California Prop 65: DEA Judgment Reinforces First Amendment Limits on Warning Requirements
A stipulated judgment between The Personal Care Products Council (PCPC) and the California Attorney General reinforces First Amendment limits on certain warning requirements under California’s Proposition 65, which requires businesses to provide warnings for exposures to chemicals listed by the State as causing cancer or reproductive harm unless an exemption applies. The judgment resolves a challenge to warnings for diethanolamine (DEA) in cosmetics and personal care products and follows recent decisions rejecting compelled Prop 65 messages where the required message goes beyond what the underlying science supports. Going forward, state and private enforcers are permanently enjoined from pursuing Prop 65 enforcement actions based on an alleged failure to warn regarding exposures to DEA in cosmetics and personal care products. Companies facing pending or threatened Prop 65 enforcement activity involving DEA or other listed chemicals with disputed toxicity evidence should consider whether the reasoning underlying these developments may affect warning, settlement, and enforcement defense strategies.
Key Takeaways
- The judgment reinforces a growing line of First Amendment decisions limiting compelled Prop 65 warnings where the warning would communicate a scientifically disputed or potentially misleading human health risk message.
- Cosmetics and personal care product companies should review active Prop 65 notices, pending enforcement actions, settlement obligations, and supply-chain documentation involving DEA or DEA-related ingredients.
- Companies facing pending or threatened Prop 65 warning claims should consider whether similar arguments may apply to other listed chemicals where the warning message may overstate or mischaracterize the current scientific evidence.
Background and Overview
California Prop 65 requires businesses to provide “clear and reasonable” warnings before knowingly and intentionally exposing individuals to chemicals listed as known to the State to cause cancer or reproductive toxicity, unless an exemption applies. DEA is a chemical that may be present in or associated with ingredients used in a range of consumer goods, including beauty, grooming, pet-care, and household-cleaning products. California listed DEA under Prop 65 as a carcinogen in 2012. Under the stipulated judgment, however, the California Attorney General and those bound by the injunction are barred from enforcing Prop 65’s cancer warning requirement for DEA in cosmetic and personal care products.
The judgment also comes at a time when DEA-related Prop 65 notices have increased significantly, particularly for cosmetics and personal care products. Against this backdrop, the stipulated judgment may be important not only for companies evaluating product warnings but also for companies managing pending notices, enforcement actions, settlements, and supply-chain questions involving DEA or related ingredients.
Prop 65 Warnings and the First Amendment
The stipulated judgment builds on a First Amendment trend that B&D previously highlighted in its 2026 California environmental outlook: courts have increasingly scrutinized Prop 65 cancer warnings where the required warning message is not purely factual and remains scientifically disputed. That trend began with the Ninth Circuit’s glyphosate decision in National Association of Wheat Growers v. Bonta and accelerated in 2025 with district court decisions involving dietary acrylamide and airborne, respirable titanium dioxide in cosmetics and personal care products.
In National Association of Wheat Growers v. Bonta, the Ninth Circuit upheld a permanent injunction barring enforcement of warning requirements for glyphosate, which was added to the Prop 65 list in 2017. The court concluded that California could not require businesses to warn consumers that glyphosate causes cancer when that message was the subject of significant scientific disagreement. In California Chamber of Commerce v. Bonta, the Eastern District of California reached a similar conclusion for Prop 65 warnings for dietary acrylamide. The court found that the warnings suggested that eating foods containing acrylamide would increase a person’s cancer risk, even though science did not clearly support that conclusion. The court also rejected revised warning language that quoted scientific agencies more carefully, finding that the overall warning still presented one side of an unresolved scientific debate.
Most directly, in Personal Care Products Council v. Bonta, the Eastern District of California applied the same reasoning to cosmetics and personal care products containing airborne, respirable titanium dioxide. The court held that Prop 65 cancer warnings identifying carcinogenicity and toxicity violated the First Amendment because the evidence of human cancer risk was inadequate or disputed. As a result, the Attorney General and private enforcers became barred from filing or prosecuting new Prop 65 enforcement actions for titanium dioxide in cosmetics and personal care products.
Together, these cases establish an important limit on Prop 65 warning requirements. California may have a strong interest in informing consumers about potential health risks, but it cannot require businesses to deliver a cancer warning if the warning’s message goes beyond the consensus of the scientific community.
The DEA Stipulated Judgment
The new stipulated consent judgment resolves PCPC’s First Amendment challenge to Prop 65 warning requirements for DEA in cosmetic and personal care products. Although the Attorney General did not concede that PCPC was correct on the merits, the parties agreed to entry of judgment for PCPC and a permanent injunction considering the current state of the relevant science surrounding the chemical, as well as the legal limitations established by recent Prop 65 First Amendment decisions. As PCPC framed the scientific dispute in its filings, the issue was whether the warning’s message—that DEA is “known” to cause cancer—overstated the evidence underlying California’s listing. PCPC argued that the listing rested on the International Agency for Research on Cancer (IARC)’s classification of DEA as only “possibly carcinogenic to humans,” which PCPC said was based principally on a single mouse study. PCPC noted that IARC found inadequate evidence for the carcinogenicity of DEA in humans, and that no governmental authority had concluded that DEA causes cancer in humans.
The stipulated judgment is significant in several respects. State and private enforcers are now permanently enjoined from pursuing Prop 65 enforcement actions based on an alleged failure to warn regarding exposures to DEA in cosmetics and personal care products. Companies facing notices or lawsuits involving DEA, cocamide DEA, or related ingredients should consider how the judgment may affect warning decisions, settlement strategy, litigation defenses, and communications with customers or suppliers. Companies should also carefully review the scope of the injunction, because its effect may depend on the chemical, product, parties, and procedural posture involved.
The judgment may also signal a practical shift in how the Attorney General approaches similar Prop 65 First Amendment challenges. Although the Attorney General did not concede that the DEA warning requirement was unconstitutional, the decision to stipulate to a permanent injunction in light of recent case law and the current state of the science demonstrates the practical significance of the developing First Amendment jurisprudence. While the stipulation does not establish a new precedent, it suggests that recent decisions are influencing how the State of California evaluates at least some Prop 65 warning disputes. That does not mean the State will stipulate to the same result in every future case, but it does suggest that recent First Amendment decisions are having a real effect on Prop 65 enforcement strategy.
Industry Implications
The stipulated judgment is most important as another sign that the First Amendment can be an effective defense against Prop 65 warning claims when the underlying science is disputed. The judgment continues a recent pattern of successful First Amendment challenges to Prop 65 cancer warnings. The judgment underscores that Prop 65 risk analysis should not end with whether there is a risk of exposure to a listed chemical. Companies should also evaluate the scientific basis for the warning, the relevant exposure pathway, the warning language, and whether recent First Amendment decisions may affect enforceability.
Beveridge & Diamond advises clients throughout California on environmental issues affecting their facilities, operations, and products, including compliance with and defense of California's Proposition 65 requirements. With an office in San Francisco, our experience includes representing clients in litigation before state and federal courts in California. Businesses benefit from our deep understanding of the interplay between California’s complex statutes and regulatory programs and federal environmental regulations and enforcement. For more information on the topics covered in this article, please contact San Francisco Office Managing Principal Susan Smith.
