The short answer
Coal tar and coal-tar pitch come from processing coal and are used in roofing, paving, and some medicines. Heavy exposure is linked to skin and lung cancers. Occupational controls and careful medical use reduce risk.
Coal tar and coal-tar pitch is classified as a known human carcinogen (IARC Group 1).
People are mainly exposed by skin contact and breathing fumes, mainly in industrial jobs.
It is most strongly linked to skin and lung cancers.
A carcinogen classification describes hazard — whether something can cause cancer — not your personal risk at a given exposure.
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The full explanation.
The simple version
Coal tar is a thick, dark liquid made when coal is heated. It goes into roofing, road paving, and some skin treatments. Long, heavy exposure is linked to skin and lung cancers. Most of that exposure happens at work.
What coal tar and coal-tar pitch is
Coal tar and coal-tar pitch are byproducts of turning coal into coke and gas. They contain polycyclic aromatic hydrocarbons, or PAHs, and those are the cancer-causing part. Coal tar is used in industry. In low concentrations it also appears in some medicated shampoos and ointments.
How people are exposed
Common ways people come into contact with it:
- Working in roofing, paving, aluminum production, or coal-tar production.
- Skin contact with hot coal-tar products, and breathing their fumes.
- Long-term use of strong coal-tar skin products. Medical products are usually low-dose.
The cancer connection
Heavy coal-tar exposure is linked to skin cancer and lung cancer. Coal-tar pitch is linked to bladder cancer in some settings. The PAHs are the main concern.
Hazard rulings on substances like this come from IARC, the World Health Organization's cancer agency. It places coal tar and coal-tar pitch in Group 1, carcinogenic to humans. That is the strongest evidence category. It means there is enough evidence that they can cause cancer in people. In the United States, the National Toxicology Program's Report on Carcinogens lists them as known to be a human carcinogen.
Hazard is not the same as risk
The Group 1 listing describes what coal tar can do under some conditions. Your personal risk is a different question, and it turns on the dose and the years. A roofer working with hot tar day after day is not in the same position as someone using a medicated shampoo now and then. Same substance, same hazard, very different risk.
How to lower your exposure
- Wear protective clothing, gloves, and respiratory protection on industrial jobs.
- Keep skin contact and fume exposure down when working with hot coal-tar products.
- Use medicated coal-tar products as directed, and ask your doctor if you are worried.
The bottom line
Coal tar and coal-tar pitch are known human carcinogens (IARC Group 1). The risk sits with heavy, repeated workplace exposure, not with a bottle of medicated shampoo. For the wider picture, see our overview of cancer prevention and what raises cancer risk.
Words to know
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Common questions
Does coal tar and coal-tar pitch cause cancer?
Yes. Coal tar and coal-tar pitch is classified as a known human carcinogen, which means there is strong evidence it can cause cancer in people. How much any one person's risk rises depends on how much they are exposed to and for how long.
How are people exposed to coal tar and coal-tar pitch?
Most exposure happens by skin contact and breathing fumes, mainly in industrial jobs.
Which cancers are linked to coal tar and coal-tar pitch?
It is most strongly linked to skin and lung cancers.
How can I reduce my exposure to coal tar and coal-tar pitch?
The main steps are protective equipment and limiting skin and fume contact at work.
Does a carcinogen label mean I will get cancer?
No. A classification is about hazard — whether coal tar and coal-tar pitch can cause cancer under some conditions — not a prediction that any one exposed person will develop cancer. Your actual risk depends on the amount and length of exposure and other factors.
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Last updated: 2026-08-10Next planned review: 2028-07-05
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How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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