Koppers is a global chemical and materials company based in Pittsburgh, Pennsylvania, United States in an art-deco 1920s skyscraper, the Koppers Tower. The corporation is divided into three business units: Carbon and Chemicals, Railroad Products and Services, and Performance Chemicals. The company specialises in manufacturing carbon chemicals from coal tar. The five main chemicals that are produced are coal pitch for steel and aluminum production, carbon black for rubber vulcanization, creosote for wood treatment, and naphthalene and phthalic anhydride for plastics and polyester. Koppers coal tar pitches are essential to manufacturing carbon anodes for aluminum smelting. Koppers also has extensive operations making creosote treated wood products, especially railroad ties and switches. Utility poles, foundations, decking materials, and wooden panneling are also produced by the company. In 1943, Koppers, at the US Governments behest, built a factory in Kobuta, Pennsylvania on the left bank of the Ohio River just downriver from Beaver, to manufacture styrene-butadiene monomer, a building block used to make a form of synthetic rubber for the World War II defense effort.