Carbon tetrachloride (CCl4, tetrachloromethane) was once used widely as a dry cleaning solvent, degreaser, spot remover, fire extinguisher agent, and antihelminthic. Because of its liver toxicity and known carcinogenicity in animals, its role has become limited; it is now used mainly as an intermediate in chemical manufacturing.
Chloroform (trichloromethane) is a chlorinated hydrocarbon solvent used as a raw material in the production of freon and as an extractant and solvent in the chemical and pharmaceutical industries. Because of its hepatic toxicity, it is no longer used as a general anesthetic or antihelminthic agent. Chronic low-level exposure may occur in some municipal water supplies owing to chlorination of biologic methanes (trihalomethanes).