In 2025, the Association of Cantonal Chemists of Switzerland (VKCS) and the Federal Food Safety and Veterinary Office (FSVO) conducted a joint nationwide campaign. The aim was to record the occurrence of per- and polyfluoroalkyl substances (PFAS) in food of animal origin. Due to their chemical properties, PFAS are water, grease and dirt repellent. They have been used for decades in many industrial processes and numerous products, such as food packaging, Teflon pans and ski wax. Due to their widespread use, PFAS enter the environment and ultimately the food chain. Humans mainly ingest PFAS through food and drinking water. As part of the campaign, the FSVO investigated the presence of various PFAS in milk and milk products made from cow's milk on the Swiss market. There are currently no legal maximum levels for these food categories. A total of 276 samples were analysed, including 86 milk samples (retail milk and bulk milk), 131 cheese samples, 20 butter samples, 20 cream samples and 19 yoghurt samples. The retail milk included whole milk as well as semi-skimmed, pasteurised and UHT milk. The collected milk came from regional cheese dairies and consisted of milk from 5 to 20 farms in each region. Cheese was the only category in which imported products were also analysed, as it plays a significant role in terms of volume in total imports. Thirty-four PFAS compounds were analysed, including the four substances regulated by the European Food Safety Authority. Further details can be found in the report on the national campaign on PFAS in animal-based foods.