Last reviewed 27 April 2022

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) require employers to control the risks to safety from fire, explosions and substances corrosive to metals. Caroline Raine provides an overview of the DSEAR Regulations in this feature article.


The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) were introduced to ensure protection against risks from fire, explosion and similar events arising from dangerous substances used or present in the workplace.

In June 2015, DSEAR was further extended to include gases under pressure and substances that are corrosive to metals. This is to allow for changes in the EU Chemical Agents Directive, ie the introduction of the classification, labelling and packaging regulations (CLP).

The need to carry out a risk assessment and have in place procedures for the safe use of chemicals is already required by the general requirements of the Health and Safety at Work, etc Act 1974 and the Management of Health and Safety at Work Regulations 1999. Many companies carry out their risk assessments on chemicals following the requirements in the Control of Substances Hazardous to Health (COSHH). However, it should be noted that flammable substances are NOT covered by the COSHH regulations and companies must ensure they adhere to the requirements in DSEAR.

DSEAR applies when:

  • there is work being carried out by an employer (or self employed person)

  • a dangerous substance is present (or is liable to be present) at the workplace

  • the dangerous substance could be a risk to the safety of people as a result of fires, explosions or similar energetic events or through corrosion to metal.

What are the requirements of DSEAR?

The Health and Safety Executive (HSE) states that employers must:

  • find out what dangerous substances are in their workplace and what the risks are

  • put control measures in place to either remove those risks or, where this is not possible, control them

  • put controls in place to reduce the effects of any incidents involving dangerous substances

  • prepare plans and procedures to deal with accidents, incidents and emergencies involving dangerous substances

  • make sure employees are properly informed about and trained to control or deal with the risks from the dangerous substances

  • identify and classify areas of the workplace where explosive atmospheres may occur and avoid ignition sources (from unprotected equipment, for example) in those areas.

And that is a neat summary of the requirements. The intention as stated above is to ensure protection against risks from fire, explosion and similar events arising from dangerous substances used or present in the workplace. And this is done via risk assessment, controls, training, planning and using the correct equipment.

Explosive atmospheres

The regulations define an explosive atmosphere as “a mixture of dangerous substances with air, under atmospheric conditions, in the form of gases, vapours, mist or dust in which, after ignition has occurred, combustion spreads to the entire unburned mixture.”

Vehicle paint spraying may create or release flammable gases or vapours, and dusts can also create explosive atmospheres, for example in flour mills. Wood dust is another good example.

Recent incidents involving explosive atmospheres

Hairspray manufacturer

In April 2022, Robert McBride Ltd, a chemical company that manufactures cleaning and hygiene products, was sentenced for safety breaches after a 31-year-old worker suffered 13% superficial burns to his right arm and hand following the ignition of flammable vapours at the company’s site in Hull.

Beverley Magistrates’ Court heard that on 21 August 2017, a batch of hairspray was being mixed in a 10,000 litre stainless steel mixing vessel. Flammable vapours were created within the mixing vessel as a result of heating. Ethanol was pumped directly into the vessel through pipework from an external storage tank. Other constituents were added to the vessel through a manway lid on the top of the vessel. The mixing process then required the addition of heat by an integral steam coil within the vessel.

As the worker was adding powders into the vessel via the lid using a metal scoop, flammable vapours leaving the vessel via the lid ignited, briefly engulfing his upper torso.

Investigating Health and Safety Executive officers found that an extraction system at the lip of the manway lid to remove vapours from this area was present, but it was not adequate to prevent a build-up of a flammable atmosphere. The ignition source is likely to have been a spark from the metal scoop, or static electricity build up on the workers clothing.

Robert McBride Ltd of Hornscroft Park, Kinswood, Hull pleaded guilty to breaching regulation 6(1) of the Dangerous Substances and Explosive Atmospheres Regulations 2002. The company was fined £480,000 and ordered to pay costs of £13,441.80.

Brake fluid fire

In November 2021, STA Vehicle Centres Ltd, a commercial vehicle servicing and repair company, was fined after two workers suffered serious burns when flammable brake cleaning fluid ignited causing a fire.

Birmingham Magistrates’ Court heard how on 27 March 2020 two employees used brake cleaning fluid to clean the grease from the walls of a vehicle inspection pit in the workshop. Shortly after they had finished this operation there was a loud bang and the entire wall of the pit where the brake cleaner had been applied became engulfed in flames. One employee managed to get out of the pit and ran to help his colleague whose clothing had caught fire, pulling him out of the pit and extinguishing the flames. Both employees received burns to their hands and legs.

Investigating Health and Safety Executive officers found the company had failed to carry out a risk assessment to consider whether it was possible to eliminate or reduce the risk. They had not considered replacing the dangerous substance with another non-flammable substance or using a different work process. Jet-washing, a safe alternative, was already in use at the company’s other site. In addition, employees were not aware of the increased risks associated with using flammable fluid in a poorly ventilated area nor the need for appropriate personal protective equipment PPE to be worn.

STA Vehicle Centres Ltd pleaded guilty to breaching s.6(1) of the Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR). It was fined £28,000 and ordered to pay costs of £926.17.

Oil Drum explosion

Rygor Commercial Ltd, a commercial vehicle dealer, was fined after a worker lost a leg when an oil drum exploded.

In January 2017, an employee of the company was using oxy-acetylene cutting equipment to cut up empty oil drums at the company’s site in Newbury. The flammable vapours in the drum ignited and the drum exploded. The lid of the drum struck the worker’s right leg.

The investigation found that the company had failed to provide a safe system of work to dispose of the empty oil drums. The risk of fire and explosion from flammable vapour residues in the drums was not identified. Safer disposal options were not secured. The company had failed to provide adequate instruction, supervision and training on the risks associated with the use of oxy-acetylene equipment.

The company was fined £400,000 plus £9600 costs under regulation 5 of DSEAR and s.2 of HSWA.

Leesons Fire

In August 2021, a fire broke out at Leeson Polyurethanes Ltd where a man died. The incident is still being investigated and the cause remails unknown.


  • Always ensure that if you are using substances that fall into the scope of DSEAR that you are following all of the requirements.

  • If you are unsure, speak to your Health and Safety Advisor or seek external help.

  • The Health and Safety Executive have an Approved Code of Practice and guidance L138 Dangerous Substances and Explosive Atmospheres Regulations 2002 which may be of use.