4-Methylimidazole (4-MEI) is listed effective January 7, 2011 as known to the state of California to cause cancer.
Proposition 65
Proposition 65, officially known as the Safe Drinking Water and Toxic Enforcement Act of 1986, was enacted as a ballot initiative in November 1986. The proposition protects the state's drinking water sources from being contaminated with chemicals known to cause cancer, birth defects or other reproductive harm, and requires businesses to inform Californians about exposures to such chemicals.
Proposition 65 requires the state to maintain and update a list of chemicals known to the state to cause cancer or reproductive toxicity.
Questions?
Questions about Proposition 65? Check our Frequently asked Questions page or visit our Proposition 65 Warnings website
About Proposition 65
The Safe Drinking Water and Toxic Enforcement Act
The Proposition 65 List
The current Proposition 65 list is dated December 29, 2023
Meetings, Hearings and Workshops
Upcoming and past meetings, hearings and workshops
Notices
All Proposition 65 Notices
Laws and Regulations
Links and downloads related to Proposition 65 statute and regulations
Warnings
Visit this website to learn about warnings for exposures to chemicals on the Proposition 65 List
How chemicals are added to the Proposition 65 list
Learn how chemicals are added to the list
Safe Use Determinations
A Safe Use Determination (SUD) is a written statement issued by OEHHA, which interprets and applies Proposition 65 and its implementing regulations to a specific set of facts in response to a request by a business or a trade group
Interpretive Guidelines for Proposition 65
An Interpretive Guideline interprets Proposition 65 and its implementing regulations, as applied to specific facts
Information Letters
Letters about Proposition 65's application from OEHHA to interested parties.
Warning Regulations
Clear and reasonable warnings
Searchable Proposition 65 Chemical Database
Search the Proposition 65 Chemical Database
Safe harbor levels
Proposition 65 No Significant Risk Levels (NSRLs) and Maximum Allowable Dose Levels (MADLs)
Reports, Notices, Documents
Metam potassium listed as known to the State to cause cancer effective December 31, 2010 via the Authoritative Bodies listing mechanism.
Extension of comment period. Solicitation of information which may be relevant to the evaluation of cocamide diethanolamine (coconut oil acid diethanolamine condensate) under consideration for possible listing within the context of the Proposition 65 administrative listing regulatory criteria.
The Safe Drinking Water and Toxic Enforcement Act of 19861 (Proposition 65 or the Act), which is codified as Health and Safety Code section 25249.5 et seq., requires the Governor to publish, and update at least annually, a list of chemicals known to the State to cause cancer or reproductive toxicity. The Act describes the mechanisms for administratively listing chemicals as known to the State to cause cancer or reproductive toxicity (Health and Safety Code section 25249.8).
On October 22, 2010, OEHHA published a notice in the California Regulatory Notice Register (Register 10 No. 43-Z) soliciting information which may be relevant to the evaluation of kresoxim-methyl (CAS No. 143390-89-0) under consideration for possible listing within the context of the Proposition 65 administrative listing regulatory criteria in Title 27 of the California Code of Regulations section 25306.
The publication of the notice initiated a 60‑day public comment period which would have closed on December 21, 2010. OEHHA has received a request from interested parties seeking an extension of the comment period to allow for the submission of complete and relevant scientific information for kresoxim-methyl. OEHHA hereby extends the public comment period for this chemical until 5 p.m., Thursday, January 20, 2011.
We encourage you to submit comments in electronic form, rather than in paper form. Comments transmitted by e-mail should be addressed to sam.delson@oehha.ca.gov. Comments submitted in paper form may be mailed, faxed, or delivered in person to the addresses below:
Office of Environmental Health Hazard Assessment
Mailing Address: P.O. Box 4010, MS-19B
Sacramento, California 95812-4010
Fax: (916) 323-8803
Street Address: 1001 I Street
Sacramento, California 95814
1Commonly known as Proposition 65, the Safe Drinking Water and Toxic Enforcement Act of 1986 is codified in Health and Safety Code section 25249.5 et seq.Extension of comment period for resoxim-methyl under consideration for possible listing within the context of the Proposition 65 administrative listing criteria.
Amendment to Title 27, California Code of Regulations, Section 25805, Specific Regulatory Levels: Chemicals Causing Reproductive Toxicity - Di-isodecyl Phthalate (DIDP)