PlanetCare JournalScience · Microplastics · Laundry
Research

Scientists tested three washing-machine filters side by side. One caught the most microfibers.

A peer-reviewed study from Politecnico di Torino compared how much each filter catches and how well it keeps working. Here's what it found.

PlanetCare editorial team · 4 min read
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PlanetCare 2.0 mounted beside a household washing machine.

Every time synthetic clothes go through the wash, they shed microfibers: tiny plastic threads that wastewater treatment can't fully catch. A single 6 kg load of acrylic clothing can release more than 700,000 of them.

In a study published in the Journal of Hazardous Materials in 2025, researchers at Politecnico di Torino ran three commercially available washing-machine filters through the same series of washes. They measured how much fibre each filter held back, how much it slowed the water and how quickly it clogged.

Curious which filter it was?See the filter that came out on top →

Key findings

  1. Most fibres caught. PlanetCare retained most of microfibers by mass, compared with the other two filters.
  2. Lowest pressure drop. It slowed the washing machine's drain flow the least of the three.
  3. Barely clogged. After 10 washes its flow performance dropped by about 8%, against about 37% for the filter that clogged most.
Sheikhi et al., Journal of Hazardous Materials 489 (2025) 137646. The study used a very fine 1.6 µm test, stricter than the 50 µm standard behind PlanetCare's 98% figure.

Regulators are starting to act. France's anti-waste law points toward microfiber filters in new washing machines, and the EU is looking at similar measures. None of that changes the machine already in your home.

Washing synthetic clothes is one of the largest sources of primary microplastics in the ocean.Summary of IUCN findings, 2017
PlanetCare 2.0 Starter Kit
The filter in the study

PlanetCare 2.0 Starter Kit

Fits the washing machine you already have. From €96, with free cartridge returns.

Questions

Before you order

Will it fit my washing machine?

Yes. PlanetCare sits between your washing machine's drain hose and your drain, so it works with practically every machine, front or top loading.

Does it slow down the wash?

No. It runs on the machine's own pump, and an automatic bypass keeps water flowing if a cartridge is full.

How often do I change the cartridge?

About every 30 washes, depending on what you wash. The bypass indicator tells you when it's time.

What happens to used cartridges?

You send them back to us for free. We clean and reuse the cartridge and recycle the fibres.

What is Auto-Refill?

An optional subscription from €7.50 a month: fresh cartridges arrive when you return the full ones. Available worldwide.

See how PlanetCare works

A short explainer: where microfibers come from, how the filter catches them, and what happens to full cartridges.