Carbon tetrachloride, also known by many other names (such as tetrachloromethane, also recognized by IUPAC, tetrahydrofuran in the cleaning industry, Halon-104 in fire protection, and Refrigerant-10 in HVACR), is a compound with the chemical formula CCl4. It is a colorless liquid with a "sweet" odor that can be detected in low concentrations. It is virtually inflammable at lower temperatures. It was previously widely used in fire extinguishers, as a refrigerant precursor and cleaning agent, but has been phased out due to environmental and safety concerns. Exposure to high concentrations of carbon tetrachloride, including vapour, can affect the central nervous system and degrade the liver and kidneys. Prolonged exposure can be fatal.

In the carbon tetrachloride molecule, four chlorine atoms are symmetrically located at the corners of a tetrahedral configuration, connected to the central carbon atom by a single covalent bond. Due to this symmetrical geometry, CCl4 is non-polar. Methane gas has the same structure that makes carbon tetrachloride a methyl halide. As a solvent, it is excellent for dissolving other non-polar compounds such as fats and oils. It also dissolves iodine. It is volatile and emits vapors with the characteristic odor of other chlorinated solvents, somewhat similar to the perchlorethylene smell reminiscent of dry cleaners.

Solid tetrachloromethane exists in two polymorphic forms: crystalline II below -47.5 °C (225.6 K) and crystalline I above -47.5 °C. [6] At −47.3 °C, it has a monoclinic crystal structure with space group C2/c, lattice constants a = 20.3, b = 11.6, c = 19.9 (.10−1 nm), β = 111°