Late last month, District Judge Daniel J. Calabretta of the Eastern District of California issued a significant ruling in Personal Care Products Council v. Bonta (Case No. 2:26-cv-00682) blocking enforcement of California’s Proposition 65 (“Prop. 65”) cancer-warning requirement for diethanolamine (“DEA”) in cosmetics and personal-care products. This ruling has significant implications for the industry.

Background

DEA is used in, or may be present as an ingredient or impurity in, cosmetics and personal-care products such as shampoos, soaps, lotions and makeup. California’s Office of Environmental Health Hazard Assessment (“OEHHA”) added DEA to the Prop. 65 list of chemicals known to cause cancer in 2012, following its classification of DEA as a “possible” human carcinogen.

For more than a decade, DEA generated relatively little Prop. 65 enforcement activity. That changed dramatically in recent years when more than 1,000 Notices of Violation (“NOVs”) were issued for alleged unwarned DEA exposures. Cosmetics and personal-care companies were increasingly forced to choose among reformulating their products, adding cancer warnings, or defending or settling costly Prop. 65 claims.

The Court’s Decision

In March 2026, the Personal Care Products Council challenged the DEA warning requirement on First Amendment grounds. The Council argued that requiring businesses to state that DEA is “known to cause cancer” was misleading because the scientific evidence does not establish that DEA is a known human carcinogen.

The California Attorney General disagreed with the Council but ultimately stipulated to entry of a permanent injunction. It was declared that, “based on the current state of the relevant science” and binding prior precedent, the Prop. 65 cancer-warning requirement for DEA in cosmetic and personal-care products cannot be constitutionally enforced.

The Court permanently enjoined the Attorney General, his officers, employees and agents, and persons acting in privity or concert with them, from filing or prosecuting new Prop. 65 lawsuits seeking cancer warnings for DEA in cosmetic and personal-care products.

What About OEHHA’s Proposed Safe Harbor?

The decision comes while OEHHA is separately developing a No Significant Risk Level (“NSRL”) for dermal exposure to DEA. OEHHA initially proposed an NSRL of 6.4 micrograms per day and recently modified the proposed level to 5.8 micrograms per day on June 10, 2026.

Ordinarily, an NSRL gives businesses a safe harbor: exposures at or below the specified level do not require a Prop. 65 cancer warning. The federal ruling, however, presents a more fundamental issue—whether California can compel a cancer warning for DEA in cosmetics and personal-care products at all under the current scientific record.

The practical significance of OEHHA’s proposed DEA safe harbor for cosmetics and personal-care products is therefore uncertain. The proposed NSRL may remain relevant to DEA exposures from other types of products that fall outside the injunction.

Implications for Industry

The decision is a major victory for the cosmetics and personal-care products industry, which faced a dramatic surge in DEA notices and related settlement demands.

The decision is also part of a broader trend. Federal courts have now restricted Prop. 65 cancer-warning enforcement involving acrylamide in foods, glyphosate, titanium dioxide in cosmetics and DEA in cosmetics and personal-care products. These cases reflect growing judicial scrutiny of warnings that communicate greater scientific certainty than the underlying evidence supports.

Key Takeaway

Businesses that have received DEA notices involving cosmetics or personal-care products should immediately reassess those claims in light of the injunction. However, the decision does not remove DEA from the Prop. 65 list, may not apply to DEA exposures from other product categories and does not necessarily eliminate warning obligations imposed by existing consent judgments or private settlement agreements. Those obligations should be reviewed individually with counsel.

Putting people first, always.

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