Introduction to Fire Safety Management

15.17
The Dangerous Substances 
and Explosive Atmospheres 
Regulations 2002 (SI 2776)
These regulations impose requirements for the purpose 
of eliminating or reducing risks to safety from fi re, explo-
sion or other events arising from the hazardous proper-
ties of a ‘dangerous substance’ in connection with work.
Dangerous substances are defi ned as:
(a) substances or preparations which are explosive, 
oxidising, extremely fl ammable, highly fl ammable or 
fl ammable, whether or not that substance or prepa-
ration is classifi ed under the Chemicals (Hazard 
Information and Packaging for Supply) Regulations 
2002
(b) substances or preparations which due to their 
physico-chemical or chemical properties and the 
way they are used or are present at the workplace 
create a risk or
(c) any dust, whether in the form of solid particles or 
fi brous materials or otherwise, which can form an ex-
plosive mixture with air or an explosive atmosphere.
Dangerous substances include: petrol; liquefi ed petro-
leum gas (LPG); paints; varnishes; solvents; and dusts 
which when mixed with air could cause an explosive 
atmosphere, for example dusts from milling and sand-
ing operations. Dangerous substances can be found, in 
varying quantities, in most workplaces.
An explosive atmosphere is an accumulation of 
gas, mist, dust or vapour, mixed with air, which has 
the potential to catch fi re or explode. An explosive 
atmosphere does not always result in an explosion, but 
if it caught fi re the fl ames would quickly travel through 
it and if this happened in a confi ned space (e.g. in plant 
or equipment) the rapid spread of the fl ames or rise in 
pressure could also cause an explosion.
15.17.1 Employers general duties – regulation 4
The employer must:
➤
Carry out a risk assessment of any work activities 
involving dangerous substances
➤
Provide measures to eliminate or reduce risks as far 
as is reasonably practicable
➤
Provide equipment and procedures to deal with 
accidents and emergencies
➤
Provide information and training to employees
➤
Classify places where explosive atmospheres 
may occur into zones and mark the zones where 
necessary.