Fashion’s green strategy is making microplastic pollution worse – study

Nike clothing the most polluting of 5 brands tested

Is Shein faking its green claims? Lab results raise fresh questions

10 December 2025

Polyester has radically changed fashion, enabling brands to flood the world with more disposable clothing, multiplying waste and pollution [1]. A new laboratory investigation has found that industry’s main response to these environmental problems is making microplastic pollution worse.

Over 100 brands claim that recycled polyester from waste plastic bottles can help reduce pollution and other environmental problems. An industry ‘challenge’ to switch to recycled polyester concludes this month. Adidas, H&M, Puma and Patagonia have already switched almost all their polyester use from virgin to recycled for sustainability reasons [2].

But new laboratory research, published today by the non-profit Changing Markets Foundation, found that recycled polyester creates 55% more microplastic pollution particles on average during washing than virgin polyester, which is less brittle. The particles were also found to be nearly 20% smaller, so more able to spread in the environment and cause harm [3]. 

A single laundry cycle can release up to 900,000 microplastic fibres. Microplastics are now so widespread they are found in the most extreme locations and circulate in all environments: soil, air, water and living organisms. It has been found in numerous human organs and is linked to a growing number of health problems [4]. 

The study focused on a relatively small number of garments from five major brands, and the results provide only an indication of likely pollution rates. T-shirts, tops, dresses and shorts sold by Adidas, H&M, Nike, Shein and Zara were tested. The study is the first to compare brands for microplastic pollution, Changing Markets believes. The brands are among the fashion world’s biggest producers and users of synthetic fabrics, according to a recent Changing Markets survey. 

Nike polyester clothing was found to be the most polluting, for both virgin and recycled fabric. The brand’s recycled polyester shed over 30,000 fibres per gram of sample clothing on average, nearly four times H&M’s average and over seven times Zara’s average. Nike has just been sanctioned for greenwash by the UK authorities, according to a press report last week.

Shein clothing also stood out in that its recycled polyester garments shed microplastics at around the same rate as its virgin polyester clothing. Changing Markets suspects some of the tested clothes labelled as recycled polyester may actually have been made of virgin polyester. Polyester “fraud” is reportedly “rife” in fashion supply chains. 

Urska Trunk, Senior Campaign Manager, Changing Markets Foundation, said: “Fashion has been selling recycled polyester as a green solution, yet our findings show it is deepening the microplastic pollution problem. It exposes recycled polyester for what it is: a sustainability fig leaf covering fashion’s deepening dependence on synthetic materials. Smarter design tweaks and end-of-pipe fixes will only scratch the surface. Real solutions mean slowing and phasing out synthetic fibre production and stopping the diversion of plastic bottles into disposable clothing.

Even before today’s findings, environmentalists concluded that fashion’s recycled polyester drive is largely greenwash. Polyester clothes recycling systems are seen as “important” but also “in development” and only able to process “around 2% of all recycled polyester”. In contrast, the drinks sector can repeatedly reuse waste plastic bottles, but now has to compete with fashion brands for them. Meanwhile, fashion’s use of virgin polyester is growing so fast that the share of recycled polyester last year actually fell. The low cost of synthetic fabrics, now being produced at record highs, has driven huge overproduction, overconsumption and waste. 

Ends

The report Spinning Greenwash: How the fashion industry’s shift to recycled polyester is worsening microplastic pollution is available here 

Notes

[1] Polyester is by far the cheapest mass market fabric, costing half as much to produce per kilo as cotton. That low cost is central to fast fashion. Polyester became the fabric of choice from the year 2000 and clearly dominates a steep rise in overall fabric production, which is today at a record high. The ultra fast fashion brand Shein, which releases thousands of new clothing lines each day, depends on polyester for 82% of its range. Just as clear is the consequence of cheaper clothing in terms of waste and pollution. The average consumer now buys 60% more clothing than in 2000, but keeps them half as long. Polyester clothing is less frequently repaired, rarely recycled into new clothing and has even created a novel category of waste plastic export (clothing) to less developed countries, where it is mostly burned or dumped. An estimated 120 million tonnes of clothing were discarded last year.

[2] Most brands in a Changing Markets survey last year plan to increase their use of recycled polyester, with many pledging to fully or nearly fully transition by 2030. 116 brands committed to using up to 100% recycled polyester by 2025 as the centrepiece of their sustainability claims. They credit recycled polyester with a wide range of environmental benefits, from reducing plastic pollution at sea to reducing the use of fabrics made from virgin plastic.

[3] The study was conducted by the Microplastic Research Group at Cukurova University in Turkey, led by professor Sedat Gündoğdu and associate professor Ilkan Özkan. The average (mean) number of microfibres shed from 14 garment types made mostly from recycled polyester from across all five brands was 12,430 fibres per gram of sample clothing. This compares to 8,028 for the nine garment types of mostly virgin polyester clothing from three brands (H&M, Nike and Shein), representing a 55% difference. A lack of suitable virgin polyester clothing samples from Zara and Adidas prevented a complete comparison between all five brands. Recycled polyester fibres were smaller than those of virgin polyester, with an average length of 0.42 vs. 0.52 millimetres, while the mass of microplastic pollution from recycled polyester was 50% greater than that of virgin polyester (0.36 vs 0.24 milligrams per gram of sample clothing). Each sample tested is thought to be representative of thousands of garments in the same production run.

[4] Overall plastic production was 475 megatonnes in 2022 and is predicted to reach 1,200 megatonnes by 2060. Some 8,000 megatonnes of plastic is now thought to contaminate the environment. Much of that from washing textiles goes into sewage sludge that is spread on farmland. Around a third of the microplastics entering oceans come from textiles, researchers estimated in 2017. Microplastic pollution is now so pervasive that it is found in meat, milk and blood of farm animals, as well as in organs throughout the human body, where scientists say it raises the risk of stroke, heart attack, cardiovascular disease, inflammation, hormonal disruption and other impacts, including premature death. The higher the quantity of microplastics, the higher the chance they will cause harm. Smaller fibres pose greater environmental and health risks, as they are better able to spread in the environment and penetrate deeper into tissues. Recycled polyester fibres often contain a wider ‘chemical cocktail’ of toxic chemicals than virgin polyester. Recycled fibres are also smaller than those from virgin polyester, so spread further in the environment and deeper into the bodies of humans and other organisms, scientists say.