OEKO-TEX Standard 100 is the certificate most often requested and least often read. Buyers ask for "the OEKO-TEX certificate" at the sampling stage, receive a PDF, file it, and never check whether the certificate covers the article they are buying, the product class their garment falls into, or the delivery date. The certificate then fails at the point where it matters, which is when a customer or a customs auditor asks what exactly was certified.

This article explains what the standard actually certifies, how the four product classes work, what a zipper certificate should contain, and how to check a certificate in a few minutes rather than trusting the logo on a sales presentation.

1. Scope: what is certified and what is not

Standard 100 is a voluntary testing and certification scheme for textile articles, textile components and accessories at all stages of processing, from yarn to finished product. Certification is issued to a specific article by an approved institute, is time-limited, and is renewed after re-testing. It is not a factory audit and it is not a management system certificate; those belong to other schemes in the same family.

A zipper can be certified in two ways. It can be certified as an article in its own right, with the certificate describing the zipper and its components, or the tape and other textile parts can be certified as components and referenced by the garment certificate. Both are legitimate, but they give the buyer different levels of assurance.

  • An article certificate for the zipper covers the tape, the dyeing, and the components listed on the certificate. This is the strongest evidence for a zipper buyer.
  • A component certificate for the tape covers the textile part only and says nothing about the slider, the coating or the assembly.
  • A garment certificate that lists "zipper" among trims may rely on the zipper supplier's own certificate, which the buyer should ask to see.

The certificate is issued against a defined article description. If the description does not match the purchase order, the certificate does not cover the purchase.

2. Key requirements: product classes and parameters

The scheme divides articles into product classes according to the intensity of skin contact and the vulnerability of the user. The classes run from products for babies and toddlers, through articles worn close to the skin, to articles used away from the skin, and finally to decoration and furnishing materials. Each class has its own limit values, and the limits become stricter as the class moves towards babies.

For a zipper, the class question is decided by the garment, not by the zipper. A zipper on a baby's sleepsuit must meet the strictest class. The same zipper on a coat lining may be acceptable at a lower class. The supplier cannot choose the class; the buyer must state it.

The parameters tested cover the chemistry that textile processing can introduce. In broad terms the scheme looks at:

  • pH value of the aqueous extract.
  • Formaldehyde, free and released.
  • Extractable heavy metals.
  • Azo dyes and the aromatic amines they can release.
  • Carcinogenic and allergy-inducing dyes.
  • Chlorinated phenols, benzenes and toluenes.
  • Phthalates, particularly in coatings and prints.
  • Organotin compounds.
  • Polycyclic aromatic hydrocarbons, relevant to rubberised and coated parts.
  • Pesticide residues and other plant-treatment chemicals in natural fibres.
  • Perfluorinated compounds used in water-repellent finishes.
  • Colourfastness, including fastness to saliva for the baby class.

The specific limit for each parameter and each class is set out in the appendix to the standard. It is revised periodically, and the certificate states the edition under which it was issued. Do not quote a limit from a previous version, and when a customer asks for a number, refer to the standard text and the certificate edition.

3. Test methods and the certification route

Testing is carried out by institutes approved under the scheme, using the methods named in the standard for each parameter. The supplier submits samples, the institute tests them against the limits for the declared product class, and if the result passes, a certificate is issued in the name of the certificate holder for the described article.

The certificate is valid for a defined period, typically one year from issue, and re-testing is required for renewal. That validity period is the single most important field on the document and the one most often ignored.

A complete certificate package for a zipper should let the buyer answer five questions:

  1. Who is the certificate holder, and is it the same legal entity that is invoicing the goods?
  2. What article is described, and does the description match the chain size, tape composition and finish on the purchase order?
  3. Which product class is certified, and does it match the garment's class?
  4. What is the certificate number and the validity date?
  5. Which production site is covered, if the certificate names one?

4. Common non-conformities

Most problems with Standard 100 certificates are documentary rather than chemical.

  • An expired certificate presented as current, because nobody checked the date.
  • A certificate covering the greige tape while the delivered zipper is dyed and coated by a different supplier.
  • A class mismatch: a class II certificate offered for a baby garment that requires the strictest class.
  • Another company's certificate number used in a sales presentation, with no commercial relationship to the actual supplier.
  • A certificate that lists a tape description but not the slider, so the metal component has no coverage at all.
  • Logo use outside the rules of the scheme, or a claim that implies the whole factory is certified when only one article is.
  • A new colour, coating or finish introduced after certification without re-testing.

5. Practical sourcing advice

State the product class in the purchase order and in the technical specification. This single sentence prevents most class mismatches, because it removes the supplier's incentive to offer the cheapest certificate that fits.

Request the certificate at quotation stage, not at shipment. Read the article description aloud and compare it with the specification. Then check the validity date against the planned delivery date, not against today's date, because a certificate that expires before the goods ship is no use to the garment factory.

Where the zipper is certified at component level, ask for the underlying test report for the tape and confirm which dyehouse and which coating line were covered. If the coating is applied by a third party, the certificate should either include that site or the buyer should accept the risk knowingly.

Keep a copy of each certificate with the shipment documents, so that the garment factory can pass it up the chain without a delay. And when a certificate is unclear, ask the institute rather than the sales agent: the certificate number can be verified, and the answer is definitive.