Follow this link to download the current Proposition 65 list that includes α-methyl styrene (CAS No. 98-83-9)
If you would like to sort the list by CAS number or date, please download the list as an Excel document. You can then sort the list by date, CAS number, or chemical name using MS Excel. The Excel document also includes the listing mechanism for each chemical listing and the safe harbor level, if one has been adopted. A hyperlink is provided for those chemicals for which the basis for listing documentation is available electronically. A hyperlink is provided for those safe harbor levels for which the risk assessment documentation is available electronically.
The Office of Environmental Health Hazard Assessment (OEHHA) within the California Environmental Protection Agency is adding α-methyl styrene (CAS No. 98-83-9) to the list of chemicals known to the state to cause reproductive toxicity for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65)1. The listing of α-methyl styrene for the endpoint of female reproductive toxicity is effective July 29, 2011.
Health and Safety Code section 25249.8(a) requires that substances identified in Labor Code section 6382(d) as causing reproductive toxicity be included on the Proposition 65 list. Labor Code section 6382(d) captures any chemicals within the scope of the federal Hazard Communication Standard that are identified as reproductive toxicants. Chemicals fall within the scope of the Hazard Communication Standard if they are listed as hazardous in the latest edition of the American Conference of Governmental Industrial Hygienists’ (ACGIH) “Threshold Limit Values (TLVs).” The TLV for α-methyl styrene (female endpoint) was established on the basis of ACGIH’s findings of female reproductive damage.
The basis for the listing of α-methyl styrene was described in a public notice published in the May 27, 2011, issue of the California Regulatory Notice Register (Register 2011, No. 21-Z). The title of the notice was “Notice of Intent to List Alpha-Methyl Styrene by the Labor Code Mechanism". The publication of the notice initiated a 30-day public comment period that closed on June 27, 2011.
Chemical |
CAS No. |
Toxicological Endpoint |
Listing Mechanism2 |
| α-Methyl styrene | 98-83-9 |
female reproductive toxicity |
LC |
1Health and Safety Code, section 25249.5 et seq.
2Listing mechanism: LC – “Labor Code” mechanism (Labor Code sections 6382(b)(1) and (d))
