Electricity in potentially explosive atmospheres
Using electricity can generate hot surfaces or sparks which can ignite an explosive atmosphere.
Explosive atmospheres can occur in places including paint spray booths, near fuel tanks, in sumps, and places where aerosols, vapours, mists, gases, or dusts exist.
Areas where there’s potential for explosive atmospheres to exists must be treated differently from other areas. The Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) require these areas to be risk assessed before new work is carried out in them, and that measures are taken to control the risks.
Take care to prevent static discharges in potentially explosive atmospheres. Measures like earth bonding and using antistatic work clothing and footwear can help to reduce the risk of static discharges.
HSE’s guidance on DSEAR explains how to comply with the Regulations.
Equipment in explosive atmospheres
Equipment and installations in potentially explosive atmospheres must be specially designed and constructed so that the risks of ignition are eliminated or reduced.
Reduce risks by:
- sealing electrical equipment so that the explosive atmosphere cannot come into contact with electrical components
- reducing the power of electrical equipment
- de-energising electrical equipment where a fault or an explosive atmosphere is detected
Product marking
Recently installed equipment should be marked with the ‘Ex’ marking, as well as the appropriate conformity assessment marking, to show it is suitable for use in potentially explosive atmospheres’. All new equipment being placed on the UK market must comply with the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations which implement the EU Directive 2014/34/EU.
New equipment must be assessed as suitable for a particular explosive atmosphere type and for this to be marked on the equipment along with ATEX markings and an appropriate conformity assessment marking. Most new equipment being sold in the UK for use in potentially explosive atmospheres must have an ATEX certificate.
New equipment and protective systems intended to be used in potentially explosive atmospheres that are placed on the market in Great Britian (England, Scotland and Wales) must be UKCA or CE marked, supplied with a Declaration of Conformity and have instructions in English.
Further guidance on Equipment for explosive atmospheres Regulations (on GOV.UK) is available from the Office for Product Safety and Standards.
Equipment for use in explosive atmospheres should be regularly inspected and maintained to ensure it does not pose an increased risk of causing a fire or explosion. Maintenance of the equipment should only be carried out by people who are competent to do so. BS EN 60079 part 17: Explosive atmospheres. Electrical installations inspection and maintenance offers guidance on the frequency and scope of maintenance required.
There’s more guidance on equipment and ATEX and explosive atmospheres.