3,4-Dihydrocyclopenta[cd]pyren-4-ol is a metabolite of a environmental pollutant and suspected human carcinogen cyclopenta[cd]pyrene (CPP).Also, it is an intermediate used in the synthesis of Acepyrene (A130950), which is a novel constituent discovered that belongs to the pyrene class of the polycyclic aromatic hydrocarbons. Acepyrene occurs in a large variety of carbon black soots, in cigarette smoke and is a major representative of PAH in car engine exhaust gases.