The Office of Environmental Health Hazard Assessment (OEHHA) is releasing the Scientific Review Panel Version 2 draft of the document Air Toxics Hot Spots Program Risk Assessment Guidelines: Technical Support Document for Exposure Assessment and Stochastic Analysis, for review by the Scientific Review Panel on Toxic Air Contaminants. This draft reflects minor revisions in response to comments by the Scientific Review Panel.(SRP). 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)). This revised draft TSD, once it is reviewed and finalized, will replace the original 2000 version of the TSD. The updated TSD reflects new scientific knowledge developed since the previous guidelines were prepared. We have updated exposure parameters (e.g., inhalation rate, food consumption rate, etc.) based on the most recent data, including exposure factors for infants and children, in accordance with the mandate of the Children's Environmental Health Protection Act (Senate Bill 25, Escutia, chapter 731, statutes of 1999, Health and Safety Code Sections 39669.5 et seq.). The SRP meeting will take place as a conference call June 25th at 1001 I Street, Sacramento, CA, and other locations. For more information on the meeting, please visit the Air Resources Board's Web Page on the Scientific Review Panel.