Introduction to Health and Safety at Work

17.11.6
Step 3 – prevention or control of 
exposure – Regulation 7
Every employer must ensure that exposure to sub-
stances hazardous to health is either:
➤
prevented or, where this is not reasonably practicable
➤
adequately 
controlled.
Preference must be given to substituting with a safer 
substance. Where it is not reasonably practicable to pre-
vent exposure, protection measures must be adopted in 
the following order of priority:
➤
The design and use of appropriate work processes, 
systems and engineering controls and the provision 
and use of suitable work equipment
➤
The control of exposure at source, including ade-
quate ventilation systems and appropriate organiza-
tional measures, and
➤
Where adequate control of exposure cannot be 
achieved by other means, the additional provision of 
suitable personal protective equipment.
The measures must include:
➤
Safe handling, storage and transport (plus waste)
➤
Reducing to a minimum required for the work the 
number of employees exposed, the level and duration 

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Summary of the main legal requirements
341
of exposure, the quantity of substance present at the 
workplace
➤
The control of the working environment including 
general ventilation
➤
Appropriate hygiene measures.
Control of exposure shall only be treated as adequate if:
➤
The principles of good practice as set out in sched-
ule 2A are applied
➤
Any workplace exposure limit approved for that sub-
stance is not exceeded, and
➤
For a carcinogen (in schedule 1 or with risk phrase 
R45, R46 or R49) or sensitizer (Risk phrases R42 or 
R42/43) or asthmagen (Section C of HSE publication 
on Asthmagens (ISBN 0-7176-1465-4) exposure is 
reduced to as low a level as is reasonably practicable.
Additionally, respiratory protective equipment must be:
➤
suitable for the purpose
➤
comply with the EC Directive Regulations or
➤
if there is no requirement imposed by these regula-
tions, be of a type or shall conform to a standard, 
approved by the HSE.
Where exposure to a Carcinogen or Biological Agent 
is involved, additional precautions are laid down in 
Regulation 7.