Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft)
Federal Register Notices
EPA is announcing a 60-day public comment period and a public listening session for the external review draft document titled, Development of a Relative Potency Factor (RPF) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft), as announced in the February 26, 2010 Federal Register Notice.
EPA is conducting a peer review and public comment of the scientific basis supporting the human health hazard and dose-response assessment of polycyclic aromatic hydrocarbon (PAH) mixtures that when finalized will appear on the Integrated Risk Information System (IRIS) database.
U.S. EPA. Development of a Relative Potency Factor (Rpf) Approach for Polycyclic Aromatic Hydrocarbon (PAH) Mixtures (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-08/012A, 2010.
PAHs are of concern as potential human health hazards, because many PAHs are demonstrated tumorigenic agents in animal bioassays and are positive in tests for genotoxicity or DNA damage. PAHs occur in the environment primarily as complex mixtures generated from the combustion of substances containing carbon and hydrogen, and rarely occur in the environment as isolated entities. The draft Relative Potency Factor approach is not a reassessment of individual PAH carcinogenicity, but rather provides a methodology for estimating cancer risk from exposure to PAH mixtures by summing doses of component PAHs after scaling the doses (with RPFs) relative to the potency of an index PAH (i.e., benzo[a]pyrene). The cancer risk is then estimated using the dose-response curve for the index PAH.
Following External Peer Review and Public Comment, the final assessment is scheduled to be posted to the IRIS Web site.
This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.
Comments on the assessment may be submitted and reviewed using the Docket ID EPA-HQ-ORD-2010-0047