The Hollywood water bottle uses polypropylene, a lighter weight more flexible material, molded at varying thicknesses for strength and flexibility, that put this water bottle to the top of its class. POLYPROPYLENE BOTTLE. PP bottles have superior clarity and lighter weight than standard LDPE bottles. They are very resilient and dishwasher safe. Hydrapak utilizes variable wall thickness manufacturing to make sure this PP bottle is easy to squeeze, no matter the hand size. Like all Hydrapak bottles, they are BPA and Phthalate free. BIG GULP VALVE. Our new TPE poppet is soft on the teeth, a snap to use, and delivers the highest flow of any bottle we know.