§ Mr. Livingstone
To ask the Secretary of State for Defence what is the Chemical Defence Establishment's evaluation of the effects of short-term exposure to lewisite. 
§ Mr. Spellar
This is a matter for the Chief Executive of the Defence Evaluation and Research Agency (DERA). I have asked the Chief Executive to write to the hon. Member.
Letter from John Chisholm to Mr. Ken Livingstone, dated 13 January 1998:I am replying to your question to the Secretary of State for Defence about the evaluation of the effects of short term exposure to lewisite as this matter is my responsibility as Chief Executive of the Defence Evaluation and Research Agency (DERA).I have nothing to add to my letter to you of 20 August 1997 (Official Report dated 27 October col. 660) in which I said that lewisite is one of a group of chemical warfare agents known as vesicants or blistering agents. I also explained that DERA's Chemical and Biological Defence Sector's evaluation, based on US human studies from the 1940s and continuing Porton Down animal studies, of the effects of short term exposure to lewisite are that both liquid and vapour forms result in chemical burns to the skin, eyes and respiratory tract. Lewisite injuries are immediately painful. The potential for widespread damage to the internal organs is significant.