HC Deb 13 February 1979 vol 962 cc470-1W
Mrs. Bain

asked the Secretary of State for Employment what recent investigations have revealed concerning precautions taken in processing and effluent treatment and disposal arising in (a) dye-handling processing and (b) textile dye stripping processes which involve benzidine azo dyes and may result in the substantial release of highly carcinogenic benzidine.

Mr. John Grant

The chairman of the Health and Safety Commission informs me that during 1978 tests were made in several dye houses in West Yorkshire to determine the quantity of amine base evolved during dye stripping processes. Nothing of significance was discovered.

The Factory Inspectorate is stressing the need to take general precautions in colour stores and dye houses to limit as far as practicable contact with benzidine azo dyes.

The water authorities and Water Research Centre are examining effluent treatment and disposal for dyes generally including benzidine azo dyes. No special problem involving benzidine azo dyes has emerged as yet.

Mrs. Bain

asked the Secretary of State for Employment if he will list in the Official Report the maximum and average levels in parts per million of free benzidine in imported benzidine azo dyes and give an assurance on the level of free benzidine which does not constitute a risk of causing bladder cancer amongst workers using the dyes.

Mr. John Grant

The chairman of the Health and Safety Commission informs me that there are approximately 250 different dyes in the class known as benzidine azo dyes which are made from the aromatic amine benzidine. Trace quantities of free benzidine are known to be present in such dyes, to the extent of a few tens of parts per million, but it is not possible to list the maximum and average levels as requested by the hon. Member since the amount may vary from batch to batch, even from the same manufacturer.

The chairman further informs me that the Health and Safety Executive has no epidemiological evidence to show that there is any risk of developing bladder cancer among workers handling benzidine azo dyes but he is unable to give an assurance on the level of free benzidine which does not constitute a risk of causing bladder cancer amongst such workers.