Police trials of CS sprays should be suspended following what is thought to be the first death of a man arrested by officers using one of the canisters, civil liberties campaigners said yesterday.
Ibrahima Sey, 29, died shortly after police used the controversial spray to restrain himduring a row with his wife outside their home in Forest Gate, east London, early on Saturday.
A post-mortem examination showed that Ghanaian-born Mr Sey collapsed after a period of exertion and was suffering from hypertensive heart disease. A Scotland Yard spokesman said: "The findings of the post-mortem do not link the death to CS incapacitant spray at this stage. Further tests will be undertaken."
Toxicology tests, involving analysis of blood, heart and brain, are being carried out to see if the spray, now being tested by 2,300 officers in 16 forces, brought about Mr Sey's collapse or contributed to his death.
But critics of the six-month trial, which began on 1 March, say that not enough is known about the effects of the spray, and two weeks ago, a leaked document from the Association of Chief Police Officers acknowledged that there were "possible health risks".
The canisters, which are supposed to be used defensively to restrain violent people, mix CS powder with a solvent and are sprayed into the face. This causes breathing difficulties, streaming eyes and nose, spasms of the eyelids and in some cases blistering to the skin. Three police officers are suing for damages, alleging that they were injured by the gas during testing of the sprays before the current trials were introduced.
Dr Alistair Hay, reader in chemical pathology at Leeds University, who has studied CS gas, said: "My major concern has been the effect on asthmatics and that it can cause people to develop a condition called reactive airways dysfunction syndrome."
Science, page 20