We spent over 6 months sourcing the fabric we us in our Original Pocket Leggings. Every ratio of polyesters, nylons and lycras crossed my table, with wildly varying qualities. My background in fabric helped me massively here, where we know other ‘new’ activewear companies lack experience heading for a shiny ‘lycra’ feel which most 90s kids cringe about. One thing I was actively engaged in doing was finding the best recycled fabric, that would come in line with our greener outlook whilst also being a market beating product. Except, what I researched and found out, as a single mind of a business, actually lead me away from that path. We’ve all seen it–on reusable shopping bags, t-shirts, leggings, or backpacks: “This product was made using recycled water bottles!” On other items, you’ll see this type of material called anything from rPET, rePET, to rePETE. No matter the name, this term describes material made using recycled PET plastic.

It sounds great, but what does it actually mean? How can water bottles be made into a fabric (that you’ll actually want to wear)? Is this process sustainable? What are the benefits of buying products made from rPET?

This trend was first pioneered by Patagonia in 1993 when they used recycled materials to make their infamous outdoor fleeces. Since then, we have witnessed a significant shift to sustainable fabrics. But are recycled fibres always better than their virgin counterparts? As shoppers, we must learn to look beyond the label and ask what is in our clothes as much as who has made them. Today, just about every apparel brand, from Sweaty Betty to Zara, brandishes the material as evidence it is “going green.” 

The appeal is clear: Recycled polyester, also known as recycled polyethylene terephthalate or rPET for short, has a smaller carbon footprint than its virgin counterpart. Reclaiming plastic waste also keeps it from becoming trash—or fodder for marine animals such as turtles and whales. 

Although companies frequently market shoes and clothing made with rPET as a guilt-free way to consume fashion, not everyone is convinced of its virtues.

Let’s start by learning what PET is. This is an abbreviation for the much longer (much less fun) term, polyethylene terephthalate; a polymer of ethylene glycol and terephthalic acid. Clearer terms? PET is the most common type of plastic resin. To create virgin PET, producers extract crude oil and natural gas from the Earth, then process and heat it to form a molten liquid. They spin this liquid into fibres to create polyester fabric, or they mold and solidify it into PET plastic containers.

As a fibre, polyester can be used to make anything from clothing and blankets to sleeping bags and carpeting. We usually call it polyester in this form, whereas in melded containers, PET is the more common name. In its plastic form, PET is used to hold anything from your favourite peanut butter or salad dressing to cleaning solution, mouthwash, and medication. Those disposable water bottles? PET. Chances are, most plastic containers in your house are made of this common plastic!

Manufacturers may not always be able to turn all salvaged plastic into new containers, but these other plastics may find a new calling as recycled polyester fabric, or rPET. This recycled polyester fabric can be used to make products including backpacks, leggings, t-shirts, and reusable grocery bags!

rPET is better for the planet (?!)

Polyester, which is typically derived from petroleum-based ingredients, accounts for more than 65% of the fibres used in the textile and apparel industry, which means that employing rPET as a direct replacement immediately takes a load off dwindling finite resources.

Creating rPET is less polluting, too. A 2017 life-cycle analysis found that manufacturing rPET generates 79% less carbon emissions than producing its virgin counterpart.

By turning unwanted bottles into fleece jackets or leggings reduces plastic waste, which is inundating waterways and clogging up landfills. To promote transparency, certain manufacturers, such as Repreve, can tag rPET across the value chain, from bottle collection to the delivery of the finished product.

Know that rPET has its limitations …

Plastics bottles tend to be mechanically rather than chemically recycled, which means they’re chopped up into flakes, melted down, and then extruded through spinnerets to create yarn for knitting or weaving into textiles.

The problem? rPET manufactured this way cannot be mechanically recycled a second time, let alone multiple times, without a steep decline in the quality of the fibres, which get progressively shorter and weaker.

While chemical recycling poses a solution, few scalable technologies can currently recycle old rPET garments into new rPET garments. The market share for chemically recycled polyester is still very low at the moment. The bottling industry’s plan to increase its use of recycled PET is something else brands should watch for, since it can impact their supply. (PepsiCo, for instance, wants to increase the recycled content of its beverage packaging to 25% by 2025, while Coca-Cola has pledged to make all its plastic bottles from 50% recycled plastics by 2030.)

Another risk with recycled polyester is that often PET water bottles contain chemicals that could be harmful for your skin. PET bottles can contain a leach ‘antimony’ which is a toxic substance that has been linked to cancer. koko+kind notes that whilst the concentration of antimony is rarely high enough in rPET clothes to affect us, finding substitutions to these chemicals will be important in the long run.

… and its critics

Maxine Bédat, founder of the New Standard Institute, a New York sustainable-fashion think tank, doesn’t see the point in taking away bottles from the bottling industry, not when it has already perfected bottle-to-bottle recycling. “If we take them away from bottling, we're taking away from a closed-loop system,” she says.

Because of this, Bédat says much of the marketing-speak around rPET—as a virtuous act that will fix everything wrong with fashion—is tantamount to greenwashing, particularly when textile suppliers such as Unifi, which owns Repreve, remains one of the world’s largest manufacturers of virgin polyester. (Recycled fibres currently make up 35% of Unifi’s business, according to Jay Hertwig, the company’s global brand sales and marketing manager, though he expects that number to hit 50% in a few years.)

But even rPET’s role in reducing the burden of ocean waste may be oversold, according to Adam Minter, a Bloomberg opinion columnist and author of Junkyard Planet: Travels in the Billion-Dollar Trash Trade. “Current volumes of extraction are astonishingly small compared to the overall volumes in the ocean,” he says. “And even if they could be scaled up to account for, say, 50% of all apparel-related polyester—and they can't be, not right now—it would still make no real difference to the problem.”

When it comes to recycled polyester or recycled fibres in general, here are some sustainable shopping tips to help you with your decision:

A brand using recycled materials is not automatically ‘circular’ as these fabrics can often not be recycled infinitely. Read our guide to circular fashion here.

Even if a brand is using recycled plastics in their collection, they cannot be called responsible if they do not pay their supply chain workers a fair living wage.

For the most environmentally conscious clothing choice, select natural fibres first such as hemp or consider fully circular alternatives.

Be sure to check for certifications on the garment, which work to guarantee specific social and environmental standards.

Verify the sustainability claims made by a brand about their clothing with a third party who evaluates their evidence so you can trust what they say.

The koko+kind takeaway:

Is Recycled Polyester Clothing Eco-Friendly?

Using recycled instead of virgin polyester reduces our dependency on fossil fuels, requires less energy, and produces fewer carbon emissions. By using plastic bottles, fishing nets, and textile waste to make RPET, waste is diverted from oceans and landfills.

However, while plastic can be recycled into RPET clothing – and even shoes, bags, and other accessories – once it becomes polyester it remains a finite product that can still end up in oceans or landfills because it’s not biodegradable. So if you buy clothing made from RPET, make the best use of it you can.

The use of RPET for clothing may also lead to a high use of dye to get consistent colors for a batch of clothes. This requires a high use of water, energy, and chemicals. Rather support brands making unique, small-batch items or ones that use natural dyes. But no matter what you wear, wash and look after your clothes with care. And speaking of laundry, there’s another inevitable problem that pops up when discussing polyester, whether virgin or recycled: microfibers.