Tetrachloromethane
A synonym for carbon tetrachloride — an organic halogen compound and versatile organic solvent whose use has diminished since the discovery that it is carcinogenic. Tetrachloromethane was once employed in dry cleaning, degreasing, and as a grain fumigant, but its liver toxicity, carcinogenicity, and ozone-depleting properties drove global phase-out under the Montreal Protocol. Any historical food-related use — such as fumigation residues — is now obsolete, and modern food plants exclude chlorinated solvents from contact with foods. Its story is a textbook case of a useful industrial chemical withdrawn once chronic hazards became clear.