The quest for speed on snow is leaving a toxic trail.
Despite increasing global awareness and racing bans, persistent ‘forever chemicals‘ known as PFAS are still being scraped off skis and into the pristine environment of Swiss winter sports regions.
New research from Empa has detected elevated concentrations of these long-lasting pollutants in snow samples from the Engadin valley, prompting an urgent call for recreational skiers to update their ski wax kits.
The persistent problem of traditional ski wax
Per- and polyfluoroalkyl substances, or PFAS, are a class of synthetic chemicals prized for their water and grease resistance.
For decades, they have been key ingredients in certain high-performance ski waxes, designed to enhance the glide of skis. However, these benefits come at a steep environmental cost.
Because PFAS do not naturally break down, they persist for centuries in the environment once released, earning them the moniker forever chemicals. Their capacity to accumulate in humans and animals underscores the vital need to restrict their usage wherever possible.
Empa’s Analytical Center researchers conducted a targeted investigation following the Engadin Ski Marathon in March 2025.
Snow samples were collected at the starting line, two kilometres down the track, and from a background control area. The results confirmed significant contamination.
Markus Zennegg, head of the Analytical Center, reported measuring relatively high levels of the specific PFAS types commonly found in ski wax. These primarily consisted of perfluorinated carboxylic acids with an even carbon chain length of 6-14 carbon atoms.
The highest readings were immediately after the starting line, which is when freshly waxed skis shed the most product. Although concentrations dropped notably after two kilometres, elevated, measurable levels of PFAS persisted in the snow even at that distance.
A risk to waterways and wildlife
The location of the contamination raises serious environmental alarms. Researcher Stefan Reimann, who collected the samples, noted that the measurable contamination was found directly above Lake Sils.
When the winter snow melts in spring, these persistent chemicals inevitably flow into the water system, presenting a long-term risk of bioaccumulation in aquatic organisms and fish.
Furthermore, the researchers’ subsequent analysis of soil samples from the same locations revealed ongoing, significant contamination.
This level of persistent chemical concentration is a cause for concern, as it poses a risk that PFAS could accumulate in the meat of grazing cattle above permissible limits when they return to the alpine pastures in the warmer months.
Ski wax bans and the recreational gap
The sporting world has already responded to the PFAS threat. Since the 2023/2024 season, the International Ski Federation (FIS) has enforced a global ban on all fluorinated ski wax in its races, including major Swiss events like the Engadin Ski Marathon.
Manufacturers have largely complied, switching their product lines to fluorine-free alternatives. The Empa team confirmed the effectiveness of this ban among elite competitors, finding no PFAS on the skis of the ten fastest professional skiers at the marathon. The findings demonstrate that achieving speed is clearly possible without using fluorine.
However, the contamination discovered by Empa suggests that the persistent pollution stems primarily from the general population of recreational skiers, rather than competitive athletes.
The researchers believe the pollution is largely due to a general lack of awareness among amateur cross-country skiers.
This is supported by the fact that elevated PFAS concentrations were found not just in the marathon tracks but also in areas used for normal cross-country trails.
An old block of ski wax can last for several years, and it is important to note that virtually all older products contain PFAS.
The call for a clean transition
The study’s findings are a critical reminder that consumer choice carries environmental responsibility.
To accelerate the clean transition and protect Switzerland’s unique alpine environment, the Empa researchers strongly recommend that the skiing public take immediate action.
Recreational skiers should inspect their gear and responsibly dispose of any old, fluorinated ski wax, replacing it with the widely available, clearly labelled fluorine-free alternatives.
The research underscores that releasing such stable and dangerous substances into the environment is not justified for the minimal performance boost in a typical race.
