creosote - Wood creosote, Coal tar creosote

A fraction of coal tar, boiling point c.250°C, containing a variety of toxic aromatic compounds giving it strong antiseptic and preservative properties.

Creosote is the name used for a variety of products: wood creosote, coal tar creosote, coal tar, coal tar pitch, and coal tar pitch volatiles.

Wood creosote

Wood creosote is a colorless to yellowish greasy liquid with a smoky odor and burned taste.

Coal tar creosote

Coal tar creosote is a thick, oily liquid typically amber to black in color. Coal tar and coal tar pitch are usually thick, black, or dark-brown liquids or semi-solids, with a smoky odor.

Coal tar products are used in medicines to treat skin diseases such as psoriasis, and also as animal and bird repellents, insecticides, animal dips, and fungicides. Coal tar creosote is the most widely used wood preservative in the United States. Coal tar, coal tar pitch (pitch), and coal tar pitch volatiles are used for roofing, aluminum smelting, and coking.

Brief direct contact with large amounts of coal tar creosote may result in a rash or severe irritation of the skin, chemical burns of the surfaces of the eyes, convulsions and mental confusion, kidney or liver problems, unconsciousness, and even death.

Long-term exposure to low levels of creosote, especially direct contact with the skin during wood treatment or manufacture of coal tar creosote-treated products has resulted in skin cancer and cancer of the scrotum. Cancer of the scrotum in chimney sweeps has been associated with long-term skin exposure to soot and coal tar creosotes.

The International Agency for Research on Cancer (IARC) has determined that coal tar is carcinogenic to humans and that creosote is probably carcinogenic to humans. The EPA has determined that coal tar creosote is a probable human carcinogen. Children exposed to creosote will probably experience the same health effects seen in adults exposed to creosote.

Studies in animals have shown birth defects in the young of mothers exposed to high levels of creosote during pregnancy, but no similar studies have been performed on humans. Because chemical components (PAHs, cresol, phenols) of coal tar creosote may be stored in body fat, they may be found in breast milk and could pass to nursing infants.

In 2003 the European Union banned creosote for amateur and unlicenced professional use, due to concerns over these health effects, noting that recent research had shown that the risk of skin cancer had perhaps been underestimated previously.