Editing Coal tar (section)

== Safety ==
Side effects of coal tar products include skin irritation, sun sensitivity, [[allergic reactions]], and skin discoloration.<ref name="WHO2008" /> It is unclear if use during [[pregnancy]] is safe for the baby and use during [[breastfeeding]] is not typically recommended.<ref>{{cite web|url=https://www.drugs.com/breastfeeding/coal-tar.html|title=Coal Tar use while Breastfeeding |website= Drugs.com|date = 2 June 2023 |archive-url= https://web.archive.org/web/20230926083525/https://www.drugs.com/breastfeeding/coal-tar.html |archive-date=26 September 2023|url-status=live}}</ref>

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.<ref name=coalcal>{{cite web| url = http://www.psoriasis.org/news/stories/2001/20011202_coalcala.php| title = The battle to save coal tar in California| date = 3 December 2001| archive-url = https://web.archive.org/web/20021029132630/http://www.psoriasis.org/coaltar.advocacy.htm| archive-date = 2002-10-29| access-date = 8 March 2013| url-status = dead}}</ref> According to the [[FDA]], coal tar concentrations between 0.5% and 5% are considered safe<ref>{{cite web| url = http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm?cfrpart=358&showfr=1&subpartnode=21:5.0.1.1.30.8| title = Drug Products for the Control of Dandruff, Seborrheic Dermatitis, and Psoriasis| author = FDA| date = 1 April 2015| access-date = 26 February 2016| url-status = live| archive-url = https://web.archive.org/web/20150918184253/http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=358&showFR=1&subpartNode=21%3A5.0.1.1.30.8| archive-date = September 18, 2015}}</ref> and effective for psoriasis.

=== Cancer ===
Long-term, consistent exposure to coal tar likely increases the risk of non-melanoma [[skin cancer]]s.<ref>{{cite journal | vauthors = Moustafa GA, Xanthopoulou E, Riza E, Linos A | title = Skin disease after occupational dermal exposure to coal tar: a review of the scientific literature | journal = International Journal of Dermatology | volume = 54 | issue = 8 | pages = 868–79 | date = August 2015 | pmid = 26183242 | doi = 10.1111/ijd.12903 | s2cid = 205189697 | doi-access = free }}</ref> Evidence is inconclusive whether medical coal tar, which does not remain on the skin for the long periods seen in occupational [[Exposure assessment#Exposure|exposure]], causes cancer, because there is insufficient data to make a judgment.<ref name=Ro2010>{{cite journal | vauthors = Roelofzen JH, Aben KK, Oldenhof UT, Coenraads PJ, Alkemade HA, van de Kerkhof PC, van der Valk PG, Kiemeney LA | display-authors = 6 | title = No increased risk of cancer after coal tar treatment in patients with psoriasis or eczema | journal = The Journal of Investigative Dermatology | volume = 130 | issue = 4 | pages = 953–61 | date = April 2010 | pmid = 20016499 | doi = 10.1038/jid.2009.389 | doi-access = free }}</ref> While coal tar consistently causes cancer in cohorts of workers with chronic occupational exposure, animal models, and mechanistic studies,<ref name=":0" /> the data on short-term use as medicine in humans has so far failed to show any consistently significant increase in rates of cancer.<ref name=Ro2010/>

Coal tar contains many [[polycyclic aromatic hydrocarbons]], and it is believed that their metabolites bind to DNA, damaging it.<ref name=":2" /> The PAHs found in coal tar and air pollution induce [[immunosenescence]] and cytotoxicity in epidermal cells.<ref>{{cite journal | vauthors = Pan TL, Wang PW, Aljuffali IA, Huang CT, Lee CW, Fang JY | title = The impact of urban particulate pollution on skin barrier function and the subsequent drug absorption | language = English | journal = Journal of Dermatological Science | volume = 78 | issue = 1 | pages = 51–60 | date = April 2015 | pmid = 25680853 | doi = 10.1016/j.jdermsci.2015.01.011 }}</ref><ref>{{cite journal | vauthors = Qiao Y, Li Q, Du HY, Wang QW, Huang Y, Liu W | title = Airborne polycyclic aromatic hydrocarbons trigger human skin cells aging through aryl hydrocarbon receptor | journal = Biochemical and Biophysical Research Communications | volume = 488 | issue = 3 | pages = 445–452 | date = July 2017 | pmid = 28526404 | doi = 10.1016/j.bbrc.2017.04.160 }}</ref> It's possible that the skin can repair itself from this damage after short-term exposure to PAHs but not after long-term exposure.<ref name="Ro2010" /> Long-term skin exposure to these compounds can produce "[[tar warts]]", which can progress to [[squamous cell carcinoma]].<ref name=":1" />

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]].<ref name=":1" /> 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.<ref name=":0">{{cite book|url=https://monographs.iarc.fr/ENG/Monographs/vol100F/mono100F-17.pdf|title=Coal-tar pitch|publisher=IARC|archive-url=https://web.archive.org/web/20160521101818/http://monographs.iarc.fr/ENG/Monographs/vol100F/mono100F-17.pdf|archive-date=21 May 2016|url-status=live|access-date=10 June 2017|quote=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}}</ref>

The [[International Agency for Research on Cancer]] lists coal tars as [[List of IARC Group 1 carcinogens|Group 1]] [[carcinogen]]s, meaning they directly cause cancer.<ref name=":0" /><ref>{{cite book | author = IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. | chapter = Chemical Agents and Related Occupations. | location = Lyon (FR) | publisher = International Agency for Research on Cancer | date = 2012 | series = IARC Monographs on the Evaluation of Carcinogenic Risks to Humans | issue = 100F | title = Coal-Tar Pitch | chapter-url = https://www.ncbi.nlm.nih.gov/books/NBK304423/ }}</ref><ref>{{Cite book|chapter-url=https://monographs.iarc.fr/ENG/Monographs/suppl7/Suppl7-58.pdf|title=IARC MONOGRAPHS SUPPLEMENT 7|publisher=IARC|pages=175|chapter=COAL-TARS (Group I)|date=1987 |isbn=9789283214113|quote=Evidence for carcinogenicity to humans (sufficient)|url-status=live|archive-url=https://web.archive.org/web/20160315151519/http://monographs.iarc.fr/ENG/Monographs/suppl7/Suppl7-58.pdf|archive-date=2016-03-15}}</ref> The U.S. Department of Health and Human Services lists coal tars as known human carcinogens.<ref>{{Cite web|url=https://ntp.niehs.nih.gov/ntp/roc/content/profiles/coaltars.pdf|title=Report on Carcinogens, Fourteenth Edition: Coal Tars and Coal-Tar Pitches|website=National Toxicology Program, Department of Health and Human Services|language=en-us|access-date=2017-06-10|url-status=live|archive-url=https://web.archive.org/web/20170201002821/https://ntp.niehs.nih.gov/ntp/roc/content/profiles/coaltars.pdf|archive-date=2017-02-01}}</ref>

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.<ref>{{cite news | vauthors = Quirmbach C |title=Milwaukee Common Council Bans Coal Tar Sealants |url=https://www.wiscontext.org/milwaukee-common-council-bans-coal-tar-sealants |publisher=Wisconsin Public Radio |date=7 February 2017}}</ref>

=== Other ===
Coal tar causes [[sun poisoning|increased sensitivity to sunlight]],<ref name="medicinenet">{{cite web |title= Sun-Sensitive Drugs (Photosensitivity to Drugs) |url= http://www.medicinenet.com/sun-sensitive_drugs_photosensitivity_to_drugs/page5.htm |date= 2008-08-22 |page= 5 |work= MedicineNet |publisher= [[WebMD]] |access-date= 8 March 2013 |url-status= live |archive-url= https://web.archive.org/web/20130317004507/http://www.medicinenet.com/sun-sensitive_drugs_photosensitivity_to_drugs/page5.htm |archive-date= 2013-03-17 }}</ref> 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 hydrocarbon]]s, was listed on 13 January 2010 as a [[substance of very high concern]] by the [[European Chemicals Agency]].<ref>{{cite web
 | title = Candidate List of substances of very high concern for Authorisation
 | url = https://echa.europa.eu/candidate-list-table/-/dislist/details/0b0236e1807d8743
 |website=echa.europa.eu/home
 | date = nd
 | access-date = 27 October 2021}}</ref>

=== 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&nbsp;mg/m<sup>3</sup> [[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&nbsp;mg/m<sup>3</sup> [[cyclohexane]]-extractable fraction over an 8-hour workday. At levels of 80&nbsp;mg/m<sup>3</sup>, coal tar pitch volatiles are [[IDLH|immediately dangerous to life and health]].<ref>{{Cite web|title = CDC&nbsp;– NIOSH Pocket Guide to Chemical Hazards&nbsp;– Coal tar pitch volatiles|url = https://www.cdc.gov/niosh/npg/npgd0145.html|website = cdc.gov|access-date = 2015-11-27|url-status = live|archive-url = https://web.archive.org/web/20151208120356/http://www.cdc.gov/niosh/npg/npgd0145.html|archive-date = 2015-12-08}}</ref>

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).