Dry cleaning

Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water. Dry cleaning still involves liquid, but clothes are instead soaked in a water-free liquid solvent (usually non-polar, as opposed to water which is a polar solvent). Tetrachloroethylene (perchloroethylene), known in the industry as "perc", is the most widely used solvent. Alternative solvents are 1-bromopropane and hydrocarbons. Most natural fibers can be washed in water but some synthetics (e.g., viscose, lyocell, modal, and cupro) react poorly with water and should be dry-cleaned if possible. The ancient Greeks and Romans had some waterless methods to clean textiles, involving the use of powdered chemicals and absorbent clay (fuller's earth). By the 1700s, the French were using turpentine-based solvents for specialized cleaning. Modern solvent-based dry cleaning may have originated in 1821 with American entrepreneur Thomas L. Jennings. Jennings referred to his method as "dry scouring". French dye-works operator Jean Baptiste Jolly developed his own method using kerosene and gasoline to clean fabrics. He opened the first dry cleaning service in Paris in 1845. Flammability concerns led William Joseph Stoddard, a dry cleaner from Atlanta, to develop in 1924 Stoddard solvent (white spirit) as a slightly less flammable alternative to gasoline-based solvents. The use of highly flammable petroleum solvents caused many fires and explosions, resulting in government regulation of dry cleaners. After World War I, dry cleaners began using chlorinated solvents. These solvents were much less flammable than petroleum solvents and had improved cleaning power. Early solvents were carbon tetrachloride and trichloroethylene (TCE), but they gradually were phased out as their adverse health effects became more known. TCE may still occasionally be used for spot cleaning of difficult stains. By the mid-1930s, the dry cleaning industry had started to use tetrachloroethylene (also called perchloroethylene or PCE) as the solvent.