The inner layer is a layer of BPA free TPU soft thin glue (EU certified, can be directly in contact with food). Due to its waterproof and anti-fouling properties, it can be washed off with a damp cloth or simply rinsed with dish detergent and water. Food stains. Heat resistant to 90 degrees, safe to put in hot food. The bag-shaped design is easy to use and is an essential food bag for snack bread.