Does your morning coffee need a warning label other than “Caution: Contents Hot”? A California judge doesn’t think so.

In August, a California judge ended a decade long lawsuit alleging that dozens of coffee roasters and retailers, including Starbucks, violated California’s Proposition 65 (“Prop 65”) by failing to warn customers about acrylamide present in coffee.

A Closer Look at Prop 65:

Prop 65 requires California to publish a list of substances that are known to cause cancer, birth defects, or other reproductive harm. The list currently contains more than 900 different naturally occurring and synthetic substances. There are four ways substances can be added to the list. Some chemicals are added after an “authoritative body” finds it can cause cancer or reproductive harm in humans or lab animals. However, many of the substances listed as causing cancer are not broadly accepted as known human carcinogens.

Prop 65 then requires businesses to provide a “clear and reasonable” warning before knowingly exposing customers to a chemical on the list, unless the level of exposure would pose no significant cancer risk. Violating Prop 65 can quickly become costly for businesses, as fines may be up to $2,500 per day for each violation.

Why is Acrylamide on the Prop 65 List?

Acrylamide has been listed by California as a carcinogen since 1990, and as a developmental and reproductive toxicant since 2011.

Acrylamide is a chemical used in many industries, including textiles, cosmetics, plastics, and food processing. It also forms in some food during high-temperature cooking processes, like frying, roasting, and baking. Acrylamide in food forms from sugars and an amino acid that are naturally present. Acrylamide is formed in coffee during the bean roasting and brewing processes. Acrylamide is also found in French fries, potato chips, roasted nuts, and many foods made from grains (such as breakfast cereals, cookies, and toast).

Various studies have shown that acrylamide increases the risk of cancer in lab animals. However, as the National Cancer Institute and the American Cancer Society point out, no scientific studies convincingly link acrylamide in food to an increased risk of cancer in humans. In June 2016, after thoroughly reviewing over 1,000 studies, the International Agency for Research on Cancer reported that coffee drinking is “unclassifiable” as to its risk of causing cancers in humans due to “inadequate evidence,” downgrading their original 1991 classification of coffee as “possibly carcinogenic to humans.”

California Office of Environmental Health Hazard Assessment (“OEHHA”) Regulation Provides Resolution

Despite the lack of a convincing link between acrylamide in food and an increased risk of cancer in humans, the coffee acrylamide litigation had been moving along since 2010. The coffee roasters and retailers lost a phase 1 trial, and several defendants had agreed to post the cancer warnings and pay millions in a settlement as the litigation moved along. In June 2019, the OEHHA, the state’s lead agency for implementation of Prop 65, adopted a regulation stating that exposure to chemicals in coffee that are created by and inherent in the process of coffee bean roasting and brewing do not pose a significant risk of cancer, exempting coffee from a Prop 65 cancer warning. OEHHA’s creation of this exemption came after FDA issued a statement in 2018 strongly supporting such a regulation. On August 25, 2020, Judge Elihu M. Berle granted summary judgment for the defendants, ruling that the defendant coffee purveyors had successfully relied on the OEHHA’s regulation to show that acrylamide found in coffee doesn’t cause cancer.

Acrylamide in Coffee Fight Highlights the Debated Value of Prop 65 Warnings

The debate over the value of Prop 65 warnings will continue when chemicals (such as acrylamide) with no proven cancer risk to humans at relevant exposure levels remain on the list. Requiring businesses to label food products as causing cancer when the scientific evidence does not prove the ingredients cause cancer in humans is problematic on many levels. Additionally, there are concerns about the burden placed on consumers to determine which Prop 65 warnings are legitimate and which warnings are not truly supported by scientific evidence. At least for now, businesses will only have to worry about warning consumers about the temperature of the coffee they serve.