Sunday, February 6, 2011


Endosulfan is an organochlorine insecticide and acaricide with a cyclodiene sub-group. It is highly toxic and can  bioaccumulate in organisms. It can also act as an endocrine disruptor i.e., it interferes with the synthesis, secretion, transport, binding, action, or elimination of natural hormones in the body that are responsible for the maintenance of homeostasis (normal cell metabolism), reproduction, development, and behavior.

Endosulfan has been used in agriculture around the world to control insect pests including whiteflys, aphids, leafhoppers, Colorado potato beetles and cabbage worms. Because of its non-specificity it impacts many beneficial insects also. It is also used as a wood preservative.

Comercial names : Beosit, Thiodan, Cyclodan, Malix, Thifor, Endocide etc.

Specifically, it is produced by the Diels-Alder reaction of hexachlorocyclopentadiene with cis-butene-1,4-diol and subsequent reaction of the adduct with thionyl chloride.Technical endosulfan is a 7:3 mixture of stereoisomers, designated α and β. α- and β-endosulfan are conformational isomers arising from the pyramidal stereochemistry of sulfur. α-Endosulfan is the more thermodynamically stable of the two, thus β-endosulfan irreversibly converts to the α form, although the conversion is slow.

Endosulfan breaks down into endosulfan sulfate and endosulfan diol, both of which, according to the EPA, have "structures similar to the parent compound and are also of toxicological concern. Since it neither  dissolves in water easily nor stick to soil particles readily, its transport to other regions is easier.

India the world's largest user of endosulfan, and a major producer with three companies—Excel Crop Care, H.I.L., and Coromandal Fertilizers—producing 4,500 tonnes annually for domestic use and another 4,000 tonnes for export.

In 2001, in Kerala, India, endosulfan spraying became suspect when linked to a series of abnormalities noted in local children. Initially endosulfan was banned, yet under pressure from the pesticide industry this ban was largely revoked.

Endosulfan is acutely neurotoxic to both insects and mammals, including humans.  Symptoms of acute poisoning include hyperactivity, tremors, convulsions, lack of coordination, staggering, difficulty breathing, nausea and vomiting, diarrhea, and in severe cases, unconsciousness. Doses as low as 35 mg/kg have been documented to cause death in humans, and many cases of sub-lethal poisoning have resulted in permanent brain damage. Farm workers with chronic endosulfan exposure are at risk of rashes and skin irritation.

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