A
process for
cleaning fabrics that does not use
water. Dry cleaning uses an
organic solvent to remove
grease and
dirt from
fabrics.
Dry cleaning was discovered in 1855 by Jean Baptiste Folly after noticing that a tablecloth that had kerosene spilled on it became sparkling clean where the kerosene touched it. He came up with the idea of selling the cleaning process.
Other dry cleaning solvents used over the years were carbon tetrachloride and trichloroethylene. Nowadays, almost all dry cleaning is done with perchlorethylene. The smell your suits have after you pick them up from the cleaners is largely due to residual "perc" as it's called. By the way, these are all chlorocarbons, closely related to flourocarbons.
Dry cleaning works best on natural fibers such as silk and wool. In fact, perc can dissolve some synthetics and must be used carefully.
There are health concerns with perc as there were for its earlier alternatives. All are carcinogenic and can cause respiratory problems. Dry cleaning establishments are now required to do vapor recovery and filtering of their perc and to limit its introduction into the environment. Employees who are expected to come into direct contact with perc must wear respirators and gloves. Due to these concerns, an alternative to dry cleaning has been created, using large computer controlled laundering devices, and water and detergents, that is supposed to allow any "dry clean only" fabric to be laundered this way. Ironically, this process is called wet cleaning.