Hexachlorocyclohexane

HCH; 1,2,3,4,5,6-Hexachlorocyclohexane; benzene hexachloride; formula: C6H6Cl6; CAS Registry Number: 608-73-1
General Structure of Hexachlorocyclohexane
Source: PubChem
Identifier: CID 727
URL: https://pubchem.ncbi.nlm.nih.gov/compound/727#section=2D-Structure

Several isomeric compounds among the group of chlorinated hydrocarbons

Commercial production of Hexachlorocyclohexane (HCH) started after the 2nd world war. During the process of synthesis which requires benzene and chlorine, a mixture of different isomers evolves. This so called technical HCH consists of 65-70% α-HCH, 7-20% β-HCH, 14-15% γ-HCH, 6-10% δ-HCH , and 1-2% ε-HCH. Of all isomers, only γ-HCH has insecticidal properties. A product consisting of at least 99% γ-HCH is called Lindane.

Technical HCH has been banned in the Federal Republic of Germany in 1977 and the uses of the insecticide Lindane are restricted to date. In the former German Democratic Republic (GDR) lindane was, next to DDT, the most widely used insecticide since the 1970s. Considerable amounts of lindane were produced in the GDR itself but it was also imported from other Eastern Bloc States.

HCH contamination of the environment is a result of former uses of products containing HCH or lindane, e.g. in agriculture and forestry, in veterinary medicine and in households. Furthermore, residues from lindane production are still present in the environment. The production of one metric ton of lindane generates about nine tons of non-insecticidal isomers which were often improvidently disposed on dumping grounds.

The three main HCH-isomers alpha, beta and gamma were included in the Stockholm POP-Convention in 2009.

Substances

  • alpha-HCH
    The main constituent of technical HCH
  • Lindane (gamma-HCH)
    Highly effective insecticide that was banned from agricultural use in 2002 and restricted in pharmaceutical use in 2007
  • beta-HCH
    Most persistent HCH-isomer with the highest potential for biomagnification

Specimen

  • Common mussel species as invasive animal in rivers and lakes with high information level for water pollution
  • Bioindicator in rivers and lakes
  • Fine insoluble mineral or organic particles in the water phase
  • Common brown alga of the coastal areas of the North and Baltic Sea
  • One of the most important edible mussel species common in the North and Baltic Sea
  • As the only viviparous fish in German nearshore waters, it is a bioindicator in nearshore coastal marine ecosystems.
  • Inshore, the herring gull mainly feeds from the sea: upon fish, mussels, and crabs.
  • A major primary producer in semi-natural and anthropogenic affected ecosystems.
  • A deciduous tree typical of ecosystems close to dense conurbations and an indicator for the characterisation of the immission situation during the vegetation period.
  • As the most dominant deciduous tree species in Central Europe, it plays a significant role in most nearly natural and also anthropogenically influenced forest ecosystems up to an altitude of 1100 m.
  • The roe deer is the most common of the larger herbivores (first order-consumer) to be found in the wild in Europe.
  • A pigeon species home in nearly every city.
  • As an organism living at ground level, it is a major driver of the decomposition of organic material (e.g. plant litter).
  • As an organism living at ground level, it is a major driver of the decomposition of organic material (e.g. plant litter).
  • Soil is livelihood and biosphere for humans, animals, plants and soil organisms. All the substances brought in are transported, transformed and/or accumulated in the soil.
  • Student groups with an even number of female and male students at the age of 20 to 29.

Sampling area

Sampling period

1982 - 2023