Chlorobenzylidene Malononitrile - CS

CS was developed in the late 1950s as a riot control substance. It is a more potent irritant than chloroacetophenone, but is less incapacitating. In the late 1960s, stocks of CS replaced CN. Presently, the US Army uses CS for combat training and riot control purposes. 

Odor Burnt to create a colorless gas with an acrid pepper-like smell. 

Vapor density Liquid density Solid density Vapor pressure Volatility Solubility 

LCtS0 (respiratory) LCtgo (percutaneous) ICtgo (respiratory) ICtgo (percutaneous) Rate of detoxification 

Skin and eye toxicity Rate of action Overexposure effects 

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Detailed Facts About Tear Agent o-Chlorobenzylidene Malononitrile (CS). Aberdeen Proving... 

Toxicology. o-Chlorobenzylidene malononitrile (CS) aerosol is a potent lacrimator and upper respiratory irritant. 

BallantyneB, Swanston DW The comparative acute mammalian toxicity of 1-chloroace-tophenone (CN) and 2-chlorobenzylidene malononitrile (CS). Arch Toxicol 40 75-95, 1978... 

Marts TC, Colgrave HF, Cross NL, et al A repeated dose study of the toxicity of inhaled 2 -chlorobenzylidene malononitrile (CS) aerosol in three species of laboratory animal. Arch Toxicol 52 183-198, 1983... 

Comparative Acute Mananalian Toxicity of 10-Chioro-5, lQ-dihydrophenarsa ine (DM7, Chloroacetophenone (CN), 2-Chlorobenzylidene Malononitrile (CS), and Oiben (b,f](1,4Joxazepine (CR) ... 

Two chemists, Carson and Stoughton (1928), synthesized 2-chlorobenzylidene malononitrile (CS) however, it was not adopted by the military as an official RCA until 1959. As a more chemically stable compound and having a greater potency with less toxicity than CN, it gradually replaced CN as the preferred RCA. CS was widely used during the Vietnam War to flush the Viet Cong out of the... 

FIGURE 12.5. Chemical structure and physicochemical properties of ortho-chlorobenzylidene malononitrile (CS). 

Chung, C.W., Giles, A.L. (1972). Sensitization of guinea pigs to alpha-chloroacetophenone (CN) and ortho-chlorobenzylidene malononitrile (CS), tear gas chemicals. J. Immunol. 109 284-93. 

Daniken, A., Friederich, U., Lutz, W.K., Schlatter, C. (1981). Tests for mutagenicity in Salmonella and covalent binding to DNA and protein in the rat of the riot control agent o-chlorobenzylidene malononitrile (CS). Arch. Toxicol. 49 15-27. 

Paradowski, M. (1979). Metabolism of toxic doses of o-chlorobenzylidene malononitrile (CS) in rabbits. Pol. J. Pharmacol. Pharm. 31 563-8. 

Kluchinsky Jr., T.A., Sheely, M.V., Savage, P.B., and Smith, P.A. 2002. Formation of 2-chlorobenzylidene-malononitrile (CS riot control agent) thermal degradation products at elevated temperatures. Journal of Chromatography A, 952 205-213. 

Ballantyne, B., Evaluation of ophthalmic hazards from an aerosol generator of o-chlorobenzylidene malononitrile (CS), Mil. Med., 144, 691-694, 1979. 

Ballantyne, B. and Swanston, D.W., 1973, The irritant potential of dilute solutions of ort/m-chlorobenzylidene malononitrile (CS) on the eye and tongue, Acta PharmcoL Toxicol., 32, 266-277, 1973. 

Bauchingher, M. and Schmid, E., Clastogenicity of 2-chlorobenzylidene malononitrile (CS) in V79 Chinese hamster cells, Mutagen. Res., 282, 231-234, 1992. 

COT, Statement on combined exposure to 2-chlorobenzylidene malononitrile (CS) and PAVA (Nonivamide) sprays, COT/OO/Od, dated January 2006, Committee on Toxicity of Chemicals in Food Consumer Products and the Environment, UK Department of Health, London, 2006. 

Holland, P. and Seabright, M., Effects of CS on lymphocyte chromosome structure, in Clinical and Preclinical Studies on Ortho Chlorobenzylidene Malononitrile (CS), Technical Note Number 82, Chemical Defence Establishment, Porton Down, Wiltshire, UK, 1971. 

Reitveld, E.C., Derlbressine, L.P.C., Waegemaekers, T.H.J.M., and Seutter-Berlage, E., 2-Chlorobenzylmer-capturic acid, a metabolite of the riot control agent 2-chlorobenzylidene malononitrile (CS) in the rat. Arch. Toxicol, 54, 139-144, 1983. 

Upshall, D., Effects of o-chlorobenzylidene malononitrile (CS) and the stress of aerosol inhalation upon rat and rabbit embryonic development, Toxicol. Appl. Pharmacol., 24, 45-59, 1973. 

Williams, K. E., Detailed Facts About Tear Agent O-Chlorobenzylidene Malononitrile (CS), United States Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, 1996. 

Figure 1. Concentration-population response curve for threshold peripheral chemosensory irritation to the human eye from an aerosol of 2-chlorobenzylidene malononitrile (CS). Probit analysis of this data gives a TC50 of 4.0 x 10-3 mg m-3...

Table 3. Peripheral chemosensory irritant potency and comparative potency of o-chlorobenzylidene malononitrile CS) and dibenz(b.f)- , 4-oxa/.cpinc (CR) aerosols0...

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