CS gas

This article is about the tear gas. For the compound with the molecular formula CS, see Carbon monosulfide.

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.

CS gas
Skeletal formula of CS gas
Space-filling model of CS gas
Names
Preferred IUPAC name
[(2-Chlorophenyl)methylidene]propanedinitrile
Other names
2-(2-Chlorobenzylidene)malononitrile
2-Chlorobenzalmalononitrile
o-Chlorobenzylidene malononitrile
Tear gas
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.018.435 Edit this at Wikidata
EC Number
  • 220-278-9
RTECS number
  • OO3675000
UNII
UN number 2810, 3276, 2811
  • InChI=1S/C10H5ClN2/c11-10-4-2-1-3-9(10)5-8(6-12)7-13/h1-5H checkY
    Key: JJNZXLAFIPKXIG-UHFFFAOYSA-N checkY
  • InChI=1/C10H5ClN2/c11-10-4-2-1-3-9(10)5-8(6-12)7-13/h1-5H
    Key: JJNZXLAFIPKXIG-UHFFFAOYAA
  • Clc1ccccc1\C=C(/C#N)C#N
Properties
C10H5ClN2[1]
Molar mass 188.6 g/mol[2]
Appearance White crystalline powder
Colourless gas when burned
Odor Pepper-like[3]
Density 1.04 g/cm3
Melting point 93 °C (199 °F; 366 K)
Boiling point 310 °C (590 °F; 583 K)[4]
Insoluble
Vapor pressure 3.4×10−5 mmHg at 20 °C
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: ToxicGHS07: Exclamation markGHS08: Health hazardGHS09: Environmental hazard
Danger
H302, H314, H330, H335, H372, H410
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)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
1
0
Lethal dose or concentration (LD, LC):
  • 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)[5]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 0.05 ppm (0.4 mg/m3)[3]
REL (Recommended)
 C 0.05 ppm (0.4 mg/m3) [skin][3]
IDLH (Immediate danger)
 2 mg/m3[3]
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).
checkY verify (what is checkY☒N ?)

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.

  1. ^ Williams KE. "Detailed Facts About Tear Agent O-Chlorobenzylidene Malononitrile (CS)]" (PDF). U.S. Army Center for Health Promotion and Preventive Medicine. Archived from the original (PDF) on 26 September 2007.
  2. ^ Heinrich U (September 2000). "Possible lethal effects of CS tear gas on Branch Davidians during the FBI raid on the Mount Carmel compound near Waco, Texas" (PDF). Archived (PDF) from the original on 25 December 2014. Retrieved 23 September 2007.
  3. ^ a b c d NIOSH Pocket Guide to Chemical Hazards. "#0122". National Institute for Occupational Safety and Health (NIOSH).
  4. ^ Hoenig, Steven L. (2006). Compendium of Chemical Warfare Agents. Springer. p. 138. ISBN 978-0-387-34626-7.
  5. ^ "o-Chlorobenzylidene malononitrile". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).