Polycyclic Aromatic Hydrocarbons (PAHs) are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. Human exposure to PAHs is typically to a mixture of PAH chemicals, not to individual PAH chemicals.
EPA's Office of Research and Development has developed a draft Integrated Risk Information System (IRIS) technical document describing the Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures to assess cancer risk from exposure to PAH mixtures. The relative potency factor approach assumes that individual PAH potencies relative to an index compound (i.e., benzo[a]pyrene, [BaP]) are added together to yield a cancer risk estimate for the whole mixture.
EPA’s Office of Research and Development has requested that the Science Advisory Board (SAB) conduct a review of this draft document.