Empa researchers warn against eternal chemicals on ski slopes

(CONNECT) Researchers from the Analytical Center at the Swiss Federal Laboratories for Materials Science and Technology(Empa) have examined Swiss ski slopes and cross-country ski trails for the presence of per- and polyfluorinated alkyl compounds (PFAS). According to a press release, the study on so-called perpetuity chemicals is based on snow samples from the Engadin Skimarathon in March 2025. It is assumed that PFAS enters the snow via older ski wax.

This is used in particular by hobby cross-country skiers, because one block of wax lasts them for several years. Skiers who ski regularly used up their stock more quickly and were more likely to buy more up-to-date, fluorine-free versions.

Snow samples were evaluated a few hours after the start of the runners from the tracks directly at the start line, samples around two kilometers after the start and a zero sample far from the trail. The highest exposure to PFAS was measured at the start line, where the skiers started with freshly waxed skis. After two kilometers, the concentration of PFAS in the snow decreased, "as the skis quickly lose their fluorine-containing wax coating through abrasion". Nevertheless, the concentrations were also measurably elevated there, according to the report.

Too much material containing PFAS is still being used, despite a ban by the International Ski Federation FIS. As of the 2023/2024 season, the use of ski waxes containing fluorine has been included as a reason for disqualification in all FIS races, including the Engadin Ski Marathon.

Markus Zennegg, Head of the Analytical Center, advises piste sports enthusiasts to switch to appropriately labeled ski waxes without fluorocarbon bindings. Fluorine-containing substances in the wax make skis glide better and help skiers reach their destination faster. According to Empa researcher Stefan Reimann from the Laboratory for Air Pollutants and Environmental Technology, "it makes no sense to release such stable substances into the environment for a few minutes".

On November 25, 2025, Empa, together with the aquatic research institute Eawag and the Ecotox Center, is organizing the online event wissen2go on the topic of PFAS from 5 to 6.15 pm. Participation is free of charge, registration is required. ce/heg