Washing ski clothing: how to cut microplastic release

After a long day on the slopes, your ski jacket goes into the washing machine. Most of us don't give it a second thought. What happens next is less obvious: every wash loosens thousands of tiny plastic fibres from synthetic performance clothing, and they are too small for wastewater treatment plants to filter out completely. These microfibres end up in rivers, lakes, seas and farmland, and eventually find their way back to us through the food chain.

The problem has reached a worrying scale: around 35% of the microplastics in our oceans come from clothing, not from plastic bags or packaging. To be precise, they come from washing synthetic textiles. Your fleece jacket, your ski trousers, your mid layer: they are mostly made of polyester, polyamide or acrylic, and they lose fibres every time they are washed.

The numbers are sobering. Pure polyester sends around 496,000 fibres into the wastewater per wash, acrylic as many as 730,000. Fleece jackets, a staple of ski clothing, are especially problematic: a new fleece jacket can release up to two grams of microfibres in a single wash. That is more than a million individual fibres.

In Germany alone, laundry sent 300 tonnes of microplastics into wastewater in 2018. Modern treatment plants do filter out more than 95%, but that only shifts the problem. 70% of the filtered sewage sludge is incinerated, which releases emissions into the air, and 30% is spread on farmland as fertiliser, where the particles build up in the soil. The remaining 5% goes straight into rivers and seas.

Now the good news: with fairly simple measures you can cut the fibres your ski clothing sheds by more than 80%. The usual advice to pick a "gentle" wash is trickier than it sounds, though. Recent research shows that if you really want to reduce microplastics, you need to do things differently from what was long assumed.

The biggest surprise in the research concerns the delicate programme. You would expect gentler washing to cause less fibre abrasion. Studies from the University of Plymouth show the opposite: delicate cycles release up to 800,000 additional microfibres per wash. That is nine times the normal amount.

The reason is water. A delicate cycle uses considerably more of it, and that extra water flushes more fibres out of the fabric. The gentler drum movement can't make up for it.

How full you load the machine matters a lot. Studies show that a small load releases five times more microplastics than a full drum. With less laundry, the ratio of water to fabric weight is worse, and the garments move around more freely, which means more mechanical friction.

High temperatures weaken synthetic fibres, so they break sooner. 30 °C is ideal, 40 °C is still fine. Keep the spin speed low or skip the spin altogether. Synthetic fabrics dry quickly in the air anyway, so you can leave out the tumble dryer too. It loosens even more fibres.

Leave fabric softener out when you wash technical clothing. According to studies it loosens more fibres and also impairs the membrane's performance. As for detergent, liquid beats powder: powder contains abrasive particles and bleach, which increase fibre abrasion.

Special laundry bags for technical clothing are the most effective step you can take straight away. Good fine-mesh bags made from sturdy material don't release microfibres themselves and cut fibre shedding from fully synthetic clothing by 86% on average.

Two things are at work here. First, there is less friction in the machine because the bag holds the clothes together. Second, broken fibres get caught in the fine mesh and stay out of the wastewater. After the wash, the fibres gather in the corners of the bag, and you can simply pick them out and put them in the general waste bin.

Not everything should share a drum. Hard items such as jeans, running shoes or hardshell jackets and trousers with zips don't belong in the same load as soft ski clothing. The friction they cause leads to noticeably more fibre loss. Wash your fleece mid layers and base layers together with other soft textiles instead.

The most effective way to reduce microplastics is simple: wash less often. Synthetic ski clothing doesn't need to go in the machine after every outing. A good airing is often enough, ideally overnight outdoors. Small stains can be rinsed out by hand, so the whole jacket doesn't have to go in the wash.

Over a normal ski season, two or three washes are plenty. As a bonus, your clothing lasts longer and the membrane keeps its performance for longer.

Next time you buy, it pays to look at other materials. For base and mid layers in particular, merino wool has plenty going for it on the slopes: it regulates temperature, absorbs moisture and barely smells even after several days. The key environmental advantage: merino doesn't shed plastic microfibres, and it needs washing far less often.

Washing merino: 30 to 40 °C at most, with a protease-free wool detergent, no fabric softener and no bleach.

Semi-synthetic fibres such as Tencel (lyocell) are another option. They are made from wood pulp, not from crude oil.

Work on stopping fibres at the source is ongoing. Researchers at the University of Bonn have developed a filter modelled on fish gills that removes more than 99% of microfibres from wastewater without clogging. Other approaches use vortex filtration, which captures more than 90% of particles and can be built into existing washing machines.

Regulation is moving too: since 2025, France has required new washing machines to have a microfibre filter. Australia plans similar rules by 2030. Until such solutions are widely available, though, it is up to us as consumers. And the measures in this article already make a real difference today.

New filter technology for washing machines is coming. Eventually. You don't have to wait for it. With these simple tips you can cut the microplastics you release by up to 90%, starting with your next wash. Seas and soils stay cleaner, your ski clothing lasts longer, and your wallet benefits too.