Separation Techniques for PFAS Quantitation and Dietary Intake from Food Packaging

Different types of food packaging or food contact materials (FCMs), including greaseproof papers, paperboard trays, cardboard, and various wrappers from the United States and 23 other locations around the world were extracted and analyzed in an attempt to quantify these materials’ extent of contamination from per- and polyfluoroalkyl substances (PFAS), according to research presented at the 2023 North American Chemical Research Workshop (NACRW) in Fort Lauderdale, Florida, USA on July 25, 2023 (1).

Brown kraft paper food containers, forks and knifes on beige background | Image Credit: © lithiumphoto - stock.adobe.com

The presentation was made by Yelena Sapozhnikova, a research chemist in the department of Residue Chemistry and Predictive Microbiology Research at the U.S. Department of Agriculture (USDA) Agricultural Research Service in Wyndmoor, Pennsylvania, USA. Sapozhnikova was assisted by Raegan B. Taylor, also of USDA, supporting previous research Sapozhnikova and Taylor conducted with Megha Bedi and Carla Ng in the Department of Civil & Environmental Engineering at the University of Pittsburgh in Pennsylvania, USA (2).

PFAS, which were a key topic of the Tuesday morning NACRW session entitled “Emerging Environmental and Food Contaminants,” are persistent in the environment and can accumulate in the human body over time. Studies have linked exposure to PFAS with adverse health effects, including increased risk of certain cancers, liver damage, immune system disruption, and developmental issues in children. The potential dangers of PFAS in food products underscore the need for stricter regulations, monitoring, and risk assessment to safeguard public health and reduce exposure to these harmful substances.

Sapozhnikova provided comments to LCGC about the research into PFAS, also widely known as “forever chemicals,” separate from the NACRW presentation, as did Bjorn Berendsen of Wageningen University & Research in The Netherlands on the same topic. Much like what Berendsen indicated to LCGC, Sapozhnikova said there remains much to be determined about “unknown” PFAS.

“TOP (total oxidizable precursor) assay results showed average ∑PFAS levels increasing 10-fold after oxidation, suggesting the presence of unidentified PFAS precursors in tested food packaging samples,” Sapozhnikova said.

Following the TOP method used for sample extraction, both targeted and nontargeted analyses were performed resulting in detection of at least one targeted PFAS in 84% of samples (1). Chief among these was 6:2 fluorotelomer phosphate diester (6:2 diPAP), followed by perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonate (PFHxS), and perfluorohexanoic acid (PFHxA) (2). However, Sapozhnikova told LCGC that all concentrations, when measured in the 20% of migrated samples in which PFAS were found, were still below the maximum tolerable weekly intake (TWI) set by the European Food Safety Authority (EFSA)—although Berendsen said previously that those standards were recently revised to much lower levels.

For the sum of four of the most common PFAS, a group that includes PFHxS, the EFSA’s maximum TWI as of the time of Sapozhnikova’s study was 4.4 ng/kg, in terms of body weight per week (1). Determined values ranged from 0.0006 ng/kg for PFHxA in tomato packaging to 1.12 ng/kg for PFHxS in cake paper. But the known presence of “unknown” PFAS undoubtedly looms as an impetus for much further research to be conducted.

For more coverage of NACRW 2023, click here.

Reference

(1) Sapozhnikova, Y.; Taylor, R.B. Analysis of PFAS in globally sourced consumer food packaging by targeted and non-targeted approaches. Presented at the 59th North American Chemical Residue Workshop, Fort Lauderdale, Florida, July 25, 2023.

(2) Sapozhnikova, Y.; Taylor, R.B.; Bedi, M.; Ng, C. Assessing per- and polyfluoroalkyl substances in globally sourced food packaging. Chemosphere 2023, 337, 139381. DOI: 10.1016/j.chemosphere.2023.139381