At the Engadine Marathon, EMPA samples revealed persistent residues: Winter sports are thus expected to undergo a chemical transition

The PFAS issue does not only concern large industrial plants, production sites or complex manufacturing cycles. The so-called eternal chemicals, known for their extreme stability and ability to persist in the environment for very long periods of time, emerge even in contexts apparently far from heavy chemistry. One of these is the cross country, where for years some waxes containing fluorine have been used to improve the glide of skis on the snow and obtain performance advantages in competitions and in the most advanced amateur practice.

The topic is particularly relevant for the Switzerland, a country where winter sports are part of the culture, the tourist economy and the territorial identity of many Alpine regions. The discovery of residues attributable to fluorinated ski waxes in snow and soil samples taken along the route of the Engadine Ski Marathon However, it shifts the debate to a broader level: it is not just a question of replacing a technical product with a commercial alternative, but of rethinking the relationship between sporting performance, environmental responsibility and the management of highly durable materials.

PFAS, short for perfluorinated and polyfluorinated alkyl compounds, include thousands of substances characterized by the presence of fluorine-carbon bonds. These bonds give them very useful properties in numerous products, from water resistance to grease repellency, as well as strong resistance to degradation. For this reason, they can persist in the environment for very long periods and accumulate in living organisms, with potential consequences for ecosystems and human health.

The case of ski waxes clearly illustrates a dynamic typical of contemporary industrial transition: materials developed to ensure high performance are progressively reevaluated in light of their environmental impacts throughout their entire life cycle. In sports, as in other sectors, the problem isn't just regulatory. It's also cultural, organizational, and informational, as many substances remain in circulation for years after bans or alternatives are introduced, especially when they're present in household supplies, personal equipment, or products purchased in the past.

FIS ban accelerated fluoride-free transition

The International Ski Federation has introduced a decisive step starting with the 2023/2024 season, banning the use of waxes containing fluoride in its competitions. The measure provides for disqualification for non-compliant use and also applies to Swiss events within the scope of FIS races, including the Engadine Marathon. The decision had an immediate impact on the supply chain: wax manufacturers have gradually converted their ranges to fluoride-based formulations. fluoride-free, making available alternatives that are more compatible with the new rules and environmental needs.

From an innovation perspective, this transition is not insignificant. For decades, fluorinated substances have been associated with greater glide efficiency, especially in snow and temperature conditions where friction between the base and the snow surface can significantly impact performance. The development of alternative products therefore requires research into materials, comparative testing, new ski preparation procedures, and an adaptation of the habits of technicians, athletes, and enthusiasts.

The most interesting finding from the EMPA analysis, however, concerns the gap between perception and performance reality. According to the researchers, the skis of the ten fastest professionals in the Engadine Marathon were tested and showed no traces of PFAS. This fact undermines the idea that fluorinated ski waxes are still essential for high-level competition and reinforces the role of alternative innovation: if modern alternatives offer comparable performance, the environmental cost of older products becomes increasingly unjustifiable.

"The skis of the ten fastest professional skiers in the Engadine ski marathon were all tested, and no traces of PFAS were detected. Apparently, therefore, you can be fast even without fluoride."

he observed Stefan Reimann, researcher at the EMPA laboratory “Luftfremdstoffe/Umwelttechnik”.

This statement introduces a key point for the sporting goods market: when a more sustainable solution achieves sufficient technical quality, resistance to change no longer depends solely on performance, but on inertia, habit, stock availability, and user information. Cross-country skiing thus becomes a concrete laboratory of responsible innovation, where regulation, scientific research and individual behavior must converge.

Starting line reveals peak of contamination

In March 2025, researchers at EMPA's Analytical Center conducted sampling during the Engadine Marathon. Snow samples were taken a few hours after the competitors' start at different locations: immediately after the starting line, approximately two kilometers from the start, and in a reference area away from the course. The aim was to verify whether, despite the ban in FIS races and the availability of alternative products, Swiss slopes were indeed free of residues attributable to fluorinated ski waxes.

The results indicate that the transition is not yet complete. The highest concentrations were measured in the starting area, where skiers begin the race with freshly groomed skis. After about two kilometers, the amount of PFAS detected in the snow had already significantly decreased, consistent with the rapid wear of the wax layer through abrasion during sliding. Even in that second area, however, the values ​​had still measurably increased compared to the reference sample.

“We measured relatively high values ​​for PFASs typical of ski wax. These are in particular perfluorinated carboxylic acids with a chain length of 6 to 14 carbon atoms.”

has explained Markus Zennegg, head of the Analytical Center at EMPA.

The technical detail is significant because it links the contamination to a family of compounds consistent with the historical use of fluorinated ski waxes. Therefore, it is not a generic indication, but a chemical signal consistent with a specific sports application. For an analytical laboratory, distinguishing the different molecules is essential: it allows for the reconstruction of possible sources, dispersion pathways, and environmental risks, avoiding vague conclusions or attributions unsupported by data.

The dynamics observed along the course also demonstrate how rapid dispersion can be. The coating applied to the skis is released into the snow already in the first sections of the slope. This means that the problem isn't confined to the preparation of the skis, but manifests itself directly in the environment where the sporting activity takes place. The snow becomes a temporary carrier, destined to then transform into meltwater during the spring.

For the Engadine, the issue takes on a particular sensitivity because part of the route develops above the Lake SilsWith seasonal melting, substances deposited in the snow can directly reach the aquatic environment, where PFAS can accumulate in organisms and the food chain. The problem, therefore, affects not only the surface of the track on race day, but the subsequent cycle of water, sediment, and local biodiversity.

The risk shifts from snow to water and pastures

One of the most significant aspects of the EMPA research is the expansion of the analysis from snow to soil. The researchers took samples from the same locations and found significant contamination by persistent chemicals. This step is important because soil represents a more stable environmental archive than snow. As snow melts and disperses, soil can retain some of the chemicals and become a secondary source of exposure over time.

The potential connection with Alpine pastures makes the issue even more concrete. According to Markus Zennegg, at certain concentrations, there's a risk that PFAS could accumulate in the meat of cattle grazing in the affected areas, potentially exceeding permitted limits. This assessment should be interpreted with caution, but it highlights a much broader impact chain than the initial act of applying ski wax.

“At such concentrations, there is already a risk that PFAS will accumulate in the meat of cattle grazing in that area and lead to an exceeding of the permitted limits,”

he warned Dr. Zennegg again.

The case highlights a principle that has become central to environmental policies: a persistent substance does not disappear when its intended use ends. It can move, dilute, settle, enter different matrices, and reemerge in compartments not immediately associated with the source of its release. In the case of ski waxes, the pathway can range from ski base to snow, from snow to meltwater, from water to lakes or soil, and even to aquatic organisms or grazing animals.

This also presents a challenge for science communication. PFAS are often perceived as a remote problem, linked to chemical industries or large-scale contamination. The Engadine Marathon example shows, however, that managing persistent substances requires attention even in everyday or recreational practices. The primary responsibility for emissions remains industrial, but consumer behavior can help reduce non-essential uses and avoidable releases.

The concept of essential use is crucial here. Not all PFAS applications have the same social, health, or technological impact. In some areas, substitution requires lengthy timeframes, complex validations, and safety assessments. In others, such as sports waxes for amateur or competitive sports that are not strictly professional, the benefit-impact ratio appears increasingly unbalanced, especially if alternatives are already available and technically effective.

Old stocks and little information are holding back the exchange rate

According to EMPA researchers, the presence of PFAS in snow isn't necessarily due to bad intentions on the part of skiers. A plausible explanation is the lack of awareness among cross-country skiers and the persistence of old products in homes, ski shops, and ski bags. A block of wax can last for several years, and, as Zennegg points out, virtually all older waxes contain PFAS.

This makes the transition more complex than a simple regulatory update. A ban on competitions can be controlled by athletes, but it doesn't automatically eliminate products already purchased, nor does it suddenly change the habits of occasional users. The fact that high concentrations were measured not only on marathon tracks, but also in the area of ​​the regular cross-country ski track, confirms that the problem affects a broader ecosystem of use.

“A block of wax can last several years. And virtually all older waxes contain PFAS.”

recalled Markus Zennegg, recommending to

“replace old products with fluoride-free variants, now commercially available and appropriately labeled.”

Here innovation does not only coincide with the formulation of a new wax, but with a process of widespread adoptionWe need understandable labeling, clear messaging at points of sale, guidance in sports clubs, training for coaches and trainers, and initiatives to recall or dispose of old stock. Without these measures, the market can offer better products without eliminating the residual use of problematic ones.

The case also highlights the need to improve chemical traceability in consumer products. For many users, distinguishing between an older fluorinated ski wax and a new fluorine-free variant may not be immediately obvious, especially when packaging and technical terminology are unfamiliar. A successful transition therefore requires a simple information infrastructure: visible signs, communication standards, and consistent messaging across manufacturers, sports federations, event organizers, and local authorities.

Stefan Reimann's quote neatly sums up the balance between sporting benefits and environmental costs. For a few minutes of advantage, or for a performance margin now reduced compared to modern alternatives, it's unreasonable to release such stable substances into the environment. This consideration goes beyond cross-country skiing and concerns many mature technologies: when a problematic material continues to be used due to inertia, the real innovation lies in making its use socially and technically unnecessary.

“It simply doesn't make sense to release such stable substances into the environment just to gain a few minutes' head start,” added Stefan Reimann.

Chemical analysis becomes environmental infrastructure

EMPA's work also highlights the growing role of analytical capabilities in managing environmental transitions. In recent months, researchers at the Analytical Center have developed tools to determine approximately 30 of the most common PFAS in various materials and environmental samples, including those from recycling processes. This is important because regulating persistent substances requires reliable, repeatable, and sufficiently sensitive measurements to distinguish actual contamination, likely sources, and exposure levels.

The availability of laboratories capable of reading the chemical signature of PFAS in snow, soil, materials and recycling streams represents a form of scientific infrastructureIt doesn't directly produce a new product, but it enables change management: it allows us to verify the effectiveness of bans, identify residual uses, assess contamination, and provide objective bases for public and private decisions. In this sense, environmental innovation concerns not only what is placed on the market, but also what can be measured and controlled.

The information collaboration between EMPA, EAWAG, and the Oekotoxzentrum, through communication tools such as the "Pocket Facts" brochure, is moving in the same direction. The complexity of PFAS requires communication capable of distinguishing between alarm and underestimation. The health effects are not yet fully understood, but scientific literature associates some of these substances with potential organ damage and serious diseases, including cancer. Caution, in the presence of highly persistent molecules, therefore becomes a rational strategy.

For the sports sector, the lesson is clear. Federations can introduce regulations, manufacturers can innovate formulations, laboratories can measure residues, but effectively reducing impact depends on a chain of shared responsibility. Event organizers, specialized shops, ski clubs, and individual athletes must help clear the gray market of old stocks and normalize the use of fluoride-free alternatives.

A symbol of transformation of technical behaviors

The Engadine Marathon thus becomes a symbolic case of the transformation of technical behavior in the Alpine environment. Not because cross-country skiing is the main source of PFAS, but because it highlights a problem often hidden in the everyday use of materials. Snow, a temporary and fragile surface, records the traces of decisions made before the race: which product to buy, which wax to keep, which habits to maintain, which risks to consider acceptable.

The most useful approach is not to demonize a sport, but to use scientific data to drive concrete change. If the fastest athletes can compete without fluoride, if alternatives are available, and if laboratories can document the persistence of residues, the direction seems clear. The challenge of the coming years will be to transform the ban into standard practice, to the point where old fluorinated ski waxes become a relic of the past and no longer an active source of contamination.

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