Dry cleaning
After World War I, dry cleaners began using chlorinated solvents. These solvents were much less flammable than petroleum solvents and were more powerful. By the mid-1930s, the dry cleaning industry had adopted tetrachloroethylene (perchloroethylene), widely called "perc", as the best solvent. It has excellent cleaning power and is stable, nonflammable, and gentle to most clothing. Some dry cleaners use different chemicals.