The BABYBJÖRN Cover for Baby Carrier is 100% Polyester. Just like the fabrics in our baby carriers, the BABYBJÖRN Cover for Baby Carrier is approved in accordance with Oeko-Tex Standard 100, class 1, which means that the fabric contains no health-hazardous substances or allergens. So it’s harmless for your child to suck and chew on the cover or the baby carrier.