Creosote from both oil shale and petroleum, and are known as oil-tar creosote when derived from oil tar, and as water-gas-tar creosote when derived from the tar of water gas. Creosote also has been made from pre-coal formations such as lignite, yielding lignite-tar creosote, and peat, yielding peat-tar creosote. The term creosote has a broad range of definitions depending on the origin of the coal tar oil and end use of the material. With respect to wood preservatives, the United States Environmental Protection Agency (EPA) considers the term creosote to mean a pesticide for use as a wood preservative meeting the
Coal tar forms: crude coal tar () or a coal tar solution () also known as liquor carbonis detergens (LCD). Named brands include Denorex, Balnetar, Psoriasin, Tegrin, T/Gel, and Neutar. When used in the extemporaneous preparation of topical medications, it is supplied in the form of coal tar topical solution USP, which consists of a 20% w/v solution of coal tar in alcohol, with an additional 5% w/v of polysorbate 80 USP; this must then be diluted in an ointment base such as petrolatum. Coal tar was a component of the first sealed roads. In its original development by Edgar Purnell Hooley,