Notice of Intent to List Chemicals by the Labor Code Mechanism: alpha-methylstyrene and 1,3-dinitropyrene

The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) intends to list the chemicals identified in the table below as known to the State to cause cancer under the Safe Drinking Water and Toxic Enforcement Act of 1986. The Act, commonly known as Proposition 65, is codified in Health and Safety Code section 25249.5 et seq. This action is being taken pursuant to the Labor Code mechanism contained in Health and Safety Code section 25249.8(a).

Background on listing by the Labor Code mechanism: Health and Safety Code section 25249.8(a) incorporates California Labor Code Sections 6382(b)(1) and 6382(d) into Proposition 65. The law requires that certain substances identified by the International Agency for Research on Cancer (IARC) be listed as known to cause cancer under Proposition 65. Labor Code section 6382(b)(1) refers to substances identified as human or animal carcinogens by IARC. Labor Code section 6382(d) refers to substances identified as carcinogens or potential carcinogens by IARC. Information regarding carcinogenicity classifications by IARC may be found at the following URL: http://monographs.iarc.fr/ENG/Preamble/CurrentPreamble.pdf (IARC Preamble).

As the lead agency for the implementation of Proposition 65, OEHHA evaluates whether listing under Proposition 65 is required.

OEHHA’s determination: Alpha-methylstyrene and 1,3-dinitropyrene each meet the requirements for listing as known to the state to cause cancer for purposes of Proposition 65.

IARC has published on its website a list entitled “Agents Classified by the IARC Monographs, Volumes 1-105” (IARC, 2012a). IARC concludes that alpha-methylstyrene and 1,3-dinitropyrene are each classified in Group 2B (the agent is “possibly carcinogenic to humans”). In Volume 101 of its series, IARC Monographs on the Evaluation of Carcinogenic Risks to Humans (IARC, 2012b), IARC concludes that there is “sufficient evidence of carcinogenicity in experimental animals” for alpha-methylstyrene. IARC also concludes that there is “sufficient evidence of carcinogenicity in experimental animals” for 1,3-dinitropyrene (Benbrahim-Tallaa et al., 2012). Therefore, these substances meet the requirements of both Labor Code sections 6382(b)(1) and (d).

Opportunity for comment: OEHHA is committed to public participation in its implementation of Proposition 65. OEHHA is providing this opportunity to comment as to whether the chemicals identified above meet the requirements for listing as causing cancer specified in Health and Safety Code section 25249.8(a). Because these are ministerial listings, comments should be limited to whether IARC has identified the specific chemical or substance as a known or potential human or animal carcinogen. Under this listing mechanism, OEHHA cannot consider scientific arguments concerning the weight or quality of the evidence considered by IARC when identifying a specific chemical or substance and will not respond to such comments if they are submitted.

OEHHA must receive comments by 5:00 p.m. on Monday, October 15, 2012. We encourage you to submit comments in electronic form, rather than in paper form. Comments transmitted by e-mail should be addressed to P65Public.Comments@oehha.ca.gov, and should include “NOIL” and the chemical name in the subject line. Comments submitted in paper form may be mailed, faxed, or delivered in person to the address below. A public workshop will be held only upon request. Such request must be made in writing to the address below to sam.delson@oehha.ca.gov within 10 days from the publication of this notice:

Mailing Address:    Sam Delson
Office of Environmental Health Hazard Assessment
P.O. Box 4010, MS-19B
Sacramento, California 95812-4010
Fax:(916) 323-8803
Street Address:1001 I Street
Sacramento, California 95814

Any public comments received will be posted on the OEHHA website after the close of the comment period.  If you have any questions, please contact Sam Delson at sam.delson@oehha.ca.gov or at (916) 445-6900.