CS gas

CS gas
Names
	Preferred IUPAC name [(2-Chlorophenyl)methylidene]propanedinitrile
	Other names 2-(2-Chlorobenzylidene)malononitrile; 2-Chlorobenzalmalononitrile; o-Chlorobenzylidene malononitrile; Tear gas
Identifiers
CAS Number	2698-41-1 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL1256101;
ChemSpider	16644 ;
ECHA InfoCard	100.018.435
EC Number	220-278-9;
IUPHAR/BPS	4158;
PubChem CID	17604;
RTECS number	OO3675000;
UNII	D8317IAV7Q;
UN number	2810, 3276, 2811
CompTox Dashboard (EPA)	DTXSID9020297 ;
	InChI InChI=1S/C10H5ClN2/c11-10-4-2-1-3-9(10)5-8(6-12)7-13/h1-5H Key: JJNZXLAFIPKXIG-UHFFFAOYSA-N ; InChI=1/C10H5ClN2/c11-10-4-2-1-3-9(10)5-8(6-12)7-13/h1-5H Key: JJNZXLAFIPKXIG-UHFFFAOYAA;
	SMILES Clc1ccccc1\C=C(/C#N)C#N;
Properties
Chemical formula	C10H5ClN2
Molar mass	188.6 g/mol
Appearance	White crystalline powder; Colourless gas when burned
Odor	Pepper-like
Density	1.04 g/cm3
Melting point	93 °C (199 °F; 366 K)
Boiling point	310 °C (590 °F; 583 K)
Solubility in water	Insoluble
Vapor pressure	3.4×10−5 mmHg at 20 °C
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H314, H330, H335, H372, H410
Precautionary statements	P260, P261, P264, P270, P271, P273, P280, P284, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P314, P320, P321, P330, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	2 1 0
	Lethal dose or concentration (LD, LC):
LCLo (lowest published)	1806 mg/m3 (rat, 45 min); 2753 mg/m3 (mouse, 20 min); 1802 mg/m3 (rabbit, 10 min); 2326 mg/m3 (guinea pig, 10 min);
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.05 ppm (0.4 mg/m3)
REL (Recommended)	C 0.05 ppm (0.4 mg/m3) [skin]
IDLH (Immediate danger)	2 mg/m3
Related compounds
Related compounds	SDBS 5-chloro-2-quinolinecarbonitrile ; 6-chloro-2-quinolinecarbonitrile ; 7-chloro-2-quinolinecarbonitrile
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

The compound 2-chlorobenzalmalononitrile (also called o-chlorobenzylidene malononitrile; chemical formula: C₁₀H₅ClN₂), a cyanocarbon, is the defining component of the lachrymatory agent commonly referred to as CS gas, a tear gas which is used as a riot control agent, and is banned for use in warfare due to the 1925 Geneva Protocol.

Exposure causes a burning sensation and tearing of the eyes to the extent that the subject cannot keep their eyes open, and a burning irritation of the mucous membranes of the nose, mouth and throat, resulting in profuse coughing, nasal mucus discharge, disorientation, and difficulty breathing, partially incapacitating the subject. CS gas is an aerosol of a volatile solvent (a substance that dissolves other active substances and that easily evaporates) and 2-chlorobenzalmalononitrile, which is a solid compound at room temperature. CS gas is generally accepted as being non-lethal.