Coal tar is a brown or black liquid of high viscosity, which smells of naphthalene and aromatic hydrocarbons. Coal tar is among the by-products when coal is carbonized to make coke or gasified to make coal gas. Coal tars are complex and variable mixtures of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds. ^[1] For other uses, see Viscosity (disambiguation). ... R-phrases , , S-phrases , , , , Flash point 79 - 87 °C Autoignition temperature 525 °C Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Naphthalene (not to be confused with naphtha) (also known as naphthalin, naphthaline, moth ball, tar... An aromatic hydrocarbon (abbreviated as AH) or arene [1] is a hydrocarbon, the molecular structure of which incorporates one or more planar sets of six carbon atoms that are connected by delocalised electrons numbering the same as if they consisted of alternating single and double covalent bonds. ... Carbonization is the term for the conversion of an organic substance into carbon or a carbon-containing residue. ... Coke Coke is a solid carbonaceous material derived from destructive distillation of low-ash, low-sulfur bituminous coal. ... ... Syngas (from synthesis gas) is the name given to gasses of varying composition that are generated in coal gasification and some types of waste-to-energy facilities. ... In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group (-OH) attached to an aromatic hydrocarbon group. ... An illustration of typical polycyclic aromatic hydrocarbons. ... Pyridine a simple heterocyclic compound Heterocyclic compounds are organic compounds which contain a ring structure containing atoms in addition to carbon, such as sulfur, oxygen or nitrogen, as part of the ring. ...

Applications

Being flammable, coal tar is sometimes used for heating or to fire boilers. Like most heavy oils, it must be heated before it will flow easily. A boiler is a closed vessel in which water or other fluid is heated under pressure. ...

It can be used in medicated shampoo, soap and ointment, as a treatment for dandruff and psoriasis, as well as being used to kill and repel head lice. When used as a medication in the U.S., coal tar preparations are considered an OTC (over-the-counter drug) pharmaceutical and are subject to regulation by the United States Food and Drug Administration. Name brands include Balnetar, Psoriasin, and Tegrin. Shampoo is a common hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair. ... A collection of decorative soaps used for human hygiene purposes. ... An ointment is a viscous semisolid preparation used topically on a variety of body surfaces. ... For the album by Ivor Cutler, see Dandruff (album). ... The head louse Head lice (Pediculus humanus capitis) are one of the many varieties of sucking lice (singular louse) specialized to live on different areas of various animals. ... Motto: (Out Of Many, One) (traditional) In God We Trust (1956 to date) Anthem: The Star-Spangled Banner Capital Washington D.C. Largest city New York City None at federal level (English de facto) Government Federal constitutional republic  - President George Walker Bush (R)  - Vice President Dick Cheney (R) Independence from... Over-the-counter (OTC) drugs are medicines that may be sold without a prescription, in contrast to prescription drugs. ... The United States Food and Drug Administration is the government agency responsible for regulating food, dietary supplements, drugs, cosmetics, medical devices, biologics and blood products in the United States. ...

Safety

According to the International Agency for Research on Cancer, preparations that include more than 5 percent of crude coal tar are Group 1 carcinogen. The International Agency for Research on Cancer (IARC, or CIRC in its French acronym) is an intergovernmental agency forming part of the World Health Organisation of the United Nations. ... Substances, mixtures and exposure circumstances in this list have been classified by the IARC as Group 1: The agent (mixture) is carcinogenic to humans. ... The hazard symbol for carcinogenic chemicals in the Globally Harmonized System. ...

Despite this, the National Psoriasis Foundation claims coal tar is a valuable, safe and inexpensive treatment option for millions of people with psoriasis and other scalp conditions, ^[2] the FDA agrees with this and states that coal tar concentrations between 0.5% and 5% are safe and effective for psoriasis and that no scientific evidence suggests that the coal tar in the concentrations seen in non-prescription treatments is carcinogenic. The NPF states that coal tar contains approximately 10,000 different chemicals, of which only about 50% have been identified ^[3], and the composition of coal tar varies with its origin and type of coal (eg: lignite, bituminous or anthracite) used to make it, so much further research remains to be done on coal tar and its derivatives. The National Psoriasis Foundation (NPF) is a non-profit US based psoriasis education and advocacy group. ... Coal Coal is a fossil fuel extracted from the ground by mining. ... Bituminous coal Bituminous coal is a relatively hard coal containing a tar-like substance called bitumen. ... Anthracite coal Anthracite (Greek Ανθρακίτης, literally a form of coal, from Anthrax [Άνθραξ], coal) is a hard, compact variety of mineral coal that has a high luster. ...

See also

• Creosote
• Cresolene
• Preservative
• Tar

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. ... Bottle of Cresolene Cresolene is a dark liquid with a pungent smell made from coal tar used in the 19th and early 20th century as a disinfectant[1] and to treat various ailments such as colds and measles. ... This article does not cite any references or sources. ... Tar can be produced from corn stalks by heating in a microwave. ...

References