Toxic food packaging chemicals found in humans

Nearly everything you can buy at the grocery store is sealed in some sort of packaging. That plastic, metal, or cardboard container is made of a myriad of chemicals. And according to new research, some potentially hazardous chemicals could be migrating from that food packaging into humans. Two studies published recently by researchers at the Food Packaging Forum detail the extent to which chemicals in food packaging can be detected in humans. The research group found over 3,600 food contact chemicals—ones that food can absorb from its container—in human blood samples from several large biomonitoring programs. The second study found that those 3,600 food contact chemicals include close to 200 potential mammary carcinogens, and 76 of them were detected in human samples. Of those 76 chemicals, 40 have already been classified as hazardous by various regulatory agencies. (J. Expo. Sci. Environ. Epidemiol. 2024, DOI: 10.1038/s41370-024-00718-2; Front. Toxicol. 2024, DOI: 10.3389/ftox.2024.1440331).

Jane Muncke, managing director of the Food Packaging Forum and last author on both papers, says the data don’t prove that the chemicals detected in human samples came from food packaging, “but I would say the chain of evidence here is pretty strong.”

Muncke says that one of the goals of this research was to look beyond the usual suspects, like “the phthalates, the PFAS, the flame retardants, and so on” and uncover the other classes of chemicals that could pose a risk to people. The forum had compiled a database of over 14,000 food contact chemicals, which were then compared with data from biomonitoring programs for this new research.

Two of the lesser known classes of chemicals detected in these human samples were synthetic phenolic antioxidants like 2,4-di-tert-butylphenol and oligomeric compounds such as polyethylene terephthalate. Other research has already implicated synthetic phenolic antioxidants and their transformation products as carcinogens. But Muncke says that for many oligomeric compounds, the monomer is typically what gets tested for toxicity—even though there’s evidence that those oligomers are what leach from packaging into food.

Beyond that, many of the chemicals found in food packaging have been defined as potential mammary carcinogens, according to the new research. These include phthalates, bisphenols, and styrene, among other chemicals. Muncke says the list of carcinogenic chemicals used in this work was based on research published earlier this year. That project used a novel, key characteristics approach instead of typical chemical risk assessment to classify chemicals as toxic. The full list of chemicals detected in human samples from this work can be browsed through a dashboard at the FCChumon Database online.

“The findings provide a clear cause for concern,” says Martin Wagner, a toxicologist at the Norwegian University of Science and Technology. Wagner was not involved in the two recently published studies, but he does serve on the forum’s scientific advisory board. “The widespread nature of human exposure and the fact that many of these chemicals will act at low concentrations and as mixtures is definitely a red flag,” he says.

But Wagner admits that the quality of the data from the meta-analyses these research studies are based on can vary, especially with respect to the studies used in the key characteristics approach. Regardless, his take-home message is that “known chemicals of concern are used and can leach from food contact materials.”

Muncke thinks that consumers should be mad about the findings from this research. “Our regulators don’t have our back,” she says. “This whole kind of approach to chemical safety is not protecting people from being exposed to hazardous chemicals.”

Working on this research has changed the way she shops, Muncke says. She now avoids buying Teflon-coated pans, plastic cutting boards and utensils, and metal cans, which often contain linings that can leach chemicals into food. Wagner adds that there’s little consumers can do to completely avoid exposure to these chemicals, but he recommends that people “minimize their consumption of packaged food in general and avoid heating food in plastic, metal or cardboard containers, because that increases the leaching of chemicals.”