Troubleshooting What material are my bottle and teat made of? Possible Baby bottle materials: PP: Polypropylene PES: Polyethersulfone (Discontinued since the beginning of 2011) Glass Advanced PES Advanced PES - Honey color Classic PP Classic PP - Milk colour-transparent or transparent pink/blue Natural PP Natural PP - Milk colour-transparent or transparent pink/blue Natural Glass Natural Glass - Glass Other materials Teat materials - all teats are made of silicon Expert tips: Ring and cup are made of PP. Adapter ring is made of PP+Silicon. Currently, ALL the Avent products which come IN CONTACT WITH FOOD are BPA FREE. In 2008 the POLYCARBONATE (PC) bottles were DISCONTINUED because they contained BPA.