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,
Coal breaker floor and slid down a gently inclined "picker table" where breaker boys removed obvious impurities such as rocks and large pieces of slate and threw them down chutes to the culm pile. The breakers also removed obviously clean lumps of coal and sent them down a separate "clean coal" chute for crushing. Lumps intermixed with impurities would go down a third chute for crushing and further cleaning. On the second level of a typical breaker, coal would be roughly sorted. The fuel would move over sorting bars, with the various sizes of coal going down different chutes. Each type of