What Is OEKO-TEX STANDARD 100 — and Why It Matters for Cashmere

If you have started reading labels, you have probably seen a small black-and-white tag with a certificate number on it and wondered whether it means anything.

It does — but it means something narrower than most people assume, and the gap between what it actually certifies and what shoppers think it certifies is worth closing.

Here is the plain version, with the limitations included.

What it is

OEKO-TEX STANDARD 100 is an independent testing and certification system for textiles, run through a network of accredited institutes. It tests finished textile products for harmful substances.

The important word is tests. This is output testing: a physical sample goes to a laboratory and is measured against defined limit values. It is not a questionnaire, a self-declaration or a membership badge. That distinction is what makes it worth something.

Certification covers every component of an article, not just the main fabric — the thread, the dye, the buttons, the labels, the trims. A sweater does not pass on the strength of its yarn alone.

What it tests for

The substance list is long. OEKO-TEX states the criteria catalogue covers more than a thousand substances, spanning those that are legally regulated, those known to be harmful but not yet regulated, and parameters relating to general skin health.

The categories that matter most in knitwear:

• Azo dyes that can release aromatic amines classified as carcinogenic
• Formaldehyde, used in wrinkle-resist and some finishing resins
• Extractable heavy metals — lead, cadmium, nickel, chromium and others
• Pesticide residues, relevant to natural fibres
• Chlorinated phenols including pentachlorophenol, used as preservatives
• Phthalates, particularly in prints and coatings
• pH value, which must sit in a skin-compatible range
• Colourfastness to perspiration, saliva and rubbing

Limits get stricter the more skin contact a product has — which brings us to the product classes.

The four product classes

This is the part most shoppers miss, and it changes what a certificate means.

Product Class I — Babies and toddlers. The strictest limits in the system, covering articles for children up to three years old.

Product Class II — Direct skin contact. Articles worn against the skin over a large surface area or for prolonged periods: shirts, underwear, bedlinen, and knitwear worn next to skin. Formaldehyde is capped at 75 mg/kg for this class, and pH must fall between 4.0 and 7.5.

Product Class III — Without direct skin contact. Outer layers such as jackets and linings.

Product Class IV — Furnishing materials. Upholstery, curtains, floor coverings.

A sweater or shawl worn against the skin should be certified to Class II. A certificate for a lower class covers a lower bar. If a brand advertises OEKO-TEX certification without naming the class, that is worth asking about.

What it does not cover

This is where the honest reading matters, because a lot of brands let shoppers over-infer.

OEKO-TEX STANDARD 100 says nothing about:

• Where the fibre came from or how it was farmed
• Animal welfare — no herd, combing or shearing standards
• Labour conditions or worker safety in production
• Carbon footprint, water use or emissions
• Organic or recycled content
• Biodegradability

It is a chemical safety standard. That is all it is, and it is genuinely good at that one thing. A brand presenting it as a general sustainability credential is stretching it — those are different standards entirely.

Why it matters specifically for cashmere

There is a common assumption that natural fibres don't need chemical testing. The reasoning goes: it came off a goat, so what's to test?

The answer is everything that happened afterwards. Cashmere is scoured, dehaired, spun, dyed and finished. Dyeing is the largest chemical input in most knitwear. Machine-washable animal-fibre garments have usually been through an anti-felting treatment. Moth-proofing exists.

The fibre being natural tells you about the raw material. Chemical testing tells you about the thing you actually put on your body. Those are different questions, and only one of them is answered by the composition label.

There is a second reason it matters more for knitwear than for most categories: contact conditions. A sweater or shawl sits against skin, over a large area, for hours at a time. That is precisely the exposure profile Product Class II exists to address.

How to verify a brand's certificate yourself

This is the best thing about the standard, and almost nobody uses it.

Every valid certificate has a unique ID. OEKO-TEX runs a free public tool — Label Check — where you enter that number and see whether the certificate is real, current, and what it covers.

Three things to check:

1. Does the number resolve? If a brand won't give you one, there isn't one.
2. Is it still valid? Certificates run for twelve months and must be renewed annually. An expired certificate is not a current claim.
3. Does it cover the right article and product class? A certificate held on one yarn is not a certificate on every product in a range.

That last point is where the most misdirection happens. "We use OEKO-TEX certified yarn" and "our garments are OEKO-TEX certified" are different statements. The first is still meaningful — under the modular system, certified components carry forward and reduce the testing burden on the finished article — but it is not the same claim, and brands blur the two constantly.

Is OEKO-TEX legitimate?

Broadly, yes, with two fair caveats.

In its favour: it is genuine third-party laboratory testing against published limit values, with annual renewal, public verification, and a global network of accredited institutes. It is not self-certification, and it is not a logo a brand can simply decide to use.

The caveats: it is paid for by the company seeking certification, which is true of essentially all industry certification and is a structural feature rather than a scandal. And its scope is narrow — it is a chemical safety standard being widely read by consumers as an all-purpose sustainability endorsement, which is a misreading brands rarely rush to correct.

Judged as what it is, it holds up well. Judged as what it is often implied to be, it falls short — because almost nothing covers all of that at once.

Common questions

What does OEKO-TEX certified mean?
It means the specific article has been laboratory-tested against defined limits for harmful substances — including all its components — and the certificate is valid for twelve months from issue.

Is OEKO-TEX the same as organic?
No, and this is the most common confusion. OEKO-TEX STANDARD 100 tests the finished product for harmful substances regardless of how the fibre was farmed. Organic certification such as GOTS addresses fibre cultivation and origin. A product can hold one, both, or neither.

How long is an OEKO-TEX certificate valid?
Twelve months. Renewal requires re-testing. A certificate number that no longer resolves as valid on Label Check is not a current claim.

Does OEKO-TEX test every single garment?
No. It certifies articles based on tested representative samples, with the certificate covering the specified articles for its validity period, supported by audit. It is not per-unit testing — no consumer textile certification is.

Is OEKO-TEX worth it for a natural fibre like cashmere?
Arguably it matters more, not less — because natural fibres carry an assumption of safety that the processing stages don't automatically justify. Dyeing and finishing are where the chemistry sits, and those apply to cashmere exactly as they apply to anything else.

Keep exploring

If you would rather judge a fibre by what was left out of it, our undyed cashmere for women and undyed cashmere for men skip the dye and bleach stages entirely, and every piece is verifiably Himalayan cashmere.