Also known a perchloroethylene (PERC), this colorless liquid is primarily used in the dry cleaning of textiles and fabrics. Often referred to simply as “dry cleaning fluid”, PERC has a sweet odor that is easily noticeable and recognizable even in extremely low concentrations. On average, worldwide production of PERC exceeds 1 million metric tons. It is generally produced on the industrial level by the high temperature chlorinolysis of light hydrocarbons, producing by products including carbon tetrachloride, hydrogen chloride, and hexachlorobutadiene. Generally the reaction is catalyzed using a combination of potassium chloride and aluminum chloride, or with activated carbon (charcoal). The resulting PERC is separated from the rest of the products via distillation. The primary reason this substance is so useful for dry cleaning clothing is that it is an excellent solvent when used on organic materials while remaining highly stable and nonflammable. This also makes it an excellent choice for degreasing metal parts and tools in the automotive and metalworking industries.