Q: What does GRS 4.0 require for recycled zipper tape?
GRS 4.0 is a voluntary standard for recycled content, chain of custody and responsible production. To be certified, a product must contain at least 20 percent recycled material by weight; to carry the GRS logo on the product, at least 50 percent recycled content is required. The standard also imposes chemical requirements through a restricted substances list, plus social, environmental and waste-management criteria at the certified site.
For zipper tape the recycled content usually sits in the polyester yarn, and it must be traceable from the recycler through the spinner, the weaver and the dyer to the finished tape. The mill holds a scope certificate listing the product categories it may certify; each shipment then needs a transaction certificate that links the quantity sold to that scope. Physical segregation and mass balance records are what make the claim defensible.
Check that the scope certificate covers tape and the correct material, that the recycled input is declared as pre- or post-consumer, and that the transaction certificate matches your invoice quantity. Percentages are verified by the certifier, so ask for the calculation rather than accepting a marketing figure.