CERT Goes After Air Fryer Manufacturers and Distributors for Formation of Acrylamide

February 28, 2021

Paustenbach and Asssociates

The Council for Education and Research on Toxics (CERT), a Proposition 65 private enforcer, filed a complaint against many manufacturers, distributors, and retailers of “air fryers” in October of 2021 for allegedly exposing consumers to acrylamide (CERT v. Ace Hardware, Complaint). This is after CERT has led a years-long effort to require coffee manufacturers and distributors to place a warning label on their product(s) for exposure to acrylamide. 

CERT describes air fryers as “a small countertop convection oven designed to simulate deep frying without submerging the food in oil” but “by coating food in a thin layer of oil while circulating air heated up to” 392°F to 482°F (CERT v. Ace Hardware, Complaint, pg. 16). Fried food is typically cooked at temperatures between 347°F and 383°F, while the lowest temperature employed for frying is 248°F (Lee et al. 2020). At temperatures above 248°F, the Maillard reaction occurs and acrylamide is mainly formed as a natural byproduct from the reaction of reducing sugars, such as glucose and fructose, with the amino acid asparagine (Lineback et al. 2012). 

Acrylamide was added to the Proposition 65 list of chemicals known to the state of California to cause cancer in 1990 after studies in laboratory rats and mice showed elevated rates of cancer (OEHHA 1990). In 1994, the International Agency for Research on Cancer (IARC) classified acrylamide as “probably carcinogenic to humans” (IARC 1994). 

CERT claims that because air fryers operate at higher temperatures than deep fryers, air fryers “present a risk for increased acrylamide formation in foods cooked in air fryers” (CERT v. Ace Hardware, Complaint, pg. 16). CERT based this claim on a study conducted by the Consumer Council of Hong Kong, who tested 12 air fryer models; however, this study is not publicly available. The Complaint reported that “[a]ll of the air fryers” tested by the Consumer Council of Hong Kong “generated acrylamide at levels that would result in exposure to consumers that greatly exceed the ‘safe harbor’ level of 0.2 µg/day long ago established by the California Office of Environmental Health Hazard Assessment” (OEHHA) (CERT v. Ace Hardware, Complaint, pg. 16).  

The results of the Consumer Council of Hong Kong study should not be taken at face value because it is unclear how they calculated a daily intake dose of acrylamide for consumers in this experiment. For example, if they evaluated a chicken that has been lightly coated in vegetable oil, then they need to perform calculations in order to determine if the daily intake dose of acrylamide from the chicken is above the safe harbor level. It also seems likely that if you remove some of the skin from the chicken, the daily intake dose to acrylamide would be substantially less. Without knowing more, we have to question whether their calculations assumed that one person ate the whole chicken in one sitting or whether it assumed that one person ate the chicken every day for one week. Thus, as you can see, exposure calculations are an important part of determining Prop 65 compliance. It is also noteworthy that three peer-reviewed studies have shown that air-fried foods reduced the formation of acrylamide when compared to deep-fried foods when fried at 356°F (Basuny and Oatibi 2016; Lee et al. 2020; Sansano et al. 2015). 

The role that acrylamide plays in increasing the risk of cancer in humans has been widely debated for over 20 years. Although high dose exposure to acrylamide has been found to increase the risk of several types of cancer in rodents, multiple epidemiological studies in humans have found no consistent evidence that dietary exposure to acrylamide is associated with any type of cancer (Lipworth et al. 2012; Virk-Baker et al. 2014). In these studies, dietary exposure to acrylamide ranged from 0.5 to 40.5 µg/kg body weight/day, which is much greater than OEHHA’s safe harbor level. Additionally, studies of occupational exposure to acrylamide have also not shown an increased risk of cancer (Pelucchi et al. 2011). More importantly, the concern over acrylamide is based on an IARC study from the mid-1990s where high doses were administered to animals in drinking water, which was a bioassay fraught with problems. 

How Can Paustenbach and Associates Help?

Our team of scientists at Paustenbach and Associates have over 40 years of experience in helping clients understand and become compliant with Proposition 65 for a variety of chemicals, including acrylamide. Our scientists are experienced at evaluating single products and diverse product lines to achieve Proposition 65 compliance. Our scientists have designed original studies to evaluate compliance with Prop 65, which often focus on bioavailability or the magnitude of exposure. We have also derived safe harbor levels for old or newly synthesized chemicals. Please contact Melinda Donnell at mdonnell@paustenbachandassociates.com for more information regarding our capabilities.


Basuny, A. M. M., & Oatibi, H. H. A. (2016). Effect of a novel technology (air and vacuum frying) on sensory evaluation and acrylamide generation in fried potato chips. Banat’s Journal of Biotechnology7(14).

CERT v. Ace Hardware. Complaint for Violations of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65) [California Health & Safety Code § 25249.6]. Accessed at: https://www.prop65clearinghouse.com/documents/73782. Accessed on February 18, 2022.

International Agency for Research on Cancer. (1994). Some industrial chemicals. IARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans60.

Lee, J. S., Han, J. W., Jung, M., Lee, K. W., & Chung, M. S. (2020). Effects of thawing and frying methods on the formation of acrylamide and polycyclic aromatic hydrocarbons in chicken meat. Foods9(5), 573.

Lineback, D. R., Coughlin, J. R., & Stadler, R. H. (2012). Acrylamide in foods: a review of the science and future considerations. Annual review of food science and technology3, 15-35.

Lipworth, L., Sonderman, J. S., Tarone, R. E., & McLaughlin, J. K. (2012). Review of epidemiologic studies of dietary acrylamide intake and the risk of cancer. European Journal of Cancer Prevention21(4), 375-386.

OEHHA. 1990. Acrylamide. Accessed at: https://oehha.ca.gov/proposition-65/chemicals/acrylamide. Accessed on February 19, 2022. 

Pelucchi, C., La Vecchia, C., Bosetti, C., Boyle, P., & Boffetta, P. (2011). Exposure to acrylamide and human cancer—a review and meta-analysis of epidemiologic studies. Annals of Oncology22(7), 1487-1499.

Sansano, M., Juan‐Borrás, M., Escriche, I., Andrés, A., & Heredia, A. (2015). Effect of pretreatments and air‐frying, a novel technology, on acrylamide generation in fried potatoes. Journal of food science80(5), T1120-T1128.

Virk-Baker, M. K., Nagy, T. R., Barnes, S., & Groopman, J. (2014). Dietary acrylamide and human cancer: a systematic review of literature. Nutrition and cancer66(5), 774-790.