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Dangerous Substances and Explosive Atmospheres Regulations 2002



The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) came into force on 9th December 2002, with some exceptions. The last part of the Regulations came into force on 30th June 2003.

They have since been amended by The Carriage of Dangerous Goods and Use of Transportable Pressure Equipment Regulations 2004, 2007 and 2011.

The Regulations implement two European Directives: the safety aspects of the Chemical Agents Directive(a) 98/24/EC (CAD) and the Explosive Atmospheres Directive 99/92/EC (ATEX 137) requiring similar legislation throughout the European Union (EU) on work involving hazardous chemical agents and explosive atmospheres.

A full copy of the Regulations can be printed and/or downloaded from:

Dangerous substances can put peoples' safety at risk from fire and explosion. DSEAR puts duties on employers and the self-employed to protect people from risks to their safety from fires, explosions and similar events in the workplace, this includes members of the public who may be put at risk by work activity.

Dangerous substances are any substances used or present at work that could, if not properly controlled, cause harm to people as a result of a fire or explosion. They can be found in nearly all workplaces and include such things as solvents, paints, varnishes, flammable gases, such as liquid petroleum gas (LPG), dusts from machining and sanding operations and dusts from foodstuffs.

Employers must:

  • find out what dangerous substances are in their workplace and what the fire and explosion 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; and
  • identify and classify areas of the workplace where explosive atmospheres may occur and avoid ignition sources (from unprotected equipment, for example) in those areas.

DSEAR revokes, repeals or modifies a large amount of old legislation relating to flammable substances and dusts. Safety standards will be maintained through a combination of the requirements of DSEAR and Approved Codes of Practice (ACoPs) reflecting good practices in the old legislation.

Content of the Regulations

  1. Citation and commencement
  2. Interpretation
  3. Application
  4. Duties under these Regulations
  5. Risk assessment
  6. Elimination or reduction of risks from dangerous substances
  7. Places where explosive atmospheres may occur
  8. Arrangements to deal with accidents, incidents and emergencies
  9. Information, instruction and training
  10. Identification of hazardous contents of containers and pipes
  11. Duty of co-ordination
  12. Extension outside Great Britain
  13. Exemption certificates
  14. Exemptions for Ministry of Defence etc
  15. Amendments
  16. Repeals and revocations
  17. Transitional provisions
    • Schedule 1: General safety measures
    • Schedule 2: Classification of places where explosive atmospheres may occur
    • Schedule 3: Criteria for the selection of equipment and protective systems
    • Schedule 4: Warning sign for places where explosive atmospheres may occur
    • Schedule 5: Legislation concerned with the marking of containers and pipes
    • Schedule 6: Amendments
    • Schedule 7: Repeal and revocation

HSE ACoPs and Guidance

All HSE documents are available to purchase or to freely download from the links below.