Coal tar the European Chemicals Agency. The exact mechanism of action is unknown. Coal tar is a complex mixture of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds. It is a keratolytic agent, which reduces the growth rate of skin cells and softens the skin's keratin. Coal tar is produced through thermal destruction (pyrolysis) of coal. Its composition varies with the process and type of coal used – lignite, bituminous or anthracite. Coal tar contains approximately 10,000 chemicals, of which only about 50% have been identified. Components include polycyclic aromatic hydrocarbons (4-rings: chrysene, fluoranthene, pyrene, triphenylene, naphthacene, benzanthracene, 5-rings: picene, benzo[a]pyrene, benzo[e]pyrene,
Calgon Carbon pond and aquarium cleaning, and removal of impurities during the manufacturing process of vitamins. The company also serves "industrial processes" applications such as liquid chemicals, catalyst support, gas and water processing, ultrapure water, and bio-based chemicals. Activated carbon, which is a small form of carbon with a large pore structure that can remove impurities, was one of the first products produced by the company in the 1940s. Initially manufacturing granular activated carbon (GAC), the company also began producing forms such as powdered, pellets, and later cloth. Pittsburgh Coke and Chemical introduced an early activated carbon system to decolorize sugar in