Electrical equipment for flammable atmospheres

Question 1

Has an assessment of the work areas and storage areas been carried out and appropriate ‘zones’ assigned in accordance with DSEAR?

Answer 1

An assessment of the work areas and storage areas should be carried out and
appropriate ‘zones’ assigned in accordance with the DSEAR 2002 and BS EN
60079-10-1 (refs 13 and 20).

Question 2

In the hazard zones identified in the DSEAR assessment, are all sources of ignition, including those associated with electrical sparks or hot surfaces of electrical apparatus, excluded or protected?

Answer 2

Where flammable or highly flammable liquids are present, although control measures are taken to minimise their uncontrolled release as far as is reasonably practicable, there will always remain the possibility of an explosive/flammable atmosphere occurring. In the hazard zones identified in the DSEAR assessment all sources of ignition, including those associated with electrical sparks or hot surfaces of electrical apparatus, should be excluded or protected

Question 3

Has certified explosion-protected electrical apparatus and cabling been selected for use in hazard zones?

Answer 3

Should it be necessary to use electrical apparatus or install wiring in hazardous
areas it is imperative that it is suitable for use in a flammable atmosphere.

Expert advice may need to be sought for this assessment, because enclosed processes may produce different zoning risk assessments from when the same flammable liquids are in use in open areas. In the former case they have a reduced exposure probability. Certified explosion-protected electrical apparatus and cabling appropriate for the relevant zones should then be selected.

All electrical equipment used in these areas shall comply with BS EN 60079-10-1 (ref 20) or equivalent. (Also see RISCAuthority recommendations RC30, ref 5.)