Teat: round natural rubber nipple 100% free of BPA, PVC and phthalates Made in Denmark. Complies with strict EN1400+A2 standards It is recommended to change the pacifier every 6 weeks. We never recommend microwave sterilization. And in this case, as it is a PP pacifier and the assembly is made with the same rubber as the teat, high temperatures can cause the pacifier to disassemble. We recommend that you heat a pan with boiling water, remove and insert the pacifier for 2 to 5 minutes.