Frequently Asked Questions What are the Philips Avent bottles and parts made of? The Philips Avent bottles are made of 100% BPA-free material. The bottles are made of polypropylene or polyethersulfone. BPA-free parts All Philips Avent parts that come in contact with breast milk and food are 100% BPA free. The Philips Avent nipples are made of Silicone and the AirFree vent insert is made out PBT and Silicone (LSR).