A fungicide based on 1,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methano-indene. It is a white powder that smells like camphor, and it was used extensively in the past for killing insects in homes, buildings, and on food crops, especially corn. It is now classified as a POP. Under the Stockholm Convention on Persistent Organic Compounds, use of this chemical in Europe is subject to restrictions.

An insecticide used for termite control and seed/seed furrow treatment; a chlorinated hydrocarbon (a chemical containing only chlorine, carbon, and hydrogen) that lingers in the environment and accumulates in the food chain. Measured in µg/L or ppb. The MCL for heptachlor is 0.4 µg/L or ppb.

An insecticide that was banned on some food products in 1975 and in all of them 1978. It was allowed for use in seed treatment until 1983. More recently it was found in milk and other dairy products in Arkansas and Missouri where dairy cattle were illegally fed treated seed.