1,2,3,4,5,6-Hexachlorocyclohexane (HCH)
Hexachlorocyclohexane (C6H6Cl6)
Other names
HCH, benzene hexachloride, 666
CAS Number
608-73-1
Properties
- white or yellow powder
- mouldy odour
- mixture of alpha, beta, gamma and delta isomers: differing three-dimensional arrangement of the chorine atom on the cyclohexane ring
- differ greatly in their biological activity
- alpha-, beta- and gamma-HCH are persistent organic pollutants
Main sources
- agriculture: insecticide
Thresholds for the reporting requirement of facilities in accordance with Annex 2 PRTRO
(Ordinance on the Register relating to Pollutant Release and the Transfer of Waste and of Pollutants in Waste Water)
- Air 10 kg/year
- Water 1 kg/year
- Soil 1 kg/year
Impacts
- carcinogenic
- toxic to humans, animals and aquatic organisms
- alpha- and gamma-HCH: affect the central nervous system (effect of mixture depends on the exact composition)
- beta- and delta-HCH: sedative (effect of mixture depends on the exact composition)
- bioaccumulation
- has a long half-life, very persistent in the environment
Measures
- all isomers banned in Switzerland since 2005
- included on the list of banned substances by the Stockholm Convention in May 2009
Further information
Last modification 16.12.2016