What Are PAHs?
ATSDR describes polycyclic aromatic hydrocarbons, or PAHs, as a group of over 100 different chemicals formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances like tobacco or charbroiled meat, usually found as mixtures such as soot. A CDC fact sheet posted by the EPA adds that PAHs occur naturally in coal, crude oil and gasoline, and that high-temperature cooking will form PAHs in meat and other foods.
ATSDR says exposure usually happens by breathing air contaminated by wildfires or coal tar, or by eating foods that have been grilled.
On cancer, ATSDR says the Department of Health and Human Services has determined that some PAHs may reasonably be expected to be carcinogens, and that some people who breathed or touched mixtures of PAHs and other chemicals for long periods have developed cancer. IARC classifies one PAH, benzo[a]pyrene, as carcinogenic to humans (Group 1), and the EPA's IRIS assessment describes benzo[a]pyrene as carcinogenic to humans based on strong and consistent evidence in animals and humans.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceATSDR describes PAHs as a group of over 100 chemicals formed during incomplete burning of coal, oil and gas, garbage, or organic substances like tobacco or charbroiled meat, usually found as mixtures such as soot. ATSDR, CDC ↗
- Government sourceATSDR says exposure to PAHs usually occurs by breathing air contaminated by wild fires or coal tar, or by eating foods that have been grilled. ATSDR, CDC ↗
- Government sourceATSDR says HHS has determined some PAHs may reasonably be expected to be carcinogens, and some people who breathed or touched PAH mixtures for long periods have developed cancer. ATSDR, CDC ↗
- Government sourceA CDC biomonitoring fact sheet posted by the EPA says PAHs occur naturally in coal, crude oil and gasoline, are produced when fuels, wood, garbage and tobacco burn, and form in meat during high-temperature cooking. CDC National Biomonitoring Program, via US EPA ↗
- Government sourceIARC Monographs Volume 100F classifies benzo[a]pyrene as a human carcinogen (Group 1), citing extensive animal evidence supported by mechanistic evidence from experimental and human studies. IARC, via NCBI Bookshelf ↗
- Government sourceThe EPA's IRIS assessment says benzo[a]pyrene is carcinogenic to humans based on strong and consistent evidence in animals and humans. US EPA, Integrated Risk Information System ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.