An OEKO-TEX Standard 100 badge on a silk pillowcase means every thread, button and accessory in it was tested for harmful substances. That is a real test with real limit values behind it, and far narrower than the badge gets read as being.
Shoppers read four reassurances into that logo: this is genuine silk, it will last, it was made decently, it is free of anything harsh against the skin. Only the last one was tested.
Which of the four you actually care about decides whether the badge is worth paying extra for. The certificate behind it has a number, an expiry date and a list of the products it covers.
OEKO-TEX Standard 100 tests every component of a certified product against limit values drawn from a list of over 1,000 harmful substances. Every laboratory value has to fall below its limit before the certificate is granted.
The criteria are pinned to global regulation: the REACH annexes, the US Consumer Product Safety Improvement Act, and the ECHA candidate list.
The count is not fixed. The catalogue is republished each March, and “over 1,000 harmful substances” is the Edition 01.2026 wording. A count quoted with no edition attached is not wrong, it is simply ageing.
“Component” is close to literal. All individual components have to be tested, not just the face fabric:
One exception exists: where a component weighs under 1% of the finished product and too little exists to test, the OEKO-TEX institute may drop that test. Its decision is not contestable.
Fibres, yarns and fabrics are certified at their own stage too, which is how a finished pillowcase rests on components certified upstream.
A product class is an intended-use category that fixes which limit values apply, not a quality ranking. Standard 100 has four of them, graded by how much skin the product touches, and silk bedding sits in class II.
| Class | What it covers |
|---|---|
| I | Babies and children up to 36 months |
| II | A large part of the surface against skin: shirts, underwear, mattresses |
| III | Only a little of the surface touching skin, such as stuffings |
| IV | Decoration material: curtains, furnishing fabrics, floor coverings |
Silk pillowcases, pyjamas and sheets all meet the class II wording, and a Standard 100 certificate for silk bedding comes back as class II.
Some brands present class I on adult bedding as a higher rating. Let’s cut through the marketing on that one. It means the goods cleared the stricter baby-article criteria, and says nothing about the silk being better silk.
A class is assigned per certificate, so only the certificate tells you which one an item carries.
A genuine badge comes with a certificate number, and OEKO-TEX runs a free public lookup called Label Check. Enter the number on the OEKO-TEX website; label numbers are case sensitive.
The result page states whether the certificate is valid. If nothing comes up, that is your answer.
A valid result shows three more things:
That last line matters most and gets read least. It tells you whether the item in your hand sits inside the certificate, or is something the brand once had tested. A scarf and a pillowcase cannot share one, because products with different uses are certified separately.
Certificates run for one year. When one expires or is withdrawn, the licence to display the mark ends immediately and without notice.
Ask any seller for the certificate number and check it yourself; a seller who holds one will show you the document. UR Silk publishes its own OEKO-TEX, Intertek and SGS certificates as scans, which is the form worth asking for.
The standard says of its own trademark that it “is not a quality label”. The mark “relates only to the as-produced state” of the textile and declares nothing about fitness for use, reaction to cleaning processes or textile labelling.
Translated, it was never a test of whether a pillowcase lasts three years, or of what happens the first time you wash it. The other gaps have somewhere else to go.
That as-produced wording is literal. A certified product loses the right to be called certified the moment it is professionally altered or treated, and the standard counts washing as treatment. The rule targets converters, not your laundry, but it shows how narrow the claim is.
Fibre content is the one boundary worth stating precisely. A certificate scope records the material composition of the products it covers, and the institute may cross-check that against the applicant’s declaration.
The mark declares nothing about textile labelling either. If your question is whether the fabric is silk at all, telling real silk from fake is a check you run yourself.
The number is the only part of an OEKO-TEX badge that proves anything. Before paying a premium for the logo, run it through Label Check and read the scope line to see whether the thing you are buying is on it.
Inside that scope the badge is a genuine signal, and a narrow one. It settles the chemistry, one of the four things a silk shopper worries about, and leaves the other three alone.
Which is why the logo turns up on every product page and the certificate number almost never does.