An article in the journal Environment Science & Technology describes migration of BPS (a close cousin of BPA) and other labelling chemicals into food:

To test the hypothesis that migration from the thermal labels on plastic film packaging is a major source of exposure to bisphenols and alternative color developers in food, we analyzed 140 packaging materials from packaged fresh food purchased in North America. No bisphenol A (BPA) was detected in either the packaging samples or thermal labels. However, significant amounts of bisphenol S (BPS) and alternative color developers (up to 214 μg/cm²) were present in thermal labels; their relative occurrence varied among stores. In a controlled experiment, we wrapped fish in film with a thermal label for 5 days at 4 °C. The fish in contact with the label contained BPS (≤1140 ng/g wet weight [ww]), 4-hydroxyphenyl 4-isoprooxyphenylsulfone (D-8) (≤230 ng/g ww), bis(2-chloroethyl)ether-4,4’-dihydroxydiphenyl sulfone monomer (D-90) (≤3.41 ng/g ww), and/or Pergafast-201 (≤1.87 ng/g ww).

The corresponding film samples were then tested using migration cells for 10 days; significantly higher BPS migration was observed systematically from the films with thermal labels compared to plain films. This study provides evidence, for the first time, that BPS and alternative thermal label color developers migrate from packaging materials into food. Further, BPS migration significantly exceeded the European Union Specific Migration Limit (50 ng/g ww), suggesting that further risk assessment studies are warranted.

This article on the same topic appeared in Science Daily.

Steps were taken in Canada to reduce the use of Bisphenol A (BPA), a toxic chemical linked to prostate and breast cancer, commonly found in plastics, the lining of food cans, water bottles, and paper receipts. But in many cases, it has been replaced with similar hormone disrupting chemicals, like Bisphenol S (BPS). A new study shows that every day Canadians are exposed to BPS in the fresh foods they eat, as chemicals migrate from labels on the packaging materials into the food.

“BPA is a chemical that can interfere with hormones in the human body and cause adverse health outcomes, including cancers, diabetes, and damage to fertility and the development of infants. Now there is growing evidence that BPS may have similar health effects,” says Stéphane Bayen, an Associate Professor in the Department of Food Science and Agricultural Chemistry. “Our study provides evidence, for the first time, that BPS and alternative chemicals found in food labels migrate through packaging materials into the food people eat,” he explains.

The researchers examined an assortment of packaged fresh food sold in Canada such as meats, cheeses, vegetables, and bakery products. They also compared fish bought from stores in Canada and the United States, and the differences between food wrapped with plastic cling wrap films with or without food labels. They found relatively high concentrations of BPS in thermal food labels, like price tags and stickers, where heat is used to print bar codes or unit prices. In contrast, they found little to no BPS in plastic wrapper films, pads, and trays.

While Canada does not currently regulate BPS, the researchers show that the amount of BPS found in the foods studied significantly exceeded the European Union limit, which regulates the permitted amount of substances released from packaging materials in contact with food.

“Considering the number of packaged food items sold with thermal labels, the actual dietary intake of BPS and other chemicals is likely to be high,” says Bayen. The study suggests a more thorough risk assessment of BPS and its ability to migrate into food from packaging is needed to help develop regulatory guidelines in the food sector.