Where the Recycled Polyester Rush Went Wrong: From the Start

As the Textile Exchange 2025 Recycled Polyester and Cotton Challenge comes to a close, Changing Markets Foundation has a rather horrifying ribbon to wrap up the multi-stakeholder organization’s joint initiative with the UNFCC: When it comes to microplastic pollution, recycled polyester is just as bad as virgin polyester.

The fashion industry’s shift to recycled polyester is increasing microplastic pollution, given the synthetic material’s recycled version sheds even more microfibers than its virgin counterpart, a new laboratory investigation found.

The watchdog group that campaigns against greenwashing tested 51 garments—from Adidas, H&M, Nike, Shein and Zara—for a study commissioned by the Changing Markets Foundation, conducted by the Microplastic Research Group at Çukurova University.

The verdict? Fashion’s favorite and flagship “sustainable” solution releases both the highest number of fibers and the finest particles—actually worsening the microplastic pollution problem, per the Changing Markets Foundation “Spinning Greenwash” report.

“Fashion has been selling recycled polyester as a green solution, yet our findings show it’s deepening the microplastic pollution problem,” said Urska Trunk, senior campaign manager of Changing Markets Foundation. “It exposes recycled polyester for what it is: A sustainability fig leaf covering fashion’s deepening dependence on synthetic materials.”

The kicker? Recycled polyester has become a “convenient cover” for the industry, per the foundation—one that lets brands claim progress in reducing reliance on virgin plastic while increasing overall synthetic fiber production. Over 100 major brands already heavily rely—and promote—this solution. Many of which market recycled polyester as a circular solution. In reality, 98 percent of it comes from downcycling plastic bottles, not old textiles.

It’s an important distinction. Deriving recycled polyester from downcycled plastic bottles is done through a process that removes them from closed-loop recycling systems and locks them into textiles that cannot be effectively recycled again. The consequences are twofold: masking the continued growth of virgin polyester and failing to address the fundamental problem of microfiber shedding.

That said, Changing Market’s 2024 Plastic Paralysis report found that 82 percent of surveyed brands plan to increase their use, with some pledging full transition by 2030.

Adidas claims that 99 percent of its polyester is recycled, as advertised on the German group’s website.

“Recycled polyester has a significant lower carbon footprint than virgin polyester and helps to reduce emissions,” an Adidas spokesperson told Sourcing Journal, citing the Microfibre Consortium’s Root Cause Analysis. “The majority of the available scientific studies show no difference between recycled and new fibers in terms of microfiber release. Fiber fragmentation is influenced by a variety of factors such as yarn specification, dyeing technology, coating or material construction; fiber type is only one of these factors.”

In 2024, H&M reported that 94 percent of the polyester it sourced was recycled, according to the Swedish brand’s annual sustainability report. That said, polyester currently accounts for approximately 22 percent of H&M’s total material basket, a spokesperson told Sourcing Journal, while cotton remains the material most used.

“As of today, our industry still needs synthetic materials for ensuring the functionality of some of our products—functionality and durability aspects that our customers appreciate and demand,” the H&M spokesperson told SJ. “We welcome reports that help push our industry forward to accelerate the necessary changes. H&M Group shares the concern about the environmental impact of fiber fragments.”

Even Patagonia, often deemed the industry’s sustainability leader, disclosed that 93.6 percent of its polyester is recycled—mostly from plastic bottles—representing more than half (52 percent) of its total materials, according to the brand’s 2025 progress report.

However, the central paradox of recycled polyester’s market growth provides proof of a calculated greenwashing strategy, per the report.

Data from Textile Exchange’s latest Materials Market Report illustrates the issue: Although recycled polyester volumes rose last year—from 8.9 million metric tons in 2023 to 9.3 million metric tons in 2024—its overall market share fell from 12.5 percent to 12 percent. Why? Virgin polyester grew even faster.

In the first study to compare brands for microplastic pollution, as far as Changing Markets can tell, the team tested T-shirts, tops, dresses and shorts sold by Adidas, H&M, Nike, Shein and Zara—brands otherwise known as the fashion world’s biggest producers and users of synthetic fibers, according to the nonprofit’s “plastic paralysis” survey conducted last September.

Neither Nike, Shein nor Zara responded to Sourcing Journal’s request for comment.

“Every fiber impacts the environment, whether it’s natural or synthetic. Each fiber has its own qualities; for every piece of clothing we design at H&M Group, we make decisions about which which we use based on environmental impact, durability, functionality, fit and recyclability,” the H&M spokesperson told SJ. “Rather than stop using them, we believe in investing in solutions and innovations—like Syre—who focuses on textile-to-textile recycled polyester, to find better and more sustainable material solutions.”

For context, the study focused on a “relatively small” number of garments from five major brands, meaning the results provide “only an indication of likely pollution rates.” More specifically, the study analyzed a total of 51 garments—13 by Zara and 11 by H&M, with nine by Adidas, Nike and Shein, respectively—covering cotton, polyester (both virgin and recycled) and polyamide (both virgin and recycled).

Overall, the study found minimal differences between the brands; what Changing Markets said underscores the fact that microfiber shedding is an industry-wide problem that “exposes the Achilles heel of the industry’s addiction to synthetic materials,” the report reads. That problem is “driven by material and construction choices—such as material type, yarn construction, weave density and finishing processes—rather than a brand-specific problem.”

“Our statistical testing found no significant difference between brands on shedding of cotton, polyamide and recycled polyamide microfibers,” the report reads. “All garments shed a similar number of fibers per gram of fabric, regardless of who made them.”

And while the study determined that shedding is systemic, polyester shows significant outliers. That said—and specifically across polyester fabrics tested—Nike showed the highest fiber release, with the greatest counts in both virgin and recycled polyester.

The “Just Do It” giant’s polyester clothing was found to shed the most microfibers among all brands tested, for both virgin and recycled fabrics. In virgin polyester, Nike garments released about 6,931 fibers per gram—nearly three times more than Shein and over seven times more than H&M.

“H&M Group’s New Growth & Ventures team invests in companies that develop technologies and software that will lead the industry toward a circular and sustainable future. In this area, we currently have investments in Ambercycle, Infinited Fiber Company and Syre,” the H&M spokesperson told SJ. “We believe that microfibers need to be addressed at several stages throughout our value chain—including design, production, use and end-of-life—which is why we cooperate with other stakeholders to find effective solutions.”

The gap widened for recycled polyester: Nike averaged roughly 30,771 fibers per gram, around 16 percent more than Adidas, nearly four times more than H&M and over seven times more than Zara, with one Nike item shedding close to 50,000 fibers per gram compared with about 1,700 from an H&M sample. Across all brands, recycled polyester was the highest-shedding fabric overall, producing smaller, more numerous and more environmentally dangerous microplastic particles than virgin polyester.

Researchers also flagged potential “recycled polyester” fraud in supply chains—particularly as Shein’s recycled garments shed at the same rate as its virgin styles—while warning that the industry’s reliance on recycled synthetics is worsening, not solving, microplastic pollution.

The ultra-fast-fashion retailer’s potential mislabeling had a material impact on the study’s overall data. The garments in question shed fibers at a rate comparable to virgin polyester, not the much higher rate seen in verified recycled products. When these suspect Shein samples were removed from the analysis, the shedding discrepancy between verified recycled polyester and virgin polyester increased from 55 percent to 72 percent. In turn, uncovering significant inconsistencies in how brands label and market their products raises serious questions about transparency and potential consumer deception.

“Smarter design tweaks and end-of-pipe fixes will only scratch the surface,” Trunk said. “Real solutions mean slowing and phasing out synthetic fiber production and stopping the diversion of plastic bottles into disposable clothing.”

The reason lies in the recycling process. The mechanical and chemical stresses involved in breaking down old plastic and reprocessing it into new yarn weaken and shorten the plastic’s polymer chains. This degradation makes the final fabric more brittle and prone to fracturing. This is not an isolated issue; the study also found that recycled polyamide sheds over three times (228 percent) as much as virgin polyamide.

For context: Recycled polyester is often made from a mix of plastic waste, primarily from used beverage bottles. This waste contains a variety of substances—including leftover dyes, additives, plasticizers, stabilizers and degradation by-products. The recycling process can’t fully remove these chemicals; it can increase the toxic load by introducing new contaminants, however. This “chemical cocktail” becomes embedded in the new clothing fibers, which are then released into the environment with every wash.

The takeaway? The promotion of recycled content hasn’t had any effect (see: led to any decrease) on overall plastic use. It’s also worth noting that “concerns about bottle-derived recycled polyester are shared by Europe’s beverage industry, which has urged policymakers since 2021 to stop the downcycling of plastic bottles into textiles,” the report reads. This concern is backed by McKinsey’s projection that recycled polyester demand will be three times higher than available supply in the United States by 2030.

Maybe the Roadmap to Net Zero will beat rPET to the punch.