The outside of the bag is a tough durable ripstop nylon. On the inside of the bag has a durable waterproof TPU lining that is nontoxic PEVA( BPA FREE) and food safe, perfect to keep your food or drink in this lunch box. Just rince under a tap and wipe clean. If water gets on the inside of the bag, simply hang your Pokeat out to thoroughly dry.
NOTE - Do not use strong oils eg sesame oil, chilli oils etc as these could stain the inside TPU bag.