Detail of BENZENE HEXACHLORIDE (608-73-1).
Structure:

Name:BENZENE HEXACHLORIDE
CAS Number:608-73-1
Molecular Formula:C₆H₆Cl₆
Molecular Weight:290.82
Properties:Technical grade contains 68.7% α-BHC, 6.5% β-BHC, and 13.5% γ-BHC
Method:Fractional crystallization. The technical grade may run 10–15% γ isomer but can be brought up to 99% (lindane).
Synonyms of BENZENE HEXACHLORIDE (608-73-1):1,2,3,4,5,6-hexachloro-cyclohexan;1,2,3,4,5,6-hexachloro-cyclohexan(mixedisomers);1,2,3,4,5,6 hexachlorocyclohexane(mixtureofisomers);ambiocide;benzahex;benzanex;benzenehexachloride,mixedisomers;benzex

NTP 10th Report on Carcinogens. IARC Cancer Review: Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man , 5 (1974),p. 47.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) .

Confirmed carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data by ingestion and skin contact. Poison by ingestion, skin contact, and subcutaneous routes. Human systemic effects by inhalation: headache, nausea or vomiting, and fever. Implicated in aplastic anemia. Experimental reproductive effects. Mutation data reported. Lindane is more toxic than DDT or dieldrin. Potentially violent reaction with dimethyl-formamide + iron. When heated to decomposition it emits highly toxic fumes of phosgene, HCl, and Cl⁻. See other benzenehexachloride entries.
A toxic organochlorine that is persistent in the environment and accumulates in mammalian tissue. For cattle, the oral LD50 <= 100 mg/kg. The various isomers have different actions; the γ (lindane) and α isomers are central nervous system stimulants, the principal symptom being convulsions. The β and Δ isomers are central nervous system depressants. The use of thermal vaporizers with lindane has caused acute poisoning by inhalation.
The dangerous acute dose of the technical mixture has been estimated at about 30 g and the dangerous dose of lindane at about 7 to 15 g. However, as already mentioned, a single dose of 45 mg (or approximately 0.65 mg/kg) of lindane caused convulsions. Lindane shows a marked difference in toxicity to different species. Its toxic effect on laboratory animals compares favorably with that of DDT, but for several domestic animals, notably calves, lindane is more toxic than DDT or dieldrin. On a chronic systemic basis the α, β and γ isomers are experimental carcinogens. Has been implicated in aplastic anemia.
Dermatitis and perhaps other manifestations based on sensitivity represent a sort of chronic, though probably not systemic intoxication, which has been observed in humans.
The signs and symptoms of confirmed acute poisoning in humans have paralleled those in experimental animals. These signs and symptoms are: excitation, hyperirritability, loss of equilibrium, clonic-tonic convulsions, and later depression.
There is some evidence that the pulmonary edema and vascular collapse may be of neurogenic origin also. The symptoms in animals systemically poisoned by the γ-isomer alone are essentially similar to those caused by mixtures, although the onset may be earlier. Workers acutely exposed to high air concentrations of lindane and its decomposition products show headache, nausea, and irritation of eyes, nose, and throat.
In rare instances, urticaria has followed exposure to lindane vapor. Unlike the signs and symptoms already mentioned, this allergic manifestation occurs only in susceptible individuals, and usually only after a period of sensitization.
Safety Information of BENZENE HEXACHLORIDE (608-73-1).
Hazard Codes:T,N
Risk Statements:21-25-40-50/53-64-48/22-20/21
Safety Statements:22-36/37-45-60-61
RIDADR:2761
RTECS:GV4375000
HazardClass:6.1(b)
PackingGroup:III

ACGIH TLV: TWA 0.5 mg/m³ (skin)