What is DSEAR?

News & views from ESUK

DSEAR stands for Dangerous Substances and Explosive Atmospheres Regulations. It is important to learn about DSEAR in the workplace to identify serious hazards and know how to assess the risk involved.

What are dangerous substances?

Dangerous substances are any substances used or present at work that could, if not properly controlled, cause harm to people because of a fire, explosion or corrosion of metal. These substances can be found in nearly all workplaces. Examples include:

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

DSEAR – Dangerous Substances and Explosive Atmospheres Regulations 2002

Dangerous substances can put peoples’ safety at risk from fire, explosion, and corrosion of metal. DSEAR requires duties on employers and the self-employed to protect people from these risks in the workplace, and to members of the public who may be put at risk by work activity. The enforcement body in the UK is the Health and Safety Executive.

DSEAR Legislation

Employers are required to find out what dangerous substances are in their workplace and what the risks are associated with those substances. They are required to put control measures in place to either remove those risks or, where this is not possible, control them. They should also put in place controls to reduce the effects of any incidents involving dangerous substances. This includes the preparation of plans and procedures to deal with accidents, incidents, and emergencies. Employees need to be properly informed about and trained to control or deal with the risks from the dangerous substances. Where explosive atmospheres could occur, they must identify and classify them, and avoid ignition sources in those areas.

How to comply with DSEAR regulations and legislation


A good starting point is to draw up a list of all the substances in your workplace that may be dangerous that would fall under the requirements of the legislation. When you do that, you should also consider the amounts of each substance that are likely to be present in the workplace. Help is at hand for identifying what is hazardous in the EU Regulation on classification, labelling and packaging of substances and mixtures, or ‘CLP’ Regulation. See attached here, which is in force from 01 May 2020.

Further, an ACOP including guidance is available, free to download from the HSE website.

Hazardous Area Drawings

Once you know what you have and where it is located, consider whether you should have hazardous area drawings for these areas. Where a hazardous area classification study has been carried out this should be recorded in the form of a drawing which identifies the hazardous areas, classification of the materials present, types of zones and their extent in plan and elevation. The classification of the zones indicates how likely it is that a hazardous atmosphere will be present.

Hazardous Area Equipment

Mechanical and electrical equipment located in; or if portable, taken into hazardous areas should be suitable for use with the material involved and the zone it is located in. Equipment and protective systems for all workplaces where explosive atmospheres may occur must be correctly selected. Good news, hazardous area equipment is clearly labelled with the zone and category, from this you should be able to work out whether it is suitable for the duty.

Signage and Marking

Hazardous areas should be correctly marked so that it is immediately obvious to personnel or contractors that they are entering a hazardous area. A typical ‘Ex’ sign is shown below:

Yellow hazard sign with EX inside

The marking of containers and pipes should be determined by risk assessment. The risk assessment should consider if and how contents of containers and pipes containing dangerous substances should be identified.

Verification, Inspection and Maintenance

Verification of hazardous areas before putting them into service is required by a competent person. Ongoing maintenance and inspection also requires competence, typically this can be demonstrated by the successful completion of a COMPEX course. The only training course I know that if completed successfully, states that you are competent.

Anti-static Workwear

Anti-static clothing and footwear may be required, this should be subject to risk assessment. This often results in employers putting in place a policy and providing this type of PPE as ‘standard issue’, reducing the risk of an ignition source due to static electricity from workwear.

Accidents, incidents, and emergencies

Employers need to protect the safety of employees by forward planning and ensuring that they have in place arrangements to deal with accidents, incidents, and emergencies, including the evacuation, escape or rescue of people. The arrangements include first aid, safety drills and testing, information on hazards, warning and response systems and means of escape.

Training and Inductions

Appropriate information, training and instruction should be given to contractors and employees on the dangerous substances present together with information on the hazards, risks, precautions, and actions necessary for them to remain safe.

DSEAR risk assessments

We have given you the basics in this blog, but there are many things that should be in place to ensure compliance with the legislation.

Learn to identify dangerous substances and explosive atmospheres, regulations, and get a certificate of success with our DSEAR training to help you carry out important risk assessments.

If you need help with DSEAR, Electrical Safety UK can help. Make an enquiry here or give us a call on 0800 652 1124. We will do our best to come and see you, to find out what help you need. If you are in the UK, our first meeting with you is normally free. If you are located outside the UK, we will only ask you to reimburse reasonable expenses for the trip.

Contact us to find out more

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