Chemicals in Wrappers Can Migrate Into Foods

Regulatory agencies interested in controlling exposure

Chemicals that line everything from fast-food wrappers to linings in pizza boxes can migrate into food, then get ingested and cause chemical contamination in the blood, according to new research from scientists at the University of Toronto.

Perfluorinated carboxylic acids (PFCAs) are the breakdown products of chemicals used to make non-stick and water- and stain-repellant products, including food packaging. PFCAs are found in the human body all over the world. According to the UT scientists’ research, much of this chemical residue in the bloodstream may come from the consumption of polyfluoroalkyl phosphate esters (PAPs), greaseproofing agents applied to paper food packaging such as fast-food wrappers and microwave popcorn bags.

In the study, rats were exposed to PAPs either orally or by injection and monitored for a three-week period to track the concentrations of the PAPs and PFCA metabolites, PFOA, in their blood. Human exposure to PAPs had already been established by the scientists in a previous study.

Researchers used the PAP concentrations previously observed in human blood together with the PAP and PFCA concentrations observed in the rats to calculate human exposure from PAP metabolism. They found the concentrations of PFCA metabolites to be significant, indicating that metabolism of PAPs could be a major source of human exposure to these chemicals.

“The reason these chemicals were originally approved to be applied to paper food wrappers is because their acute toxicity is low,” said Jessica D’Eon, PhD, a postdoctoral fellow in the department of chemistry at the University of Toronto and the paper’s lead author. “But the product they’re metabolized into, PFCAs, has a much longer lifetime in the body—almost five years. Our study confirms that you could have relatively low exposure to PAPs, and still have relatively high concentration of PFCAs in the body.”

Regulatory authorities in Canada, Europe, and the U.S. have expressed interest in controlling exposure to PAPs and PFCAs. “There are new generations of compounds that are safer and aren’t metabolized into long-lived chemicals in the body,” said Dr. D’Eon. “If we can get a better idea of the sources of contamination, we can provide better information to allow governments to proceed with regulating them.”