Assessing per- and polyfluoroalkyl substances in globally sourced food packaging

Authors: Sapozhnikova, Yelena; TAYLOR, RAEGYN - Oak Ridge Institute For Science And Education (ORISE); BEDI, MEGHA - University Of Pittsburgh; NG, CARLA - University Of Pittsburgh

Submitted to: Chemosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/29/2023
Publication Date: 6/29/2023
Citation: Sapozhnikova, Y.V., Taylor, R., Bedi, M., Ng, C. 2023. Assessing per- and polyfluoroalkyl substances in globally sourced food packaging. Chemosphere. 337:139381. https://doi.org/10.1016/j.chemosphere.2023.139381.
DOI: https://doi.org/10.1016/j.chemosphere.2023.139381

Interpretive Summary: Per- and polyfluoroalkyl substances (PFAS), also known as "forever chemicals", are ubiquitous contaminants in the environment, food, and humans. Diet is considered one of the major sources of PFAS exposure, and the use of PFAS in food contact materials is a potential source of this exposure. In this study, we investigated the occurrence and levels of PFAS in consumer food packaging from the USA and 23 other countries, including packaging for dairy, dry meats, bakery, packaged meals, produce and other types of food. Several analytical approaches including sample extraction and migration, targeted analysis and non-targeted suspect screening, plus total oxidizable precursor (TOP) assay were utilized to widen the analytical scope and provide a better picture of PFAS levels. The results showed PFAS presence in 84% of the extracted samples and in 20% of the migration samples. Calculated weekly intake values for four PFAS measured in migration samples were below the established European Food Safety Authority (EFSA) maximum total weekly intake level of 4.4 ng/kg body weight/week.

Technical Abstract: The purpose of this study was to investigate presence and levels of per- and polyfluoroalkyl substances (PFAS) in food packaging originating from different geographic locations. Food packaging samples were extracted and analyzed by targeted analysis with liquid chromatography-mass spectrometry (LC-MS) before and after a total oxidizable precursor (TOP) assay. Additionally, full scan high resolution MS (HRMS) was used to screen for PFAS not included in the targeted list. Of the 88 food packaging samples, 84% had detectable levels of at least one PFAS, with 6:2 fluorotelomer phosphate diester (6:2 diPAP) found most frequently and at the highest levels (224 ng/g). Other frequently detected substances (in 15-17% of samples) were PFHxS, PFHpA and PFDA. Shorter chain perfluorinated carboxylic acids PFHpA (C7), PFPeA (C5) and PFHxS (C6) were present at levels up to 51.3, 24.1 and 18.2 ng/g, respectively. Average 'PFAS levels were 28.3 ng/g and 381.9 ng/g before and after oxidation with the TOP assay. 25 samples with highest frequency of detection and amounts of measured PFAS were selected for migration experiments with food simulants to better understand potential dietary exposure. PFHxS, PFHpA, PFHxA and 6:2 diPAP were measured in the food simulants of five samples at concentrations ranging from 0.04 to 12.2 µg/kg and at increasing concentrations over the 10-day migration period. To estimate potential exposure to PFAS that has migrated from food packaging samples, weekly intake (WI) was calculated using relative potency factors to convert migration concentrations to PFOA equivalents. These ranged from 0.0006 ng/kg body weight/week for PFHxA exposure in tomato packaging to 1.1200 ng/kg body weight/week for PFHxS exposure in cake paper. These values were below the established EFSA maximum tolerable weekly intake (TWI) of 4.4 ng/kg body weight/week for the sum of PFOA, PFNA, PFHxS and PFOS.