Why the Oeko-Tex® 100 Label Is the Most Important Thing to Look for When Shopping Your Kids (and for you!)
Young people are especially vulnerable to the chemicals found in plastics used in clothing. The Minderoo Foundation’s Plastic Health Report (2023) highlights that children are disproportionately affected by chemical exposure because their skin barrier is thinner and more permeable, and because their bodies are still developing. When plastics in clothing shed microfibres or when toxic dyes leach from fabrics, these chemicals can be absorbed more easily through a child’s skin.
This is why safe fabrics and certifications matter so much more for kids than for adults. The fabric your child wears every day sits directly against their skin, absorbs sweat, and can impact their comfort, health, and even the environment.
(Although the endocrine disrupting chemicals in plastics can have big negative affects on adult fertility - more on that in another post).
At Billie Green, we’ve done the deep dive so you don’t have to. Here’s what every parent should know when choosing clothing for their child.
Look for the Oeko-Tex® Standard 100 Label First
The Oeko-Tex® Standard 100 is the gold standard for fabric safety. It tests finished fabrics for more than 100 harmful substances—including pesticides, heavy metals, formaldehyde, and toxic dyes. This certification is vital because even natural fibres like cotton can be treated with harmful chemicals during dyeing or finishing.
The German research institute Hohenstein (a founding member of Oeko-Tex®) confirms that Oeko-Tex® 100 ensures “the fabric is harmless to human health in every respect of production, right down to dyes and prints.”
So, if you take one thing away from this: always check for Oeko-Tex® Standard 100 certification on kids’ clothing.
The Problem With Conventional Cotton
Cotton sounds natural - but conventional cotton comes with major downsides:
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It uses 16% of the world’s insecticides and 6% of pesticides, despite covering only 2.5% of global farmland (Pesticide Action Network).
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It’s water-hungry: a single T-shirt can use up to 2,700 litres of water (WWF).
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When dyed with toxic chemicals, it can leach residues onto the skin.
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Cotton absorbs and holds moisture, which means when kids get sweaty, it stays damp, loses shape, and can irritate sensitive skin.
Why TENCEL™ Lyocell & Modal Fabrics Are Next-Gen
Enter TENCEL™ fabrics—a family of fibres made by Lenzing™ in Austria. These fabrics are setting new standards for sustainability and comfort.
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Sustainably sourced: Made from FSC-certified wood pulp (from responsibly managed forests).
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Closed-loop production: Uses just one non-toxic, biodegradable solvent (NMMO), which is recovered and reused at a rate of over 99% (European Commission BAT Reference Document).
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Breathable & moisture-wicking: Keeps you cool and dry, even in warm weather or during active play.
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Naturally stretchy & soft: Perfect for bras, underwear, and everyday wear where comfort matters most. The level of softness is unmatched.
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Naturally hypoallergenic: Ideal for kids with sensitive skin and eczema, even more so than cotton.
- Safe: Certified with Oeko-Tex® 100.
Compare this to bamboo viscose, which is often marketed as “eco,” but in reality, it’s processed with an enormous number of harsh chemicals like sodium hydroxide and carbon disulfide. These are toxic to workers and the environment and to the end user. The fibre quality is also quite low, particularly with bras and underwear. The only plus? Bamboo is breathable - but TENCEL™ gives you that and more.
Where Organic Cotton Fits In
Organic cotton is a step in the right direction:
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No synthetic pesticides or fertilisers.
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Better for soil health and biodiversity.
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Gentler on sensitive skin.
But here’s the catch: organic cotton still needs to be Oeko-Tex® 100 certified to account for toxic dyes or finishes that may be applied later. For bras and activewear, organic cotton also needs help with stretch. That’s why blends usually include 10–20% spandex (elastane) to provide proper support. Another downside? Organic Cotton, like regular cotton holds onto moisture, so it’s not ideal for sweaty, all-day wear. But overall, it is an excellent go-to.
Polyester & Nylon: Can sometimes be ‘Certified Safe’, But Still Problematic
You may see Oeko-Tex® certified polyester or nylon clothing on the market. It’s true: these fabrics CAN (sometimes) pass tests for hazardous chemicals. But here’s what certifications can’t solve:
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Microplastic shedding: Every wash releases tiny plastic fibres into waterways. Research shows microplastics are now found in human lungs, blood, and placentas (Minderoo Foundation, 2023).
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Non-biodegradable: Stays in landfill and soil for centuries.
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Poor comfort: Polyester and nylon are non-breathable. They dry fast so you may think they are keeping you ‘dry’ but trap heat, leading you to sweat more. They also hold onto odours and can irritate sensitive skin.
Our advice, if you’re going to wear synthetics, wear them to the gym or whilst you’re exercising and take them off as soon as you are done. But really, you don’t want your open pores absorbing that stuff anyway.
In short: while Oeko-Tex® polyester is chemically “safe,” it’s not safe for our planet—or for the next generation’s health.
The Billie Green Difference
At Billie Green, we combine the best of TENCEL™ Lyocell and Modal with carefully selected organic cotton blends to give teens and tweens underwear and bras that are:
🌿 Certified safe (Oeko-Tex® Standard 100)
🌿 Ultra-low spandex (between 5 - 9%)
🌿 Breathable, moisture-wicking, and naturally odour-resistant
🌿 Supportive and comfortable for growing bodies
Our mission is simple: to take the confusion out of labels and give families next-gen fabrics that are kind to skin, stylish, and truly sustainable.
✅ Key takeaway for parents: If there’s one label to check, make it Oeko-Tex® Standard 100. Then choose fabrics like TENCEL™ and organic cotton blends that combine comfort, performance, and sustainability.
Because our kids deserve better than clothes made from fossil fuels.
References
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Minderoo Foundation. (2023). Plastic Health Report 2023. Minderoo Plastic Health Hub
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Pesticide Action Network (PAN). (2019). Cotton and Pesticides. PAN UK
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World Wildlife Fund (WWF). (n.d.). The Impact of a Cotton T-Shirt. WWF Cotton
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Hohenstein Institute. (n.d.). Oeko-Tex® Standard 100 Explained. Oeko-Tex®
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European Commission. (2017). Best Available Techniques Reference Document (BREF) for the Textiles Industry. European IPPC Bureau
- Lenzing AG. (2024). TENCEL™ Sustainability and Production Process. TENCEL™ Official
