framework for doing exactly that.

DSEAR applies whenever three conditions are met:

• Work is being carried out by an employer or a self-employed person
• A dangerous substance is present, or is likely to be present, at the workplace
• That substance could pose a risk to the safety of people through fire, explosion, or corrosion

The phrase ‘dangerous substance’ covers more than most people expect.

The HSE defines it as any substance or mixture that could, if not properly controlled, cause harm as a result of a fire, explosion, or corrosion of metal.

This includes flammable liquids such as petrol, solvents, paints, thinners, and adhesives; flammable gases including LPG and acetylene; combustible dusts such as wood dust, flour, and metal powders; gases under pressure; and substances corrosive to metals.

In practical terms, there are very few light industrial or commercial workshop environments that do not involve at least one of these.

That is why DSEAR matters to small businesses, and why ESI: Fire Safety sees it as one of the most commonly overlooked compliance obligations for businesses trading in industrial estates, trade parks, and workshop premises across Surrey.

Does My Business Actually Need to Comply?

The quickest way to answer this is to work through a simple checklist. If you answer yes to any of the following questions, DSEAR applies to your workplace and a formal risk assessment is required:

Question	Answer
Do you store or use petrol, diesel (in certain circumstances), solvents, thinners, or paints?	Yes  /  No
Do you use flammable cleaning products or degreasers?	Yes  /  No
Do you store or use gas cylinders, including LPG, acetylene, argon, or oxygen?	Yes  /  No
Do your processes produce dust, including wood dust, metal dust, or powder?	Yes  /  No
Do you carry out hot work such as welding, cutting, grinding, or brazing?	Yes  /  No
Do you spray flammable liquids, including paint, lacquer, or adhesive?	Yes  /  No
Do you store aerosols with flammable propellants?	Yes  /  No
Do you use adhesives, resins, or coatings that contain solvents?	Yes  /  No
Is your workplace poorly ventilated and used with any of the above?	Yes  /  No

If you answered yes to even one of these questions, DSEAR applies to your business. The size of your operation does not matter. A sole trader running a small workshop has the same legal obligations as a larger employer when dangerous substances are present. DSEAR also applies to the self-employed.

How DSEAR Applies to Different Types of Business

DSEAR applies differently depending on what your business does.

Here is a breakdown of the most common business types ESI: Fire Safety encounters in light industrial and commercial settings across Surrey, and what DSEAR means in practice for each.

Vehicle Repair Workshops and Garages

Motor vehicle repair is one of the most DSEAR-intensive environments in the small business world. The HSE has published specific guidance on DSEAR for the motor vehicle repair (MVR) sector, reflecting how many dangerous substances and ignition risks are present in a typical garage.

The main dangerous substances in a vehicle repair workshop include:

• Petrol: stored in cans and drums for draining fuel tanks, and present in vehicle fuel systems throughout the working day. Petrol is highly flammable and the vapour it produces is heavier than air, meaning it sinks and pools rather than dispersing upward. Vehicle inspection pits are a particular concern for petrol vapour accumulation.
• Waste engine oil: often stored in drums and in some cases burned in waste oil heaters. Diesel and waste oil contaminated with petrol can have a much lower flash point than clean diesel and must be treated with care.
• Flammable solvents and degreasers: used for parts cleaning, brake cleaning, and general workshop cleaning. Many of these products contain highly flammable compounds.
• Paints, primers, and thinners: used in bodyshop and preparation work. Spray painting with solvent-based paints creates a significant explosive atmosphere risk, particularly in poorly ventilated areas.
• Acetylene, oxygen, and LPG: used in welding and cutting operations. These gases are under pressure and present both fire and explosion risks.
• Aerosols: many workshop products including lubricants, brake cleaners, and touch-up paints are supplied in aerosol form with flammable propellants.
• Airbags and seat belt pre-tensioners: classified as explosive devices under certain legislation and requiring careful storage and handling.

Under DSEAR, vehicle repair workshops must carry out a risk assessment covering all of these substances, classify any zones where an explosive atmosphere could form (vehicle inspection pits, spray booths, fuel storage areas, and paint mixing rooms are the most common), ensure that equipment in zoned areas is appropriate for use there, and put in place controls and emergency procedures.

Spray booths in garages and bodyshops A spray booth where solvent-based paint is applied is typically classified as a Zone 1 hazardous area under DSEAR. This means that all fixed electrical equipment inside the booth must be ATEX-rated (explosion-proof), the ventilation must be designed and maintained to prevent vapour accumulation, and sources of ignition must be strictly controlled. A standard domestic light fitting or a non-ATEX-rated extraction fan is not appropriate in a spray booth. If your spray booth was installed a long time ago and has not been assessed under DSEAR, it is worth reviewing urgently.

Commercial Printers

Commercial printing businesses, including lithographic printers, screen printers, digital print finishers, and sign makers, use a range of substances that fall within the scope of DSEAR.

The HSE has published specific guidance on fire and explosion risks in the printing industry, recognising that flammable materials are a routine part of print production.

The main substances of concern include:

• Cleaning solvents: used to clean printing presses, screens, blankets, and rollers. Solvent naphtha, isopropanol (IPA), and similar products are widely used and are flammable. IPA has a flash point of around 12 degrees Celsius, which means it produces flammable vapour at normal working temperatures.
• Inks and coatings: solvent-based inks contain flammable carriers. UV-curable inks are less of a fire risk from a flammable vapour perspective, but cleaning chemicals used with UV systems often still contain solvents.
• Adhesives and laminates: used in finishing operations. Many adhesive products are solvent-based and present flammable vapour risks during application and drying.
• Aerosols: anti-set-off spray powder in offset litho printing and a range of aerosol maintenance products used around print machinery.
• Drying ovens and dryers: heat-set printing operations use dryers to cure inks. These involve elevated temperatures in the presence of solvent vapours and require specific DSEAR consideration.

Static electricity is a particular concern in print environments because paper, film, and some substrates can build up significant static charges. Static discharge in the presence of solvent vapour is a credible ignition source and must be considered in the DSEAR risk assessment. The HSE advises that static generation should be controlled through earth bonding and, where appropriate, anti-static additives or footwear.

For printing businesses, the areas requiring zoning under DSEAR typically include press cleaning areas, solvent and ink storage, and ink mixing rooms. The assessment should also consider how solvents are stored, decanted, and disposed of, and whether quantities stored in the work area comply with HSE guidance on flammable liquid storage.

Woodworking and Carpentry Workshops

Wood dust is one of the most frequently misunderstood dangerous substances in small business settings. Many carpenters and joiners think of wood dust primarily as a health hazard, governed by COSHH. It is that, but it is also a dangerous substance under DSEAR. Fine wood dust suspended in air can form a combustible, explosive atmosphere.

The HSE’s guidance is clear: wood waste usually has a dust explosion risk where the mean particle size is less than 200 microns, and where as little as 10% of the mixture contains dust finer than 75 microns. In practical terms, this means that the fine dust produced by sawing, routing, turning, sanding, and machining operations in a woodworking workshop can, under the right conditions, ignite and explode. The finer the dust, the higher the risk.

Potential ignition sources in a woodworking workshop include:

• Overheated electric motors on machinery
• Sparks from contact between metal components and sawblades
• Static electricity build-up on dust in extraction systems and filter units
• Hot surfaces from friction
• Standard electrical fittings in dust-laden atmospheres

Under DSEAR, woodworking businesses need to assess the dust explosion risk, classify zones within the dust extraction and collection system (typically Zone 20 inside equipment where dust is continuously present, Zone 21 in areas adjacent to collection points, and Zone 22 in the wider workshop area if dust accumulations are possible), and ensure that equipment in those zones is ATEX-rated.

The dust extraction and collection system itself is a critical focus. Filter units, cyclones, and dust bins can accumulate fine dust to concentrations that are within the explosive range. Explosion venting panels on filter housings are required in many woodworking installations. Extraction ducting must be earthed to prevent static discharge.

A furniture workshop in the UK was fined over 16,000 pounds in 2023 following an HSE investigation into repeated failures around wood dust, including failure to maintain dust extraction systems properly. DSEAR non-compliance in woodworking is actively enforced, not overlooked.

If your workshop uses stains, lacquers, or finishing products, there is an additional DSEAR dimension. Many wood finishing products are solvent-based and create flammable vapour during application and drying. A spray finishing area in a carpentry workshop may require its own zone classification and specific controls.

Metal Engineering Workshops and Fabricators

Engineering workshops carrying out machining, fabrication, welding, grinding, and cutting operations encounter dangerous substances across several categories.

• Welding and cutting gases: acetylene, oxygen, and LPG are all dangerous substances. Acetylene in particular is unstable at pressures above 1.5 bar and requires specific storage and handling precautions. The HSE produces guidance specifically on the safe use of acetylene.
• Metal dusts and powders: aluminium, magnesium, titanium, and certain other metal dusts are combustible and can form explosive atmospheres. This is less commonly appreciated than organic dusts but is a genuine DSEAR concern in machining operations.
• Coolants and cutting fluids: some machining coolants contain flammable components. Misting of fluids during machining can create flammable atmospheres in certain conditions.
• Flammable solvents: used for degreasing, cleaning, and surface preparation before painting or coating.
• Spray painting and coating: many fabrication businesses apply paint or protective coatings as a final stage, creating the same spray painting DSEAR risks as in a bodyshop.

Hot work, which includes welding, cutting, grinding, and brazing, creates ignition sources that must be carefully managed in relation to any flammable substances nearby.

A permit-to-work system for hot work is good practice and in many cases a DSEAR requirement where flammable substances are present.

Other Light Industrial and Commercial Premises

Beyond these specific sectors, DSEAR touches a wide range of other small business activities that might not immediately be associated with fire or explosion risk:

• Cleaning and laundry businesses: many industrial cleaning products, dry cleaning solvents, and degreasers are flammable. Some dry cleaning fluids are classified as flammable liquids under DSEAR.
• Hairdressers and beauty salons in industrial or commercial settings: aerosols, some alcohol-based products, and acetone used in nail treatments are all potentially within scope.
• Sign makers and display manufacturers: solvent-based inks, adhesives, and cleaning products used in sign production frequently contain flammable substances.
• Food production units: flour, grain, sugar, and other food dusts are combustible and have caused serious industrial explosions. Smaller food production businesses are not exempt from DSEAR.
• Horticultural and garden machinery businesses: storage of petrol for machinery is explicitly listed by the HSE as an activity covered by DSEAR.

What DSEAR Actually Requires You to Do

DSEAR sets out a clear sequence of obligations. For most small businesses, the process is manageable when approached systematically.

1. Carry Out a DSEAR Risk Assessment

This is the foundation of everything else. A DSEAR risk assessment must identify all dangerous substances present in your workplace, assess the risks they present, and determine what controls are needed. It is distinct from your general Health and Safety risk assessment and from your fire risk assessment, though it should be consistent with both.

The assessment must consider:

• What dangerous substances are present, in what quantities, and what their hazardous properties are
• How they are stored, used, handled, and disposed of
• What work processes involve or could release dangerous substances
• What sources of ignition are present or could be introduced
• Whether ventilation is adequate to prevent dangerous accumulations
• What happens if something goes wrong, including the consequences for people in and around the workplace

For businesses with five or more employees, the significant findings of the risk assessment must be recorded in writing. For smaller operations, written records are not strictly required by law but are strongly recommended. If there is ever an incident and you cannot demonstrate that a proper assessment was carried out, the legal consequences are substantially worse.

The assessment must be carried out by a competent person. For some straightforward workplaces with limited and well-understood hazards, a business owner with appropriate knowledge and HSE guidance may be able to do this. For more complex situations, including spray booths, dust extraction systems, and premises with multiple substance types, specialist assessment is advisable.

2. Classify Hazardous Zones

Where explosive atmospheres can form, Regulation 7 of DSEAR requires those areas to be classified into hazardous zones. For gases and vapours, the zones are:

• Zone 0: where an explosive atmosphere is present continuously or for long periods (typically inside storage tanks and containers)
• Zone 1: where an explosive atmosphere is likely to occur in normal operation occasionally (typically spray booths, areas around open solvent containers, fuel transfer points)
• Zone 2: where an explosive atmosphere is unlikely during normal operation but could occur for short periods in abnormal conditions (typically the wider area around solvent storage, vehicle inspection pits in some configurations)

For combustible dusts, the equivalent zones are Zone 20 (continuous presence of explosive dust cloud, typically inside extraction equipment), Zone 21 (likely during normal operation, typically around collection points), and Zone 22 (unlikely, short duration, typically the wider workshop area with potential dust accumulation).

Once zones are classified, all equipment used within those zones must be appropriate for the zone. This is where the ATEX requirement comes in. Electrical and mechanical equipment in hazardous zones must be specifically rated and certified for use in explosive atmospheres. Standard light fittings, switches, motors, and angle grinders are not suitable for use in classified zones.

3. Put Control Measures in Place

With dangerous substances identified and zones classified, the regulations require you to eliminate or reduce the risks so far as is reasonably practicable.

The hierarchy of control measures runs from most to least preferable:

• Substitution: replace the dangerous substance with a safer alternative. For example, switching from a low flash point solvent cleaner to a water-based or high flash point alternative can eliminate or significantly reduce the DSEAR risk.
• Reduction: use the minimum quantity of dangerous substance necessary for the task. Do not stockpile large volumes of flammable liquids in the workshop.
• Prevention of release: keep containers sealed when not in use, maintain equipment to prevent leaks, and use closed transfer systems where practical.
• Ventilation: ensure adequate ventilation to prevent dangerous concentrations building up. Local exhaust ventilation (LEV) is particularly important for dust and vapour control.
• Control of ignition sources: eliminate or control sources of ignition in areas where explosive atmospheres can form. This includes enforcing no-smoking rules, controlling hot work through permits, using ATEX-rated equipment in zoned areas, and controlling static electricity.
• Mitigation: put measures in place to limit the consequences if an incident does occur. This includes explosion venting on dust collection equipment, automatic suppression systems in high-risk areas, and clear emergency procedures.

4. Sort Out Your Storage

How you store dangerous substances matters significantly under DSEAR.

The HSE provides clear guidance on flammable liquid storage in workplaces.

The key points for small businesses are:

• A maximum of 50 litres of highly flammable liquids (those with a flash point below ambient temperature) should be kept in workrooms, stored in a fire-resistant metal cabinet with a self-closing lid.
• For flammable liquids with a higher flash point (up to 60 degrees Celsius), the maximum for workroom storage is 250 litres.
• Larger quantities should be stored in a dedicated external flammable storage unit, bunded to contain spills, and positioned away from ignition sources, building openings, and escape routes.
• Gas cylinders must be stored upright, secured against falling, and kept in a ventilated area away from heat sources and combustible materials. Acetylene and oxygen cylinders must be stored separately.
• Storage areas should be clearly labelled with appropriate hazard signage.

5. Train Your Staff

All employees who work with or near dangerous substances must be informed about the risks and trained in the relevant control measures and emergency procedures.

This does not need to be an elaborate training programme for most small businesses, but it must be meaningful.

Staff should understand what substances in your workplace are dangerous, why they are dangerous, what controls are in place and why those controls matter, and what to do in an emergency.

Induction training for new starters working in areas with DSEAR risks is particularly important. It is also good practice to refresh training when new substances are introduced, when processes change, or when an incident or near-miss occurs.

6. Establish Emergency Procedures

DSEAR requires that procedures are in place to deal with accidents and emergencies involving dangerous substances.

For most small businesses, this means:

• A clear procedure for dealing with spills of flammable liquids, including what to do, how to stop ignition sources, how to ventilate the area, and how to dispose of contaminated materials safely
• A procedure for gas cylinder incidents, including how to identify a leak, how to isolate the supply, and when to evacuate
• Knowledge of how to contact the emergency services and what information to give them
• For businesses with significant DSEAR risks (particularly those using acetylene), it may be appropriate to notify your local fire and rescue service of the substances present on site

Emergency procedures should be written down, communicated to all staff, and reviewed regularly.

7. Keep Records and Review

DSEAR is not a one-off exercise.

The risk assessment must be reviewed whenever there are changes to the substances used, the processes carried out, or the layout of the workplace.

It should also be reviewed periodically even when nothing has changed, to ensure it remains current.

Annual review is good practice for most small businesses.

Records to keep include the DSEAR risk assessment and zone classification documents, records of staff training, maintenance records for LEV systems and other safety-critical equipment, and any incident or near-miss records.

DSEAR and COSHH: Understanding the Difference

Two separate sets of obligations, often confused DSEAR and COSHH (Control of Substances Hazardous to Health Regulations 2002) both deal with substances in the workplace, but they address different types of risk. COSHH is concerned with risks to health from exposure to substances, covering effects such as dermatitis, respiratory disease, and long-term organ damage from solvent exposure. DSEAR is concerned with risks to safety from fire, explosion, and corrosion. Many substances, including solvents, are subject to both. A solvent cleaner might be covered by COSHH because long-term exposure can damage health, and by DSEAR because it creates a flammable atmosphere risk. Businesses need to comply with both sets of regulations, and the assessments should be consistent with each other.

DSEAR and Your Fire Risk Assessment

Your fire risk assessment, required under the Regulatory Reform (Fire Safety) Order 2005, is a separate document from your DSEAR assessment.

However, the two must be consistent and should cross-refer.

Government guidance is explicit on this point: special technical and organisational measures around dangerous substances fall outside the scope of the Fire Safety Order and are a matter for DSEAR.

In practice, this means your fire risk assessment should note the presence of dangerous substances and refer to your DSEAR assessment for the detail.

Your DSEAR assessment should inform the fire risk assessment’s conclusions about ignition sources, flammable materials, and emergency procedures.

If there is a conflict between the two documents, something has gone wrong.

What Happens if You Do Not Comply?

DSEAR is enforced by the Health and Safety Executive.

Non-compliance is treated as a serious matter, and enforcement action can take several forms:

• Improvement Notices: requiring specific action within a defined timeframe
• Prohibition Notices: requiring an immediate stop to dangerous activities until the risk is controlled
• Prosecution: DSEAR non-compliance is a criminal offence. Fines for serious breaches can be substantial and there is no upper limit in the Crown Court. Directors and managers can be personally prosecuted where they are personally at fault.

Beyond enforcement, the consequences of an incident involving a dangerous substance can be catastrophic. Explosions and flash fires in workshops cause serious burns, blast injuries, and deaths.

They destroy businesses, equipment, and premises. The financial cost of an explosion, even one where nobody is seriously hurt, vastly exceeds the cost of proper compliance.

The HSE actively inspects light industrial premises, particularly following complaints, incidents, or near-misses. Businesses in the motor vehicle repair, woodworking, and print sectors are all subject to sector-specific HSE inspection programmes.

ESI: Fire Safety and DSEAR for Small Businesses in Surrey

ESI: Fire Safety carries out DSEAR assessments for small and medium-sized businesses across Surrey, including businesses on industrial estates and trade parks in Guildford, Woking, Reigate, Redhill, Epsom, Farnham, Leatherhead, Dorking, Godalming, Staines-upon-Thames, and the wider South East.

We work with businesses in a wide range of sectors, including:

• Vehicle repair workshops, MOT centres, and bodyshops
• Commercial and trade printers
• Woodworking, joinery, and furniture manufacturing workshops
• Metal engineering and fabrication businesses
• Sign makers and display manufacturers
• General light industrial trade units where flammable substances are stored or used

Our approach is practical and proportionate. We understand that small business owners are not health and safety professionals, and we aim to give you clear, jargon-free guidance on what your specific business needs to do.

We carry out the DSEAR risk assessment, complete the Hazardous Area Classification, produce the documentation you need, and advise on the practical control measures required.

A DSEAR assessment from ESI: Fire Safety gives you the legal documentation you need, a clear picture of the risks in your workplace, and practical guidance on how to address them. We work around your business hours and aim to make the process as straightforward as possible.

Frequently Asked Questions

I have only one or two employees. Does DSEAR still apply?

Yes. DSEAR applies to all employers, including those with a single employee, and to the self-employed. The size of your business does not determine whether DSEAR applies. What matters is whether dangerous substances are present in your workplace. The requirement to record findings in writing applies to workplaces with five or more employees, but the underlying duty to assess and control risks applies regardless of size.

My business has a fire risk assessment. Is that enough?

No. A fire risk assessment under the Regulatory Reform (Fire Safety) Order 2005 covers general fire precautions such as means of escape, fire detection, and fire fighting equipment. DSEAR covers the specific risks from dangerous substances, including zone classification, ATEX equipment requirements, and substance-specific controls. Government guidance is explicit that these are separate obligations. You need both.

I store petrol in cans for a machine. Do I need a DSEAR assessment?

Yes. The HSE specifically lists the storage of petrol as a fuel for cars, boats, or horticultural machinery as an example of activity covered by DSEAR. Even a small quantity of petrol stored on site requires a risk assessment, appropriate storage arrangements, and control of ignition sources in the storage area.

We produce wood dust in our workshop. Is that really a DSEAR issue?

Yes. Wood dust is classified as a dangerous substance under DSEAR when it is airborne in concentrations that could form an explosive atmosphere. Fine wood dust produced by sawing, routing, sanding, and machining falls within scope. The dust extraction and collection system, which is where fine dust accumulates in greatest concentrations, typically contains hazardous zones under DSEAR that require ATEX-rated equipment.

How long does a DSEAR assessment take?

For a small business with straightforward operations, an initial DSEAR assessment can typically be completed in a single site visit followed by a report.

For more complex premises with multiple substance types, spray booths, or extensive dust extraction systems, more time may be needed. ESI: Fire Safety will give you a clear indication of what is involved when we discuss your business.

How often does the DSEAR assessment need to be reviewed?

DSEAR requires the assessment to be reviewed when there is reason to believe it may no longer be valid, or when there have been significant changes to the substances used, the processes carried out, or the workplace layout.

Annual review is recommended as good practice for most small businesses.

The assessment should always be revisited when you introduce a new substance, install new equipment, or change a work process.

A Final Word

DSEAR is one of those regulations that many small business owners discover only when something goes wrong, or when the HSE comes to call.

The reality is that for businesses working with flammable liquids, combustible dusts, or pressurised gases, DSEAR compliance is not optional and it is not difficult to achieve with the right support.

Getting a proper DSEAR assessment done is about more than meeting a legal requirement.

It is about understanding the real risks in your workplace, making your business genuinely safer for your staff and anyone who visits, and protecting what you have built from the kind of catastrophic incident that a fire or explosion can cause.

If you would like to discuss a DSEAR assessment for your business, get in touch with ESI: Fire Safety. We are here to make compliance straightforward and to keep your workplace safe.