Heptachlor is an insecticide. It was used against ants, termites, against mosquitos of the genus Anopheles, that can spread malaria and as a general pesticide. In humans, heptachlor damages the liver, and the central nervous system. It may cause cancer. It is sold as a powder. The Diels-Alder reaction is used to produce it. The compound is very stable and can stay in the environment for decades.