§ Mr. Llew SmithTo ask the Secretary of State for Defence what quantities of nerve gas stocks have been disposed of; what locations were used for this dumping; and what monitoring has been done subsequently of these sites.
§ Mr. SoamesThe United Kingdom has undertaken the disposal of sizeable quantities of nerve agents on three occasions since 1946. In 1946, British forces disposed of some 3,000 tons of captured German WWII munitions containing nerve agent in hulks scuttled in the Skagerrak. An additional 17,000 tons of captured German munitions were similarly dumped at sea in the north Atlantic in 1955–56. No subsequent monitoring of the Atlantic dump sites was undertaken in view of their depth—over 2,000 m—and because, on exposure to sea water, nerve agents rapidly decompose to non-toxic compounds through dilution and hydrolysis. Monitoring of the Skagerrak sites by the Norwegian Defence Research Establishment in 1990 and the Swedish Maritime Department in. 1992 showed no evidence of nerve agents or their decomposition products.
Finally, some 20 tons of nerve agent produced prior to 1956 was destroyed by chemical hydrolysis and dilution at the former Chemical Defence Establishment, Nancekuke, Cornwall in 1968. Following tests to ensure the hydrolysed material was harmless to the marine environment, it was discharged into the sea. Additionally, from time to time, small quantities of agents are destroyed routinely by chemical methods and incineration at CBDE, Porton Down.