Dangerous and explosive substances (DSEAR) safety

Dangerous substances are substances used or stored at work that could, if not properly controlled, cause explosive atmospheres. The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) require the risks from dangerous substances to be removed or controlled to protect people from explosion and fire.

Dangerous substances are flammable gases, mists or vapours or combustible dusts. Examples found at work include:

  • solvents
  • paints and varnishes
  • flammable gases
  • liquid petroleum gas (LPG)
  • dusts from machining and sanding operations
  • dusts from food stuffs
  • pressurised gases
  • substances corrosive to metal

The Health and Safety Executive have a wide range of up-to-date information and resources to help you decide if a substance is dangerous:


The University must prevent or reduce the risk from dangerous substances. The person responsible for the dangerous substance, as outlined in the Health and Safety PolicyHealth and Safety PolicyHealth and Safety Policy, should ensure the following process is carried out:

Identify dangerous substances

Find out what dangerous substances you have and the fire and explosion risk. You can refer to the safety data sheet for the substance. It will give you information on the hazardous and dangerous properties of the substance.

Dangerous dusts are any substance that can burn and which exists in a fine powder. It is strongly recommended that a departmental dangerous substance inventory is kept and maintained detailing the substances and where they are stored.

Risk assessment

Carry out a risk assessment and record it. This is a careful examination of the dangerous substance hazards you use and store at work, and the likelihood of creating a explosive atmosphere, potential ignition sources and the expected consequences and who could be harmed.

Further advice on risk assessing dangerous substances can be found in the resources section. Advice is also available from Health and Safety Advisory Service.

Control measures

Put in place control measures to either remove or, where this isn't possible, control the risks. This will be the arrangements to reduce the likelihood of an explosion and the consequences if it does, including emergency arrangements. Schedule 1 General safety measures (.pdf) in the DSEAR Regulations details what must be considered when selecting and implementing risk controls.


Provide information, instruction and training for employees and others to control or deal with the risk.

Zoning and ignition sources

Identify and classify areas of the workplace where explosive atmosphere may occur and avoid ignition sources in those areas. For more information on zoning and ignition sources go to hazardous area classification and control of ignition sources.

Also see

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