California’s Office of Environmental Health Hazard Assessment has announced that it intends to list atrazine as a carcinogen under Proposition 65.
- Under Prop 65, enacted in 1986, businesses selling or distributing products in California must provide consumers with clear, concise warnings regarding significant exposure to chemicals in products that may cause cancer, birth defects and other reproductive harm according to the state’s criteria.
Since Prop 65 was first passed by California voters in a referendum by a near 2-to-1 vote, the list of chemicals subject to regulation under its scope has grown from 30 to more than 900.
Why Add Atrazine?
Most recently, OEHHA has proposed that atrazine, a commonly used herbicide applied to crops including corn, wheat, sugarcane, pineapples and macadamia nuts, be added to the list as a known carcinogen. This was prompted by a 2025 finding by the International Agency for Research on Cancer that atrazine is “probably carcinogenic to humans,” which triggers review under California law.
- OEHHA is providing an opportunity to comment by November 9.
Once a chemical is added to the Prop 65 list, businesses have one year from the official listing date to provide clear and reasonable warnings via product labels, signs or notices if exposures exceed safe harbor levels. The state’s updated short-form and long-form warning requirements (effective January 1, 2025, with mandatory full compliance required by January 1, 2028) mandate naming a specific chemical on labels. Generic labels to cover the potential presence of any listed substance are no longer sufficient.
ICYMI: California Updates Prop 65 Short-Form Warning Requirements
Potential Impacts To The Branded Merchandise Industry
The risk is fairly low for most companies in the branded merchandise and promotional products industry, as atrazine is used primarily in agriculture. The most likely exposure route for atrazine in consumer products would be residual traces found in food items, but a public statement on atrazine from the U.S. Centers for Disease Control says, “it has not been found in many food samples, and then only at very low levels.”
That said, companies may want to test their processed food products out of an abundance of caution, such as packaged baked goods, tortilla chips or items containing high-fructose corn syrup.
Review Product Formulas, Testing And Compliance Strategy
This proposed addition is a useful reminder to review your company’s product formulations and testing, as well as your Prop 65 strategy.
As shared in the October meeting of the Association’s Product Responsibility Action Group, there are nearly 1,000 chemicals listed under Prop 65, but lawsuits concentrate on about 20 substances, and roughly two-thirds involve just lead and phthalates. Companies can use the state’s Prop 65 Notice of Violation data as a leading indicator of which chemicals citizen enforcers and plaintiffs’ attorneys – the chief enforcement avenue for Prop 65 – are targeting.
- Settlement agreements name specific chemicals of concern and provide a testing framework, but it’s important to remember that those agreements and the limits they enumerate are only binding to the signatory parties.
OEHHA maintains a helpful Prop 65 FAQ page to help businesses understand relevant provisions of the law and their operational obligations.
Read about other recent regulatory updates in our PRAG Regulatory Roundup for October 2026.
