Good chemistry: How more sustainable fibers are replacing PFAS

• More sustainable alternatives from bio-based to recycled
• New Gore-Tex ePE membrane
• End-of-life: hazardous waste or recyclable?
• Care & use: Consumer knowledge counts

PFCs or PFAS, i.e. perfluorinated or polyfluorinated alkyl substances, were long considered the perfect match for outdoor clothing thanks to their outstanding water and dirt-repellent properties: In DWRs (Durable Water Repellency), i.e. coated impregnation, but also in the manufacture of membranes, which are often used in waterproof clothing. The problem is that these "forever chemicals" do not decompose in conventional processes in nature. Instead, they accumulate, even in ever-increasing quantities. And everywhere: the chemicals have been detected in polar ice, in food and even in human blood. Their harmful effects on health are also well known. There has been a political response at European level with a proposal to ban PFAS, thus initiating a more active search for solutions in the industry. "There have long been substitutes, especially for consumer products such as textiles or packaging, and a ban is long overdue. For special applications, good alternatives must first be developed - but in my view, the proposal allows enough time for this," says Prof. Dr. Henner Hollert, Professor of Evolutionary Ecology and Environmental Toxicology at the Johann Wolfgang Goethe University in Frankfurt am Main.

Although it has been in the works for a while, the PFAS phase-out for outdoor brands is complex due to the performance demands placed on the products. Functionality and practicality are weighed against the environmental impact. Pioneers like Vaude and Fjallräven have been relying on PFAS-free impregnation and membranes for around a decade and voluntarily converted their collections step by step. But the search for alternatives was not easy. Especially for components such as zippers was more complicated than expected, as there were no waterproof alternatives on the market.

Other product and component manufacturers are following suit, but the solution has not yet been found. According to a Globetrotter study most of the brands surveyed now expect to have banned PFAS from their products by 2027.

There are various approaches to using more sustainable alternatives. More and more brands are using PFC-free alternatives in the production of their clothing - such as the materials and membranes from Polartec or Sympatex. In some cases, recycled polyester or polyamide and thinner materials are also used, which in turn reduces CO₂ emissions. Membranes such as Futurelight or Dermizax are also taking this approach.

Another development approach is moving towards bio-based materials. This includes, for example Biolona plant-based nylon fabric that Polartec plans to gradually replace petroleum-based products in fabrics and membranes from 2023. Also Modern Meadow also relies on biomass in the production of its waterproof and breathable Bio-Tex Shield membrane technology. Because the material is particularly abrasion-resistant, two-layer use can also save material compared to a three-layer construction, thus reducing the carbon footprint. Vaude and UPM are working together to produce outerwear made from biomass. In the world's first biorefinery, which is due to go into operation at the end of 2023, it should also be possible to produce fabrics for membrane production in the future.

Gore-Tex, which is often used synonymously with waterproof clothing, has also launched a new, more sustainable ePE membrane. Compared to previous products, it can be made thinner and therefore requires less material, saving carbon dioxide during production. The company has been working on this for around ten years with brand partners such as Patagonia and also uses recycled polyester in the manufacturing process.

The expanded polyethylene (ePE) material platform is produced similarly to PTFE (polytetrafluoroethylene) membranes, for which Gore is known. However, it does not use PFAS in the membrane and impregnation. "The great thing about it is that it performs just as well," says Lara Wittmann, Global Strategic Marketer at W.L. Gore & Associates. However, development is already continuing and, according to Wittmann, a more sustainable version of the Gore-Tex Pro membrane, the ingredient brand's best-performing product, is set to follow in two years' time.

Of course, the move towards PFAS-free materials is a good and correct one. In the medium to long term, however, it is just as important that a jacket can be recycled at the end of its life. However, the combination of three different materials, such as in a three-layer jacket, makes recycling difficult or even impossible. Instead of being reused or recycled, this often means: off to the bin!

So it's all the better that brands such as Jack Wolfskin and Mammut are in the process of using mono-materials for the membrane, outer layer and base layer, making waterproof clothing recyclable. In 2024, various collections, for example made from 100% polyester, will be launched on the market that are both made from recycled material and can be recycled again.

Would it now be best for us as consumers to switch directly to a new, more sustainable membrane, i.e. to buy a new waterproof jacket? Experts clearly say no. This is because the harmful release of PFAS is primarily an issue during production and disposal. The most sustainable product is therefore still the one you already have. It causes neither newly released CO₂ during production nor other harmful emissions.

That's why it also makes sense to look after the products properly or repair them so that they can be worn for as long as possible. In the case of Gore-Tex products, for example, this means that they must be washed regularly and the membrane cleaned in order to remain functional. After washing and drying, the garment should be heat-treated again, either in the tumble dryer or by ironing with a towel in between, so that the membrane's permanent water-repellent properties are reactivated.

At the same time, the intended use of the garment also plays an important role, which we should all critically reconsider when we need something new. Does the membrane really have to be oil-repellent? Do we only wear the three-layer jacket to walk the dog or to climb the next four-thousander? Accordingly, we should decide whether there is no alternative to the PTFE performance membrane, or whether a natural or at least more sustainable version might also offer the desired performance and keep us dry when walking the dog.