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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. [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."

Reference Link

NTP: Polycyclic Aromatic Hydrocarbons

Exposure Assessment

1-Hydroxypyrene (1-HP) in urine = Nq at end of shift at end of workweek; If presence of 1-HP in urine above 1ug/L, then evidence of occupational exposure to PAHs; [ACGIH]

Reference Link

ATSDR - ToxFAQs - Polycyclic Aromatic Hydrocarbons (PAHs)

Adverse Effects
Reproductive Toxin


Links to Other NLM Databases
Toxicity Information

Chemical Information

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Related Information in HazMap

Industrial Processes with risk of exposure:


Activities with risk of exposure: