NOTRE DAME, Ind. — Over the last few years, scientists are only now beginning to scratch the surface of understanding PFAS, or per- and polyfluoroalkyl substances. Referred to as “forever chemicals,” they seem to be in everything we use on a daily basis. Now, researchers from Notre Dame are showing for the first time that PFAS may be able to seep into food through plastic containers, and how temperature may impact this process.
The study authors explain that plastic containers, which commonly contain household cleaners, pesticides, personal care products, and even food, often test positive for PFAS.
“Not only did we measure significant concentrations of PFAS in these containers, we can estimate the PFAS that were leaching off creating a direct path of exposure,” says Graham Peaslee, a professor of physics in the Department of Physics and Astronomy at Notre Dame, in a university release.
Studies frequently advise against using these types of containers for packaging food, but there currently aren’t any regulations stopping companies from using them. The specific type of plastic involved is called fluorinated high-density polyethylene (HDPE) plastic. Manufacturers often store pesticides in them as well, adding another way for PFAS to potentially contaminate food.
In 2021, the Environmental Protection Agency announced the PFAS Strategic Roadmap, describing their promise to get on top of widespread PFAS exposure. The plan involves developing a more in-depth, evidence-based understanding of the effects PFAS exposure have on health and the environment, and from there addressing how to mitigate further contamination of resources.
Plastics can start leaching into food almost immediately
To explore PFAS in plastics, Peaslee and graduate student Heather Whitehead, tested various fluorine-treated HDPE containers. Scientists add fluorine to this mix to create a thin layer of a fluoropolymer that enhances container performance and makes them durable over long storage periods. Usually, the material is stable, but during manufacturing, PFAS can migrate into foods. As such, the team designed experiments to measure the ability of these chemicals to leach from the container by testing various foods and solvents at different temperatures — such as olive oil, ketchup, and mayo.
The researchers found parts-per-billion levels of PFAS that could spread into both solvents and food matrices in just one week, which is enough to pose a significant risk to consumers.
“We measured concentrations of PFOA that significantly exceeded the limit set by the EPA’s 2022 Health Advisory Limits,” Peaslee says. “Now, consider that not only do we know that the chemicals are migrating into the substances stored in them, but that the containers themselves work their way back into the environment through landfills. PFAS doesn’t biodegrade. It doesn’t go away. Once these chemicals are used, they get into the groundwater, they get into our biological systems, and they cause significant health problems.”
Hopefully, these findings can urge more scientists, researchers, and officials to consider the greater impact that PFAS may have on human health and the environment.
The findings appear in the journal Environmental Science & Technology Letters.