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Guidance: what you need to know – DSEAR

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In 2008/09, there were 259 reported workplace injuries from fire at work and 107 injuries and three deaths as a result of explosions.
The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) require employers to control risks from fire and explosions.
Failure to comply with DSEAR cost Veolia Environmental Services Ltd £240,000 in fines and costs following a fire in 2007.

This article outlines the background to DSEAR and its requirements. The next issue of Connect will give more information on control measures for particular types of substances, as well as the emergency arrangements you need to make and the information, instruction and training you must provide.

What is DSEAR?

DSEAR is the Dangerous Substances and Explosive Atmospheres Regulations 2002. Employers had until 30 June 2006 to implement some parts of the regulations, such as equipment and protective systems. Today, all organisations must comply fully with DSEAR. The regulations require risks of explosion to be eliminated or reduced as far as is reasonably practicable. You should also replace any dangerous substance with a less dangerous substance wherever possible.

What is a dangerous substance?

While “dangerous” can be applied to many substances, DSEAR legislation is specific about what qualifies as a dangerous substance under the legislation:

a substance or preparation that meets the criteria in the Approved Classification and Labelling Guide (L131) for classification as explosive, oxidising, extremely flammable, highly flammable or flammable, whether or not that substance or preparation is classified under the Chemicals (Hazard Information and Packaging for Supply) Regulations 2008 (CHIP).
a substance or preparation that, because of its physicochemical or chemical properties, and the way it is used, or is present in, the workplace, creates a risk of fire or explosion
any dust, whether in the form of solid particles or fibrous materials, that can form an explosive mixture with air or an explosive atmosphere.

DSEAR only applies to substances which cause harm as a result of their flammable or explosive properties. It doesn’t apply to substances that cause harm because they’re toxic or carcinogenic. In a second article we’ll look at examples of dangerous substances under DSEAR.

What is an explosive atmosphere?

Under DSEAR, an explosive atmosphere occurs when air mixes with flammable substances in the form of gases, vapours, mists or dusts under atmospheric conditions, in which the entire unburned mixture will catch fire if it is ignited. A potentially explosive atmosphere means an atmosphere which could become explosive due to local and operational conditions.

Where did DSEAR come from?

ATEX 95 is the short name given to the EU 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. This was implemented by the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations (EPS) 1996 (amended 1998, 2001, and 2005). ATEX 95 and the EPS Regulations set out the requirements for the supply of equipment and protective systems for all places in which explosive atmospheres may occur. ATEX 137 or Directive 99/92/EC on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres, also known as the workplace or users directive covers the health and safety of workers in places where potentially explosive atmospheres may be present.

What should I be doing?

You may already be doing much of what you need to do if you’re complying with other health and safety legislation. In particular:

the general duty imposed on employers by the Health and Safety at Work etc Act 1974 includes an obligation (section 6) on suppliers and manufacturers of dusts that can explode, particularly where these are new substances, to inform anyone affected about the properties of the substance
the Management of Health and Safety at Work Regulations 1999 outline the requirements for employers to carry out suitable and sufficient assessment of risks to health and safety, including those relating to fire
the Regulatory Reform (Fire Safety) Order 2005 explains an employer’s duty to take precautions to prevent fires, and to provide a means of escape for employees in the event of a fire. In particular, article 12 confirms the need to eliminate and substitute dangerous substances where possible, and to make sure dangerous substances are handled, stored and transported safely. Schedule 1 part 1 lists matters to be considered in a risk assessment in respect of dangerous substances
regulation 12 of the Provision and Use of Work Equipment Regulations 1998 requires employers to take measures to prevent work equipment catching fire or exploding. Having taken all reasonable measures to reduce the likelihood of a fire or explosion, the employer should minimise the consequences of a fire or explosion
the Workplace (Health, Safety and Welfare) Regulations 1992 require cleaning and maintenance of the workplace and of equipment, ventilation of enclosed workspaces and appropriate storage and prompt removal of waste products
regulation 5 of the Control of Substances Hazardous to Health Regulations (COSHH) 2002 excludes any substance which is “hazardous to health solely by virtue of its … explosive or flammable properties”. However, where a potentially explosive dust can damage health through inhalation, controlling the levels of dust in the air for COSHH purposes will contribute to a reduction in the explosion risk.

So what does DSEAR require?

DSEAR expands the requirements of pre-existing health and safety legislation in these key areas:

in each area of the workplace, risk assessments should consider the potential of substances being used or stored to create an explosive atmosphere
on the basis of this specific risk assessment, areas should be classified with a zone number according to the type of explosive atmosphere and the likelihood, frequency and duration of the explosive atmosphere
areas where explosive atmospheres may occur should be marked with a warning “EX” sign
a ‘permit to work’ system should be in place and used appropriately
equipment and protective systems should be chosen according to the EPS Regulations to protect classified areas from sources of ignition
static electricity should be controlled, for example by providing anti-static clothing where needed
where there remains a risk of fire or explosion after all reasonably practicable safety measures have been taken, an employer should follow the instructions given in Regulation 8 of DSEAR with regards to arrangements to deal with accidents, incidents and emergencies
employees and contractors should be given appropriate information, instruction, and training
workplaces with classified areas should have the adequacy of the explosion control and other safety measures verified by a person or organisation competent to consider the particular risks in the workplace

Risk assessment and classification of areas

The table below shows the classification of places where explosive atmospheres may occur according to schedule 2 of DSEAR 2002.

	Likelihood, frequency and duration of explosive atmosphere
Type of explosive atmosphere:	Continuously or for long periods or frequently	Likely to occur occasionally	Not likely in normal operation, or for short periods only
Explosive atmosphere in the form of gas, vapour or mist	Zone 0	Zone 1	Zone 2
Explosive atmosphere in the form of a cloud of combustible dust	Zone 20	Zone 21	Zone 22

The DSEAR risk assessment should be recorded, and should include:

drawings of the workplace showing hazardous zones
information about dangerous substances used or stored in each zone
a description of the work activities that have been considered
assumptions made in the risk assessment
equipment used in each zone.

More information from the HSE on classification of areas is available in Explosive atmospheres – classification of hazardous areas (zoning) and selection of equipment.

The British Compressed Gases Association (BCGA) has a useful guidance note GN 13 DSEAR Risk Assessment that provides detailed example risk assessments.

HSE links

The HSE microsite on fire and explosion includes sections under DSEAR and ATEX.

There’s more information on DSEAR and ATEX in the HSE electricity microsite.

The HSE short guide Fire and explosion: how safe is your workplace (INDG370) provides a brief introduction to DSEAR 2002.

A second short guide, Safe working with flammable substances (INDG 227) explains how to use the “VICES” principles of Ventilation, Ignition control, Containment, Exchange/eliminate and Separation to control risks from flammable substances.

More detailed advice is given in the HSE Approved Code of Practice and Guidance (ACoP) to DSEAR, Dangerous substances and explosive atmospheres. (L138)

There are five further ACoPs covering different aspects of DSEAR: