Knitwear Yarn Certifications: GRS, RWS, and OEKO-TEX Explained

Why Yarn Certifications Matter in Knitwear Sourcing

As fashion brands commit to sustainability, yarn certifications have become a critical part of the sourcing conversation. But with a alphabet soup of acronyms—GRS, RWS, OEKO-TEX, GOTS—it's easy to get lost. For buyers, understanding these certifications is essential to ensure that the claims you make to your customers are accurate and that your supply chain meets your sustainability goals. In this article, we decode the three most common certifications for knitwear yarns: GRS, RWS, and OEKO-TEX.

GRS (Global Recycled Standard)

The GRS is the leading certification for recycled materials. It verifies that a product contains a minimum of 20% recycled content (for the GRS logo, 50% is required). More importantly, it also covers environmental and social criteria across the entire supply chain, including traceability, chemical management, and worker welfare.

For knitwear, GRS is commonly applied to recycled polyester, recycled cotton, and recycled wool. If you are sourcing recycled cashmere or recycled wool sweaters, GRS certification ensures that the recycled content is verified and that the production process meets strict standards. At YL Knit, we offer GRS-certified recycled cashmere as part of our sustainable line.

What to check: Always request the GRS certificate and verify the scope (which products are covered) and the certification body. Also, ask for transaction certificates that link your specific order to the certified material.

RWS (Responsible Wool Standard)

The RWS is a voluntary standard that addresses the welfare of sheep and the land they graze on. It ensures that wool comes from farms with a progressive approach to managing their land and from sheep that have been treated responsibly. The standard also tracks the wool from farm to final product.

For buyers sourcing merino wool or other wool sweaters, RWS provides assurance that the wool is ethically produced. It is particularly relevant for brands that want to avoid mulesing and ensure sustainable land management. Note that RWS is not a certification of the finished product's quality; it focuses on the raw material and its chain of custody.

What to check: Confirm that the supplier holds a valid RWS certificate and that the wool content in your product is covered by the scope. As with GRS, transaction certificates are key to linking your order to certified wool.

OEKO-TEX Standard 100

OEKO-TEX Standard 100 is a certification for textiles that have been tested for harmful substances. It is not specifically about sustainability, but it is a crucial health and safety certification. The standard sets limit values for chemicals that are harmful to human health, including substances like formaldehyde, heavy metals, and azo dyes.

For knitwear, OEKO-TEX Standard 100 ensures that the yarn and finished garment are safe for the wearer, which is especially important for products marketed to children or sensitive skin. Many buyers require OEKO-TEX certification as a baseline for quality and safety. YL Knit's facilities are OEKO-TEX certified, and we can provide certification for the products we manufacture.

What to check: Look for the OEKO-TEX certificate number and verify that the product class (e.g., Class I for baby articles) matches your target market. Also, ensure that the certificate covers the specific yarn or garment, not just the factory.

How to Verify and Avoid Greenwashing

With the rise of greenwashing, it's vital to go beyond the logo on a hangtag. Here are practical steps for buyers:

• Request certificates and scope documents: Ask your supplier for the actual certificate and check the scope. Certificates have expiry dates and must be renewed annually.
• Use transaction certificates: For GRS and RWS, transaction certificates (TCs) are issued for each shipment, linking the certified material to your order. Verify that the TC matches your purchase order.
• Audit the supply chain: Certifications are only as good as the audits behind them. Ask about the certification body and whether the supplier has been audited recently.
• Check for clarity: If a supplier claims a product is "sustainable" without specifying the certification, ask for evidence. Legitimate certifications are transparent and verifiable.
• Stay updated: Standards evolve. As of 2026, GRS and RWS are undergoing revisions, so ensure you are aware of the latest versions.

YL Knit's Approach

At YL Knit, we hold OEKO-TEX and GRS certifications, and we are committed to transparency. Our team can provide the necessary documentation and guide you through the certification requirements for your market. Whether you need GRS-certified recycled cashmere or RWS-certified wool, we can help you source responsibly.

In conclusion, understanding yarn certifications is a vital part of sustainable knitwear sourcing. By knowing what each certification covers and how to verify it, you can make informed decisions and build trust with your customers. For more detailed guidance, refer to our article on sustainable knitwear certifications.