beta-Hexachlorocyclohexane

β-hexachlorocyclohexane

Names
IUPAC name β-1,2,3,4,5,6-hexachlorocyclohexane
Other names β-HCH β-Benzenehexachloride β-BHC
Identifiers
CAS Number	319-85-7
ChEBI	CHEBI:28428
ChEMBL	ChEMBL389022
ChemSpider	10468512
Jmol 3D model	Interactive image
InChI InChI=1S/C6H6Cl6/c7-1-2(8)4(10)6(12)5(11)3(1)9/h1-6H/t1-,2-,3+,4+,5-,6- Key: JLYXXMFPNIAWKQ-CDRYSYESSA-N InChI=1/C6H6Cl6/c7-1-2(8)4(10)6(12)5(11)3(1)9/h1-6H/t1-,2-,3+,4+,5-,6- Key: JLYXXMFPNIAWKQ-CDRYSYESBR
SMILES Cl[C@H]1[C@H](Cl)[C@@H](Cl)[C@H](Cl)[C@@H](Cl)[C@@H]1Cl
Properties
Chemical formula	C6H6Cl6
Molar mass	290.83 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

β-hexachlorocyclohexane (β-HCH) is an organochloride which is one of the isomers of hexachlorocyclohexane (HCH).^[1] It is a byproduct of the production of the insecticide lindane (γ-HCH). It is typically constitutes 5-14% of technical grade lindane,^[2] though it has not been produced or used in the United States for more than 20 years, i.e. since 1985.^[1] As of 2009, the Stockholm Convention on Persistent Organic Pollutants classified (α-HCH) and (β-HCH) as Persistent 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 on cotton 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, are neurotoxic, cause oxidative stress, and damage the brain's dopaminergic system. Human studies show that exposure to beta-HCH is linked to Parkinson's and Alzheimer's disease.^[3] Beta-HCH was present in elevated levels in some patients as recently as 2009. It was manufactured by exhausting chlorination of benzene and for this reason was called erroneously beta-BHC. This synnonym still persists.

In March 2005, the Italian National Monitoring System on Chemical Residuals in Food of Animal Origin detected levels of the pesticide beta-hexachlorocyclohexane (ß-HCH) that were 20 times higher than the legal limit of 0.003 mg/kg in bulk milk from a dairy farm in the Sacco River valley. ß-HCH, a lindane isomer and possible human carcinogen, 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]}

See also

• α-Hexachlorocyclohexane

References

1. Toxicological Profile for Alpha-, Beta-, Gamma-, and Delta-Hexachlorocyclohexane, U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry, August 2005
2. beta-hexachlorocyclohexane (Beta HCH), Draft Risk Profile, May 2007
3. Medscape Medical News, Pesticide Exposure Linked to Parkinson's, Alzheimer's Disease, July 2009
4. , Beta-hexachlorocyclohexane contamination in dairy farms of the Sacco River Valley, Latium, Italy, 2005. A retrospective cohort study
5. , Valle del Sacco: a poisoned land

External links

• beta-Hexachlorocyclohexane (beta-HCH) Quickview – US EPA
• Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1α,2β,3α,4β,5α,6β)- – NIST