OEKO-TEX and GRS: What Certificates to Request per Lot
Two certificates do most of the compliance work in activewear sourcing, and both are regularly misunderstood. OEKO-TEX STANDARD 100 says the article has been tested for harmful substances. The Global Recycled Standard says the recycled content claim is traceable. Neither says the fabric will perform, and neither is interchangeable with the other. Knowing exactly which document you need at which stage keeps the claim on the hangtag and the shipment moving.
OEKO-TEX: which certificate, and what it covers
STANDARD 100 is an article certificate issued for a defined product and product class, and it is the one you want for fabric, elastic, foam pads and hardware. Product class II covers articles with a large area of skin contact, which is the correct class for a sports bra. The limits behind it include formaldehyde at 75 ppm for class II measured to ISO 14184-1, pH between 4.0 and 7.5 measured to ISO 3071, extractable heavy metals, banned azo colorants tested to EN 14362-1, nickel release under EN 1811 for metal components, and perfluorinated compounds under the current annex. OEKO-TEX MADE IN GREEN adds traceability and social criteria and carries a product ID that can be verified. STeP and ECO PASSPORT are facility and chemical input programmes rather than article certificates, so do not accept them in place of one.
GRS: scope certificate and transaction certificate
The Global Recycled Standard works through two documents. The scope certificate proves a company is certified to carry out a defined process such as spinning, knitting or dyeing. The transaction certificate is issued per shipment and states the recycled input quantities and the certified content percentage for the goods you bought. Hangtag claims rest on the transaction certificate, not on the scope certificate. Ask for it inside the purchase order, require it before final payment, and check that the quantity matches your commercial invoice. Check the current Textile Exchange labelling rules before printing a logo, because the minimum percentage required for consumer-facing use of the mark is not the same as the minimum for certification.
What to request per lot, and when
At sampling: a valid OEKO-TEX STANDARD 100 certificate covering the proposed fabric at class II, and the mill's GRS scope certificate if a recycled claim is planned. At pre-production: lab reports for the performance tests in your spec, tied to a dye lot. At shipment: the transaction certificate for that lot, a lot-level restricted substance declaration, and a packing list carrying dye lot numbers. Keep the OEKO-TEX certificate in date, since it is issued for a limited period and an expired certificate is treated as no certificate at all.
The failure patterns to look for
Four things go wrong repeatedly. The certificate names a trading company rather than the mill that made the fabric. The product category is out of scope, for example a certificate covering woven fabric used to support a knit claim. The transaction certificate quantity is lower than the shipped quantity, which means part of the goods is uncertified. And the certificate expired between order and shipment. All four are visible in a five-minute check, and all four invalidate the claim.
Verification is free
Issuing bodies publish verification tools for certificate and label numbers. Use them. Record the certificate number, issue date, expiry date, certified entity and product scope in your own file alongside the dye lot, so that when a retailer asks a year later you can answer in an hour rather than a week.
OEKO-TEX answers the safety question, GRS answers the content question, and the transaction certificate answers both for your specific shipment. Ask for all three, in the right order, and verify every one.
