OEKO-TEX Standard 100

OEKO-TEX Standard 100 tests the finished textile itself — fabric, thread, buttons, zipper tape, anything that touches skin — against a list of restricted substances stricter than most countries' legal limits: azo dyes, formaldehyde, heavy metals, pesticide residue, phthalates, and dozens more. Products are sorted into four classes, with Class I, covering baby items up to age three, carrying the tightest limits, and Class IV, non-skin-contact decoration, the loosest.

For a buyer, this is the certification that matters most on infant onesies, toddler tees, and anything sold as skin-contact apparel — a Class I pass means the fabric has been lab-tested for substances a newborn's skin handles worse than an adult's. We won't quote an infant line without asking the blank supplier for their current Standard 100 certificate number first.

Verify the claim at oeko-tex.com rather than trusting a printed logo — certificates are product-specific and expire annually, so a supplier's fabric can lose certification between orders. Pair it with the class number, since a Class III or IV pass on adult outerwear tells a different story than a Class I pass on a onesie.

Buyers commonly assume OEKO-TEX means the cotton was grown organically or the factory treats workers fairly. It says neither: Standard 100 is exclusively a chemical-safety test on the finished product, and a shirt can be OEKO-TEX certified while grown conventionally and sewn in a facility with no labor audit at all.