HC Deb 11 March 1968 vol 760 cc227-8W
Mr. Dalyell

asked the Secretary of State for Defence what is the toxicity of CS gas, ortho chloro benzyl malono

for the secondment of a senior police officer.

Following is the information;

nitrile, developed at the Chemical Defence Establishment, Porton; and whether it is lethal.

Mr. Mason

The toxicity of CS vapour, expressed in milligram minutes per cubic metre to give a 50 per cent. probability of death, has been estimated from experimental evidence to be 45,000 for rats and 150,000 for larger animals comparable with man. The latter is 50,000 times the dose which can be tolerated by a human being and about 200,000 times the amount needed to disperse rioters. CS has been used on a world-wide basis for about seven years, but no authenticated report has been received of death or injury resulting from its inhalation.