Caustic, << KAWS tihk, >> is the common name for certain chemicals that can burn or eat away substances, especially organic material. The term caustic comes from the Greek word kaustos, which means burning. Two important caustics are caustic soda–often called lye–whose chemical name is sodium hydroxide (NaOH), and caustic potash, known chemically as potassium hydroxide (KOH). Other caustics include caustic alcohol, caustic baryta, caustic lime, and lunar caustic.
Caustic soda is used in the manufacture of such products as paper, soap, and textiles. It is also an ingredient in many household drain cleaners, because it can readily break down grease and other wastes that clog pipes. Caustic potash is used primarily to make soft soaps that dissolve easily in water. Manufacturers produce caustic soda from sodium chloride–common table salt–through a process called electrolysis. Caustic potash is produced from potassium chloride.
See also Alkali metal ; Base ; Electrolysis ; Sodium hydroxide ; Silver nitrate .
