Per- and polyfluoroalkyl substances (PFAS) in raw milk from milk vending machines in Switzerland

Abstract

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that can enter the human food chain mainly via food of animal origin. The present study investigated the occurrence of PFAS in raw milk obtained from milk vending machines across Switzerland and evaluated the results in the context of existing guideline values and available national and international data. A total of 87 raw milk samples were collected between June and October 2025 from ten Swiss cantons and analysed for 30 PFAS using LC-MS/MS. Among all analysed PFAS, only perfluorooctane sulfonate (PFOS) was detected at concentrations above the limit of quantification (LOQ; 10 pg/g). The majority of samples showed PFOS concentrations below the LOQ, indicating generally low PFAS contamination in raw milk. Exceedances of the indicative level of 20 pg/g (commission recommendation (EU) 2022/1431, 2022) were observed in 7 samples (8%), with a clear regional clustering. PFOS concentrations in samples exceeding the indicative level ranged from 54 to 419 pg/g, with a median concentration of 147 pg/g. These values were substantially higher than those reported in the Swiss Nationale Kampagne 2025. In conclusion, raw milk from vending machines in Switzerland generally shows low PFAS contamination; however, the occurrence of regionally confined PFOS hotspots with markedly elevated concentrations underscores the need for targeted investigations and follow-up monitoring. These findings contribute to a more differentiated assessment of PFAS exposure through raw milk and support the importance of region-specific surveillance strategies in direct-marketing food systems.