In the summer of 2014 we switched to making the chamber and plunger out of polypropylene. This means that all of the AeroPress parts except the silicone seal are now made of polypropylene. We made the change because tests indicated the polypropylene is more durable. We regret the polypropylene is less transparent but feel the additional durability is more important. All materials used in the AeroPress are made in the USA and are FDA and EU approved for use in contact with food. Read more about the materials here.