Kasablanka corporation ensures varieties of laboratory plastic products. This is an iso 9001-2000 certified company. Polycarbonate petri dishes are part of those products. This dishes are made of polycarbonate are transparent crystal clear and autoclavable up to 120 deg. C. It`s fully shock resistant non toxic unbreakable stackable body makes them more durable and available in 4" size. Polypropylene dishes are translucent and also autoclavable up to 120 deg. C. Its excellent ridges prevent bases from sticking.