Replacement per- and polyfluoroalkyl substances (PFAS), which have been heralded as safe for use in food packaging, break down into toxic PFAS that leak into our food and environment, suggests a study published today in Environmental Science & Technology Letters.
Due to the known exposure risks of using smaller PFAS molecules such as PFOA and PFOS in food-contact materials, many companies have pivoted to using larger polymeric PFAS to make their wrappers, bowls, and other fast-food packaging water- and grease-repellant. These polymeric PFAS are promoted as “safer” alternatives that are inert and too heavy to escape from products.
However, this study provides the first evidence that polymeric PFAS used in food packaging break down into smaller molecules that are still harmful and can leach into food and the environment.
“It’s clear that polymers aren’t the harmless loophole the PFAS industry was counting on them to be,” said Marta Venier, co-author and an assistant professor at the Paul H. O’Neill School of Public and Environmental Affairs. “Their use in food packaging still leads to harmful and persistent PFAS contaminating the food we eat, and after it’s thrown away, our air and drinking water.”
The researchers tested 42 paper-based wrappers and bowls collected from fast-food restaurants in Toronto. A PFAS that is known to be toxic—6:2 FTOH (6:2 fluorotelomer alcohol)—was the most abundant compound detected in these samples. The polymeric PFAS in the samples can transform into this compound, thereby adding to a consumer’s exposure to it.
Critically, the researchers found that the concentration of PFAS declined by up to 85% after storing the products for two years under normal conditions (at room temperature and in the dark). Much of these losses were consistent with the breakdown of the polymeric PFAS added to the fast-food packaging. These results contradict claims that polymeric PFAS are immobile and do not create exposure risks.
Some smaller PFAS molecules have been associated with a wide range of serious health harms, from cancer to obesity to more severe COVID-19 outcomes, and they contaminate the drinking water of many millions. Only a small fraction of the thousands of PFAS have been tested for toxicity, and all PFAS (including polymers) are either extremely persistent in the environment or break down into extremely persistent PFAS.
These concerns have prompted 11 U.S. states to ban PFAS from most food packaging, and major chains such as McDonald’s and Chick-fil-A have committed to becoming PFAS-free by 2025.
“There has been great progress toward phasing out PFAS, polymers included, from fast-food packaging in the U.S.,” said co-author Arlene Blum, Executive Director of the Green Science Policy Institute. “However, this study calls into question the safety of polymeric PFAS for many of its uses. The best course of action to protect our children and future generations is to eliminate the whole class of PFAS from all non-essential uses, from food packaging to rain jackets, as soon as possible.”