The bag also features a grip seal zip lock zipper that will lock in the freshness of the items stored inside. Crafted from food safe polyethylene and coated with foil ions and glossy finish, these bags provide a smell-proof, durable and flexible solution for all your storage needs.For added security, the bag can be heat sealed and opened again by its tear notch. While these bags are perfect for storing dried products, it is NOT recommended to use these bags to store liquids.