Agent Name
Alternative Name
Major Category
Other Classes
CLASSES; Arenes, polycyclic; Arenes, polycyclic, dihydroxyepoxy; Aromatic hydrocarbons, fused-ring; Aromatic polycyclic hydrocarbons; Dihydroxyepoxy polycyclic aromatic hydrocarbons; PAH; PAHs; Polyarenes; Polycyclic dihydroxyepoxy aromatic hydrocarbons; Polynuclear aromatic hydrocarbons; Aromatic hydrocarbons, polycyclic; Polycylic compounds, arom. Hydrocarbons; [ChemIDplus]; Benzo[a]pyrene (BaP); Benzo[e]pyrene; Chrysene; Dibenz[a,h]anthracene; Anthracene; Benzo[c]phenanthrene; Pyrene; Fluoranthene; Cholanthrene; Benz[a]acridine; Benzo[g]chrysene; Phenanthrene; Benz[a]anthracene
Polycyclic Aromatic Hydrocarbons
Occur as needles, plates, crystals, leaflets, or prisms ranging from colorless to pale yellow to golden yellow; [HSDB]
"PAHs are a group of chemicals that are formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances. PAHs can be man-made or occur naturally. . . . A few of the PAHs are used in medicines and to make dyes, plastics, and pesticides." [ATSDR ToxFAQs] PAHs are present in coal tar, creosote, crude oil, tobacco smoke, barbecue smoke, waste oils, engine exhausts, as well as in fresh foods and natural waters. As products of combustion, the hundreds of different PAHs almost always occur mixed with many other different chemicals. [CHEMINFO]
These compounds consist of two or more fused aromatic rings. "Several PAHs are carcinogenic in animals and BAP [Benzo(a)pyrene] is the best known and most studied PAH. Other individual PAHs are often listed as 'suspected' human carcinogens because there are little or no data relating exposure to the specific isolated compound to human carcinogenicity; humans are almost invariably exposed to PAH mixtures and not to single compounds. Coal tar pitch volatiles, a diverse group of complex mixtures containing PAHs, are confirmed human carcinogens. . . . Dermal route of exposure may sometimes contribute most to PAH absorption." [ACGIH] They are solids at room temperature. More than 100 PAHs have been identified. [Sullivan, p. 1241] Mixtures of PAHs that are IARC group 1 carcinogens include coal tars and pitches, mineral oils (untreated & mildly treated), shale oils, and soots. Exposures to these mixtures occur in coal gasification, coke production, aluminum production, and iron and steel founding. [Siemiatycki, p. 335] Exposure to soot in chimney sweeping is a known human carcinogen; Other occupational exposures to PAHs classified as Group 1 are coal gasification, coke production, coal-tar distillation, paving and roofing with coal-tar pitch, and aluminum production. [IARC Volume 92 (2010)] In high-dose animal studies, benzo(a)pyrene causes testicular and ovarian damage, reducing fertility. [Frazier] Heterocyclic aromatic compounds (HACs) are "PAHs having any one carbon atom in a ring replaced by a nitrogen, oxygen, or sulfur atom." [HSDB] See "Soots," "Coal tar pitch volatiles," "Coke oven emissions," and "Shale oils." See "Benzo(a)pyrene."
Biomedical References

Exposure Assessment

1-Hydroxypyrene (1-HP) in urine = 2.5 ug/L at end of shift at end of workweek; (Adjusted for the Pyrene to Benzo(a)pyrene ratio); 3-Hydroxybenzo(a)pyrene (3-HBAP) in urine = Nq at end of shift at end of workweek; [TLVs and BEIs]

Adverse Effects

Reproductive Toxin

Diseases, Processes, and Activities Linked to This Agent