Chemicals Listed by the Labor Code Mechanism: alpha-methylstyrene and 1,3-dinitropyrene

Nov 2, 2012

The Office of Environmental Health Hazard Assessment (OEHHA) within the California Environmental Protection Agency is adding α-methyl styrene (alpha-methylstyrene) (CAS No. 98-83-9) and 1,3-dinitropyrene (CAS No. 75321-20-9) to the list of chemicals known to the State of California to cause cancer for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65¹). The listing of these two chemicals is effective November 2, 2012.

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 or NTP. Information regarding carcinogenicity classifications by IARC may be found at the following URL: http://monographs.iarc.fr/ENG/Preamble/CurrentPreamble.pdf (IARC Preamble).

The basis for the listing of α-methyl styrene (alpha-methylstyrene) and 1,3-dinitropyrene was described in a public notice published in the September 14, 2012, issue of the California Regulatory Notice Register (Register 2012, No. 37-Z). The title of the notice was “Notice of Intent to List Chemicals by the Labor Code Mechanism”. The publication of the notice initiated a public comment period that closed on October 15, 2012. No public comments were received.

A complete, updated Proposition 65 list is published elsewhere in this issue of the California Regulatory Notice Register and is available on the OEHHA website.