COSHH - Coverage: Prevention
The regulations cover preventing or controlling the exposure of individuals to a substance hazardous to health where such people are associated directly with an employer's activity that gives rise to exposure, for example, employees or contractors who handle a substance hazardous to health in their jobs (such as those manning petrol pumps in a non-self-service filling station), or customers or other members of the public who handle a substance hazardous to health in obtaining goods or services (such as when using a petrol pump in a self-service filling station).
The regulations also cover preventing or controlling the exposure of people to a substance hazardous to health where they are NOT associated directly with an employer's activity that gives rise to exposure. Typical examples of this would be employees or contractors whose jobs do not involve a substance hazardous to health but are carried out sufficiently close to such a substance to be at risk (such as those working in the accounts office at a chemical works, or any workers exposed to legionnaire's disease from the employer's water tanks).
With regard to non-employees, an example would be customers or members of the public who happen to be sufficiently close to a substance hazardous to health to be at risk (such as those visiting or near to a vehicle body repair and spray shop, or neighbours and passers-by exposed to legionnaire's disease from a nearby employer's water tanks).