Coal tar

Coal tar
Clinical data
Trade namesBalnetar, Cutar, others
Other namesliquor carbonis detergens (LCD)
liquor picis carbonis (LPC)[1]
AHFS/Drugs.comMultum Consumer Information
Routes of
administration
Topical
ATC code
Legal status
Legal status
  • US: OTC / Rx-only
Identifiers
CAS Number
ChemSpider
  • none
UNII
CompTox Dashboard (EPA)
ECHA InfoCard100.029.417 Edit this at Wikidata

Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal.[2][3] It is a type of creosote. It has both medical and industrial uses.[2][4] Medicinally it is a topical medication applied to skin to treat psoriasis and seborrheic dermatitis (dandruff).[5] It may be used in combination with ultraviolet light therapy.[5] Industrially it is a railroad tie preservative and used in the surfacing of roads.[6] Coal tar was listed as a known human carcinogen in the first Report on Carcinogens from the U.S. Federal Government, issued in 1980.[7]

Coal tar was discovered circa 1665 and used for medical purposes as early as the 1800s.[6][8] Circa 1850, the discovery that it could be used as the main raw material for the synthesis of dyes engendered an entire industry.[9] It is on the World Health Organization's List of Essential Medicines.[10] Coal tar is available as a generic medication and over the counter.[4]

Side effects include skin irritation, sun sensitivity, allergic reactions, and skin discoloration.[5] It is unclear if use during pregnancy is safe for the baby and use during breastfeeding is not typically recommended.[11] The exact mechanism of action is unknown.[12] It is a complex mixture of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds.[2] It demonstrates antifungal, anti-inflammatory, anti-itch, and antiparasitic properties.[12]

  1. ^ Berenblum I (September 1948). "Liquor picis carbonis; a carcinogenic agent". British Medical Journal. 2 (4577): 601. doi:10.1136/bmj.2.4577.601. PMC 2091540. PMID 18882998.
  2. ^ a b c "Background and Environmental Exposures to Creosote in the United States" (PDF). cdc.gov. September 2002. p. 19. Archived (PDF) from the original on 25 January 2017. Retrieved 13 January 2017.
  3. ^ Vallee Y (1998). Gas Phase Reactions in Organic Synthesis. CRC Press. p. 107. ISBN 9789056990817.
  4. ^ a b Hamilton R (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. X. ISBN 9781284057560.
  5. ^ a b c World Health Organization (2009). Stuart MC, Kouimtzi M, Hill SR (eds.). WHO Model Formulary 2008. World Health Organization. p. 308. hdl:10665/44053. ISBN 9789241547659.
  6. ^ a b Hornbostel C (1991). Construction Materials: Types, Uses and Applications. John Wiley & Sons. p. 864. ISBN 9780471851455. Archived from the original on 2017-09-18.
  7. ^ First Annual Report on Carcinogens. National Technical Reports Library. 1980.
  8. ^ Sneader W (2005). Drug Discovery: A History. John Wiley & Sons. p. 356. ISBN 9780471899792. Archived from the original on 2017-09-18.
  9. ^ "History The Early Years (1863–1881)". Bayer AG. Retrieved 4 February 2021.
  10. ^ World Health Organization (2019). World Health Organization model list of essential medicines: 21st list 2019. Geneva: World Health Organization. hdl:10665/325771. WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  11. ^ "Coal Tar use while Breastfeeding | Drugs.com". www.drugs.com. Archived from the original on 18 January 2017. Retrieved 13 January 2017.
  12. ^ a b Maibach HI (2011). Evidence Based Dermatology. PMPH-USA. pp. 935–936. ISBN 9781607950394. Archived from the original on 2017-09-18.