Made from Polypropylene (PP) plastic our 10ml PP Mushroom Jars w/ Tab provide a durable package with excellent moisture barrier. Polypropylene is stable at high temperatures, up to 220°F (104°C) which is considered one of its major advantages. Polypropylene jars can be used in an autoclave and offers the potential for steam sterilization. Polypropylene is compatible with high filling temperatures which allows for its use with hot fill products. Polypropylene has excellent chemical resistance, but provides poor impact resistance in cold temperatures.