chloroethene

Chloroethene, commonly called vinyl chloride, is an organochlorine compound with the formula C2H3Cl. It is a colorless gas at room temperature with a sweet odor and is highly flammable. It is toxic to humans and is classified as a carcinogen, with long-term exposure linked to liver angiosarcoma among other health effects. Vinyl chloride polymerizes readily to polyvinyl chloride (PVC), one of the world's most widely used plastics.

Industrial production is dominated by the dehydrochlorination of ethylene dichloride (1,2-dichloroethane). Ethylene reacts with chlorine to form EDC (C2H4Cl2), which is then dehydro-chlorinated at elevated temperatures to yield vinyl chloride and hydrogen chloride: C2H4Cl2 → C2H3Cl + HCl. The vinyl chloride is purified and dried, then sold as monomer for polymerization. Alternative routes exist but are less common.

Vinyl chloride monomer is the primary feedstock for polyvinyl chloride (PVC) resin and copolymers. PVC is used in pipes, siding, flooring, cables, and various consumer products due to its durability and cost. The monomer can also be copolymerized with other vinyl monomers to tailor properties.

Vinyl chloride is a hazardous substance; exposure can affect the nervous system and liver, and the substance is categorised as a human carcinogen by several health agencies. It is tightly regulated in production, handling, transport, and emissions, with strict occupational exposure limits and containment to minimize release. In the environment, vinyl chloride is volatile and degrades primarily by reaction with hydroxyl radicals in the atmosphere; releases to air, water, and soil are treated to prevent fires and exposures.