The primary use of ferric chloride is to remove impurities in water and for wastewater treatment. Ferric chloride is also one of the few water treatment chemicals that can sequester odors. Ferric Chloride, also know as Iron(III) chloride, and Iron chloride, is an industrial scale commodity chemical compound. Its chemical formula is FeCl3 and its CAS is 7705-08-0. When dissolved in water, the compound undergoes hydrolysis resulting in a brown highly corrosive, acidic solution that is used as a flocculent in sewage treatment and drinking water production. Anhydrous iron(III) chloride is a strong Lewis acid that is used as a catalyst in organic synthesis. Ferric chloride is harmful, highly corrosive, and acidic. The anhydrous material is a powerful dehydrating agent. Although poisoning in humans is rare, ingestion of ferric chloride can result in serious morbidity and mortality. The most common use of ferric chloride is in solution. When dissolved it forms a light brown aqueous solution with a faint hydrochloric acid odor. It is highly corrosive to most metals and probably corrosive to tissue. It is noncombustible and primarily used in sewage treatment and water purification. Industrial uses include the manufacture of pigments, plating agents and surface treating agents, process regulators, and solids separation agents. Ferric chloride is produced industrially by a process called direct chlorination, the reaction of dry chlorine with scrap iron at 500-700 degrees Centigrade.