Tetrachloroethylene

Tetrachloroethylene is a colorless, volatile chlorinated solvent used chiefly in dry cleaning and metal degreasing. It is also called perchloroethylene or PCE.

Dry cleaning: A textile-cleaning process that uses solvents instead of water as the main cleaning medium. Tetrachloroethylene became a widely used solvent for removing grease and stains from garments.
Volatility: The tendency of a substance to vaporize at a given temperature. Tetrachloroethylene readily enters air from exposed liquid and contaminated surfaces.
Tetrachloroethylene toxicity: The harmful effects of tetrachloroethylene exposure on human health. Exposure can affect the nervous system, and long-term exposure is associated with cancer risk.
Trichloroethylene: A chlorinated solvent formerly used in degreasing and other industrial applications. It is a closely related solvent with three chlorine atoms rather than tetrachloroethylene’s four.
Vapor degreasing: A metal-cleaning process in which solvent vapor condenses on parts and dissolves oils and contaminants. Tetrachloroethylene’s volatility made it useful for cleaning metal parts in vapor-degreasing equipment.
Henry's law: A relation describing how a dissolved gas or volatile compound partitions between water and air. It helps predict tetrachloroethylene’s transfer from groundwater into soil gas and indoor air.
Occupational exposure: Contact with hazardous substances that occurs while performing work. Dry-cleaning and degreasing workers can inhale vapor or contact liquid tetrachloroethylene.
1,1,1-Trichloroethane: A chlorinated solvent once used in cleaning and degreasing before restrictions curtailed its use. It served as a degreasing alternative but differs in composition and environmental behavior.
Metalworking fluids: Fluids used to cool, lubricate, or clean materials during machining and other metalworking operations. Degreasing with tetrachloroethylene removes oils left by metalworking fluids.
Dense non-aqueous phase liquid: A liquid denser than water that does not readily dissolve in it and can sink through groundwater. Released tetrachloroethylene can form a DNAPL that migrates downward through aquifers.

Linked from 5 pages

Homestake experimentBroader topic: Thousands of tons of this chlorine-rich liquid formed Homestake’s detector target.