Unfun fact: natural fabric isn't automatically low-tox. And a synthetic fabric isn't automatically full of chemicals. Confusing, we know! So let’s talk about it…
You've probably seen the phrase low-tox or non-tox floating around, in wellness circles, on brand websites, in your Instagram feed. But what does it actually mean when it comes to your activewear? And why does it matter?
The clothing you train in sits against your skin for hours at a time, often while you're sweating, with your pores open. What's in your clothes and what it might be doing to your body, is worth understanding. So let’s get into it…
What Is Low-Tox, Exactly?
Low-tox is shorthand for low-toxicity, activewear that's been made without (or tested to be free of) the harmful chemicals that turn up in a lot of conventional clothing.
The chemicals most worth knowing about are PFAS and BPA (read more on them in the ‘for the extra curious’ section below).
So How Do You Know If Your Activewear Has Them?
This is where it gets tricky and where it’s easy to be misled.
You can't always tell from the label alone. A natural fabric isn't automatically low-tox. And a synthetic fabric isn't automatically full of chemicals.
Take bamboo, it’s a natural fibre, fast-growing, low-pesticide, genuinely sustainable in the ground. But most bamboo fabric sold today is bamboo viscose or rayon, produced through a chemical-intensive process involving solvents like carbon disulfide and sodium hydroxide [8]. The finished fabric may be soft and breathable, but without independent certification, there's no guarantee it's free from processing residues.
Bamboo isn't alone in this. Conventional cotton, despite being a natural plant, is one of the most pesticide-heavy crops in the world and is routinely treated with chemical finishes for wrinkle resistance and softness after processing. Even wool is commonly treated with chlorine-based shrink-proofing agents. The word ‘natural’ on a label describes where a fibre started, not what happened to it on the way to becoming your leggings.
The real distinction isn't natural vs synthetic — it's certified vs uncertified. A recycled polyester that's been independently tested can be a cleaner choice than an uncertified bamboo or cotton fabric that's been through heavy chemical processing. What matters is whether someone with no stake in the sale has actually verified what's in it.
The easiest way to know is to look for third party certifications:
OEKO-TEX® Standard 100 is the one we use at Earthletica. It tests the entire garment — every fibre, dye, thread and trim — against more than 1,000 harmful substances. Our fabrics are certified at Product Class I, the strictest level available (it's the standard required for baby clothing). We don't add chemical treatments. What's on the label is what's in the fabric.
Bluesign® is another reputable certification to look for — it focuses on responsible chemical use throughout the manufacturing process, with particular attention to environmental and worker safety.
Both of these are independently verified. They're not marketing claims. That distinction matters in an industry where ‘clean’ and ‘mindfully made’ can mean almost anything.
Does Low-Tox Mean No Plastics?
This is where the conversation can get more muddled.
Chemicals and plastics are related issues, but they're not the exact same. You can have fabric that's been tested clean of harmful chemicals and still contains plastic fibres.
In activewear, plastic primarily comes from elastane - the stretch fibre blended into nylon and polyester to give fabric its compression and recovery. Removing forever chemicals from the manufacturing process doesn't remove the elastane. And elastane, for now, remains essential to performance.
At Earthletica, our activewear uses 75% recycled materials - post-consumer waste, recycled fabric scraps and reclaimed ocean plastics that would otherwise end up in landfill or the sea. That's genuinely better than using virgin synthetic fibres. But we're honest that recycled synthetics still contain plastic, and that elastane can still shed microplastics when washed, a separate and real environmental issue that we talk about openly.
What we can say is this; our fabrics are low-tox, made from recycled materials, and tested to prove it. That's meaningful progress, even if it isn't the whole answer.
Where We're Going Next
Elastane is the piece we're not done thinking about.
The good news is that plant-based alternatives are getting closer to being commercially viable. One of the most promising is a natural rubber filament harvested from rubber trees that mimics conventional elastane in stretch and recovery, without the plastic [6]. Other startups are exploring bio-based elastane from rice husks, spider silk proteins and lab-grown materials [7]. The innovation is real and it's moving fast.
We're watching all of it closely, and where the performance of a garment allows, we already move away from synthetic fibres entirely. Our outerwear uses OEKO-TEX® and GOTS certified organic cotton: plastic-free, naturally breathable, and free from the chemical treatments that follow so many natural fabrics through the supply chain.
More of that is the direction we're heading. We're not there across every product yet, supportive, fit to body pieces still require elastane. But we're not standing still either.
The Short Answer
Low-tox activewear means fabric that's been independently tested to be free of harmful chemicals. It means your body isn't being treated as an afterthought in the design process. And it means the brand making your gear is willing to be specific about what's in it and what isn't.
That's the standard we hold ourselves to. And it's the standard we think you deserve to ask for.
For the extra curious…
You might have heard PFAS and BPA, I thought it was worth explaining what they actually are and why it matters.
PFAS (per- and polyfluoroalkyl substances) are synthetic chemicals used in fabric to create water resistance, stain resistance and sweat-wicking properties. They're known as "forever chemicals" because they don't break down — in the environment or in your body. Research confirmed that most PFAS can be absorbed through human skin [1], and another study found that sweat dramatically increases how much your skin absorbs from fabric during exercise [2]. PFAS have been linked to hormone disruption, immune suppression, impaired liver function and, in the case of one specific compound (PFOA), the International Agency for Research on Cancer has classified it as carcinogenic to humans [3].
BPA (bisphenol A) is a chemical found in certain polyester-spandex blends. It's an endocrine disruptor, meaning it mimics oestrogen and can interfere with the body's hormonal function. The Center for Environmental Health tested popular activewear brands and found BPA at levels up to 40 times California's legal limit [4] [5]. Research shows BPA can be partially absorbed through the skin — and that heat, sweat and friction during exercise increase that absorption.
It's worth noting that the science on how much of these chemicals crosses from fabric into the body is still developing. The risks from ingestion (food and water) are better established than those from clothing specifically. But the evidence is clear that consistent exposure is something to consider.
References
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University of Birmingham — New study confirms forever chemicals are absorbed through human skin (2024): birmingham.ac.uk
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The Conversation — PFAS 'forever chemicals' can be absorbed through human skin (2026): theconversation.com
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The Conversation — A probe into 'forever chemicals' in activewear lays bare fashion's greenwashing problem (2026): theconversation.com
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Center for Environmental Health — New Testing Shows High Levels of BPA in Sports Bras and Athletic Shirts (2023): ceh.org
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Forbes — Worrisome BPA Levels Found In Sportswear By Nike, Adidas, Patagonia And More (2023): forbes.com
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The Interline — Introducing YULASTIC® — A new, natural, and sustainable alternative to elastane (2025): theinterline.com
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Materiom — Tackling microplastics: fashion brands explore bio-based alternatives to elastane (2025): materiom.org
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All Cotton and Linen — Is Bamboo Clothing Toxic? Top Myths vs. Facts (2026): allcottonandlinen.com
