| SUMMARY: Exposure to hexachlorocyclohexane happens mostly from eating contaminated foods (plants, meat, and milk) or in the workplace by breathing contaminated air. Hexachlorocyclohexane can cause blood disorders, dizziness, headaches, and seizures in people. This chemical has been found in at least 239 of 1,416 National Priorities List sites identified by the Environmental Protection Agency. |
What is hexachlorocyclohexane?
(Pronounced hexa-klor'o-cy'klo-hex-ane)
Hexachlorocyclohexane (HCH) is a manufactured chemical that does not occur naturally in the environment. It exists in eight chemical forms (called isomers). One of these forms, gamma-HCH (also known as lindane) is a white solid substance that may evaporate into the air as a colorless vapor with a slightly musty odor.
Lindane was used as an insecticide on fruit and vegetable crops (including greenhouse vegetables and tobacco) and forest crops (including Christmas trees). It is still used in ointments to treat head and body lice, and scabies.
Lindane has not been produced in the United States since 1977. It is still imported to and formulated in the United States. Its use is restricted by the Environmental Protection Agency (EPA) and can be applied only by a certified applicator. Technical-grade HCH is a mixture of several different forms of HCH; it was also used as an insecticide in the United States, but hasn't been produced here since 1983.
What happens to hexachlorocyclohexane when it enters the environment?
How might I be exposed to hexachlorocyclohexane?
How can hexachlorocyclohexane affect my health?
Levels of exposure to HCH that produce harmful health effects are generally much higher than normally received by the general population.
Some people who swallowed large amounts had seizures and sometimes died. Some people who were exposed to very large amounts of HCH or who used it often had blood disorders and seizures. Some people who breathed contaminated workplace air during the manufacturing of pesticides had blood disorders, dizziness, headaches, and changes in the levels of sex hormones.
Animals fed high levels of HCH had convulsions and some became comatose. Liver and kidney effects occurred at moderate levels. A reduced ability to fight infection was reported in animals given moderate levels of HCH.
Animal studies show a decreased ability to reproduce when fed moderate to high levels of HCH. We do not know if HCH affects the ability of people to reproduce or if it causes birth defects in humans.
How likely is hexachlorocyclohexane to cause cancer?
The Department of Health and Human Services has determined that HCH may reasonably be anticipated to be a carcinogen. Liver cancer has been seen in laboratory rodents that ate alpha-, beta-, gamma-, or technical-grade HCH for a long period of time.
Is there a medical test to show whether I've been exposed to hexachlorocyclohexane?
Laboratory tests can measure HCH in blood, urine, and semen. These tests do not tell you how much HCH you've been exposed to or if harmful effects will occur. The tests are not routinely available at your doctor's office.
Has the federal government made recommendations to protect human health?
The EPA has set a limit in drinking water of 0.2 parts of lindane per billion parts of water (0.2 ppb). The EPA requires that spills or accidental discharges of lindane into the environment of 1 pound or more must be reported to the EPA.
The Occupational Safety and Health Administration (OSHA), the National Institute for Occupational Safety and Health (NIOSH), and the American Conference of Governmental Industrial Hygienists (ACGIH) recommend a maximum level of 0.5 milligrams lindane per cubic meter (0.5 mg/m³) of workplace air for an 8-hour workday, 40-hour workweek. These agencies advise avoiding eye and skin contact because this may be a route of significant exposure.
Glossary
Where can I get more information?
ATSDR can tell you where to find occupational and environmental health clinics. Their specialists can
recognize, evaluate, and treat illnesses resulting from exposure to hazardous substances. You can also contact
your community or state health or environmental quality department if you have any more questions or concerns.
For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop E-29
Atlanta, GA 30333
Phone: 404-639-6000
FAX: 404-639-6315
U.S. Department of
Health and Human Services
Public Health Service
Agency for Toxic Substances and Disease Registry
Last Update: September 1, 1995
Charlie Xintaras /
chx1@cdc.gov