Switching from virgin to recycled polyester looks virtuous. New evidence suggests it may be making the problem worse.
Polyester transformed fashion by making clothes cheap, plentiful and disposable. It also multiplied pollution. The industry’s preferred answer—recycled polyester made from plastic bottles—has now been challenged by new laboratory research showing that it can shed significantly more microplastics than virgin polyester.
A study published by Changing Markets Foundation found that recycled polyester garments released around 55% more microplastic particles during washing than virgin polyester equivalents. The fibres were also about 20% smaller, making them more mobile in air and water—and potentially more harmful. A single laundry cycle can release up to 900,000 microplastic fibres, which now contaminate soil, oceans, the atmosphere and even human organs.
The findings complicate a sustainability narrative embraced by more than 100 brands. An industry “challenge” to switch from virgin to recycled polyester concludes this month; companies such as Adidas, H&M, Puma and Patagonia have already made the shift for most of their polyester use. The rationale is straightforward: recycling bottles into clothing reduces waste and emissions. The science, it seems, is less obliging.
The laboratory tests covered a limited sample of garments—T-shirts, tops, dresses and shorts—from five major brands. Even so, the variation was striking. Nike’s polyester garments, both virgin and recycled, shed the most microplastics. Recycled Nike items released over 30,000 fibres per gram, several times higher than rivals. Shein’s recycled polyester shed microplastics at roughly the same rate as its virgin versions, raising concerns about mislabelling—an issue the report says is widespread in opaque supply chains.
The broader implication is uncomfortable. Recycled polyester appears more brittle, fragmenting more readily in use and wash. That undermines claims that it is an unambiguous environmental win. As Urska Trunk of Changing Markets puts it, recycled polyester risks becoming a “sustainability fig leaf” that masks fashion’s growing reliance on synthetic fibres.
Critics add two structural problems. First, textile-to-textile recycling remains marginal—able to process only around 2% of recycled polyester—while bottle-to-bottle recycling in beverages is far more circular. Fashion’s appetite for bottles diverts feedstock from systems that reuse plastic repeatedly. Second, the sheer growth of synthetic fibre production overwhelms efficiency gains: despite more recycling, the share of recycled polyester has recently fallen as virgin output surges.
If the aim is to curb pollution rather than rebrand it, the study suggests a harsher prescription. Incremental design tweaks and filters may help at the margins. But the bigger levers lie elsewhere: slowing production, reducing dependence on synthetics, and designing clothes to last. Recycling, it turns out, cannot wash away fashion’s excesses.
