Pull the lint filter out of a tumble dryer and look at the grey felt in your hand. That is not dust from the room. That is the clothes. The washing machine produces the same thing, you just never see it, because it leaves in the water.
France decided to do something about that before anyone else. Under article 79 of its anti-waste law, every new domestic washing machine sold there since 1 January 2025 must be fitted with a microfibre filter. It is the first mandate of its kind anywhere in the world. Nothing similar is in force in Spain today, and I am not going to pretend a Spanish requirement is imminent when I have no basis for saying so. But appliance manufacturers do not build one machine for France and another for everywhere else if they can avoid it, and that is usually how a national rule becomes a European default.
Why this matters more for school clothes than for most wardrobes
Shedding is heavily a synthetics question, and school kit is heavily synthetic. PE tops, tracksuit bottoms, fleeces and waterproofs are polyester or polyester blends for perfectly good reasons: they dry overnight in a flat with no outdoor space, they take a fall on gravel without tearing, and they cost a third of the wool alternative. I do not think parents should feel bad about owning them. I own them. But a fleece is a very large surface area of loose synthetic fibre, and it is usually the garment that goes in the machine most often.
Cotton sheds too. It matters less in this specific respect, because cellulose fibres break down in water over months rather than persisting, though that is a partial defence and not an absolution. The practical point is simply that if you know which of your child's garments are polyester, you know which loads are worth thinking about.
What you can do with the machine you already have
There are three categories of retrofit and they are not equally good. External filters plumb into the machine's outlet hose and catch fibres on the way out. They are the most effective option and the most expensive, typically over a hundred euros, and they need emptying. Wash bags, the zip-up mesh kind, perform well in independent testing and cost a fraction of that; you put the synthetics inside and wipe the collected fuzz from the corner afterwards. Laundry balls that tumble loose in the drum are the cheapest and, in the testing I have seen, the least effective. If you buy one thing, buy a bag and put the PE kit in it.
The free options are the good ones
Everything that reduces shedding is something you were probably better off doing anyway. Wash cooler and shorter, which on its own cut microfibre release by up to 52 per cent in the Leeds work I have written about elsewhere. Fill the drum properly, because garments with room to swing abrade each other harder. Wash synthetics less often; a PE top that has been worn once in a gym hall usually needs airing rather than a cycle. And air dry, because the tumble dryer sheds as aggressively as the wash and vents straight into the room.
None of this requires buying anything, which is why I lead with it. The filter mandate is welcome and I hope it spreads, but a filter on a machine still running 85 minute hot cycles is catching a problem that did not need to be created.
The part that is our job, not yours
A parent cannot reduce shedding from a garment whose composition they cannot find out. Half the school kit in circulation carries a label reading nothing more specific than a blend percentage, and blends are precisely where the guidance gets complicated. Each of our garments carries a scannable record of what is actually in it, lot by lot, because I think knowing you are washing 100 per cent cotton rather than a 65/35 blend should not require you to take anyone's word for it. That is the honest limit of what care advice can do. Everything after that is a design decision made long before the garment reached your machine.