Tetrachlormethan

Tetrachlormethan, also known as carbon tetrachloride, is a chlorinated hydrocarbon with the formula CCl4. It is a colorless, dense, nonflammable liquid at room temperature, with a boiling point of 76.7°C, a density around 1.59 g/cm3, and it is immiscible with water. It has a sweet odor at high concentrations. It is produced industrially by chlorination of methane or by rearrangement of chlorinated methanes and is not naturally occurring in significant amounts.

Uses and production: Historically, carbon tetrachloride was a widely used solvent for fats, oils, waxes, and resins and was employed in dry cleaning and as a degreasing agent. Today its use is largely restricted due to toxicity and environmental concerns, and it is mainly limited to chemical manufacturing as an intermediate in the production of other chlorinated compounds, including phosgene.

Health and safety: Tetrachlormethan is highly toxic to humans. Inhalation or ingestion can cause liver and kidney damage; chronic exposure may be carcinogenic in animals and is suspected to pose cancer risk in humans. The compound is metabolized in the liver to reactive species such as phosgene, a potent pulmonary irritant. Because of these hazards, exposure is controlled with ventilation, containment, and protective equipment; consumer exposure is rare.

Environmental and regulation: It is an ozone-depleting substance with chlorine atoms that contribute to ozone layer loss. Production and use have been curtailed under the Montreal Protocol and related regulations. Residual environmental releases persist due to its persistence and historical usage and require proper handling and disposal.

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