Tetrachloroethylene, also known under the systematic name
tetrachloroethene, or
perchloroethylene ("
perc" or "
PERC"), and many other names, is a
chlorocarbon with the formula Cl
2C=CCl
2. It is a colorless liquid widely used for
dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid." It has a sweet odor detectable by most people at a concentration of 1 part per million (1 ppm). Worldwide production was about one million
metric tons in 1985.