fbpx
Wikipedia

Coal tar

February 13, 2023

This article is about the substance. For the book, see Coal Tar: How Corrupt Politics and Corporate Greed Are Killing America's Children.

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.[7]

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
  • 8007-45-2
ChemSpider
  • none
UNII
  • R533ESO2EC
CompTox Dashboard (EPA)
  • DTXSID1027683
ECHA InfoCard100.029.417

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]

Uses

Medicine

Coal tar is used in medicated shampoo, soap and ointment. It demonstrates antifungal, anti-inflammatory, anti-itch, and antiparasitic properties.[12] It may be applied topically as a treatment for dandruff and psoriasis, and to kill and repel head lice.[5] It may be used in combination with ultraviolet light therapy.[5]

Coal tar may be used in two forms: crude coal tar (Latin: pix carbonis) or a coal tar solution (Latin: liquor picis carbonis, LPC) also known as liquor carbonis detergens (LCD).[12][13][14] 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.

Construction

Main article: Sealcoat

Coal tar was a component of the first sealed roads. In its original development by Edgar Purnell Hooley, tarmac was tar covered with granite chips. Later the filler used was industrial slag. Today, petroleum derived binders and sealers are more commonly used. These sealers are used to extend the life and reduce maintenance cost associated with asphalt pavements, primarily in asphalt road paving, car parks and walkways.[citation needed]

Coal tar is incorporated into some parking-lot sealcoat products used to protect the structural integrity of the underlying pavement.[15] Sealcoat products that are coal-tar based typically contain 20 to 35 percent coal-tar pitch.[15] Research[16] shows it is used throughout the United States of America, however several areas have banned its use in sealcoat products, [17][18][19] including the District of Columbia; the city of Austin, Texas; Dane County, Wisconsin; the state of Washington; and several municipalities in Minnesota and others.[20][21]

Industry

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.[22]

A large part of the binder used in the graphite industry for making "green blocks" is coke oven volatiles (COV), a considerable portion of which is coal tar. During the baking process of the green blocks as a part of commercial graphite production, most of the coal tar binders are vaporised and are generally burned in an incinerator to prevent release into the atmosphere, as COV and coal tar can be injurious to health.[23][24]

Coal tar is also used to manufacture paints, synthetic dyes (notably tartrazine/Yellow #5), and photographic materials.[25]

In the coal gas era, there were many companies in Britain whose business was to distill coal tar to separate the higher-value fractions, such as naphtha, creosote and pitch. Many industrial chemicals were first isolated from coal tar during this time. These companies included:[26][27]

In modern times, coal tar is mostly traded as fuel and an application for tar, such as roofing. The total value of the trade in coal tar is around US$20 billion each year.[28]

Safety

Side effects of coal tar products 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.[29]

According to the National Psoriasis Foundation, coal tar is a valuable, safe and inexpensive treatment option for millions of people with psoriasis and other scalp or skin conditions.[30] According to the FDA, coal tar concentrations between 0.5% and 5% are considered safe[31] and effective for psoriasis.

Cancer

Long-term, consistent exposure to coal tar likely increases the risk of non-melanoma skin cancers.[32] Evidence is inconclusive whether medical coal tar, which does not remain on the skin for the long periods seen in occupational exposure, causes cancer, because there is insufficient data to make a judgment.[33] While coal tar consistently causes cancer in cohorts of workers with chronic occupational exposure, animal models, and mechanistic studies,[34] the data on short-term use as medicine in humans has so far failed to show any consistently significant increase in rates of cancer.[33]

Coal tar contains many polycyclic aromatic hydrocarbons, and it is believed that their metabolites bind to DNA, damaging it.[35] The PAHs found in coal tar and air pollution induce immunosenescence and cytotoxicity in epidermal cells.[36][37] It's possible that the skin can repair itself from this damage after short-term exposure to PAHs but not after long-term exposure.[33] Long-term skin exposure to these compounds can produce "tar warts", which can progress to squamous cell carcinoma.[38]

Coal tar was one of the first chemical substances proven to cause cancer from occupational exposure, during research in 1775 on the cause of chimney sweeps' carcinoma.[38] Modern studies have shown that working with coal tar pitch, such as during the paving of roads or when working on roofs, increases the risk of cancer.[34]

The International Agency for Research on Cancer lists coal tars as Group 1 carcinogens, meaning they directly cause cancer.[34][39][40] The U.S. Department of Health and Human Services lists coal tars as known human carcinogens.[41]

In response to public health concerns regarding the carcinogenicity of PAHs some municipalities, such as the city of Milwaukee, have banned the use of common coal tar-based road and driveway sealants citing concerns of elevated PAH content in groundwater.[42]

Other

Coal tar causes increased sensitivity to sunlight,[43] so skin treated with topical coal tar preparations should be protected from sunlight.

The residue from the distillation of high-temperature coal tar, primarily a complex mixture of three or more membered condensed ring aromatic hydrocarbons, was listed on 13 January 2010 as a substance of very high concern by the European Chemicals Agency.[44]

Mechanism of action

The exact mechanism of action is unknown.[12] Coal tar is a complex mixture of phenols, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic compounds.[2]

It is a keratolytic agent, which reduces the growth rate of skin cells and softens the skin's keratin.[45][38]

Composition

Coal tar is produced through thermal destruction (pyrolysis) of coal. Its composition varies with the process and type of coal used – lignite, bituminous or anthracite.[38]

Coal tar is a mixture of approximately 10,000 chemicals, of which only about 50% have been identified.[46][better source needed] Most of the chemical compounds are polycyclic aromatic hydrocarbon:[47][48]

Others: benzene, toluene, xylenes, cumenes, coumarone, indene, benzofuran, naphthalene and methyl-naphthalenes, acenaphthene, fluorene, phenol, cresols, pyridine, picolines, phenanthracene, carbazole, quinolines, fluoranthene.[38] Many of these constituents are known carcinogens.[50][35]

Derivatives

Various phenolic coal tar derivatives have analgesic (pain-killer) properties. These included acetanilide, phenacetin, and paracetamol aka acetaminophen.[51] Paracetamol may be the only coal-tar derived analgesic still in use today.[52] Industrial phenol is now usually synthesized from crude oil rather than coal tar.[53]

Coal tar derivatives are contra-indicated for people with the inherited red cell blood disorder glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency), as they can cause oxidative stress leading to red blood cell breakdown.[54]

Society and culture

Coal tar is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system.[10] Coal tar is generally available as a generic medication and over the counter.[4]

Regulation

Exposure to coal tar pitch volatiles can occur in the workplace by breathing, skin contact, or eye contact. The Occupational Safety and Health Administration (OSHA) has set the permissible exposure limit) to 0.2 mg/m3 benzene-soluble fraction over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 0.1 mg/m3 cyclohexane-extractable fraction over an 8-hour workday. At levels of 80 mg/m3, coal tar pitch volatiles are immediately dangerous to life and health.[55]

When used as a medication in the United States, coal tar preparations are considered over-the-counter drug pharmaceuticals and are subject to regulation by the Food and Drug Administration (FDA).

See also

References

  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 d "Background and Environmental Exposures to Creosote in the United States" (PDF). cdc.gov. September 2002. p. 19. (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 c Hamilton R (2015). Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab-Coat Edition. Jones & Bartlett Learning. p. X. ISBN 9781284057560.
  5. ^ a b c d e f 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. from the original on 2017-09-18.
  7. ^ 14th Report on Carcinogens (PDF). 2016.
  8. ^ Sneader W (2005). Drug Discovery: A History. John Wiley & Sons. p. 356. ISBN 9780471899792. from the original on 2017-09-18.
  9. ^ "History The Early Years (1863–1881)". Bayer AG. Retrieved 4 February 2021.
  10. ^ a b 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. from the original on 18 January 2017. Retrieved 13 January 2017.
  12. ^ a b c d e Maibach HI (2011). Evidence Based Dermatology. PMPH-USA. pp. 935–936. ISBN 9781607950394. from the original on 2017-09-18.
  13. ^ Hughes J, Donnelly R, James-Chatgilaou G (2001). Clinical pharmacy : a practical approach - Society of Hospital Pharmacists of Australia. South Yarra: Macmillan Publishers Australia. p. 114. ISBN 9780732980290.
  14. ^ Paghdal KV, Schwartz RA (August 2009). "Topical tar: back to the future". Journal of the American Academy of Dermatology. 61 (2): 294–302. doi:10.1016/j.jaad.2008.11.024. PMID 19185953.
  15. ^ a b Mahler BJ, Van Metre PC (2 February 2011). "Coal-Tar-Based Pavement Sealcoat, Polycyclic Aromatic Hydrocarbons (PAHs), and Environmental Health". U.S. Geological Survey Fact Sheet. from the original on 2013-03-28. Retrieved 8 March 2013.
  16. ^ Van Metre PC, Mahler BJ (December 2010). "Contribution of PAHs from coal-tar pavement sealcoat and other sources to 40 U.S. lakes". The Science of the Total Environment. 409 (2): 334–44. Bibcode:2010ScTEn.409..334V. doi:10.1016/j.scitotenv.2010.08.014. PMID 21112613.
  17. ^ "City of Austin Ordinance 20051117-070" (PDF). 17 November 2005. (PDF) from the original on 2013-05-31. Retrieved 8 March 2013.
  18. ^ "District Bans Coal-Tar Pavement Products". 26 June 2009. from the original on 2012-12-26. Retrieved 8 March 2013.
  19. ^ "Ordinance 80 : Establishing Regulations on Coal Tar Sealcoat Products Application and Sale" (PDF). Dane County Office of Lakes and Watersheds. 1 July 2007. (PDF) from the original on 2011-08-24. Retrieved 8 March 2013.
  20. ^ "Coal Tar Free America – Bans". from the original on 2014-10-06. Retrieved 8 March 2013.
  21. ^ Mahler BJ (14 April 2011). (PDF). PAHs Increasing in Urban U.S. Lakes. Environmental and Energy Study Institute. Archived from the original (PDF) on 5 October 2011. Retrieved 8 March 2013.
  22. ^ Speight JG (2015). "Coal gasification processes for synthetic liquid fuel production". In Luque R, Speight JG (eds.). Gasification for Synthetic Fuel Production. Woodhead Publishing Series in Energy. pp. 201–220 (212). doi:10.1016/B978-0-85709-802-3.00009-6. ISBN 978-0-85709-802-3. 9.5.1 Coal tar chemicals: Coal tar is a black or dark brown liquid or a high-viscosity semi-solid that is one of the by-products formed when coal is carbonized. Coal tars are complex and variable mixtures of polycyclic aromatic hydrocarbons (PAHs), phenols, and heterocyclic compounds. Because of its flammable composition, coal tar is often used for fire boilers in order to create heat. They must be heated before any heavy oil flows easily.
  23. ^ "CDC - Immediately Dangerous to Life or Health Concentrations (IDLH): Coal tar pitch volatiles - NIOSH Publications and Products". www.cdc.gov. 2018-11-02. Retrieved 2021-10-05.
  24. ^ Speight JG (2015). Asphalt materials science and technology. Amsterdam: Elsevier Science. p. 60. ISBN 978-0-12-800501-9. OCLC 922698102.
  25. ^ Hathaway AW (2011). Remediation of Former Manufactured Gas Plants and Other Coal-Tar Sites. Taylor & Francis Group.
  26. ^ Ronalds BF (2019). "Bonnington Chemical Works (1822-1878): Pioneer Coal Tar Company". International Journal for the History of Engineering & Technology. 89 (1–2): 73–91. doi:10.1080/17581206.2020.1787807. S2CID 221115202.
  27. ^ Smith M. . Igg.org.uk. Archived from the original on 2013-06-19. Retrieved 8 March 2013.
  28. ^ "Coal Tar Oil | OEC".
  29. ^ "Coal Tar use while Breastfeeding | Drugs.com". www.drugs.com. from the original on 18 January 2017. Retrieved 13 January 2017.
  30. ^ . 3 December 2001. Archived from the original on 2002-10-29. Retrieved 8 March 2013.
  31. ^ FDA (1 April 2015). "Drug Products for the Control of Dandruff, Seborrheic Dermatitis, and Psoriasis". from the original on September 18, 2015. Retrieved 26 February 2016.
  32. ^ Moustafa GA, Xanthopoulou E, Riza E, Linos A (August 2015). "Skin disease after occupational dermal exposure to coal tar: a review of the scientific literature". International Journal of Dermatology. 54 (8): 868–79. doi:10.1111/ijd.12903. PMID 26183242. S2CID 205189697.
  33. ^ a b c Roelofzen JH, Aben KK, Oldenhof UT, Coenraads PJ, Alkemade HA, van de Kerkhof PC, et al. (April 2010). "No increased risk of cancer after coal tar treatment in patients with psoriasis or eczema". The Journal of Investigative Dermatology. 130 (4): 953–61. doi:10.1038/jid.2009.389. PMID 20016499.
  34. ^ a b c d Coal-tar pitch (PDF). IARC. IARC. (PDF) from the original on 21 May 2016. Retrieved 10 June 2017. it was concluded that there is sufficient evidence in humans for the carcinogenicity of occupational exposures during paving and roofing with coal tar pitch. ... Six coal-tar pitches and three extracts of coal-tar pitches all produced skin tumours, including carcinomas, when applied to the skin of mice
  35. ^ a b "COAL TAR - National Library of Medicine HSDB Database". toxnet.nlm.nih.gov. from the original on 2017-05-28. Retrieved 2017-06-10.
  36. ^ Pan TL, Wang PW, Aljuffali IA, Huang CT, Lee CW, Fang JY (April 2015). "The impact of urban particulate pollution on skin barrier function and the subsequent drug absorption". Journal of Dermatological Science. 78 (1): 51–60. doi:10.1016/j.jdermsci.2015.01.011. PMID 25680853.
  37. ^ Qiao Y, Li Q, Du HY, Wang QW, Huang Y, Liu W (July 2017). "Airborne polycyclic aromatic hydrocarbons trigger human skin cells aging through aryl hydrocarbon receptor". Biochemical and Biophysical Research Communications. 488 (3): 445–452. doi:10.1016/j.bbrc.2017.04.160. PMID 28526404.
  38. ^ a b c d e Roberts L (2014). "Coal Tar". In Wexler P (ed.). Encyclopedia of Toxicology (Third ed.). Oxford: Academic Press. pp. 993–995. doi:10.1016/b978-0-12-386454-3.00012-9. ISBN 9780123864550. composition of coal tar will be influenced by the process used for pyrolytic distillation as well as by the original composition of the coal ... He then demonstrated excess cancers occurring in laboratory animals when coal tar is applied to the ears and skin ... [therapeutic effect] is thought to involve decreased epidermal proliferation ... Coal tar is classified as a human carcinogen ... Both inhalation and dermal routes of exposure are considered hazardous.
  39. ^ IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. (2012). "Chemical Agents and Related Occupations.". Coal-Tar Pitch. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Lyon (FR): International Agency for Research on Cancer.
  40. ^ "COAL-TARS (Group I)" (PDF). IARC MONOGRAPHS SUPPLEMENT 7. IARC. p. 175. ISBN 9789283214113. (PDF) from the original on 2016-03-15. Evidence for carcinogenicity to humans (sufficient)
  41. ^ "Report on Carcinogens, Fourteenth Edition: Coal Tars and Coal-Tar Pitches" (PDF). National Toxicology Program, Department of Health and Human Services. (PDF) from the original on 2017-02-01. Retrieved 2017-06-10.
  42. ^ Quirmbach C (7 February 2017). "Milwaukee Common Council Bans Coal Tar Sealants". Wisconsin Public Radio.
  43. ^ "Sun-Sensitive Drugs (Photosensitivity to Drugs)". MedicineNet. WebMD. 2008-08-22. p. 5. from the original on 2013-03-17. Retrieved 8 March 2013.
  44. ^ "Candidate List of substances of very high concern for Authorisation". echa.europa.eu/home. nd. Retrieved 27 October 2021.
  45. ^ . apps.who.int. Archived from the original on 2017-04-20. Retrieved 2017-06-10. keratolytic agent that inhibits excessive proliferation of epidermal cells by reducing DNA synthesis and mitotic activity to normal levels
  46. ^ Heinz-Gerhard F (May 1963). "The Challenge in Coal Tar Chemicals". Industrial & Engineering Chemistry. 55 (5): 38–44. doi:10.1021/ie50641a006.
  47. ^ Creosote. US: Agency for Toxic Substances Disease Registry, Division of Toxicology, Dept. of Health and Human Services, Public Health Service. 2002. OCLC 816079578.
  48. ^ "Public Health Statement for Creosote". Agency for Toxic Substances and Disease Registry. September 2002.
  49. ^ Betts WD (1997). "Tar and pitch". Kirk-Othmer Encyclopedia of Chemical Technology (5th ed.). New York: John Wiley & Sons, Inc. doi:10.1002/0471238961. ISBN 9780471238966.
  50. ^ . eur-lex.europa.eu. Archived from the original on 2015-10-19. Retrieved 2017-06-10. ...are classified as carcinogens of category 1B in accordance with Annex VI to Regulation (EC) No 1272/2008 of the European Parliament
  51. ^ Dronsfield A (1 July 2005). "Pain relief: from coal tar to paracetamol". Education in Chemistry. Vol. 42, no. 4. Royal Society of Chemistry. pp. 102–105. from the original on 13 October 2017. Retrieved 14 June 2018.
  52. ^ Brown T, Dronsfield A, Ellis P (1 July 2005). "Pain relief: from coal tar to paracetamol". Royal Society of Chemistry.
  53. ^ Jones AW (June 2011). "Early drug discovery and the rise of pharmaceutical chemistry". Drug Testing and Analysis. 3 (6): 337–44. doi:10.1002/dta.301. PMID 21698778.
  54. ^ US EPA National Center for Environmental Assessment (15 March 2009). "Hematologic Disorders". hero.epa.gov. Retrieved 21 April 2020.
  55. ^ "CDC – NIOSH Pocket Guide to Chemical Hazards – Coal tar pitch volatiles". www.cdc.gov. from the original on 2015-12-08. Retrieved 2015-11-27.

External links

 
Look up coal tar in Wiktionary, the free dictionary.
  • "Coal Tar Pitch Volatiles". Occupational Safety & Health Administration. 22 March 2012. Retrieved 8 March 2013.
  • "NIOSH Pocket Guide to Chemical Hazards – Coal Tar Pitch Volatiles". Centers for Disease Control and Prevention. 11 April 2011. Retrieved 13 September 2013.
  • Engelhaupt E (19 November 2008). "Parking lots create sticky pollution problem". Environmental Science and Technology. 43 (1): 3. Bibcode:2009EnST...43....3E. doi:10.1021/es803118b.
  • Lunge G (1911). "Coal-Tar" . In Chisholm H (ed.). Encyclopædia Britannica. Vol. 6 (11th ed.). Cambridge University Press. pp. 595–599.

February 13, 2023
coal, this, article, about, substance, book, coal, corrupt, politics, corporate, greed, killing, america, children, thick, dark, liquid, which, product, production, coke, coal, from, coal, type, creosote, both, medical, industrial, uses, medicinally, topical, . This article is about the substance For the book see Coal Tar How Corrupt Politics and Corporate Greed Are Killing America s Children 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 7 Coal tarClinical dataTrade namesBalnetar Cutar othersOther namesliquor carbonis detergens LCD liquor picis carbonis LPC 1 AHFS Drugs comMultum Consumer InformationRoutes ofadministrationTopicalATC codeD05AA WHO Legal statusLegal statusUS OTC Rx onlyIdentifiersCAS Number8007 45 2ChemSpidernoneUNIIR533ESO2ECCompTox Dashboard EPA DTXSID1027683ECHA InfoCard100 029 417Coal 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 Contents 1 Uses 1 1 Medicine 1 2 Construction 1 3 Industry 2 Safety 2 1 Cancer 2 2 Other 3 Mechanism of action 4 Composition 5 Derivatives 6 Society and culture 6 1 Regulation 7 See also 8 References 9 External linksUses EditMedicine Edit Coal tar is used in medicated shampoo soap and ointment It demonstrates antifungal anti inflammatory anti itch and antiparasitic properties 12 It may be applied topically as a treatment for dandruff and psoriasis and to kill and repel head lice 5 It may be used in combination with ultraviolet light therapy 5 Coal tar may be used in two forms crude coal tar Latin pix carbonis or a coal tar solution Latin liquor picis carbonis LPC also known as liquor carbonis detergens LCD 12 13 14 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 Construction Edit Main article Sealcoat Coal tar was a component of the first sealed roads In its original development by Edgar Purnell Hooley tarmac was tar covered with granite chips Later the filler used was industrial slag Today petroleum derived binders and sealers are more commonly used These sealers are used to extend the life and reduce maintenance cost associated with asphalt pavements primarily in asphalt road paving car parks and walkways citation needed Coal tar is incorporated into some parking lot sealcoat products used to protect the structural integrity of the underlying pavement 15 Sealcoat products that are coal tar based typically contain 20 to 35 percent coal tar pitch 15 Research 16 shows it is used throughout the United States of America however several areas have banned its use in sealcoat products 17 18 19 including the District of Columbia the city of Austin Texas Dane County Wisconsin the state of Washington and several municipalities in Minnesota and others 20 21 Industry Edit 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 22 A large part of the binder used in the graphite industry for making green blocks is coke oven volatiles COV a considerable portion of which is coal tar During the baking process of the green blocks as a part of commercial graphite production most of the coal tar binders are vaporised and are generally burned in an incinerator to prevent release into the atmosphere as COV and coal tar can be injurious to health 23 24 Coal tar is also used to manufacture paints synthetic dyes notably tartrazine Yellow 5 and photographic materials 25 In the coal gas era there were many companies in Britain whose business was to distill coal tar to separate the higher value fractions such as naphtha creosote and pitch Many industrial chemicals were first isolated from coal tar during this time These companies included 26 27 Bonnington Chemical Works British Tar Products Lancashire Tar Distillers Midland Tar Distillers Newton Chambers amp Company owners of Izal brand disinfectant Sadlers ChemicalsIn modern times coal tar is mostly traded as fuel and an application for tar such as roofing The total value of the trade in coal tar is around US 20 billion each year 28 Safety EditSide effects of coal tar products 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 29 According to the National Psoriasis Foundation coal tar is a valuable safe and inexpensive treatment option for millions of people with psoriasis and other scalp or skin conditions 30 According to the FDA coal tar concentrations between 0 5 and 5 are considered safe 31 and effective for psoriasis Cancer Edit Long term consistent exposure to coal tar likely increases the risk of non melanoma skin cancers 32 Evidence is inconclusive whether medical coal tar which does not remain on the skin for the long periods seen in occupational exposure causes cancer because there is insufficient data to make a judgment 33 While coal tar consistently causes cancer in cohorts of workers with chronic occupational exposure animal models and mechanistic studies 34 the data on short term use as medicine in humans has so far failed to show any consistently significant increase in rates of cancer 33 Coal tar contains many polycyclic aromatic hydrocarbons and it is believed that their metabolites bind to DNA damaging it 35 The PAHs found in coal tar and air pollution induce immunosenescence and cytotoxicity in epidermal cells 36 37 It s possible that the skin can repair itself from this damage after short term exposure to PAHs but not after long term exposure 33 Long term skin exposure to these compounds can produce tar warts which can progress to squamous cell carcinoma 38 Coal tar was one of the first chemical substances proven to cause cancer from occupational exposure during research in 1775 on the cause of chimney sweeps carcinoma 38 Modern studies have shown that working with coal tar pitch such as during the paving of roads or when working on roofs increases the risk of cancer 34 The International Agency for Research on Cancer lists coal tars as Group 1 carcinogens meaning they directly cause cancer 34 39 40 The U S Department of Health and Human Services lists coal tars as known human carcinogens 41 In response to public health concerns regarding the carcinogenicity of PAHs some municipalities such as the city of Milwaukee have banned the use of common coal tar based road and driveway sealants citing concerns of elevated PAH content in groundwater 42 Other Edit Coal tar causes increased sensitivity to sunlight 43 so skin treated with topical coal tar preparations should be protected from sunlight The residue from the distillation of high temperature coal tar primarily a complex mixture of three or more membered condensed ring aromatic hydrocarbons was listed on 13 January 2010 as a substance of very high concern by the European Chemicals Agency 44 Mechanism of action EditThe exact mechanism of action is unknown 12 Coal tar is a complex mixture of phenols polycyclic aromatic hydrocarbons PAHs and heterocyclic compounds 2 It is a keratolytic agent which reduces the growth rate of skin cells and softens the skin s keratin 45 38 Composition EditCoal tar is produced through thermal destruction pyrolysis of coal Its composition varies with the process and type of coal used lignite bituminous or anthracite 38 Coal tar is a mixture of approximately 10 000 chemicals of which only about 50 have been identified 46 better source needed Most of the chemical compounds are polycyclic aromatic hydrocarbon 47 48 polycyclic aromatic hydrocarbons 4 rings chrysene fluoranthene pyrene triphenylene naphthacene benzanthracene 5 rings picene benzo a pyrene benzo e pyrene benzofluoranthenes perylene 6 rings dibenzopyrenes dibenzofluoranthenes benzoperylenes 7 rings coronene methylated and polymethylated derivatives mono and polyhydroxylated derivatives and heterocyclic compounds 34 49 Others benzene toluene xylenes cumenes coumarone indene benzofuran naphthalene and methyl naphthalenes acenaphthene fluorene phenol cresols pyridine picolines phenanthracene carbazole quinolines fluoranthene 38 Many of these constituents are known carcinogens 50 35 Derivatives EditVarious phenolic coal tar derivatives have analgesic pain killer properties These included acetanilide phenacetin and paracetamol aka acetaminophen 51 Paracetamol may be the only coal tar derived analgesic still in use today 52 Industrial phenol is now usually synthesized from crude oil rather than coal tar 53 Coal tar derivatives are contra indicated for people with the inherited red cell blood disorder glucose 6 phosphate dehydrogenase deficiency G6PD deficiency as they can cause oxidative stress leading to red blood cell breakdown 54 Society and culture EditCoal tar is on the World Health Organization s List of Essential Medicines the most effective and safe medicines needed in a health system 10 Coal tar is generally available as a generic medication and over the counter 4 Regulation Edit Exposure to coal tar pitch volatiles can occur in the workplace by breathing skin contact or eye contact The Occupational Safety and Health Administration OSHA has set the permissible exposure limit to 0 2 mg m3 benzene soluble fraction over an 8 hour workday The National Institute for Occupational Safety and Health NIOSH has set a recommended exposure limit REL of 0 1 mg m3 cyclohexane extractable fraction over an 8 hour workday At levels of 80 mg m3 coal tar pitch volatiles are immediately dangerous to life and health 55 When used as a medication in the United States coal tar preparations are considered over the counter drug pharmaceuticals and are subject to regulation by the Food and Drug Administration FDA See also EditCoal oil Wood tarReferences Edit 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 a b c d 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 Vallee Y 1998 Gas Phase Reactions in Organic Synthesis CRC Press p 107 ISBN 9789056990817 a b c Hamilton R 2015 Tarascon Pocket Pharmacopoeia 2015 Deluxe Lab Coat Edition Jones amp Bartlett Learning p X ISBN 9781284057560 a b c d e f 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 a b Hornbostel C 1991 Construction Materials Types Uses and Applications John Wiley amp Sons p 864 ISBN 9780471851455 Archived from the original on 2017 09 18 14th Report on Carcinogens PDF 2016 Sneader W 2005 Drug Discovery A History John Wiley amp Sons p 356 ISBN 9780471899792 Archived from the original on 2017 09 18 History The Early Years 1863 1881 Bayer AG Retrieved 4 February 2021 a b 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 Coal Tar use while Breastfeeding Drugs com www drugs com Archived from the original on 18 January 2017 Retrieved 13 January 2017 a b c d e Maibach HI 2011 Evidence Based Dermatology PMPH USA pp 935 936 ISBN 9781607950394 Archived from the original on 2017 09 18 Hughes J Donnelly R James Chatgilaou G 2001 Clinical pharmacy a practical approach Society of Hospital Pharmacists of Australia South Yarra Macmillan Publishers Australia p 114 ISBN 9780732980290 Paghdal KV Schwartz RA August 2009 Topical tar back to the future Journal of the American Academy of Dermatology 61 2 294 302 doi 10 1016 j jaad 2008 11 024 PMID 19185953 a b Mahler BJ Van Metre PC 2 February 2011 Coal Tar Based Pavement Sealcoat Polycyclic Aromatic Hydrocarbons PAHs and Environmental Health U S Geological Survey Fact Sheet Archived from the original on 2013 03 28 Retrieved 8 March 2013 Van Metre PC Mahler BJ December 2010 Contribution of PAHs from coal tar pavement sealcoat and other sources to 40 U S lakes The Science of the Total Environment 409 2 334 44 Bibcode 2010ScTEn 409 334V doi 10 1016 j scitotenv 2010 08 014 PMID 21112613 City of Austin Ordinance 20051117 070 PDF 17 November 2005 Archived PDF from the original on 2013 05 31 Retrieved 8 March 2013 District Bans Coal Tar Pavement Products 26 June 2009 Archived from the original on 2012 12 26 Retrieved 8 March 2013 Ordinance 80 Establishing Regulations on Coal Tar Sealcoat Products Application and Sale PDF Dane County Office of Lakes and Watersheds 1 July 2007 Archived PDF from the original on 2011 08 24 Retrieved 8 March 2013 Coal Tar Free America Bans Archived from the original on 2014 10 06 Retrieved 8 March 2013 Mahler BJ 14 April 2011 Causes of Increasing Concentrations of Polycyclic Aromatic Hydrocarbons PAHs in U S Lakes PDF PAHs Increasing in Urban U S Lakes Environmental and Energy Study Institute Archived from the original PDF on 5 October 2011 Retrieved 8 March 2013 Speight JG 2015 Coal gasification processes for synthetic liquid fuel production In Luque R Speight JG eds Gasification for Synthetic Fuel Production Woodhead Publishing Series in Energy pp 201 220 212 doi 10 1016 B978 0 85709 802 3 00009 6 ISBN 978 0 85709 802 3 9 5 1 Coal tar chemicals Coal tar is a black or dark brown liquid or a high viscosity semi solid that is one of the by products formed when coal is carbonized Coal tars are complex and variable mixtures of polycyclic aromatic hydrocarbons PAHs phenols and heterocyclic compounds Because of its flammable composition coal tar is often used for fire boilers in order to create heat They must be heated before any heavy oil flows easily CDC Immediately Dangerous to Life or Health Concentrations IDLH Coal tar pitch volatiles NIOSH Publications and Products www cdc gov 2018 11 02 Retrieved 2021 10 05 Speight JG 2015 Asphalt materials science and technology Amsterdam Elsevier Science p 60 ISBN 978 0 12 800501 9 OCLC 922698102 Hathaway AW 2011 Remediation of Former Manufactured Gas Plants and Other Coal Tar Sites Taylor amp Francis Group Ronalds BF 2019 Bonnington Chemical Works 1822 1878 Pioneer Coal Tar Company International Journal for the History of Engineering amp Technology 89 1 2 73 91 doi 10 1080 17581206 2020 1787807 S2CID 221115202 Smith M GANSG Coal Tar Distillers Igg org uk Archived from the original on 2013 06 19 Retrieved 8 March 2013 Coal Tar Oil OEC Coal Tar use while Breastfeeding Drugs com www drugs com Archived from the original on 18 January 2017 Retrieved 13 January 2017 The battle to save coal tar in California 3 December 2001 Archived from the original on 2002 10 29 Retrieved 8 March 2013 FDA 1 April 2015 Drug Products for the Control of Dandruff Seborrheic Dermatitis and Psoriasis Archived from the original on September 18 2015 Retrieved 26 February 2016 Moustafa GA Xanthopoulou E Riza E Linos A August 2015 Skin disease after occupational dermal exposure to coal tar a review of the scientific literature International Journal of Dermatology 54 8 868 79 doi 10 1111 ijd 12903 PMID 26183242 S2CID 205189697 a b c Roelofzen JH Aben KK Oldenhof UT Coenraads PJ Alkemade HA van de Kerkhof PC et al April 2010 No increased risk of cancer after coal tar treatment in patients with psoriasis or eczema The Journal of Investigative Dermatology 130 4 953 61 doi 10 1038 jid 2009 389 PMID 20016499 a b c d Coal tar pitch PDF IARC IARC Archived PDF from the original on 21 May 2016 Retrieved 10 June 2017 it was concluded that there is sufficient evidence in humans for the carcinogenicity of occupational exposures during paving and roofing with coal tar pitch Six coal tar pitches and three extracts of coal tar pitches all produced skin tumours including carcinomas when applied to the skin of mice a b COAL TAR National Library of Medicine HSDB Database toxnet nlm nih gov Archived from the original on 2017 05 28 Retrieved 2017 06 10 Pan TL Wang PW Aljuffali IA Huang CT Lee CW Fang JY April 2015 The impact of urban particulate pollution on skin barrier function and the subsequent drug absorption Journal of Dermatological Science 78 1 51 60 doi 10 1016 j jdermsci 2015 01 011 PMID 25680853 Qiao Y Li Q Du HY Wang QW Huang Y Liu W July 2017 Airborne polycyclic aromatic hydrocarbons trigger human skin cells aging through aryl hydrocarbon receptor Biochemical and Biophysical Research Communications 488 3 445 452 doi 10 1016 j bbrc 2017 04 160 PMID 28526404 a b c d e Roberts L 2014 Coal Tar In Wexler P ed Encyclopedia of Toxicology Third ed Oxford Academic Press pp 993 995 doi 10 1016 b978 0 12 386454 3 00012 9 ISBN 9780123864550 composition of coal tar will be influenced by the process used for pyrolytic distillation as well as by the original composition of the coal He then demonstrated excess cancers occurring in laboratory animals when coal tar is applied to the ears and skin therapeutic effect is thought to involve decreased epidermal proliferation Coal tar is classified as a human carcinogen Both inhalation and dermal routes of exposure are considered hazardous IARC Working Group on the Evaluation of Carcinogenic Risks to Humans 2012 Chemical Agents and Related Occupations Coal Tar Pitch IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Lyon FR International Agency for Research on Cancer COAL TARS Group I PDF IARC MONOGRAPHS SUPPLEMENT 7 IARC p 175 ISBN 9789283214113 Archived PDF from the original on 2016 03 15 Evidence for carcinogenicity to humans sufficient Report on Carcinogens Fourteenth Edition Coal Tars and Coal Tar Pitches PDF National Toxicology Program Department of Health and Human Services Archived PDF from the original on 2017 02 01 Retrieved 2017 06 10 Quirmbach C 7 February 2017 Milwaukee Common Council Bans Coal Tar Sealants Wisconsin Public Radio Sun Sensitive Drugs Photosensitivity to Drugs MedicineNet WebMD 2008 08 22 p 5 Archived from the original on 2013 03 17 Retrieved 8 March 2013 Candidate List of substances of very high concern for Authorisation echa europa eu home nd Retrieved 27 October 2021 WHO Model Prescribing Information Drugs Used in Skin Diseases Keratoplastic and keratolytic agents Coal tar apps who int Archived from the original on 2017 04 20 Retrieved 2017 06 10 keratolytic agent that inhibits excessive proliferation of epidermal cells by reducing DNA synthesis and mitotic activity to normal levels Heinz Gerhard F May 1963 The Challenge in Coal Tar Chemicals Industrial amp Engineering Chemistry 55 5 38 44 doi 10 1021 ie50641a006 Creosote US Agency for Toxic Substances Disease Registry Division of Toxicology Dept of Health and Human Services Public Health Service 2002 OCLC 816079578 Public Health Statement for Creosote Agency for Toxic Substances and Disease Registry September 2002 Betts WD 1997 Tar and pitch Kirk Othmer Encyclopedia of Chemical Technology 5th ed New York John Wiley amp Sons Inc doi 10 1002 0471238961 ISBN 9780471238966 EUR Lex 32013R1272 EN EUR Lex eur lex europa eu Archived from the original on 2015 10 19 Retrieved 2017 06 10 are classified as carcinogens of category 1B in accordance with Annex VI to Regulation EC No 1272 2008 of the European Parliament Dronsfield A 1 July 2005 Pain relief from coal tar to paracetamol Education in Chemistry Vol 42 no 4 Royal Society of Chemistry pp 102 105 Archived from the original on 13 October 2017 Retrieved 14 June 2018 Brown T Dronsfield A Ellis P 1 July 2005 Pain relief from coal tar to paracetamol Royal Society of Chemistry Jones AW June 2011 Early drug discovery and the rise of pharmaceutical chemistry Drug Testing and Analysis 3 6 337 44 doi 10 1002 dta 301 PMID 21698778 US EPA National Center for Environmental Assessment 15 March 2009 Hematologic Disorders hero epa gov Retrieved 21 April 2020 CDC NIOSH Pocket Guide to Chemical Hazards Coal tar pitch volatiles www cdc gov Archived from the original on 2015 12 08 Retrieved 2015 11 27 External links Edit Look up coal tar in Wiktionary the free dictionary Coal Tar Pitch Volatiles Occupational Safety amp Health Administration 22 March 2012 Retrieved 8 March 2013 NIOSH Pocket Guide to Chemical Hazards Coal Tar Pitch Volatiles Centers for Disease Control and Prevention 11 April 2011 Retrieved 13 September 2013 Engelhaupt E 19 November 2008 Parking lots create sticky pollution problem Environmental Science and Technology 43 1 3 Bibcode 2009EnST 43 3E doi 10 1021 es803118b Lunge G 1911 Coal Tar In Chisholm H ed Encyclopaedia Britannica Vol 6 11th ed Cambridge University Press pp 595 599 Portal Medicine Retrieved from https en wikipedia org w index php title Coal tar amp oldid 1136196285, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.