Quick answer
Yes — but only the synthetic ones. Polyester, nylon, acrylic and fleece shed tiny plastic fibres every time they're washed, and researchers have measured hundreds of thousands of fibres from a single load. Clothes made from cotton, linen and wool also shed fibres, but those are cellulose or protein, not plastic, and they biodegrade in water. What you buy matters more than how you wash — though how you wash matters too.
It's the kind of thing you read once and then can't unsee: the fleece jacket that's been through forty washes, the polyester leggings that come out of the machine slightly fuzzier than they went in. All that fuzz went somewhere. Here's what the research actually says, without the panic.
What actually comes off in the wash
A 2019 study published in Scientific Reports measured what synthetic garments release during a normal domestic wash cycle. The researchers found between 124 and 308 milligrams of microfibres per kilogram of washed fabric — which, counted individually, worked out to somewhere between 640,000 and 1,500,000 fibres per wash load.
Those numbers sound enormous, and they are, but scale matters: the fibres themselves are minuscule. Most measured around 360–660 micrometres long and 12–16 micrometres across — thin enough to slip straight through wastewater treatment filters and out into rivers and the North Sea.
Washing isn't the only route, either. A separate 2020 study found that simply wearing synthetic clothes releases comparable quantities of fibres into the air through ordinary friction and movement — which, for a four-year-old, is a lot of friction and movement.
Which garments in a kid's wardrobe shed most
Not all synthetics behave the same way. Loosely constructed, brushed and mechanically finished fabrics — fleece above all — shed dramatically more than tightly woven ones. In one study, mechanically treated polyester samples dominated by fleeces and jerseys released roughly six times more microfibres by weight than nylon samples.
| Garment | Typical fibre | Shedding risk |
|---|---|---|
| Fleece jacket or mid-layer | Polyester, often recycled PET | Highest |
| Soft toys and plush blankets | Polyester plush | Very high |
| Leggings, sportswear, swimwear | Polyester or nylon with elastane | Moderate to high |
| Rain jacket outer shell | Coated polyester or nylon | Low (tightly woven) |
| T-shirts, sweats, denim | Organic cotton | Sheds fibres, but not plastic |
Blends deserve a mention of their own. A cotton-polyester mix isn't half as bad as pure polyester — the two fibre types behave differently under mechanical stress, and blends can shed heavily. If a label reads 60% cotton / 40% polyester, treat it as a synthetic for laundry purposes.
Does cotton shed too? Honestly, yes
This is the part that usually gets left out of sustainable-brand copy, so let's say it plainly: cotton sheds fibres in the wash as well. Research comparing cotton, rayon and polyester laundering found that cellulose-based fabrics actually released more fibre by weight than polyester in some tests — roughly 0.2–4 mg per gram of fabric, against 0.1–1 mg/g for polyester.
The difference isn't quantity. It's what happens next. Cotton and rayon microfibres biodegrade in natural aquatic environments; polyester microfibres essentially don't. Every fibre a fleece sheds is still out there. Every fibre a cotton tee sheds breaks down. That's the whole argument, and it's enough of one — it doesn't need exaggerating.
Six things that measurably reduce shedding
None of these require buying a new wardrobe. They're changes to what you already do on a Tuesday evening.
- Wash full loads, not half ones. Counterintuitive, but well documented: a fuller drum means a lower water-to-fabric ratio and less of the mechanical thrashing that tears fibres loose. Research on washing load and polyester release found this makes a real difference.
- Go colder and shorter. A 2020 study by Northumbria University and Procter & Gamble found that switching to a cold, short cycle substantially cut microfibre release. Temperature, cycle length and agitation all add up.
- Turn things inside out. Less direct abrasion on the outer face of the fabric, less fuzz in the drum.
- Line-dry. Tumble dryers shed additional fibres and vent them straight into the air. Line-drying skips that entirely — and is gentler on elastic and prints besides.
- Consider a filter or wash bag. Independent test results vary widely, and it's worth knowing that: plumbed-in external filters have been reported to capture 80–90% of fibres, while wash bags like the Guppyfriend are reported anywhere from roughly 54% to 86% depending on the garment and the test. Even the lower end is meaningful. France's 2020 anti-waste law (AGEC) legislated for microfibre filters on new washing machines, and the EU has been discussing similar requirements.
- Wash synthetics less often. A fleece worn over a cotton layer stays clean far longer than one worn against skin. Airing beats washing more often than we admit.
What this means when you're buying
The most effective intervention happens before anything reaches your machine. A few habits worth keeping:
Read the composition label, not the marketing. "Eco", "conscious" and "recycled" tell you nothing about shedding — recycled polyester sheds exactly like virgin polyester. The fibre percentages on the inside seam tell you everything.
Prioritise the layers worn closest and washed most. Base layers, pyjamas, everyday tees and trousers get washed constantly, so that's where natural fibres pay off most. A waterproof shell washed four times a year is a different calculation — sometimes synthetic genuinely is the right tool.
Buy fewer things that last longer. A garment worn by two or three children, then passed on again, is a garment that never needed making twice. That's the logic behind our Twice Loved pieces and behind cutting everything oversized in the first place — and you can see how it works across the full collection.
FAQ
Is recycled polyester better for microplastics?
Not for shedding. Recycled polyester diverts plastic bottles from landfill, which is a genuine benefit, but the fibre behaves the same in a washing machine as virgin polyester. It's a different environmental argument, not the same one.
Do new clothes shed more than old ones?
Generally the first several washes release the most, as loose fibres from manufacturing and cutting come away. Shedding tends to decline after that, though it doesn't stop — and garments that pill or brush up with age can shed more again.
Should I throw out the polyester clothes we already own?
No. Throwing away a functional garment is worse on every count — the fibres were already made, and landfill or incineration doesn't undo that. Wear them until they're finished, wash them cold and full, and choose differently next time you replace them.
Is bamboo viscose a natural fibre for this purpose?
Bamboo viscose is a regenerated cellulose fibre — chemically processed, but cellulose at the end of it, so like rayon it is expected to biodegrade in water rather than persist as plastic. The processing itself is a separate sustainability question.
Do front-loading machines really shed less?
A 2016 study from the University of California, Santa Barbara found top-loading machines produced significantly more microfibres than front-loaders, which is consistent with what we know about mechanical agitation. Most Dutch households already have front-loaders.
Does any of this affect my child's health directly?
Research on the health effects of microplastic exposure in children is still developing and we won't overstate it. What's better established is the environmental persistence. If you'd like to reduce household exposure to airborne fibres anyway, natural-fibre bedding, pyjamas and soft furnishings plus regular ventilation are sensible, low-cost steps.