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 law 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 the list of chemicals subject to the law’s requirements.

Questions about Proposition 65? Visit our Proposition 65 Warnings website.

Proposition 65 Resources

About Proposition 65

The Safe Drinking Water and Toxic Enforcement Act

The Proposition 65 List

The current Proposition 65 list is dated December 08, 2025

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, interpreting and applying Proposition 65 regulations to specific facts in response to a request by a business or trade group

Interpretive Guidelines for Proposition 65

An Interpretive Guideline interprets Proposition 65 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

June 6, 2014: Change to the Basis for Listing for Hexafluoroacetone and Phenylphosphine as Known to the State of California to Cause Reproductive Toxicity

Effective June 6, 2014, the basis for the listing of hexafluoroacetone and phenylphosphine under Proposition 65 as known to cause reproductive toxicity has changed. Originally the two chemicals were added to the Proposition 65 list as causing reproductive toxicity via the “Labor Code mechanism” . The new mechanism is the state’s qualified experts mechanism.

May 23, 2014: Extension of Comment Period - Title 27, California Code of Regulations Proposition 65 Potential Amendments to Article 6 Clear and Reasonable Warnings

Notice of Public Workshop for potential amendments to Article 6, Clear and Reasonable Warnings. The notice also announced a pre-regulatory workshop that was held on April 14, 2014. Extension of comment period.

May 21, 2014: May 21, 2014 Developmental and Reproductive Toxicant Committee Meeting

Meeting announcement and meeting outcome whether Hexafluoroacetone, Phenylphosphine and Chlorsulfuron should remain listed under Proposition 65 as known to cause reproductive toxicity.

May 4, 2014: Extension of Comment Period - Notice of Intent to List Ethylene Glycol

Extension of comment period on OEHHA's intent to list ethylene glycol as known to the State to cause reproductive toxicity under the Safe Drinking Water and Toxic Enforcement Act of 1986.

May 2, 2014: Chemical Listed Effective May 2, 2014 as Known to the State of California to Cause Cancer: N,N-Dimethyl-p-Toluidine

OEHHA is adding N,N-dimethyl-p-toluidine to the list of chemicals known to the state to cause cancer via the authoritative bodies mechanism.