Meeting of the Scientific Review Panel for Toxic Air Contaminants on October 30, 2008

The Office of Environmental Health Hazard Assessment (OEHHA) is required to develop guidelines for conducting health risk assessments under the Air Toxics Hot Spots Program (Health and Safety Code Section 44360(b)(2)). 

A revision of the guidelines for noncancer risk assessment was approved by the Scientific Review Panel for Toxic Air Contaminants (SRP) on June 18, 2008.  The SRP has also been reviewing revised RELs derived using this updated methodology.  At the meeting on October 30, 2008, the SRP will be reviewing a further draft of the documents describing the proposed new Reference Exposure Levels (RELs) for acetaldehyde, acrolein, arsenic, formaldehyde, manganese and mercury.  These documents are available for download below.  The drafts contain revisions, visible in underline, pursuant to the discussion at the June 18th SRP meeting and other comments from Panel members.  Two of these documents (those describing the RELs for acetaldehyde and manganese) have substantial revisions to the text.  In the case of acetaldehyde a different study was chosen as the basis of the acute REL.

Also for consideration at the October 30th meeting we are presenting the revised Technical Support Document for Cancer Potency Factors.  This describes updated methodology for estimation of cancer potency factors for use in the Air Toxics Hot Spots program, including consideration of the impact of early in life exposures.  This document is a revision of the draft which we provided for public review from June 23rd to August 22nd.  The document, the comments received, and our responses to these comments, are available for download below.

The agenda, timing and location of the meeting are given on the California Air Resources Board’s web site at


Comment Date: 
Oct 10, 2008