Benzo[a]pyrene (BaP)

CASRN 50-32-8

IRIS Toxicological Review of Benzo[a]pyrene (External Review Draft)

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The IRIS Toxicological Review of Benzo[a]pyrene was released for external peer review in September 2014. The EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) conducted a peer review of the scientific basis supporting the benzo[a]pyrene assessment and released a final report of their review in April 2016. Information regarding the peer review can be found at the SAB's website.


U.S. EPA. IRIS Toxicological Review of Benzo[a]pyrene (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-14/312, 2014.

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Benzo[a]pyrene is a five-ring polycyclic aromatic hydrocarbon that is relatively insoluble in water and has low volatility. It is ubiquitous in the environment primarily as a result of incomplete combustion emissions. Natural sources of benzo[a]pyrene include forest fires and volcanoes, and anthropogenic sources include stoves/furnaces burning fossil fuels (especially wood and coal), motor vehicle exhaust, and various industrial combustion processes. Major sources of occupational exposure involve production of aluminum, coke, graphite and silicon carbide, as well as coal tar distillation. Major sources of non-occupational exposure involve tobacco products and diet (e.g., barbequed or charred meats).

In September 2014, EPA submitted the draft IRIS assessment of benzo[a]pyrene (see downloads) to the agency’s Science Advisory Board (SAB) for peer review and comments. EPA had previously released a draft of the assessment for public comment (see related links), held a public meeting about the draft, and then revised it based on the comments received. The SAB Chemical Assessment Advisory Committee (CAAC), augmented for the review of the draft IRIS assessment of benzo[a]pyrene (CAAC-benzo[a]pyrene panel), will review this draft assessment. Details about the CAAC-Benzo[a]pyrene panel, meeting dates, and times will be announced in a Federal Register Notice released by the SAB. The notice will provide information on how the public can participate in the BaP external peer review meetings, as well as instructions about how to provide comments to the SAB. Additional information on the SAB-CAAC review of benzo[a]pyrene is on the SAB website.


Date Description
01-Jun 2011EPA initiated the interagency science consultation on the draft Toxicological Review of Benzo[a]pyrene.
02-Jun 2012A revised interagency science consultation draft Toxicological Review of Benzo[a]pyrene was provided for further review by other federal agencies and the Executive Office of the President.
03-Aug 2013EPA released a public comment draft for review and comments. EPA also released the interagency science consultation documents, comments from reviewers, and EPA's response to major comments. [Federal Register Notice: Aug 21, 2013]
04-Oct 2013EPA announced an extension of the public comment period from October 21, 2013 to November 21, 2013. [Federal Register Notice: Oct 24, 2013]
06-Dec 2013EPA held a public meeting to engage stakeholders in early discussions on the draft IRIS assessment and draft charge.
07-Jan 2014EPA announced a request for nominations for experts to augment the SAB CAAC committee for the upcoming review of the draft benzo[a]pyrene assessment. [Federal Register Notice Jan 28, 2014].
08-Sep 2014SAB released a list and biosketches of potential candidates to augment the SAB CAAC for the upcoming review of the draft benzo[a]pyrene assessment.
09-Sep 2014EPA transmitted the external peer review draft benzo[a]pyrene assessment, including responses to major public comments, and the draft charge to the peer reviewers to the SAB. This draft and related materials were also posted on the IRIS website.
10-Apr 2016EPA's SAB released a final report of their review of the draft IRIS assessment (see downloads). [SAB's Benzo[a]pyrene Review Page]


Following public comment and external peer review, the assessment will be revised taking into consideration peer review and public comments. The assessment will then undergo a final EPA internal review and a review by other federal agencies and the Executive Office of the President. Once final, the assessment will be posted to the IRIS database.

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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.

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Comments on the assessment may be submitted and reviewed using the Docket ID EPA-HQ-ORD-2011-0391

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