[Assessment of health effects of CS gas]

O-chlorobenzylidene malononitrile (CS) gas or aerosol is by no means a harmless tear-gas, as often is described; in particular, CS is a very effective irritating war gas. The effects of CS on humans are relatively unknown because publications in this respect are mostly on military medical research, partly classified as secret, and brought to the knowledge of a small number of experts only. CS is highly soluble in water, and hence the effects in police water jets are very low. The efficacy of CS-containing water-jetting consists only in the pressure of the jet stream. Medically, in police use, CS is therefore considered to be harmless. Military medical research results, however, show that persons older than 30 years, those under physical strain, and those with hitherto undetected aneurysm are especially at risk.