Control of Substances Hazardous to Health

Assessment before use[edit]

The Regulations require that an assessment of the risk to health is carried out before work with a hazardous substance begins, and that steps are taken to prevent or adequately control exposure.^[1] The sequence matters: the assessment precedes the work rather than documenting it afterwards.

Control is required to be achieved by measures other than personal protective equipment so far as is reasonably practicable, with PPE used where adequate control cannot be achieved otherwise.^[1] Reaching for gloves and a mask first, and treating them as the control, inverts the order the Regulations set.

Why it is separate from authorisation[edit]

A biocidal product may be authorised for use on roofs and still be a substance hazardous to health for the person applying it. Authorisation under the Biocidal Products Regulation answers whether the product may be supplied and used;^[3] COSHH answers what must be done to protect the person using it.^[1]

Conflating the two produces a common and mistaken inference: that because a product is authorised, no assessment is needed. The two regimes are addressed to different people about different risks.

Dilution, decanting and mixing[edit]

Concentrate is more hazardous than the diluted solution, and the point of highest exposure in roof cleaning is usually decanting and mixing rather than application. That is a practical consequence of the assessment requirement rather than a separate rule, but it is where the assessment most often has work to do.