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| Names | |
|---|---|
| Preferred IUPAC name (1r,2r,3r,4r,5r,6r)-1,2,3,4,5,6-Hexachlorocyclohexane | |
| Other names β-HCH β-Benzenehexachloride β-BHC | |
| Identifiers | |
| |
3D model (JSmol) | |
| 1907338 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.005.703 |
| EC Number |
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| KEGG | |
| UNII | |
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| Properties | |
| C6H6Cl6 | |
| Molar mass | 290.83 g/mol |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
β-Hexachlorocyclohexane (β-HCH) is anorganochloride which is one of the isomers ofhexachlorocyclohexane (HCH).[1] It is a byproduct of the production of theinsecticidelindane (γ-HCH). It is typically constitutes 5–14% oftechnical-grade lindane,[2] though it has not been produced or used in the United States since 1985.[1] As of 2009, theStockholm Convention on Persistent Organic Pollutants classified α-hexachlorocyclohexane and β-HCH aspersistent organic pollutants (POPs), due to the chemical's ability to persist in the environment,bioaccumulative,biomagnifying, and long-range transport capacity.
This pesticide was widely used during the 1960s and 1970s, particularly oncotton plants. Although banned as a pesticide more than 30 years ago, traces of beta-HCH can still be found in water and soil. Animal studies show that organochlorine pesticides, including beta-HCH, areneurotoxic, causeoxidative stress, and damage the brain'sdopaminergic system. Human studies show that exposure to beta-HCH is linked toParkinson's andAlzheimer's disease.[3] β-HCH was present in elevated levels in some patients as recently as 2009.It was manufactured by exhausting chlorination ofbenzene and for this reason was called erroneously β-BHC. This synonym still persists.
In March 2005, the Italian National Monitoring System on Chemical Residuals in Food of Animal Origin detected levels of the pesticide β-HCH that were 20 times higher than the legal limit of 0.003 mg/kg in bulk milk from a dairy farm in theSacco River valley. β-HCH, a lindaneisomer and possible humancarcinogen, was subsequently found in milk from several neighboring farms. A study was therefore undertaken to evaluate the extent and risk factors for contamination.[4][5]
