Proposed Reference Exposure Levels for Toluene Diisocyanate and Methylene Diphenyl Diisocyanate – SRP Drafts
The Office of Environmental Health Hazard Assessment (OEHHA) is releasing two State’s Science Review Panel on Toxic Air Contaminants (SRP) review draft documents, one summarizing the toxicity and derivation of Reference Exposure Levels (RELs) for Toluene Diisocyanate (TDI) and the other summarizing the toxicity and derivation of RELs for Methylene Diphenyl Diisocyanate (MDI). These documents are for review and comment by the panel at the Science Review Panel Meeting on December 12, 2014. RELs are airborne concentrations of a chemical that are not anticipated to result in adverse non–cancer health effects for specified exposure durations in the general population, including sensitive subpopulations.
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)). In response to this statutory requirement, OEHHA develops RELs for many air pollutants. The MDI and TDI RELs were developed using the most recent “Air Toxics Hot Spots Program Technical Support Document for the Derivation of Noncancer Reference Exposure Levels,” finalized by OEHHA in 2008.
These two draft documents were released for a 75-day public review and comment period on July 4, 2014. Two sets of comments were received during this period for the draft document on RELs for TDI and one set of comments was received for the draft document on RELs for MDI. Responses to these comments are also being released at this time.
We are not seeking further comments from the public on the draft Guidance Manual at this time.
Please direct any inquiries concerning technical matters or availability of the documents to:
Dr. John Budroe
Chief, Air Toxicology and Risk Assessment Section
Air, Community, and Environmental Research Branch
Office of Environmental Health Hazard Assessment
1515 Clay Street, 16th Floor
Oakland, CA, 94612
Telephone: (510) 622-3145
Information about dates and agenda for meetings of the Scientific Review Panel can be obtained from the California Air Resources Board web page at: http://www.arb.ca.gov/srp/srp.htm.
- Extension of Public Comment Period for Proposed Revised Reference Exposure Levels For Toluene Diisocyanate And Methylene Diphenyl Diisocyanate 2014Aug 22, 2014Notice of Public Comment/Workshops for Proposed Revised Reference Exposure Levels for Toluene Diisocyanate and Methylene Diphenyl DiisocyanateJul 4, 2014Extension of Public Comment Period for Proposed Revised Reference Exposure Levels For Toluene Diisocyanate And Methylene Diphenyl DiisocyanateJun 17, 2010Notice of Public Workshops on Proposed Reference Exposure Levels for Methylene Diphenyl Diisocyanate, Toluene Diisocyanate, and CaprolactamJun 2, 2010