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 January 03, 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

Effective December 8, 2025, the Office of Environmental Health Hazard Assessment has added the developmental toxicity endpoint to the reproductive toxicity listing of bisphenol S (BPS) under Proposition 65. This addition was done via the “State’s Qualified Experts” listing mechanism, based on the Developmental and Reproductive Toxicant Identification Committee’s determination that this chemical was clearly shown to cause developmental toxicity.
Effective December 8, 2025, the Office of Environmental Health Hazard Assessment added N-methyl-N-formylhydrazine to the Proposition 65 list as a carcinogen. This listing was done via the “State’s Qualified Experts” mechanism, based on the Carcinogen Identification Committee’s determination that this chemical was clearly shown to cause cancer.
OEHHA has selected p,pʹ-bisphenol chemicals for the DARTIC’s review for possible listing under Proposition 65 as causing reproductive toxicity. p,pʹ-Bisphenol chemicals include p,pʹ-bisphenols, and ethers and esters of p,pʹ-bisphenols.
The Office of Environmental Health Hazard Assessment has adopted No Significant Risk Levels for titanium dioxide (airborne, unbound particles of respirable size)of 440 micrograms per day for airborne, unbound titanium dioxide particles with diameters of 10 micrometers or less, and 44 micrograms per day for airborne, unbound titanium dioxide particles with diameters of 0.8 micrometers or less.
OEHHA will convene a meeting of the Developmental and Reproductive Toxicant Identification Committee (DARTIC). At this meeting the DARTIC will consider the possible listing of bisphenol S (BPS) based on developmental toxicity. OEHHA is also opening a 45-day public comment period on the hazard identification document entitled “Evidence on the Developmental Toxicity of Bisphenol S."