Responsible Fashion Lab

Activewear is one of the most intimate clothing categories we own. Leggings, sports bras, base layers and gym sets are worn close to the body, often with sweat, heat and friction — and many people now wear them far beyond the workout.
But activewear is also one of the most synthetic categories in fashion.
In this solo episode of Responsible Fashion Lab, Maria continues the conversation from last week’s episode with Dr Leonardo Trasande on microplastics, plastic-related chemicals and health exposure. This time, the focus is activewear: why performance clothing became so dependent on polyester, nylon and elastane, what those fibres do well, and where the health and environmental concerns begin.
The episode looks at why synthetics dominate performance clothing, why stretch is especially hard to replace, and why sweat-wicking is not the same as breathability. It also explores natural and lower-synthetic alternatives including merino wool, organic cotton, hemp, alpaca and TENCEL™ Lyocell — and where these materials can realistically work.
Maria also looks at blends as the practical middle ground, from merino with nylon for durability to cotton or lyocell with elastane for movement. The episode also explains newer claims such as bio-based elastane, degradable stretch fibres and plant-based nylon — and why “bio-based” does not automatically mean plastic-free, biodegradable or circular.
A practical episode for anyone who wants to understand activewear more clearly: what to wear for different types of movement, what to check on the label, which claims need more detail, and how to buy better without falling for greenwashing.
In this episode:
Why activewear became so synthetic
What polyester, nylon and elastane actually do
Why sweat, heat and friction matter for close-contact clothing
Why sweat-wicking is not the same as breathability
Why stretch is the hardest part to replace
Where merino, cotton, hemp, alpaca and TENCEL™ Lyocell can work
Why blends can be a practical middle ground
What bio-based elastane, degradable stretch and plant-based nylon really mean
How to read activewear claims more carefully
What to check before buying leggings, sports bras, base layers or gym sets
The future of activewear is probably not one perfect fibre. It is better matching: the right material, for the right activity, with fewer unnecessary synthetics and more honest claims.

Microplastics are now part of the public conversation. We hear about them in water, food, air, soil and increasingly in the human body. But the word “microplastics” can make the issue sound simpler than it is.
Plastic exposure is not only about tiny plastic particles. It can also involve the chemicals added to plastics, the substances used to make materials flexible, durable, colourful, water-resistant or flame-resistant, and the way plastic breaks down over time.
In this episode of Responsible Fashion Lab, Maria speaks with Dr. Leonardo Trasande, paediatrician, professor and leading researcher in children’s environmental health, about plastics, plastic-related chemicals and human health.
The episode looks at what endocrine-disrupting chemicals are, why hormones are so important to development and long-term health, and how exposure can happen through food, air, dust and skin contact. It also looks at why pregnancy and childhood are especially sensitive windows, and why prevention matters.
Maria and Dr. Trasande also bring the conversation back to clothing. How should we think about synthetic textiles, activewear, sweat, heat and skin contact? Can chemicals used in plastic products also be relevant to fashion? And why is clothing part of the wider conversation about the materials we live with every day?
A practical episode for anyone who wants to understand microplastics and plastic-related chemicals more clearly: what the issue really includes, how exposure can happen, which questions matter for clothing, and what simple steps can help reduce exposure.
In this episode:
Why “microplastics” is only part of the plastics and health conversationWhat plastic-related chemicals areWhat endocrine-disrupting chemicals meanWhy phthalates, bisphenols, PFAS and flame retardants matterHow plastic exposure can happen through food, air, dust and skin contactWhy low-level exposure can still matterWhy pregnancy and childhood are especially sensitive windowsHow synthetic textiles and activewear fit into the conversationWhy sweat, heat and close skin contact can affect exposureWhy detox claims around microplastics need cautionWhat practical steps can reduce exposure in everyday life
Plastic is not just a waste problem. It is also a materials, chemicals and human health question.
To learn more about Dr. Leonardo Trasande’s work, visit LeoTrasande.com, follow him on social media under Leo Trasande, or find his research through NYU Langone’s Center for the Investigation of Environmental Hazards.

Wool is one of the most useful fibres in fashion. It can be warm, breathable, moisture-managing, odour-resistant and long-lasting. It can work in winter knitwear, base layers, coats, tailoring and even lightweight dresses.
But not all wool is created equal.
In this solo episode of Responsible Fashion Lab, Maria looks at wool beyond the word on the label. What makes some wool soft and some wool itchy? What is the difference between coarse wool, fine wool, merino, lambswool, virgin wool, cashmere and alpaca? Why is merino used in performance clothing? And when does a “wool blend” stop being mainly about wool?
The episode also looks at the harder questions: animal welfare, mulesing, shearing, land management, overgrazing, cashmere and desertification risk, wool processing, superwash treatments, mothproofing, dyeing, blends and traceability.
Maria also explains what certifications such as RWS, ZQ, NATIVA, Responsible Alpaca Standard and OEKO-TEX can — and cannot — tell us.
A practical episode for anyone who wants to understand wool more clearly: how to read the label, what to check before buying, which claims need more detail, and why “natural” does not automatically mean responsible.
In this episode:
Why wool behaves differently from cotton, linen and synthetics
Why some wool feels soft and some feels itchy
What fibre fineness, staple length and garment construction mean
The difference between merino, lambswool, virgin wool, cashmere and alpaca
Why lightweight wool is not only for winter
Why merino is used in base layers and performance clothing
The animal welfare issues behind conventional wool
What overgrazing means and why cashmere raises land-management questions
What superwash, mothproofing and other wool finishes can mean
Why wool blends need careful reading
What RWS, ZQ, NATIVA, RAS and OEKO-TEX actually tell us
Wool can be natural, breathable, long-lasting and high-performing. But the label needs more than one word.

Cotton is one of the most familiar fabrics in our wardrobes. It is natural, breathable and widely trusted — but cotton is not one simple category.
In this solo episode of Responsible Fashion Lab, Maria looks at what sits behind cotton: conventional cotton farming, pesticides, fertilisers, GMO cotton, water use, organic cotton, Better Cotton, regenerative cotton, recycled cotton, Fairtrade cotton and Cotton made in Africa.
The episode asks a practical question: when a label says “cotton”, what does that actually tell us — and what does it leave out?
We cover:
• why cotton is so widely used• why “natural” does not automatically mean low-impact or safe• pesticides, fertilisers and cotton farming• how GMO cotton changed pest-control systems in India, China and Burkina Faso• why cotton’s water impact depends on geography, irrigation and local water stress• what organic cotton changes — and what it does not• the difference between organic, in-conversion, Better Cotton, regenerative, recycled, Fairtrade and Cotton made in Africa• why cotton can still be dyed, bleached, finished and blended• what certifications such as GOTS, OCS, OEKO-TEX STANDARD 100 and Better Cotton actually mean• how to read a cotton label more carefully
The aim is not to make cotton sound good or bad. It is to understand that cotton’s impact depends on how it is grown, processed, certified and blended.
Because the word “cotton” is only the beginning of the story.

Viscose is one of the most common fibres in fashion — and one of the most misunderstood.
You may see it on labels as viscose, rayon, modal, lyocell, bamboo viscose, TENCEL™ Lyocell or LENZING™ ECOVERO™. 
It can be soft, fluid, breathable and a better alternative to polyester in many garments. But viscose is not as simple as the words “plant-based”, “wood-based” or “bamboo” can make it sound.
In this solo episode of Responsible Fashion Lab, Maria explains what viscose actually is: a regenerated cellulose fibre that usually starts with wood, bamboo or another plant source, but becomes fabric through chemical processing.
The episode looks at the two big concerns with conventional viscose — forest sourcing and chemical processing — and explains how modal and lyocell differ from standard viscose. It also unpacks why “bamboo fabric” is often bamboo viscose or bamboo rayon, rather than a simple natural bamboo fibre.
Maria also explains what shoppers should look for on a label or product page, including LENZING™ ECOVERO™, TENCEL™ Lyocell, FSC, PEFC, CanopyStyle, clear fibre percentages and brand disclosure.
A practical episode for anyone who wants to understand viscose more clearly — not to dismiss it, but to know when it is a better option, when it needs more questions, and how to avoid vague material claims.
In this episode:
What viscose is and why it is called a regenerated cellulose fibre
Why viscose is plant-based in origin but man-made in production
The key concerns with conventional viscose
The difference between viscose, rayon, modal and lyocell
Why “bamboo fabric” is often not what it sounds like
Why forest sourcing matters
What LENZING™ ECOVERO™ and TENCEL™ Lyocell tell us
How FSC, PEFC and CanopyStyle fit into the picture
What to check before buying viscose, modal or lyocell garments

What should we think about when clothing sits directly on our skin for hours?
In this solo episode of Responsible Fashion Lab, Maria looks at the connection between fashion, skin and the body — and why the garments closest to us deserve more attention.
The episode focuses on the “first layer”: underwear, bras, leggings, tights, sleepwear, base layers, activewear and children’s clothing. These are the pieces worn closest to the body, often with heat, sweat and friction, which means fabric choice, dyes, finishes and certifications matter more.
Maria explains why the fibre label is only part of the story, and why terms such as wrinkle-free, stain-resistant, water-repellent, anti-odour, antibacterial, easy-care, coated, bonded and super-stretch can be clues that additional processing or chemical finishes may be involved.
The episode also looks at textile contact dermatitis, disperse dyes, formaldehyde-based wrinkle-resistant finishes, PFAS in water-repellent and stain-resistant products, and what certifications such as OEKO-TEX Standard 100, GOTS, bluesign and ZDHC can — and cannot — tell us.
A practical episode for anyone who wants to understand what sits closest to the skin, how to read clothing claims more carefully, and where to be more selective without overthinking every purchase.
In this episode:
Why the first layer matters most
How dyes, finishes and coatings can affect clothing
Why “easy-care” and “performance” often mean more processing
What PFAS are and why they matter in textiles
Why activewear deserves extra attention
How to approach underwear, sleepwear and children’s clothing
What OEKO-TEX, GOTS, bluesign and ZDHC actually tell us
Simple steps for shopping more carefully
 

In this episode of Responsible Fashion Lab, I’m speaking with Professor Natascha Radclyffe-Thomas about what sustainability in fashion really means, and how we can begin to understand it more clearly.
We look at the key pillars of responsible fashion: materials, people, production, business models, education, regulation, and the role of shoppers.
What does it mean for a garment to be “sustainable”?How should we think about natural fibres, synthetic materials, overproduction, labour, circularity and care?And what questions can we ask before we buy?
This is a thoughtful and practical conversation about fashion as a system — and how greater awareness can help us make more informed choices.
 
You can find Natascha here:
X / Twitter: @fashionnataschaLinkedIn: Natascha Radclyffe-Thomas

What is your clothing really made of?
In this solo episode of Responsible Fashion Lab, Maria looks at one of the simplest but most revealing places to start: the fabric label.
Before we ask whether a garment is sustainable, responsible, natural, recycled or premium, we first need to understand its material composition. Is it made from natural fibres, synthetic fibres, semi-synthetic fibres — or a blend of several materials?
This episode is a practical guide to reading clothing labels more critically. Maria explains why fabric composition matters, why polyester is still plastic even when it feels soft, why recycled polyester is not a perfect solution, and why blends can make garments harder to understand, harder to recycle, and easier to market in misleading ways.
The episode also looks at how brands use language such as “wool blend”, “silk touch”, “linen feel”, “eco fabric” or “recycled materials” — and why the actual percentages on the label often tell a more honest story than the product title.
A short, practical episode for anyone who wants to make more informed clothing choices without perfectionism or panic — just with more awareness.
In this episode:
Why the fabric label is the first clue
The difference between natural, synthetic and semi-synthetic fibres
Why polyester is a plastic-based textile
Why recycled polyester is still polyester
Why blends can be a red flag
How product language can shape what we assume
Five simple questions to ask before buying clothes
Responsible fashion is not only an environmental conversation. It is also about our bodies, our skin, our homes, and the everyday environments we live in.

Jo Ward and Jo Inham, founders of Our Fashion Fix and former retail insiders, explain how fashion decisions are made long before shoppers see a garment. They cover supply-chain realities, materials, carbon impacts, the Digital Product Passport, and why transparency and practical tools matter.
The episode mixes industry experience with actionable advice—carbon literacy training, repairing, resale and smarter buying—to help brands and consumers make more informed, sustainable choices.
You can find our guests following the links:
Our Fashion Fix | Discover Sustainable Solutions
Instagram
 
 
 

I didn’t know what my clothes were made of — and that’s where this podcast begins. In this first episode of Responsible Fashion Lab, I break down what’s really behind everyday fabrics, and why so much of it has gone unquestioned — setting the foundation for a series focused on moving from confusion to clarity through conversations with scientists, industry experts, and researchers, so we can make more informed choices about what we wear.