Creosote mixed with coal-tar creosote, or fortified with pentachlorophenol. Water-gas-tar creosote is also derived from petroleum oil or shale oil, but by a different process; its distilled during the production of water gas. The tar is a by-product resulting from enrichment of water gas with gases produced by thermal decomposition of petroleum. Of the creosotes derived from oil, it is practically the only one used for wood preservation. It has the same degree of solubility as coal-tar creosote and is easy to impregnate into wood. Like standard oil-tar creosote, it has a low amount of tar acids and tar bases, and
Coal tar Coal tar Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It has both medical and industrial uses. It may be applied to the affected area to treat psoriasis and seborrheic dermatitis (dandruff). It may be used in combination with ultraviolet light therapy. Industrially it is a railway tie preservative and used in the surfacing of roads. Side effects include skin irritation, sun sensitivity, allergic reactions, and skin discoloration. It is unclear if use during pregnancy is safe for the baby and use during breastfeeding is not typically