In a decision building on a string of recent industry wins, a federal district court granted a permanent injunction, which extended an earlier issued preliminary injunction, prohibiting the filing of new lawsuits to enforce Prop 65’s warning requirement based on alleged exposure to titanium dioxide from cosmetics and personal care products.
On August 12, 2025, Chief Judge Nunley of the Eastern District of California ruled [1] that compelling businesses that sell cosmetics and personal care products to provide a Prop 65 cancer warning for Listed Titanium Dioxide (airborne, unbound particles of respirable size) violates the First Amendment because the warning is not purely factual and is controversial. [2] The court found the industry group plaintiff met all the same tests it did when the judge issued its earlier preliminary injunction order in 2024, reaffirming that there were no developments in the evidentiary record or the warning language sufficient to change the court’s earlier conclusion that compelling the Prop 65 cancer warning was unconstitutional.[3]
California’s Safe Drinking Water and Toxic Enforcement Act of 1986 (also known as “Proposition 65” or “Prop 65”) [4] is a “right-to-know” law that requires the governor of California to publish and maintain a list of chemicals known to the State of California to cause cancer or reproductive toxicity (Prop 65 List). [5] Absent an exemption, Prop 65 requires businesses with 10 or more employees to provide a clear and reasonable warning to consumers before knowingly and intentionally exposing them to chemicals on the Prop 65 List. [6]
The mandate to provide the Prop 65 warning is considered compelled commercial speech by the government that is subject to a First Amendment challenge. Typically, Prop 65 enforcers contend the challenged warning survives scrutiny because Prop 65 advances a substantial government interest—namely, preserving public health and California’s interest in protecting consumers from exposure to chemicals on the Prop 65 List. [7] However, the nature of the listing of titanium dioxide (TiO2) and the application to exposures from cosmetics and personal care products raised issues of whether the government’s interest was sufficient under the circumstances.
The US District Court for the Eastern District of California found that the warning in this instance would be misleading and issued an order preventing further enforcement of compelling a Prop 65 warning for exposures to TiO2 in all cosmetic and personal care products on First Amendment grounds.
THE TIO2 CANCER RISK ASSESSMENT DEBATE
Titanium dioxide is used as a whitening pigment and is commonly used in cosmetic and personal care products, including toothpaste, sunscreen, and makeup. The US Food and Drug Administration has determined titanium dioxide may be safely used in these products with some limitations. [8] Health risks have been identified with respect to exposures to TiO2, particularly as a food additive and potential inhalation.
In 2011, the Office of Environmental Health Hazard Assessment placed titanium dioxide (airborne, unbound particles of respirable size) on the Prop 65 List of carcinogens based on the International Agency for Research on Cancer’s (IARC) 2010 determination that the substance is “possibly carcinogenic to humans” due to “sufficient evidence” of carcinogenicity in animals, citing two studies involving experimental rats that inhaled titanium dioxide where an increased rate of lung tumors was observed.
Subsequent research, including that of the IARC, found there was inadequate evidence to draw the conclusion that titanium dioxide is possibly carcinogenic to humans, not just in experimental animals.
ESTABLISHING IMPORTANT PRECEDENT FOR A FIRST AMENDMENT CHALLENGE TO A PROP 65 WARNING
The primary argument presented to the court challenged the constitutionality of “the compulsion of a cancer warning that misleads consumers into believing a product will increase their risk of cancer when the sum of all available evidence does not indicate it will.” [9]
In the August 12 order, Judge Nunley concludes that the “totality” of the Prop 65 warning for titanium dioxide is misleading because it conveys the core message that using a cosmetic or personal care product containing Listed Titanium Dioxide poses a risk of cancer in humans. The district court held it would be reasonable for the average consumer to read the warning and conclude that Listed Titanium Dioxide may cause them cancer or increase their chances of obtaining cancer, when there was no evidence in the record to show this was true or “much less any ‘sufficient scientific consensus’ to support this message.” [10]
Scientific disagreement as to whether Listed Titanium Dioxide causes cancer in humans also renders the Prop 65 cancer warning controversial. Because the Prop 65 warning in this case is misleading, and “not purely factual and uncontroversial” it therefore violated the First Amendment’s protections against government-compelled commercial speech.
THE IMMEDIATE IMPACT OF THE COURT’S PERMANENT INJUNCTION AND DECLARATORY RELIEF
The district court’s issuance of a permanent injunction and grant of declaratory relief should halt the dozens of pending lawsuits alleging failure to warn of Listed Titanium Dioxide and prevent the filing of any new lawsuits with similar allegations. This is a significant win for cosmetics and personal care products manufacturers, suppliers, distributors, retailers, and other entities involved in the supply chain for these everyday products. The ruling should prevent additional claims and promotes the application of scientific rigor in the application of the warning requirements imposed by Prop 65.
[1] The Personal Care Products Council v. Rob Bonta, No. 2:23-CV-01006-TLN-JDP, 2025 WL 2323833 (E.D. Cal. Aug. 12, 2025).
[2] Id. at *13, *16
[3] Id. at *6.
[4] California’s Safe Drinking Water and Toxic Enforcement Act of 1986 (Prop 65), Cal. Health & Safety Code §§ 25249.5, et seq.
[5] Cal. Health & Safety Code § 25249.8(a).
[6] Cal. Health & Safety Code §§ 25249.5, 25249.6, 25249.11(b).
[7] Id. at *14 (citing Nat'l Ass'n of Wheat Growers v. Bonta, 85 F.4th 1263, 1283 (9th Cir. 2023) (“California unquestionably has a substantial interest in preserving the health of its citizens.”)).
[8] See 21 C.F.R. §§ 73.1575(b) (color additive in drugs), 73.2575(b) (cosmetics), 73.575(c) (color additive in foods), 352.10 (sunscreen).
[9] Id. at *6.
[10] Id. at *7.
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