A man-made compound previously used to control termites and other insects. Even though production of heptachlor was phased out of use in the United States during the late 1980's it remains in soil and hazardous waste sites. It is clearly toxic to animals and humans but, the International Agency for Research on Cancer (IARC) has determined that heptachlor is not classifiable as to its carcinogenicity to humans. (From ATSDR Public Heath Statement, April 1989).