On August 11, 2025, the U.S. District Court for the Eastern District of California issued a significant ruling in Personal Care Products Council v. Bonta, striking down California’s Proposition 65 (“Prop 65”) cancer warning requirement for titanium dioxide in cosmetics and personal care products.
Background
Prop 65 requires businesses with 10 or more employees to provide “clear and reasonable” warnings before exposing consumers to chemicals listed by California as known to cause cancer or reproductive harm. Titanium dioxide (Ti02), a common agent found in many personal care products, including cosmetics, was added to the Prop 65 list in 2011 after the International Agency for Research on Cancer (IARC) classified airborne, unbound respirable particles of titanium dioxide as a possible human carcinogen. This classification was based primarily on animal inhalation studies involving rats, with human data remaining inconclusive. Despite widespread safe use approvals by the U.S. Food and Drug Administration (FDA), dozens of Prop 65 lawsuits have targeted cosmetics manufacturers for failing to include Prop 65 cancer warnings on products containing titanium dioxide. Many companies elected to apply warnings rather than engage in costly litigation.
The Court’s August Decision
The Personal Care Products Council, representing a number of large cosmetics companies, challenged the requirement on First Amendment grounds. The Court agreed, holding that the compelled warnings were unconstitutional compelled speech by being “not purely factual” and “uncontroversial.”
- Not purely factual: The Court found that while each sentence in a Prop 65 warning might be technically accurate, the overall message to consumers—that titanium dioxide in cosmetics increases cancer risk—was misleading, given the lack of scientific consensus on that topic.
- Controversial: Because of ongoing scientific debate and the absence of conclusive human evidence, the warning improperly elevated one side of an unresolved issue.
Given that the warning was not purely factual and controversial, the Court found that it failed constitutional scrutiny. The Court noted California could inform the public about the science of Ti02 through less burdensome means, such as public education campaigns.
As a result, the Court permanently enjoined the California Attorney General and private enforcers from filing or prosecuting new Prop 65 lawsuits over Ti02 in cosmetics and declared the warning requirement unconstitutional. The Court’s reasoning is in line with another case decided earlier this year (California Chamber of Commerce v. Rob Bonta), which found that Prop 65 warnings for dietary acrylamide are misleading and controversial because the science is unclear as to whether acrylamide is a human carcinogen. The Court also concluded that requiring such warnings violates the First Amendment.
Implications for Industry
This decision is a major victory for the cosmetics and personal care products sector, which has faced years of costly Prop 65 litigation and warning requirements. By removing the requirement to include Prop 65 cancer warnings for Ti02, businesses avoid both the chilling effect of compelled speech and the reputational harm of alarming consumers without strong scientific basis.
Key Takeaway
Ti02 Prop 65 warnings as to cancer risk on personal care products are no longer required, unless and until this matter is successfully appealed. However, because the Court’s order “does not alter any existing consent decrees, settlements, or agreements,” prior settlements with Ti02 warning obligations should be analyzed in conjunction with the Court’s order to assess whether warnings are still required.
