Chemicals Listed May 27, 2005 and May 31, 2005 as Known to the State of California to Cause Cancer or Reproductive Toxicity: 2-bromopropane (2-BP) (CAS No. 75-26-3) and 1-hydroxyanthraquinone (CAS No. 129-43-1)

The Office of Environmental Health Hazard Assessment (OEHHA) of the California Environmental Protection Agency is adding 2-bromopropane (2-BP) (CAS No. 75-26-3) and 1-hydroxyanthraquinone (CAS No. 129-43-1) to the list of chemicals known to the state to cause cancer or reproductive toxicity for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Health and Safety Code section 25249.5, Proposition 65). The listing of 1-hydroxyanthraquinone is effective May 27, 2005 and the listing of 2-bromopropane (2-BP ) is effective May 31, 2005.

Health and Safety Code section 25249.8(a) requires that certain substances identified by the International Agency for Research on Cancer (IARC) or the National Toxicology Program (NTP), as described in Labor Code sections 6382(b)(1) and (d), be included on the Proposition 65 list. Labor Code section 6382(b)(1) references substances identified as human or animal carcinogens by IARC, and Labor Code section 6382(d) references substances identified as carcinogens or potential carcinogens by IARC or NTP. 1-Hydroxyanthraquinone (CAS No. 129-43-1) was identified by the IARC as an animal carcinogen.

The basis for the listing of 1-hydroxyanthraquinone on the Proposition 65 list was described in OEHHA's Request for Comments on Proposed Listing of 1-Hydroxyanthraquinone As Known to Cause Cancer published in the December 10, 2004, issue of the California Regulatory Notice Register (Register 2004, No. 50-Z). Specifically, in 2002, IARC issued the monograph Some Traditional Herbal Medicines, Some Mycotoxins, Naphthalene and Styrene (Volume 82) in its series IARC Monographs on the Evaluation of Carcinogenic Risks to Humans . In this monograph, IARC concluded that, “there is sufficient evidence in experimental animals for the carcinogenicity of 1-hydroxyanthraquinone.”

2-Bromopropane (2-BP) (CAS No. 75-26-3) is listed as a chemical known to the State of California to cause reproductive toxicity for the female and male endpoints. The listing of this chemical is based on a formal identification by an authoritative body (i.e., the National Toxicology Program (“NTP”) that the chemical causes female and male reproductive toxicity. Regulations governing the listing of chemicals under the “authoritative bodies” mechanism are published in Title 22, Cal. Code of Regs. Section 12306.

The reader is directed to the Notice of Intent to List 2-Bromopropane (2-BP) published in the April 1, 2005, issue of the California Regulatory Notice Register (Register 2005, No. 13-Z) for the documentation supporting OEHHA's determination that the criteria for administrative listing have been satisfied for this chemical. The documentation was developed to explain the basis for listing this chemical via the authoritative bodies provision of Proposition 65.

Two public comments were received on the proposed listing of 1-hydroxyanthraquinone during the 30-day comment period which closed on January 10, 2005. No public comments regarding the listing of 2-bromopropane (2-BP) were received during the 30-day public comment period which closed on May 2, 2005.

OEHHA analyses of dose-response data to establish the no significant risk level (NSRL) for 1-hydroxyanthraquinone and the maximum allowable dose level (MADL) for 2-bromopropane (2-BP) under Proposition 65 have not been conducted. The priority status of the development of such analyses will be announced in a future OEHHA Proposition 65 Status Report for Safe Harbor Levels.

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

Cancer

Chemical CAS No. Toxicological Endpoint Listing Mechanism1
1-Hydroxy-anthraquinone

129-43-1

Cancer

LC

Reproductive Toxicity

Chemical CAS No. Toxicological Endpoint Listing Mechanism1
2-bromopropane (2-BP)

75-26-3

Female reproductive and male reproductive toxicity

AB

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1Listing mechanism:

AB – “authoritative bodies” mechanism (Title 22, Cal. Code of Regs. Section 12306)

LC – “Labor Code” mechanism (Labor Code sections 6382(b)(1) and (d))