Seirogan ingredient. That ingredient in the West may otherwise go by such names as "wood creosote", "beechwood creosote", or "liquid pitch oil", and should be distinguished from industrial "coal-tar creosote". To emphasize the distinction, wood creosote in Japan is sometimes called by such names as and minor variants thereof. The wood creosote is blended with two or more recognized in for their antiseptic and other effects, but the additional ingredients used are different among manufacturers (See under #Chemical composition for a sampling of formulas). Some quarters (perhaps kanpō medicine practitioners and others) insist however that "Seirogan is not strictly speaking kanpō
Coal tar skin can repair itself after short-term exposure to PAHs, but not after long-term exposure. Coal tar was one of the first chemical substances proven to cause cancer from occupational exposure, during research in 1775 on the cause of chimney sweeps' carcinoma. Modern studies have shown that working with coal tar pitch, such as during the paving of roads or when working on roofs, increases the risk of cancer. Coal tar contains many polycyclic aromatic hydrocarbons, and it is believed that their metabolites bind to DNA, damaging it. Long-term skin exposure to these compounds can produce "tar warts", which can progress