This resuable hot pot is BPA free and made of 100% food grade material that is safe and hygenic to use. Firm Twist lock and handles : The firm locking lid of this casserole does not allow the heat to esacpe. The lid needs to be twisted sideways for quick and easy access during a meal and the integrated handles promotes easy portability. Double walled insulation: This set of casserole has a double insulation wall and a stainless steel inner surface that keeps the food hot and fresh for a long time.