The polycarbonate bottles are the ones that contain BPA in the plastic. These are hard, really clear plastic. The bottles made out of the softer, more hazy/milky plastic are okay. These include the regular old Gerber bottles, Medela bottles, and Playtex Drop-ins (well the drop-in liners have no BPA, the outside bottle part probably does). We plan to use both of these again with our second. Can't afford the Born-free ones and glass seems to dangerous with our tile floors.