Toxaphene is an organochlorine insecticide that is similar to
other compounds such as endrin, dieldrin, aldrin, dichlorodiphenyltrichloroethane
(DDT), lindane, and chlordecone.
Manufacturing of toxaphene was started in the 1940s and
was highly effective on cotton and certain food crops. In
addition to its use as an insecticide, toxaphene was also used
to eliminate certain species of fish in aquatic environments.
Toxaphene itself consists of a mixture of hundreds of
different chemicals with a major identified toxic component
being heptachlorobornane. The use of toxaphene peaked in
1974 after DDT was banned in 1972 with nearly
400 000 metric tons being distributed into the environment
(both land and aquatic uses). This use began to subside, yet
nearly 100 000 metric tons was still used in 1980 shortly
before the complete ban on toxaphene usage. Large quantities
of toxaphene were released into the environment. The
overall chlorine content of toxaphene is nearly 70% by
weight with most of the organic compounds comprising
toxaphene being chlorinated. The molecular weight of the
various components of toxaphene can range from 308 to
551 g mol-1. The mean formula weight is approximately
414 g mol-1. Toxaphene can be found as an yellowish-waxy
substance that is relatively volatile and can be transported in
the atmosphere. If inhaled, especially in larger quantities,
toxaphene has been shown to cause significant damage to
the lungs/respiratory tract, central nervous system, and
kidneys. The use of toxaphene as an insecticide was banned in the early 1980s and completely banned in the United
States in 1990. In addition to its ban in North America,
toxaphene has been also banned in Europe, yet its use in
developing countries still persists. Toxaphene is not readily
soluble in water and tends to deposit in the soil and sediment,
as well as the atmosphere. Microorganisms in the soil
tend to degrade toxaphene very slowly. Toxaphene does not
degrade as slowly as DDT but has been demonstrated to
persist in the environment for extended and significant
periods of time.
