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China - Final Regulatory Action
Hexachlorocyclohexane, alpha isomer CAS number:
Date circular:

Chemical name: Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1.alpha.,2.alpha.,3.beta.,4.alpha.,5.beta.,6.beta.)-

Final regulatory action has been taken for the category: Pesticide

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action:

The production, circulation, use, import and export of alpha-HCH have all been banned in China.

The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

Since March 26th 2014, the production, circulation, use, import and export of alpha-HCH have all been banned in China.

The reasons for the final regulatory action were relevant to: Human health and environment

Summary of known hazards and risks to human health:

Alpha-HCH is the isomer with the highest neurotoxic potential beside gamma-HCH, Alpha-HCH has been classified as possibly carcinogenic to humans (group 2B) by the International Agency for Research on Cancer (I ARC), based on inadequate evidence of carcinogenicity in humans and sufficient evidence for carcinogenicity to animals.
Alpha-HCH causes liver hyperplasia and liver tumors in (laboratory) rodents. From is known that alpha-HCH affects the immune system; animal experiments immunosuppressive effects were observed in humans exposed to technical HCH as well.
Epidemiological studies indicate an elevated incidence of breast cancer after exposure to alpha-HCH as well as hormonal disorders leading to infertility and abortions. A possible association with intrauterine growth retardation and aplastic anemia has been postulated.
Based on the hazard profile and the exposure scenarios it can be concluded that alpha-HCH may adversely affect wildlife and human health in contaminated regions. The United States Environmental Protection Agency (USEPA) estimated, based on daily intake rates for the Arctic population, elevated cancer rates, though estimates are very conservative. It has to be considered that the liver is the target organ for all HCH-isomers, thereby leaving the risk of additive effects. Moreover the indigenous Arctic population as well as wildlife are exposed to a broad range of POP s including all HCH isomers and other pollutants leading to probably additive effects. Nevertheless Arctic public health authorities believe the significant social, cultural and economic benefits of traditional foods outweigh the risks of contaminants such as HCH at present but give another reason for the quick control and elimination of all HCH isomers from traditional foods.

Expected effect of the final regulatory action in relation to human health:

To protect the environment and human health.

Summary of known hazards and risks to the environment:

Alpha-HCH is susceptible to abiotic and biotic degradation at variable rates and degrees, depending on e.g. environmental media, site and climate. Alpha-HCH is expected to rapidly degrade in tropical conditions, whereas it accumulated in colder climates. Alpha-HCH is moderately persistent in soil. Based on values from aquatic compartments i.e. Arctic freshwater and sea water, it can be concluded that alpha-HCH shows high persistence in water in colder regions.
The physico-chemical properties of alpha-HCH allow the dispersal of the substance from its sources to the Arctic by a combination of long-range atmospheric transport and ocean currents. High levels of alpha-HCH have been detected in the Arctic Ocean, where it has built a large reservoir and is present in marine as well as in terrestrial species.
Alpha-HCH exposure levels in local areas have declined after worldwide prohibitions and restrictions. However regions with recent exposure and/or high pollution can still show elevated levels. A special concern also arises from exposure of hazardous waste sites and dumping grounds from disposed alpha-HCH residues from lindane production. Due to its persistence, alpha-HCH can still be detected regularly at low background levels in the environment. Elevated levels have also been reported from the Arctic (levels in the Arctic Ocean are higher than in temperate oceans and lakes). Though alpha-HCH levels in air decreased more than twenty-fold from the 1980s onwards, there has been only a modest change in higher marine and terrestrial predators e.g. fur seals or polar bears.
Because alpha-HCH is present in the terrestrial and aquatic food chains, alpha-HCH may bio-accumulate and bio-magnify in biota and Arctic food webs. The bio-magnification factors (predator-prey comparison) for many of the examined species are greater than I (one). Some animals, especially birds, but also mammals, have the potential to metabolize alpha-HCH. As this is an enantioselective biotransformation, a distinctive accumulation of (+) or (-) alpha-HCH can occur in mammals (depending on the species).

Expected effect of the final regulatory action in relation to the environment:

To protect the environment and human health.

Date of entry into force of the final regulatory action: 26/03/2014