Also known as organochlorines, these synthetic organic compounds contain chlorine. They tend to be persistent in the environment and to biomagnify in the food chain. Chlorinated hydrocarbons that are pesticides include DDT, aldrin, dieldrin, heptachlor, chlordane, lindane, endrin, mirex, hexachloride, and toxaphene. Most chlorinated hydrocarbon pesticide uses have been canceled because of their persistence, propensity to bioaccumulate, and toxicity to nontarget species.