Recycled polyester under scrutiny over microplastic pollution

New research suggests that the fashion industry’s flagship to plastic waste – switching from virgin to recycled polyester – may be exacerbating microplastic pollution, one of fashion’s most pervasive environmental impacts.

More than 100 global fashion brands promote recycled polyester, typically sourced from waste plastic bottles, to cut emissions and reduce pollution. Major players including Adidas, H&M, Puma and Patagonia have already converted most of their polyester use to recycled material.

Brittle fibres

However, research published by the non-profit Changing Markets Foundation found that recycled polyester sheds, on average, 55% more microplastic particles during washing than virgin polyester because the secondary fibres are more brittle. The fibres released were also nearly 20% smaller, increasing their ability to disperse widely in the environment and potentially cause harm.

A single household laundry cycle releases up to 900 000 microplastic fibres. These particles have now been detected in soil, air and water and in living organisms. Scientific studies have also identified microplastics in numerous human organs, adding to concern over links to adverse health effects.

Nike – highest

The Changing Markets Foundation study analysed T-shirts, tops, dresses and shorts from Adidas, H&M, Nike, Shein and Zara. The companies are among the fashion sector’s largest producers and users of synthetic fibres.

Nike garments were found to shed the highest levels of microplastics, for both virgin and recycled polyester. On average, Nike’s recycled polyester released more than 30 000 fibres per gram of fabric – almost four times the level measured for H&M and more than seven times that of Zara.

‘Claims undermined’

Urska Trunk, senior campaign manager at Changing Markets Foundation, said the findings undermine claims that recycled polyester is a sustainable fix. She argued that incremental design improvements and filtration solutions will not address the root problem, calling instead for a slowdown and phase-out of synthetic fibre production.

Environmental groups have long questioned recycling polyester, pointing out that current textile-to-textile systems process only a small fraction of polyester waste. Meanwhile, the diversion of plastic bottles into clothing has created competition with the drinks sector, which can recycle bottles multiple times.