Sustainable Textile Certifications —
GRS, OEKO-TEX & Higg Index Explained
A brand asks for "GRS certified recycled yarn." Another wants "OEKO-TEX compliance." A third mentions "we track our Higg Index score." These certifications sound similar but measure completely different things — one verifies recycled content, another tests for harmful substances, and a third assesses environmental impact of the manufacturing process itself. Confusing them leads to sourcing the wrong yarn for the wrong claim. 🌱
This guide sorts the major sustainability certifications relevant to polyester and blended yarn into clear categories, explains what each one actually verifies, and helps you know which certification to ask for — or provide — for a given claim. ✅
🗂️ Three Categories of Certification
The biggest source of confusion is treating all "sustainability certifications" as one thing. They actually fall into three distinct categories, each answering a different question: 🔍
Material Content
"Is this yarn actually made from what it claims?" Verifies recycled or organic content through chain-of-custody tracking. E.g. GRS, RCS, GOTS.
Product Safety
"Is this yarn safe against harmful substances?" Tests the finished product for chemical residues, regardless of what it's made from. E.g. OEKO-TEX Standard 100.
Process / Impact Assessment
"How much environmental impact does making this product cause?" Measures and scores the manufacturing process itself. E.g. Higg Index (MSI/FEM).
A yarn can be GRS certified (proven recycled content) but that certification says nothing about whether it passed chemical safety testing — you'd still need OEKO-TEX for that claim. Equally, an OEKO-TEX certified yarn could be 100% virgin polyester — that certification says nothing about recycled content. Always match the certification to the specific claim you need to make.
♻️ GRS — Global Recycled Standard
🧪 OEKO-TEX Standard 100
📊 Higg Index (Higg MSI / Higg FEM)
📋 Other Certifications You Might Encounter
| Certification | Category | What It Covers |
|---|---|---|
| RCS (Recycled Claim Standard) | Material Content | Similar to GRS but without the social/environmental production criteria — just verifies recycled content chain-of-custody |
| GOTS (Global Organic Textile Standard) | Material Content | For organic natural fibres (cotton, wool) — not directly applicable to polyester, relevant for blends |
| bluesign® | Process / Impact | Assesses chemical inputs and resource use across the entire textile manufacturing chain |
| OEKO-TEX STeP | Process / Impact | Certifies sustainable production facilities (separate from Standard 100's product testing) |
| Global Recycled Standard (fibre-specific: rPET) | Material Content | Same GRS framework specifically applied to recycled PET flake/chip/fibre supply chains |
| ISO 14001 | Process / Impact | General environmental management system certification for a factory (not textile-specific) |
🎯 Which Certification Do You Actually Need?
🔗 The Chain-of-Custody Challenge
For material content certifications like GRS, the certification isn't a one-time factory audit — it's a chain-of-custody system that must hold at every single step: 📦
- ♻️ Recycler (turns bottles/waste into rPET chip) — must be GRS certified
- 🧵 Yarn spinner (turns chip into yarn) — must be GRS certified, and buy only from certified recyclers
- 🏭 Fabric mill (knits/weaves the yarn) — must be GRS certified, and buy only from certified spinners
- 👕 Garment maker (cuts and sews) — must be GRS certified to make the final claim on the garment label
If any single link in this chain isn't certified — even if every other step is — the final product cannot legally carry the GRS claim. This is why buyers should always request the current GRS Transaction Certificate (TC) from their immediate supplier, and ideally verify the supplier's own certification is current (certifications expire annually and must be renewed).
✅ How to Verify a Certification Is Genuine
- 📄 Request the actual certificate — not just a logo on a quotation. Certificates show a scope, certificate number, and validity dates
- 🔍 Check the issuing body's database — GRS certificates can be verified via Textile Exchange's certified entity database; OEKO-TEX certificates via the OEKO-TEX label check tool
- 📅 Check the validity dates — certifications expire (typically annually) and must be renewed; an expired certificate is not valid
- 🎯 Check the scope matches your product — a certificate may cover certain products/facilities but not others within the same company
- 📋 For GRS, request a Transaction Certificate (TC) — this is issued per shipment and is the actual proof for that specific order, not just the company-level scope certificate
Yaakan supplies GRS-certified recycled polyester yarn with full chain-of-custody documentation and Transaction Certificates per shipment, and can provide relevant OEKO-TEX-compliant product data for your certification needs. Ask us for current certificates specific to your order — we're happy to share documentation upfront so you can verify before committing.
📝 Summary
- 🗂️ Three categories: Material Content (GRS, RCS, GOTS), Product Safety (OEKO-TEX), Process/Impact (Higg Index, bluesign)
- ♻️ GRS — verifies recycled content via chain-of-custody; needed for "made from recycled" claims
- 🧪 OEKO-TEX Standard 100 — tests for harmful substances in the finished product; needed for safety claims, especially baby/skin-contact
- 📊 Higg Index — scores environmental impact of materials/facilities; used for retailer scorecards, not a pass/fail label
- 🎯 Match the certification to your specific claim — they measure different things and aren't interchangeable
- 🔗 Chain-of-custody certs (GRS) require every supply chain step to be certified — one gap breaks the claim
- ✅ Always verify certificates directly with the issuing body's database, and request shipment-specific Transaction Certificates for GRS
Need certified yarn with proper documentation? Contact Yaakan — GRS-certified recycled polyester and OEKO-TEX-compliant options available, with full documentation provided upfront. 👇
Source Certified Sustainable Yarn
GRS-certified recycled polyester with Transaction Certificates, plus OEKO-TEX-compliant options. Tell us your certification requirement; we'll send documentation and free samples.