§ Mr. Livingstone
To ask the Secretary of State for Defence for what reasons his Department stopped exposing service personnel at the defence nuclear biological and chemical centre at Winterbourne Gunner to mustard agent; and what health and safety guidelines applied to such exposure. 
§ Dr. Reid
I regret that surviving records reveal very little about the exposure of personnel to Mustard Agent at the Defence Nuclear, Biological and Chemical Centre (DNBCC). It is known, however, that, between 1966 and 1980, students at the Centre were exposed to a small amount of the Agent, about the size of a pinhead, on their wrist as part of Confidence Training. The intention was to prove and give confidence to the chemical agent decontamination process which was taught by the Centre and which the students were expected to teach to members of their parent units on their return. The practice was stopped on advice from the Chemical Biological Defence Establishment at Porton Down because it was not compatible with emerging health and safety guidelines.
Procedures for the conduct of the test were laid down in a NBC Defence Training Pamphlet and were explicit in their instructions as to the safety precautions to be observed, but no specific health and safety guidelines were extant at the time covering these specific types of test. I regret that no further details are available.