Federal Court Permanently Blocks Prop 65 DEA Cancer Warnings for Cosmetics
Cosmetics and personal care product manufacturers using DEA no longer need to comply with California Prop 65 cancer warning requirements for the ingredient, and the ruling creates a replicable legal strategy to challenge other Prop 65 warnings based on contested science.
On June 23, 2026, the U.S. District Court for the Eastern District of California entered a permanent injunction barring the California Attorney General from enforcing Proposition 65 cancer warning requirements for diethanolamine (DEA) in cosmetics and personal care products, via a stipulated judgment with the Personal Care Products Council. The ruling is the fourth recent First Amendment victory against Prop 65 warning mandates, following successful challenges to glyphosate, acrylamide, and titanium dioxide requirements. The court found the DEA warning was not purely factual, as it relied solely on an IARC 'possible carcinogen' classification with no independent human or consistent animal study support. In-house counsel for DEA-containing personal care product manufacturers can immediately cease Prop 65 warning compliance for the ingredient, and may assess whether other Prop 65 listed chemicals with similarly limited scientific backing are viable for challenge under the same compelled speech theory.