Pure Pail? Diaper Pail Refill Bags are made of 7-layers of thin plastic film to create an odor barrier. These bags are constructed so oxygen can?t pass through the layers, making it impossible for smelly diaper odors to escape! But just to make sure, we had our bags laboratory tested. They passed with flying colors. Features: Superior Odor Control: Laboratory tested 7-layer odor barrier bags Designed for Ease of Use: Individually sized No cutting. No canisters. Cost Effective Refill System: Holds more diapers than the leading brands Roll of 25 bags holds up to 1, 375 diapers.