The 9th Circuit Court of Appeals blocked future acrylamide lawsuits from being filed after the federal court ruled that there is not enough evidence proving that the substance causes cancer. 

As a result of the decision made March 18, business owners in California, such as fast food restaurant operators, can’t be forced to place a cancer warning label at their place of business. 

Acrylamide is a substance that’s formed during the heating process of certain foods. In 2002, Swedish researchers discovered that the compound naturally forms when certain foods such as potatoes and other starchy foods are cooked.

The FDA clarifies this, noting that acrylamide forms from the sugars and asparagine found in potato and cereal-grain-based foods when they are cooked at high temperatures such as during the process of frying, roasting, or baking. Coffee beans also release the substance during the roasting process. 

Acrylamide lawsuits have been ongoing for almost two decades. The first acrylamide lawsuit was filed the same year the substance was discovered by the Council for Education and Research on Toxics (CERT). The organization claimed that acrylamide should come with a cancer warning label in California because of the state’s passage of Proposition 65, a California voter initiative passed in 1986. 

Prop 65, otherwise officially known as the Safe Drinking Water and Toxic Enforcement Act, lists several naturally occurring and artificially made chemicals that are known to cause cancer.  

According to, in 2019 there were 899 private settlements of Proposition 65 lawsuits costing $30 million and 615 out-of-court settlements with payments of $12.5 million. 

The 9th Circuit’s stay on acrylamide upholds a U.S. District Court’s temporary injunction. In explaining their decision, the 9th Circuit’s panel stated, “A reasonable person might think that they would consume a product that California knows will increase their risk for cancer. Such a consumer would be misled by the warning because the State of California does not know if acrylamide causes cancer in humans.”

California has listed 900 substances that regulators have deemed carcinogenic. But the research on acrylamide has been largely conducted on mice. The FDA notes that “In research studies, high levels of acrylamide caused cancer in laboratory animals, but the levels of acrylamide used in these studies were much greater than those found in human food.” 

According to the 9th Circuit’s opinion, The National Cancer Institute found no consistent evidence that exposure to acrylamide from food is associated with cancer. 

In 2020 and in the first half of 2021, 594 acrylamide pre-suit notices were filed, according to the Consumers Brand Association, ClaimsJournal reported. A District Court in Los Angeles will ultimately rule on a permanent injunction on acrylamide lawsuits.