asked the Secretary of State for Employment what is the lowest level of noise considered by his Department to constitute a serious threat to hearing; and if he will make a statement.

[pursuant to his reply, 19 November 1979]: Guidance on levels of noise exposure which are regarded as a serious hazard to hearing is contained in the code of practice for reducing the exposure of employed persons to noise. The code, whilst recognising that, because of the large inherent variations of susceptibility between individuals, these levels do not remove all risk of damage, recommends an upper limit of 90dB(A) for eight hours per day, or an equivalent exposure, for workers not wearing ear protection and that sound should be reduced to lower levels where reasonably practicable.