Method development and screening of extractable organofluorine (EOF) and targeted PFAS analysis in food packaging materials

Abstract: Per- and polyfluoroalkyl substances (PFAS) have been manufactured and used in differentapplications for several decades, including food packaging materials. During the last 20 yearsthese compounds have been acknowledged as hazardous for humans and the environment, anddifferent regulations on PFAS have been established on both national and international levels.Companies started to phase-out long-chain PFAS, including both PFOA and PFOS, around 20years ago. Since PFAS are persistent, this cause concerns both for our health and theenvironment, as well as possible PFAS contamination in new products due to the recycling ofmaterials. The aim of this study was to find an effective method to extract PFAS from differentfood packaging materials; analyze the samples for their extractable organofluorine (EOF)content using combustion ion chromatography; as well as analyze targeted PFAS in the samplesusing ultra-high performance liquid chromatography tandem mass spectrometry. The findingsof this study suggest that none of the selected samples had EOF contents above the Danishindicator value of 20 mg/kg dw TOF set to determine whether PFAS has been intentionallyadded to a material, and that only two samples exceeded the limit of detection for EOF. Atakeaway bowl made out of 100% sugarcane contained the highest EOF content while the outerpackaging of a cereal box contained the second highest EOF. Both PFOA and PFOS, alongwith other long-chain PFAS were detected in a majority of the samples. The lowest total PFASconcentrations when analyzing for targeted PFAS was detected in the sugarcane take awaybowl. The highest total PFAS concentration was detected in an egg carton, followed by theouter packaging of a cereal box (same as above) and the outer box of a waffle mix. The targetedPFAS was detected in almost all samples, with PFNA and 6:2 diPAP being the most frequentlydetected PFAS. PFCAs, PFSAs, FTSAs, FOSAAs and PAPs were detected in a majority of thesamples. The highest concentrations were measured for diSAmPAP in a majority of thesamples. Mass balance calculations of the sugarcane bowl showed that the targeted PFAS onlyaccounted for 0.04% of the extractable organofluorine content. In conclusion, none of thesamples displayed EOF contents higher than the Danish indicator value, suggesting that noneof the samples were intentionally treated with PFAS. However, targeted PFAS analysis of thesesamples showed that they still contain PFAS, that could be further recycled along with therecycling of paper and board food packaging materials. Considering the persistence of PFASand that these compounds can remain in the recycling chain, with the risk of also being releasedinto the environment, it is of importance that PFAS is not introduced in any of the stages in apaper or board containers life cycle.