Recycled polyester claims: RCS, GRS and the paper trail

Why can’t a laboratory test prove recycled content?

Because recycled and virgin PET are the same polymer. Fibre-composition tests, such as the ISO 1833 methods, report how much polyester and elastane a fabric contains; they are not designed to show where the polyester came from. Textile Exchange, which owns the Recycled Claim Standard (RCS) and the Global Recycled Standard (GRS), does not accept tracer technologies as an equivalent to chain-of-custody certification.

What counts as recycled is defined as well. RCS uses the ISO 14021 definitions: pre-consumer material diverted from the waste stream during manufacturing, excluding rework, regrind or scrap that the same process could reclaim, and post-consumer material that end users can no longer use for its intended purpose. The FTC’s Green Guides draw the same line and add that pre-consumer claims need evidence the material would otherwise have become waste.

Which certificate proves what?

A scope certificate is often presented as proof, but it is only the first document in the chain. Textile Exchange runs a public directory of certified companies built from scope-certificate data, and a tool for authenticating transaction certificates issued by active certification bodies since October 2022. Use both, and check that each transaction certificate’s product description, quantity and composition match what was actually delivered.

Who must be certified before a garment can carry an RCS or GRS claim?

For products sold to consumers, Textile Exchange’s Content Claim Standard and Standards Claims Policy require certification at every site that owns or physically handles the material, up to and including the brand, with narrow exceptions for some traders, distributors and retailers. Brand certification took effect on 1 April 2023, and private-label retailers count as brands. The garment maker needs its own scope certificate or must be listed as a subcontractor on a certified organisation’s scope. If any link is missing, the logo and the standard’s name are off the table.

The brand must also hold transaction certificates for everything it buys with a claim, check deliveries against them, and submit every hang tag, printed or sewn label and online claim to its certification body for approval. The approved wording states the percentage, the standard, the generic material name (recycled polyester, not a yarn trade name) and the certifier with its licence number or TE-ID. Minimum content depends on the label:

• RCS 100: 95–100% recycled content.
• RCS Blended: 5–95% recycled content.
• GRS: 50–100% for consumer-facing labels (from 20% for business-to-business use), plus social, environmental and chemical requirements at processing sites.

How is the recycled percentage calculated?

By weight of the whole finished product or of a clearly named component, never as a share of the polyester alone. The FTC’s Green Guides allow an unqualified recycled claim only when the entire product, apart from minor incidental parts, is recycled; anything less must be qualified by amount or percentage by weight. Textile Exchange’s policy likewise works by weight and lets non-certified trims, such as labels, be left out of the calculation.

In the hypothetical tee below, the body fabric could carry an 88% claim as a named component, or the garment an 83% claim, which Textile Exchange allows to be stated as a minimum, such as at least 80%. It falls in the RCS Blended band and could never be called 100% recycled, because the elastane alone rules that out.

What do US, EU and UK rules add?

Certification does not replace consumer law, and RCS itself advises sellers to check which recycled-content claims each country of sale allows. In practice, a plain statement of recycled content by weight is the safest format, provided you can prove it, while a brand’s own ‘recycled’ seal is now risky in the EU. The rules that matter most:

• United States: the Green Guides (16 CFR 260.13) limit recycled content to material recovered from the waste stream before or after consumer use, and require partial content to be qualified by weight.
• European Union: fibre labels must use the names in Regulation (EU) No 1007/2011, so the composition reads polyester; the Commission’s FAQ allows the word ‘recycled’ as separate, non-misleading information, for example “polyester – recycled fibres”.
• European Union, since 27 September 2026: Directive (EU) 2024/825 bans sustainability labels not based on a certification scheme or set by public authorities, generic claims such as eco-friendly without recognised excellent environmental performance, and claims that present one aspect as the whole product.
• United Kingdom: the CMA’s Green Claims Code expects environmental claims to be truthful, clear and substantiated, and treats a false recycled-content claim as always liable to mislead.

What should go in the order file?

Recycled polyester is not one of SenLin’s confirmed stock specifications, and SenLin publishes no RCS or GRS scope certificate. Treat it as a custom material request (custom development starts from 300–500+ pieces, confirmed by style) and raise the claim at enquiry, so the fabric source and composition are written into the costed bill of materials and the certification route is agreed before the quotation is fixed. SenLin’s performance fabrics blend polyester or polyamide with elastane, so plan for a percentage claim rather than 100%.

Timing matters this year. RCS 3.0, effective since 1 July 2026, becomes mandatory for audits from 31 December 2026, the same day Textile Exchange’s Materials Matter Standard, which absorbs RCS and GRS, becomes effective; it is mandatory from 31 December 2027. Ask suppliers which standard their next audit will use.

Decide the claim before choosing the fabric, because it dictates which suppliers are eligible, then record in the order:

• The exact claim wording, the standard, and whether it is for consumers or business buyers.
• The mill’s scope certificate number, checked in Textile Exchange’s directory.
• Transaction certificates for each shipment that feeds your order.
• The garment maker’s certification route: its own scope certificate or a subcontractor listing.
• Target recycled percentage for the fabric and the garment, with trims identified.
• Which certification body approves the labels, and who keeps the records.