Creosote (CAS #8001-58-9), a distillation product of coal tar, is a thick, oily liquid, amber to black in colour, and is one of the most widely used wood preservatives.About 300 chemicals have been identified in creosote, but there may be as many as 10000 other chemicals in the mixture.The majority of these identified chemicals have been associated with harmful health effects.In nature, creosote treated wood are usually placed at open air and therefore in direct contact with water (submerged and overwater structures), rainwater and the water contained in the soil (poles or sleepers).