Thread’s jersey knit fabric has completed the Material Health Safety Certification process through the Cradle to Cradle Institute. This process included breaking down each product used in the manufacturing down to the molecular level to ensure that our fabric isn’t causing human or ecological harm.
While our production processes passed certification standards, we learned about the issue of antimony and recycled polyester. Antimony is present in PET bottles (soda and water bottles) and can be released in the heating processes required for recycling the rPET into fiber.
We conducted additional third party testing and, while antimony levels were very close to being under the 100 ppm that is required by the institute for higher ratings, we cannot ignore the presence of antimony in rPET. This resulted in a bronze rating.
While the finished recycled fiber itself presents no harm, we cannot score above a bronze rating because of the release of antimony in production processes. If you look through the Cradle to Cradle Certifications, you’ll notice that no recycled polyester yarns or fabric have scored above a bronze material health rating because of this issue.
You can find our certification page on the Cradle to Cradle website.