Chemical Listed Effective January 7, 2011 as Known to the State of California to Cause Cancer: 4-Methylimidazole (4-MEI)

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The Office of Environmental Health Hazard Assessment (OEHHA) within the California Environmental Protection Agency is adding 4-methylimidazole (CAS No. 822-36-6) to the list of chemicals known to the state to cause cancer for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65¹).  The listing of 4-methylimidazole is effective January 7, 2011. 

4-Methylimidazole (CAS No. 822-36-6) is being listed as a chemical known to the State of California to cause cancer.  The listing of 4-methylimidazole is based on formal identification by an authoritative body², the National Toxicology Program (NTP), that the chemical causes cancer.  The criteria used by OEHHA for the listing of chemicals under the “authoritative bodies” mechanism can be found in Title 27, Cal. Code of Regs., section 25306³. 

The reader is directed to the Notice of Intent to List 4-methylimidazole published in the March 13, 2009 issue of the California Regulatory Notice Register (Register 2009, No. 11‑Z) for the documentation supporting OEHHA’s determination that the criteria for administrative listing have been satisfied for this chemical. 

Because of the significant public interest in this chemical, a Notice of Proposed Rulemaking identifying a proposed No Significant Risk Level (NSRL) is being published concurrently with this listing notice. Documents related to the proposed adoption of a NSRL for 4-methylimidazole are available on the OEHHA website at http://www.oehha.ca.gov/prop65/law/index.html. 

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 at http://www.oehha.ca.gov/prop65.html.

¹Health and Safety Code, section 25249.5 et seq.

²See Health and Safety Code section 25249.8(b) and Title 27, Cal. Code of Regs., Section 25306.

³All further referenced sections are from Title 27 of the Cal. Code of Regulations.

⁴Listing mechanism:  AB – “authoritative bodies” mechanism (Title 27, Cal. Code of Regs. Section 25306).