Extension of Public Comment Period for the Proposed Reference Exposure Levels for Hexamethylene Diisocyanate

The Office of Environmental Health Hazard Assessment (OEHHA) released a draft document, Hexamethylene Diisocyanate Reference Exposure Levels, for public review on December 1, 2017, for a 60-day public review period.  OEHHA received a request from the American Chemistry Council Aliphatic Diisocyanates Panel to extend the public comment period. This notice extends the comment period to February 14, 2018.

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 hexamethylene diisocyanate Reference Exposure Levels 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.

After the close of the public comment period, the documents will be revised as appropriate by OEHHA, and peer reviewed by the State’s Scientific Review Panel on Toxic Air Contaminants in 2018. 

Please direct your comments on the documents, in writing or by e–mail, and 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

E–mail: John.Budroe@oehha.ca.gov (link sends e-mail)

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. (link is external)