When PFAS pollutants enter the environment, they remain there for centuries, harming people and nature. Despite increasing bans, these “forever chemicals” continue to be used in many products, including ski wax. As a result of abrasion during skiing, the toxins then end up on cross-country ski trails, as snow samples from the Engadine show. The study also shows how good modern PFAS-free ski waxes are.
Per- and polyfluorinated alkyl compounds – PFAS for short – are found in numerous everyday products to give them certain properties. This makes the objects, for example, heat-resistant or repels water, grease and dirt. In ski wax, fluorocarbon compounds from this class of substances are used to improve the gliding properties of the ski. However, the use of PFAS is controversial. The “forever chemicals” are extremely stable, remain in nature for centuries, accumulate in living beings and harm them. Many of these chemicals are also toxic to humans and are linked to a variety of illnesses, from organ damage to cancer.
The previously widespread use of these chemicals is therefore increasingly being restricted or banned. For example, ski waxes containing fluorine have been banned in all International Ski Federation FIS races since the 2023/2024 season. The ski wax manufacturers have also switched their range to fluorine-free products. But how much has the ban on PFAS in ski wax already achieved and how many of the chemicals can still be found on the slopes and trails?
Snow samples from the Engadin Ski Marathon
Researchers led by Markus Zennegg from the Swiss Federal Materials Testing and Research Institute (Empa) have now investigated this. To do this, they took samples at the Engadin Ski Marathon in March 2025. A few hours after the runners started, they took snow samples from the various lanes directly after the start line, as well as further samples around two kilometers after the start and a blank sample far from the cross-country ski trail. In addition, they took samples from the normal cross-country ski trail in the Swiss ski resort, which was not part of the marathon route. They then tested the snow for PFAS in the laboratory.
The result: “We measured relatively high values for the typical PFAS from ski wax,” reports Zennegg. “These are particularly the perfluorinated carboxylic acids with an even chain length of six to 14 carbon atoms.” The concentrations were highest at the starting line, where the runners started with freshly waxed skis. After two kilometers, significantly fewer PFAS remained in the snow because the skis quickly lose their fluorine-containing wax coating due to abrasion. Nevertheless, the PFAS concentrations were measurably increased there too. The team also found increased PFAS concentrations in the tracks of the normal cross-country ski trail.
This is particularly worrying because of the proximity of the cross-country ski trails to nearby Lake Sils. When the snow melts in spring, the eternal chemicals are washed into the water and can accumulate in aquatic organisms and fish, the team explains. Soil samples taken later from the same places in the Engadine also show that the chemicals from the ski wax also ended up in the soil and the plants growing on it after the snow melted. “At the concentrations we measured, there is already a risk that PFAS will accumulate in the meat of the cattle grazing there and lead to the permitted limit values being exceeded,” explains Zennegg.
PFAS-free ski waxes are still not used enough
The fluorine-containing substances in ski wax are intended to get cross-country skiers to their destination faster. However, modern fluorine-free waxes now also fulfill this purpose. The gliding properties of the skis now hardly differ after treatment with the various waxes. “The skis of the ten fastest professional runners at the Engadine Ski Marathon were all tested and no PFAS were found,” says co-author Stefan Reimann from Empa. “So apparently you can be fast without fluorine.”
But where do the PFAS come from if not from the cross-country skiing professionals? The Empa researchers suspect that many hobby cross-country skiers in particular continue to use fluorine-containing ski waxes because they have not yet been made aware of the topic or still have leftover wax at home. “One block of wax can last for several years and virtually all older ski waxes contain PFAS,” says Zennegg. For the sake of the environment, he recommends that all skiers replace old waxes with fluorine-free versions that are labeled accordingly in stores.
Source: Empa – Federal Materials Testing and Research Institute