Dangerous Substances and Explosive Atmospheres Regulations 2002

  • Operations notice: 58
  • Issue date: Jan 2003

A short guide for the offshore industry

This notice provides practical advice to offshore employers and the self-employed about the basic requirements of the Dangerous Substances and Explosive Atmospheres Regulations 2002 (SI 2002/2776) (DSEAR) which came into force on 9 December 2002. It highlights certain key features of the Regulations and, in particular, their application to the offshore industry. It is not intended to be a comprehensive guide to the Regulations. A Guide to DSEAR will be published in early 2003.

What is DSEAR?

The DSEAR regulations are concerned with protecting workers against risks from fire, explosion and similar events arising from dangerous substances used or present in the workplace. DSEAR implements the requirements of two EU worker protection directives, Directive 99/92/EC on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres (Explosive Atmospheres Directive (ATEX 137)), and Directive 98/24/EC on the protection of the health and safety of workers from the risks related to chemical agents at work (Chemical Agents Directive (CAD)). A third Directive, 94/9/EC on the approximation of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres (ATEX) has been implemented in the UK by the Equipment and Protective Systems Intended for use in Potentially Explosive Atmospheres Regulations 1996 [EPS]. Operations Notice 59 provides further information about EPS.

DSEAR applies to offshore installations and connected activities on the UKCS, except that the following regulations do not apply offshore:

  • Regulation 5 (2) (f)(g)(h)(i)
  • Regulation 5 (4) (c)
  • Regulation 6 (4) (d)
  • Regulation 6 (5) (b)(e)
  • Regulation 7
  • Regulation 8 (1) (d)(e)
  • Regulation 11
  • Schedule 1 (paragraphs 5,6)

Who has duties under DSEAR?

DSEAR places duties on all employers and the self employed, including installation owners, installation operators and contractors. These duties expand on the general duties under the Health and Safety at Work etc Act 1974 and on the requirements of the Management of Health and Safety at Work Regulations 1999. Compliance with the Act and the 1999 Regulations, therefore, will make a significant contribution to compliance with the requirements of DSEAR.

DSEAR overlaps to a large extent the requirements of the Offshore Installations (Prevention of Fire and Explosion, and Emergency Response) Regulations 1995 (PFEER), which place duties on installation owners and operators. Compliance with PFEER, where it applies, will also contribute significantly to compliance with DSEAR.

What is a dangerous substance?

DSEAR gives a detailed definition of 'dangerous substance' which should be referred to for more information, but it includes any substance or preparation which, because of its properties or the way it is used, could cause harm to people from fires and explosions. Dangerous substances include: petrol; liquefied petroleum gas (LPG); paints; varnishes; solvents; and dusts which, when mixed with air, could cause an explosive atmosphere. Dangerous substances can be found, in varying quantities, in most workplaces.

What is an explosive atmosphere?

An explosive atmosphere is an accumulation of gas, mist, dust or vapour which, when mixed with air, has the potential to catch fire or explode.

What are the main requirements of DSEAR for employers and the self-employed offshore?

You must:

  • carry out a risk assessment of any work activities involving dangerous substances;
  • provide measures to eliminate or reduce risks as far as is reasonably practicable;
  • provide equipment and procedures to deal with accidents and emergencies;
  • provide information and training to employees.

What does DSEAR require me to do?

As said previously, most of the risk reduction measures and controls required by DSEAR should already have been covered through compliance with other regulations. However, all employers will need to review their existing measures, to the extent necessary, to identify if there is anything else they need to do. In reviewing and, where necessary, revising their arrangements, employers, owners and operators should co-operate with each other as required by regulation 8 of the Offshore Installations and Pipeline Works (Management and Administration) Regulations 1995. This is particularly important where duties overlap.

Who will enforce DSEAR?

HSE's Offshore Safety Division enforces DSEAR in the offshore industry.


  • Dangerous Substances and Explosive Atmospheres Regulations(SI 2002/2776) The Stationery Office 2002 ISBN 0 11 042957 5
  • The Stationery Office (formerly HMSO) publications are available from The Publications Centre, PO Box 276, London SW8 5DT, Tel: 0870 600 5522, Fax: 0870 600 5533, Website: www.clicktso.com (they are also available from bookshops).
  • Seven steps to successful substitution of hazardous substancesHSG110 HSE Books 1994 ISBN 0 7176 0695 3
  • Controlling the risks in the workplace INDG163 HSE Books 1995 ISBN 0 7176 0904 9
  • The Idiot's guide to CHIP - Chemical (Hazard Information and Packaging for supply) Regulations 2002 INDG 350 HSE Books 2002 ISBN 0 7176 2333 5
  • Safe handling of combustible dusts HSG103 HSE Books 1994 ISBN 0 7176 0725 9
  • The safe use and handling of flammable liquids HSG140 HSE Books 1996 ISBN 0 7176 0967 7
  • The storage of flammable liquids in containers HSG 51 HSE Books 1998 ISBN 0 7176 1471 9
  • Prevention of fire and explosion, and emergency response on offshore installations L65 HSE Books 1997 ISBN 0 7176 1386 0

HSE priced and free publications are available by mail order from:

HSE Books, TSO Customer Services, PO Box 29, Norwich, NR3 1GN.

Tel: +44 (0)333 202 5070
Website: https://books.hse.gov.uk/

Further information

Any queries relating to this notice should be addressed to:

Health and Safety Executive
Hazardous Installations Directorate
Offshore Division
Lord Cullen House
Fraser Place
AB25 3UB

This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice

Updated 2021-02-16