Chemical Properties
BHC is a white-to-brownish crystalline solid
with a musty, phosgene-like odor.
Physical properties
Although β-BHC is a solid at room temperature, the odor threshold concentration is 0.32 μg/kg
(Sigworth, 1964).
Uses
β-1,2,3,4,5,6-Hexachlorocyclohexane is an organochloride which is one of the isomers of hexachlorocyclohexane and is also an byproduct of insecticide Lindane (L465990).
Definition
ChEBI: The beta-isomer of hexachlorocyclohexane.
General Description
Colorless crystals. Corrosive to aluminum and many other metals.
Air & Water Reactions
Slightly soluble in water.
Reactivity Profile
Halogenated aliphatic compounds, such as BETA-HCH, are moderately or very reactive. Reactivity generally decreases with increased degree of substitution of halogen for hydrogen atoms. Materials in this group may be incompatible with strong oxidizing and reducing agents. Also, they may be incompatible with many amines, nitrides, azo/diazo compounds, alkali metals, and epoxides. Dehydrochlorination occurs in the presence of alkalis.
Health Hazard
ACUTE/CHRONIC HAZARDS: Highly toxic carcinogen. May cause irritation on contact. Hazardous decomposition products.
Safety Profile
Confirmed carcinogen
with experimental neoplastigenic data.
Mildly toxic by ingestion. When heated to
decomposition it emits very toxic fumes of
Cl-, HCl, and phosgene. See also
BENZENE HEXACHLORIDE and other
benzenehexachloride entries.
Potential Exposure
The major commercial usage of BHC
is based upon its insecticidal properties. α-BCH is used as
an Agricultural chemical, pesticide, pharmaceutical, and
veterinary drug. The 7-isomer has the highest acute toxic ity, but the other isomers are not without activity. It is gen erally advantageous to purify the 7-isomer from the less
active isomers. The γ-isomer acts on the nervous system of
insects, principally at the level of the nerve ganglia. As a
result, lindane has been used against insects in a wide range
of applications including treatment of animals, buildings,
humans for ectoparasites, clothes; water for mosquitoes;
living plants; seeds and soils. Some applications have been
abandoned due to excessive residues, e.g., stored food stuffs. By voluntary action, the principal domestic producer
of technical grade BHC requested cancellation of its BHC
registrations on September 1, 1976. As of July 21, 1978, all
registrants of pesticide products containing BHC voluntar ily canceled their registrations or switched their former
BHC products to lindane formulations.
Environmental Fate
Soil. No biodegradation of β-BHC was observed under denitrifying and sulfate-reduc ing conditions in a contaminated soil collected from The Netherlands (Bachmann et al.,
1988). In four successive 7-day incubation periods, β-BHC (5 and 10 mg/L) was recalci trant to degradation in a settled domestic wastewater inoculum (Tabak et al., 1981).
Chemical/Physical. Emits very toxic fumes of chlorides, hydrochloric acid and phos gene when heated to decomposition (Lewis, 1990). β-BHC will not hydrolyze to any
reasonable extent (Kollig, 1993).
Shipping
UN2761 Organochlorine pesticides, solid, toxic,
Hazard Class: 6.1; Labels: 6.1-Poisonous materials.
Incompatibilities
Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explo sions. Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides. Decomposes on contact
with powdered iron, aluminum, zinc, and on contact with
strong bases producing trichlorobenzene.
Waste Disposal
A process has been developed
for the destructive pyrolysis of benzene hexachloride @
400 500℃ with a catalyst mixture which contains 5 10%
of either cupric chloride, ferric chloride; zinc chloride; or
aluminum chloride on activated carbon.
