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

Dec 5, 1997: Request for Information on Methyl Tertiary-Butyl Ether (MTBE)
Request for information on Methyl Tertiary-Butyl Ether (MTBE), a chemical to be considered by OEHHA’s Science Advisory Board’s Carcinogen Identification Committee and Developmental and Reproductive Toxicant (DART) Identification Committee.
Oct 31, 1997: Correction to the List of Chemicals Known to the State to Cause Cancer or Reproductive Toxicity: Di-n-propyl isocinchomeronate, (MGK Repellent 326), MeIQ(2-Amino-3,4-dimethylimidazo, [4,5-f]quinoline), and Polybrominated biphenyls
Correction to the List of Chemicals Known to the State to Cause Cancer or Reproductive Toxicity: correction of CAS numbers for Di-n-propyl isocinchomeronate, (MGK Repellent 326), MeIQ(2-Amino-3,4-dimethylimidazo, [4,5-f]quinoline), and Polybrominated biphenyls
Oct 24, 1997: Chemicals Listed Effective October 24, 1997 as Known to the State to Cause Cancer: 2,4,5-Trimethylaniline and its strong acid salts, 5-Chloro-o-toluidine and its strong acid salts, and Quinoline and its strong acid salts
Chemicals listed effective October 24, 1997 as known to the State to cause cancer or reproductive toxicity by the State's Qualified Experts: 2,4,5-trimethylaniline and its strong acid salts, 5-chloro-o-toluidine and its strong acid salts, and quinoline and its strong acid salts.

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