Arent Fox LLP

03/30/2022 | News release | Distributed by Public on 03/30/2022 13:06

Ninth Circuit Blocks New Acrylamide Warning Lawsuits Under Proposition 65


As we previously reported, in 2019, the California Chamber of Commerce filed suit against the State of California in federal district court, requesting that the State and private enforcers be enjoined from requiring Proposition 65 warnings on foods that contain acrylamide. Since then, manufacturers and distributors of certain food products have been anxiously awaiting judicial guidance on this controversial issue. On March 17, 2022, the Ninth Circuit agreed with a lower court and upheld a preliminary injunction halting any Proposition 65 lawsuit alleging the need for a carcinogen warning on foods containing acrylamide.

Background on Proposition 65 and Acrylamide

Proposition 65 requires businesses to warn Californians about significant exposures to chemicals it has determined to cause cancer, congenital disabilities, or other reproductive harm. Since California has the sixth-largest economy in the world, manufacturers of consumer goods worldwide may be liable if they fail to abide by Proposition 65 regulations, including detailed warning requirements, for goods imported into California.

Acrylamide is listed under Proposition 65 as a carcinogen and reproductive toxin. It is a controversial chemical on the Proposition 65 list because it can form in some foods during high-temperature cooking processes, such as frying, roasting, grilling, and baking. It is produced as the result of a reaction between two common food components:

  • Asparagine.
  • An amino acid that is naturally present in many foods and also formed by the human body.
  • A reducing sugar such as glucose or fructose.

Common sources of acrylamide in the human diet include breakfast cereals, crackers, cookies, roasted coffee, French fries, potato chips, and roasted nuts.

The District Court Proceedings

On March 29, 2021, the US District Court for the Eastern District of California granted a preliminary injunction temporarily preventing the State of California and private parties from enforcing Proposition 65 against manufacturers and distributors who do not provide a Proposition 65 warning on foods containing acrylamide. View our previous analysis here.

The Ninth Circuit Proceedings

Following the preliminary injunction, an intervening defendant, the Council for Education and Research on Toxics (CERT), appealed to the Ninth Circuit, claiming the injunction was an unconstitutional restraint of its interest in pursuing Proposition 65 lawsuits. The District Court's preliminary injunction stayed while the Ninth Circuit evaluated the merits of the appeal. On March 17, 2022, the Ninth Circuit held that given the unsettled science over whether acrylamide in food causes cancer in humans, the District Court did not abuse its discretion in concluding that the warning was controversial and preliminary enjoining its application. The injunction expressly states, "While this action is pending… no person may file or prosecute a new lawsuit to enforce the Proposition 65 warning requirement for cancer as applied to acrylamide in food and beverage products." The injunction does not address Proposition 65 warnings as applied to acrylamide as a reproductive toxin.

The Ninth Circuit also held that the District Court did not abuse its discretion in finding the acrylamide warning misleading because "[a] reasonable person might think that they would consume a product that California knows will increase their risk for cancer. . . such consumer would be misled by the warning because the state of California does not know if acrylamide causes cancer in humans." This decision prohibits the filing of new acrylamide lawsuits while the District Court case continues on the merits.

Following the Ninth Circuit's decision, CERT filed a petition urging the Court to review en banc its decision to uphold the District Court's ruling. In the petition, CERT argued that the three-judge appellate panel ignored US Supreme Court authority that weighs against preliminary injunctions as unlawful prior restraints and failed to consider evidence CERT has used to win Proposition 65 cases at the state court level. To date, the Ninth Circuit has not acted on CERT's petition.


  1. The District Court's decision on the merits of the case could lead to a permanent injunction eliminating the need for acrylamide warnings for food products, at least as applied to acrylamide as a carcinogen.
  2. The preliminary injunction only precludes lawsuits regarding the Proposition 65 warning requirement for cancer as applied to acrylamide in food products and does not address the warning requirement for reproductive toxicity.
  3. Companies are encouraged to consult counsel for advice on how to comply with Proposition 65 as it concerns food products containing acrylamide in light of the evolving issues surrounding this particular chemical.