Clause 7.7.1 of BS 5306-8 (Fires involving live electrical equipment) states “Only electrically non-conductive extinguishing media, such as non-conductive powder, carbon dioxide or clean agent, should be used on live electrical equipment. Extinguishers containing such media should be provided throughout the premises for use on common electrical hazards (e.g. lighting and small appliances).”

It also adds a warning to stress, “Before any extinguisher is discharged onto live electrical equipment, it is expected that the equipment will be disconnected/isolated. Even where cut-off protection is provided, a fire can cause this to fail, and therefore the use of electrically conductive extinguishing media could result in electrocution. The electrical supply to consumer units/fuse boards will always remain live, except where there is a complete failure of the supply.”

Where electrical equipment is present, fire extinguishers that contain “electrically non-conductive extinguishing media” that is water or water-based may not be suitable in line with Clause 4 of BS 5306-8 (due to purified water potentially reassuming its natural properties and rendering the originally purified water electrically conductive).

BAFE SP101 Registered Organisations will be able to advise the Responsible Person (i.e. the customer) on suitable fire extinguishers for their premises that meet all the requirements of BS 5306-8 and the BAFE SP101 Scheme (which includes additional parts of BS 5306 to also be followed).

Further Information

Clause 4 of BS 5306-8:2023* (Provision of extinguishers – General recommendations) states that, “Water conducts electricity. Use of purified water (e.g. distilled, deionized or de-mineralized) on a fire introduces CO2 from the air, impurities from the products of combustion, and an increase in temperature. This causes the water to reassume its natural properties, and as a result can render the originally purified water electrically conductive.”

This would include “water-based media” examples of which are stated in BS 5306-8 as, “water-with-additive, foam, alcohol-resistant foam and wet chemical.”

Clause 5.4 of BS 5306-8 discussing electrical conductivity states “Only electrically non-conductive extinguishing media, such as non-conductive powder, carbon dioxide, or other clean agent should be specified for use on live electrical equipment.”

*BS 5306-8:2023 is the British Standard for Fire extinguishing installations and equipment on premises Part 8: Selection and positioning of portable fire extinguishers – Code of practice. All information provided is used from this version of the British Standard.

Every effort is made to ensure that the information provided is accurate and up to date as of time of publishing. Any sources of information are stated appropriately. No legal responsibility is accepted for any errors or omissions.