Sustainable clothing carries a lot of labels. Most of them are marketing terms with no definition behind them — "eco-friendly", "natural", "chemical free". A few are real certifications with a testing body, a standard, and a certificate number you can check.
OEKO-TEX Standard 100 is one of the real ones. It is also widely misunderstood, including by brands that hold it.
What it actually tests
OEKO-TEX Standard 100 is a certification for harmful substances in textiles. An independent laboratory tests the material against a list of regulated and unregulated chemicals — azo dyes that release carcinogenic amines, formaldehyde, heavy metals like lead and cadmium, chlorinated phenols, phthalates, pesticide residues, and more.
Two things make it stricter than it first sounds:
Every component is tested. Not just the fabric — thread, buttons, zips, prints, labels. A garment cannot be certified with an uncertified zip.
Limits scale with skin contact. Products are grouped into four classes. Class I, for items intended for babies and toddlers, carries the tightest limits of the four. Something certified for infant use has cleared a higher bar than an outer jacket.
Certificates are valid for a year and must be renewed, with testing repeated. It is not a one-time badge.
What it does not cover
This is where it gets misread. OEKO-TEX Standard 100 is a substance safety certification. It does not certify:
- Antibacterial or antimicrobial performance. Different property, different test entirely — AATCC 100 or ISO 20743.
- Organic status. That is GOTS or a similar organic standard.
- Environmental impact of production. Water use, emissions and effluent treatment are covered by other OEKO-TEX schemes, not Standard 100.
- Labour conditions. Separate certifications again.
- Durability or quality. A fabric can be certified safe and still wear out quickly.
So when a brand cites OEKO-TEX as proof that its fabric is antibacterial, the certificate does not support that claim. It supports a different, still valuable claim: the fabric has been independently tested and is free from harmful substances.
The bamboo fabric question
Bamboo clothing is worth understanding properly, because the marketing around it is unusually loose.
Most bamboo clothing is viscose made from bamboo. Bamboo pulp is dissolved using chemical solvents and regenerated into fibre. The result is soft, breathable, moisture-wicking and genuinely pleasant to wear — those properties are real and are why people like it.
What does not survive that process is the raw plant's antimicrobial compound, sometimes called bamboo kun. The chemical steps involved break down the original plant compounds. This is why the US Federal Trade Commission treats "naturally antibacterial" claims on bamboo viscose as deceptive, and has issued warning letters to dozens of retailers over bamboo labelling and benefit claims.
There is a labelling dimension too: in the US, fabric produced this way must be described as "viscose from bamboo" or "rayon made from bamboo" rather than simply "bamboo".
None of this makes bamboo fabric a bad choice. Softness, breathability, moisture handling and a fast-renewing raw material are all real advantages. It just means the antibacterial claim needs a test report behind it, not an assumption about the plant.
How to read textile claims
A rough hierarchy, strongest to weakest:
- Named certification with a body and standard — "OEKO-TEX Standard 100, certified by the OEKO-TEX Association". Checkable.
- Named test method with a result — "tested to ISO 20743, 99% reduction". Checkable if they will share the report.
- Specific factual claims — fibre composition, GSM, origin. Verifiable in the product.
- Undefined marketing terms — "chemical free", "non-toxic", "100% natural". These have no agreed definition. "Chemical free" is not achievable in any material sense; water is a chemical.
When a brand moves from tier four to tier one, that is a good sign. It means they have something specific to point at.
Where we stand
We list the certifications our vendors hold, name the certifying body, and say what each one covers — on our vendor certifications page. Where a claim is not backed by a certificate or test report, we would rather leave it off the page than have you take it on trust.
The bamboo fabric in our bamboo clothing range is OEKO-TEX Standard 100 certified, covering the full range of bamboo fabric products — which means independently tested and free from harmful substances, including for products intended for infants.