The epidemiology studies and various case reports revealed no convincing evidence of chlordanes carcinogenicity in humans, except for a weak association with leukemia and neuroblastoma. Oral studies in animals have confirmed that chlordane induces liver tumors in mice, but not rats, exposed to high levels.
Chronicduration inhalation and dermal studies were not located, but it seems likely that the carcinogenicity of chlordane in mice is not routedependent, because the pharmacokinetic data in animals indicate that absorption occurs following any route of exposure, and because the liver is a target organ for noncancer effects regardless of route of exposure. Most genotoxicity tests with chlordane yielded negative results, suggesting an epigenetic mechanism of carcinogenicity.
The Department of Health and Human Services (DHHS) determined that chlordane may reasonable be anticipated to be a human carcinogen. The International Agency for Research on Cancer (IARC) determined that chlordane may possibly cause cancer in humans. According to the U.S. EPA Carcinogen List there is a sufficient evidence of chlordane carcinogenicity from animal studies with inadequate or no data from epidemiologic studies in humans, there for it is classified as a Category B2, Probable human carcinogen.