The term 'so far as is reasonably practicable' is used several times in the COSHH Regulations, and needs to be clearly understood in the context of these Regulations.

It has been interpreted by the courts as allowing economic considerations to be taken into account as one factor with, for example, time or trouble, to be set against the risk.

It is reasonably practicable to take measures up to the point where the taking of further measures becomes grossly disproportionate to any residual risk.

The greater the risk, the more likely it is that it is reasonable to go to substantial expense, trouble and invention to reduce it.

However, if the risk is small, it would not be considered reasonable to go to great expense.

Ultimately, the judgement is an objective one based on the health risks and not on the size or financial position of the employer.

Where the hazardous substance has been allocated a WEL (Workplace Exposure Limit) and also been designated as either an Asthmagen, Mutagen or Carcinogen the health risks are considered to be greater and therefore the amount of expense trouble and invention to which it is reasonable to go to reduce exposure will be greater than for other substances.