Recycled polyester releases more microplastics

When the sustainable solution may make the problem worse.
In recent years, recycled polyester has become the symbol of “eco-friendly” fashion: promoted as a virtuous alternative to virgin polyester, it has been adopted by dozens of global brands as a strategy to reduce the industry’s environmental impact. However, a recent scientific study raises serious doubts about the true sustainability of this fiber and challenges a previously widespread and little-examined narrative.

The results of the “Spinning Greenwash” study

The Changing Markets Foundation, a nonprofit organization working on environmental sustainability, commissioned research from the Microplastic Research Group at Çukurova University (Turkey) to compare the release of microplastics between recycled and virgin polyester fabrics. The results reveal a surprising and worrying situation:
The recycled polyester garments tested released an average of approximately 55% more microfibers than those made from virgin polyester during wash cycles.

In terms of average quantity, the study recorded approximately 12,430 microfibers per gram in recycled fabrics, compared to 8,028 microfibers per gram in virgin polyester.

The microfibers released from recycled fabrics are smaller—with an average length of approximately 0.42 mm versus 0.52 mm—making them more easily dispersed and potentially more harmful to ecosystems and human health.

The 51 items analyzed came from five major fashion brands — Adidas, H&M, Nike, Shein, and Zara — and included items such as t-shirts, tops, dresses, and shorts.

What does this mean for the environment?

Microplastics are a globally recognized environmental problem: they are found in soil, waterways, and oceans, but also in living organisms, including human tissue, and are associated with potentially adverse effects on biological systems.

A single wash cycle can release hundreds of thousands of microfibers into wastewater, which treatment systems struggle to fully filter, allowing these particles to enter the environmental and food chains.

Where do all those tiny microfibers end up?

The answer is everywhere. Not just in the seas and rivers, but also in the air we breathe, in the soil of our fields, in the most remote sediments, even in the organic tissues of living beings. According to an Italian report on micro and nanoplastics in the human body (Vera Studio 2024), synthetic textiles are among the most significant sources of microplastics linked to home laundry processes, and certain technical steps like pre-washing can release far greater quantities of microfibers than simple washing and rinsing.

This is the reality: what we wear, wash, and use every day comes into contact with environments we can no longer separate from our daily lives. Yet, amid this scientific reality, some marketing narratives remain reassuring. The Changing Markets Foundation uses a powerful symbolic image to describe many companies’ communications: it calls it a “sustainability fig leaf,” a fig leaf that covers a deep dependence on synthetic materials without properly addressing the problem of microplastics (The Ecologist). And the message comes from an authoritative voice: Urska Trunk, senior campaign manager at Changing Markets, told The Ecologist very clearly that “fashion has sold recycled polyester as a green solution, yet our findings show it exacerbates the problem of microplastic pollution.”

Why is this phrase so important? Because it directly challenges the core of the global textile industry’s green narrative. It’s not about demonizing recycling—but about highlighting the fact that sustainability cannot be a superficial promise, based on catchy claims, if products continue to release significant amounts of microplastics.

And this awareness isn’t just for scientists or environmentalists. It’s about us, our consumption, our washing habits, and, ultimately, the future of our communities and the planet we inhabit.

Why does recycled material release more microplastics?

According to the authors of the Changing Markets study, the difference can be traced back to the structural characteristics of recycled fibers. During recycling processes—both mechanical and chemical—the polyester polymer chains shorten and weaken, making the fibers more fragile and prone to breakage. This leads to a greater release of microfibers during use and washing.

Labeling and transparency: another critical issue

The Changing Markets study also found discrepancies in brand claims: some garments advertised as being made from recycled polyester exhibited shedding behavior similar to that of virgin fabrics. In some cases, online labels and descriptions did not match the fiber information physically displayed on the garments, raising concerns about potentially misleading marketing practices.

What Other Research Says

In addition to the Changing Markets Foundation study, other scientific research is helping to clarify the situation, showing that recycled polyester is not automatically a better solution in terms of microfiber release. A study published in Environmental Pollution in 2024 found that, during home washing, recycled polyester garments can release more microfibers than virgin polyester ones, likely due to the lower mechanical strength of fibers subjected to recycling and heat treatments. Analyses conducted by The Microfibre Consortium confirm this trend in several cases, indicating, in some samples, a release of up to twice as many microfibers, often finer in size and therefore potentially more impactful on ecosystems and the food chain. However, the data also show strong variability: fabric structure, yarn type, production processes, and washing conditions significantly influence the results, with some tests showing less marked differences between virgin and recycled materials.

Overall, the scientific literature converges on one key point: polyester recycling reduces upstream plastic waste, but it does not solve—and can sometimes exacerbate—the problem of microplastic dispersion, confirming the need for a broader approach that includes material innovation, responsible textile design, and strategies to overall reduce the amount of synthetic fibers in circulation.

Microfibers and the Fabric Life Cycle: Beyond Home Washing

When discussing microplastics and microfibers, the common debate often focuses on release during home washing. However, recent research highlights that several stages of textile production are also significant sources of microfiber emissions. A study published in Scientific Reports monitored microfiber emissions in a large textile manufacturing plant and found that wet processing—such as dyeing and finishing—can release up to 25 times more microfibers than home washing cycles, with dyeing accounting for over 95% of emissions under some conditions. These findings suggest that the environmental impact of textiles is not reduced simply by changing the type of fiber (virgin or recycled), but requires optimization and mitigation from the earliest stages of production, for example, through lower dyeing temperatures, shorter process times, and the use of yarns and textile structures that minimize fiber shedding.

How Garment Care and Design Influence Microfiber Release

The amount of microfibers released from a garment depends not only on the material, but also on manufacturing techniques and care conditions. Different cutting and sewing methods, as well as washing conditions, can significantly influence the release of microplastics into the environment. Research published in Science of the Total Environment (2023, R Rathinamoorthy, S Raja Balasaraswathi) demonstrated that the use of more advanced cutting techniques such as laser or ultrasonic cutting can reduce microfiber release by up to 15–20 times compared to traditional scissors, while choosing specific stitch patterns and stitch densities can further reduce fraying. The use of multiple needles increases the release of microfibers across different variations of the same stitch pattern. For example, a 45.27% increase in microfiber release was reported with the 4-thread (2-needle) overlock stitch compared to the 3-thread (1-needle) stitch.

Furthermore, studies conducted on actual laundry loads (Science of the Total Environment, 2023, R Rathinamoorthy, S Raja Balasaraswathi) indicate that parameters such as temperature and cycle length influence the amount of microfibers released, with shorter, colder cycles, full loads, and high-efficiency washing machines reducing release. These findings highlight how changes in garment design and household care practices can help reduce microplastic shedding, complementing efforts to develop more sustainable materials.

An illusory solution or an intermediate step?

The findings of the Changing Markets study do not imply that all recycled materials are useless or that recycling has no value. Rather, they highlight a critical point: reducing environmental impact cannot be solely achieved by transitioning to “recycled” materials if they continue to release significant microplastics.

In other words, if the goal is a truly sustainable textile system, it is necessary to consider:

• design strategies that minimize the release of microfibers (e.g., low-release yarns, more compact textile structures, and less degrading finishes);
• technologies for capturing microfibers in domestic and industrial washing processes;
• an overall reduction in reliance on synthetic fibers—recycled or otherwise—in favor of alternative materials with a lower microplastic impact.

What we can do, concretely

For brands
• design garments with low-linting yarns and more compact structures;
• improve industrial processes, especially dyeing and finishing;
• adopt less fraying cutting and sewing techniques;
• communicate clearly and verifiably;
• invest in microfiber-capturing technologies in industrial laundries and supply chains.

For fashion buyers and consumers
• wash at low temperatures and shorter cycles;
• prefer full loads;
• use more efficient washing machines when possible;
• consider using certified filters or microfiber-capturing devices;
• above all: reduce dependence on fast fashion and synthetics, even recycled ones.
It’s not “buying nothing anymore.”
It’s buying better, less, more consciously.

Toward a broader vision of sustainability

This research is part of a broader debate on sustainability strategies in the fashion industry, which requires integrated and transparent approaches. It’s not just about replacing raw material A with B, but about rethinking production, consumption, and end-of-life models of garments with a truly circular perspective.
For consumers and industry professionals, the study is an invitation to look beyond “recycled” labels and evaluate concrete, independent data to make choices that truly make a difference.