Tetrachloroethylene

December 19, 2017

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Get your holiday duds cleaned by me.
What molecule am I?

Tetrachloroethylene, often called perchloroethylene (PCE or 鈥減erc鈥�), is a colorless, nonflammable liquid that is widely used for dry cleaning鈥攚hich, of course, is not actually dry. It is聽not聽abbreviated as TCE because that is conventionally used for trichloroethylene.

In 1821, legendary chemist Michael Faraday discovered how to make PCE by heating hexachloroethane until it decomposed, with molecular chlorine as the byproduct. This process led to today鈥檚 wide variety of production methods in which light hydrocarbons or chlorohydrocarbons are heated in the presence of chlorine, with or without a catalyst, to yield a combination of PCE and many other chlorocarbons. The crude mixture must be separated by distillation

In addition to dry cleaning, PCE is used industrially as a solvent, degreaser, refrigerant, and starting material for fluorocarbon production. Its use in dry cleaning聽聽because of improved solvent recycling systems and worker health concerns (it is a probable carcinogen). Despite this downturn, its overall worldwide production is slowly increasing.

Potential PCE replacements for dry cleaning include 1-bromopropane, silicone fluids, and liquified carbon dioxide, all of which have health, environmental, or economic drawbacks. So when you send your holiday finery out for cleaning, it鈥檚 most likely that it will be treated with PCE.

MOTW update: June 26, 2023

Tetrachloroethylene聽is聽also known as perchloroethylene or 鈥減erc鈥�, it is a nonflammable solvent widely used in dry cleaning. It is also a suspected carcinogen that has come under scrutiny by the US Environmental Protection Agency.

This month, EPA announced that it is proceeding to . It proposed a rule to phase it out from all consumer uses in 2 years and from dry-cleaning uses within 10 years. This was after a 2020 agency finding that the solvent , such as neurological, kidney, liver, and immunological effects.