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How Sustainable Is Recycled Polyester? Here's the Truth

Many brands use recycled polyester as part of their 'sustainable' sourcing efforts. But how sustainable is it, really? We investigate.

Written by
Erika Schwerdfeger

The harmful environmental impacts of polyester, a synthetic polymer made from petroleum, have been increasingly well-documented. Because of that, many brands and retailers have advertised the use of recycled polyester as a greener alternative.

Retailers like American Eagle, Marine Layer, and Inditex (the parent company of Zara) cite the use of recycled polyester as part of their sustainable sourcing efforts. Gap Inc., which oversees Gap, Old Navy, Athleta, Intermix, and Banana Republic, has done the same. Even brands with clout in the sustainability sphere are no stranger to it, from Patagonia to Outdoor Voices

In the fashion industry, the material has become something of a symbol of “sustainable” corporate values. But just how eco-friendly is recycled polyester, really? 

First Thing's First: What Is Recycled Polyester?

The chemical name for the fiber is recycled polyethylene terephthalate, or rPET. While non-recycled PET is synthetic fiber derived from the chemical reaction of crude oil and other materials, rPET is the same man-made fiber—it just uses recycled instead of virgin material. This is made possible by the thermoplastic quality of PET: Polyester, a plastic polymer, can be melted down and refashioned into new forms over and over while maintaining its strength and durability. 

This thermoplasticity makes polyester an obvious candidate for recycling projects, and clearly brands have taken note. From Aerie to Zara, retailers have jumped into the fray to begin incorporating it into their collections. Some—like Inditex, Adidas, and Reebok—have even made promises to fully replace virgin polyester with rPET by a certain benchmark. (For Inditex and subsidiaries such as Zara, that time is 2025; for Adidas and Reebok, 2024.)  

Where Things Get Complicated

More than one complexity emerges when looking at the full life cycle of rPET-based clothing. Apparel made from rPET can either be made with PET from discarded textiles, or PET from other plastics, like plastic bottles. Marine Layer, American Eagle, Nike, and Asics are just a few brands that explicitly mention that their recycled poly comes from plastic or plastic bottle waste.

This is, of course, is commendable—diverting plastic waste from landfills and from Earth’s oceans is not exactly an egregious offense. This framing does, however, obscure a bigger picture—the fact that using plastic waste as the source for recycled polyester garments virtually eliminates chances that that product can be re-recycled much longer.

In essence, it removes them from the plastics-recycling loop and drops them into the nearly-nonexistent textile recycling loop—a process that's not nearly as robust or established. "The technology for textile-to-textile recycling is still in its infancy," reports The Guardian, and "only 1 percent of all clothing is recycled." This means that an rPET-based piece of clothing is suddenly a far less viable candidate for any future recyclings. 

Thus the issue does not have to do with the impacts of rPET being made, which is indisputably a more planet-friendly process than making virgin PET. It's with what happens when the next consumer once again discards it. “Today, mechanical recycling is mainly used to take plastic bottles and turn them into garments,” said Francois Souchet of the Ellen MacArthur Foundation. “As it is today, bottles that have been turned into garments are no longer recyclable.”

The fact that the limited textile-to-textile recycling capacity means we have narrow, or nonexistent, recourse to actually close the loop and recycle rPET apparel continuously means the positive impacts of rPET are more negligible than they're often made out to be. Especially by the corporations looking to profit from the eco-conscious consumer.

How Recycled Polyester Hurts the Planet

The reduction of plastic waste—especially that of which ends up in our oceans and waterways—is an excellent and worthy goal (necessary, in fact). But the mechanical recycling process that turns plastic bottles into rPET garments effectively negates the recycling goal and prevents it from being recycled in the same manner again.

Even though the manufacturing process uses less energy and has a lower carbon footprint than virgin PET, the end-of-life for rPET pretty closely matches that of any other non-recyclable you’d throw away. Aka sitting in a landfill, biodegrading at a staggeringly slow rate. 

Another angle to the pitfalls of rPET is a vice common to fabrics of all kinds: microfiber shedding. In the washing process, all textiles will shed micro materials. But the fibers that come from synthetic fabrics, like polyester, pose a greater risk than others. Circles in the scientific community call these synthetic debris “fibrous microplastics,” which sounds sinister even if you don’t know the harm that microplastics do to marine species and habitats.

These microfibers that slough off in the wash and enter oceans and other bodies of water can be easily mistaken by aquatic creatures for food—a risk well-documented by numerous studies on the amount of microplastics in fish and sea life. Besides that, there's also concern that chemicals used in the manufacture of plastics are now being introduced to marine ecosystems by the inundation of plastics into the environment—a problem that will persist whether the source synthetic fabric was recycled or not.

Should Companies Use Recycled Polyester?

None of this is to say that brands and companies should not be using rPET. As mentioned, the production of the recycled material is far better for the environment than its non-recycled counterpart derived from fossil fuel. What it does mean is that rPET is not, at least currently, a sustainable or sufficient end goal when it comes to transforming the fashion industry