Introduction to Health and Safety at Work

17.12.2 Scope of Regulations
Dangerous substance
The regulations give a detailed interpretation of 
danger-
ous substance
, which should be consulted. In summary 
it means:
➤
a substance or preparation that because of its chem-
ical and sometimes physical properties and the way 
it is present and/or used at work, creates a fi re or 
explosion risk to people; for example, substances like 
petrol, LPG, paints, cleaners, solvents and fl ammable 
gases
➤
any dusts which could form an explosive mixture 
in air (not included in a substance or preparation); 
for example, many dusts from grinding, milling or 
sanding.
Explosive atmosphere
The Regulations give the defi nition as:
a mixture under atmospheric conditions, of 
air and one or more dangerous substances in 
the form of gases, vapours, mists or dusts, in 
which, after ignition has occurred, combus-
tion spreads to the entire unburned mixture.
17.12.3 Application
The Regulations do not in general apply to:
➤
ships under the control of a master,
➤
areas used for medical treatment of patients
➤
many gas appliances used for cooking, heating, hot 
water, refrigeration, etc. (except an appliance specif-
ically designed for an industrial process), gas fi ttings
➤
manufacture, use, transport of explosives or chem-
ically unstable substances
➤
mine, quarry or borehole activities
➤
activity at an offshore installation
➤
the use of means of transport (but the Regulations 
do cover means of transport intended for use in a 
potentially explosive atmosphere).
17.12.4 Risk Assessment – Regulation 5
The risk assessment required by Regulation 5 must 
include:
➤
the hazardous properties of the dangerous substance
➤
suppliers information and safety data sheet
➤
the circumstances of the work including –
➤
work processes and substances used and their 
possible interactions
➤
the amount of substance involved
➤
risks of substances in combination
➤
arrangements for safe handling, storage and 
transport and any waste which might contain 
dangerous substances
➤
high risk maintenance activities
➤
likelihood of an explosive atmosphere
➤
likelihood of ignition sources, including electrostatic 
discharges being present
➤
scale of any possible fi re or explosion
➤
any places connected by openings to areas where 
there could be an explosive atmosphere
➤
any additional information which may be needed.