Dangerous Substances & Explosive Atmospheres

The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) set out minimum requirements for the protection of workers from fire and explosion from dangerous substances and potentially explosive atmospheres.

DSEAR applies where there is present any substance or mixture of substances with the potential to create a risk from energetic (energy-releasing) events such as fire, explosions, thermal runaway from exothermic reactions etc. Such substances, known in DSEAR as dangerous substances, include:

  • flammable substances
  • oxidisers
  • explosives
  • petrol
  • liquefied petroleum gas (LPG)
  • paints and varnishes
  • solvents
  • certain types of dust that are explosive (e.g. wood, 'organic' or certain metal dusts)
  • ALL gases under pressure
  • Substances corrosive to metals

The main requirements of DSEAR are that:

an assessment is made of all the risks that may arise from the use of Dangerous Substances and in particular:

  • a specialist risk assessment may be needed for the fire and explosion risks of any work activities involving dangerous substances
  • measures are undertaken to eliminate, or reduce as far as is reasonably practicable the identified fire and explosion risks
  • residual risks are controlled in order to mitigate the detrimental effects of a fire or explosion (see guidance on Safety Office website)
  • equipment is provided and procedures put in place to deal with accidents and emergencies
  • information and precautionary training given

Additionally, where significant flammable/explosive atmospheres may occur:

  • workplaces should be classified into hazardous and non-hazardous places
  • any hazardous places should be classified into zones on the basis of the frequency and duration of an explosive atmosphere, and where necessary marked with a sign
  • equipment in classified zones should be safe and satisfy the requirements of The Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 1996
  • the workplaces should be verified as meeting the requirements of DSEAR, by a competent person

Note: DSEAR removes the need for licensing the storage of petrol and other petroleum spirits in the workplace.

 For further information contact a member of staff for chemical safety adviceor a member of the Fire Safety Unit.

Guidance and risk assessments forms available:

Guidance on DSEAR

DSEAR risk assessment form

Hazardous Substances Policy

Hazardous substance risk assessment form