o-Chlorobenzylidene malonitrile
Agent Name
o-Chlorobenzylidene malonitrile
Major Category
Toxic Gases & Vapors
Synonyms
((2-Chloro-phenyl)methylene)propanenitrile; (o-Chlorobenzal)malononitrile; (o-Chlorobenzylidene)malononitrile; 2-Chlorobenzalmalononitrile; 2-Chlorobenzylidene malonitrile; 2-Chlorobenzylidene malononitrile; 2-Chlorobenzylidenemalononitrile; 2-Chlorobmn; Alonitrile; CS; CS (lacrimator); Malononitrile, (o-chlorobenzylidene)-; Propanedinitrile, ((2-chlorophenyl)methylene); TL 238; beta,beta-Dicyano-o-chlorostyrene; chlorobenzylidenemalononitrile; o-Chlorobenzylidene malonitrile; o-Chlorobenzylidene malononitrile; o-Chlorobenzylidenemalonic nitrile; ortho-Chlorobenzylidene malononitrile; OCBM; [ChemIDplus] UN2811
Description
White crystalline solid with a pepper-like odor; [NIOSH]
Sources/Uses
Occupational exposures can occur during the manufacturing and formulation of OCBM for a riot control agent; [NIOSH Guidelines for Chemical Hazards]
Comments
This is the active ingredient in the "CS" type of tear gas. No CS-related deaths have been reported. [NIOSH Guidelines for Chemical Hazards] A potential skin sensitizer; Sufficient data not available to recommend a SEN notation; Median incapacitating dose is 12-20 mg/m3; Incapacitating symptoms within 20 seconds and persist for 5-10 minutes after removal to fresh air; [ACGIH] A lachrymator; [HSDB] A skin sensitizer; Severely irritating to the eyes, skin, and respiratory tract; [ICSC]
Skin Designation (ACGIH)
Yes
Ceiling (ACGIH)
0.05 ppm, inhalable fraction and vapor
Excerpts from Documentation for IDLHs
Human data: It has been reported that median incapacitating concentrations range from 12 to 20 mg/m3 after about 20 seconds of exposure [U.S. Depts of Army and Air Force 1963] and that a 2minute exposure to concentrations between 2 and 10 mg/m3 was considered "intolerable" by 6 of 15 persons [Army 1961]. In another study, 3 of 4 volunteers exposed to 1.5 mg/m3 for 90 minutes developed headaches and 1 volunteer developed slight eye and nose irritation; human volunteers have found concentrations greater than 10 mg/m3 to be extremely irritating and intolerable for more than 30 seconds because of burning and pain in the eyes and chest [Punte et al. 1963]. Exposures above 14 mg/m3 for 1 hour produced extreme irritation, erythema, and vesication of the skin of volunteers [Weigand 1969].
Vapor Pressure
3E-05 mm Hg
Lethal Concentration
LCLo (rat) = 1,806 mg/m3/45M
ACGIH Carcinogen
Not Classifiable
Diseases
Occupational diseases associated with exposure to this agent: