Lansinoh Labs Breast Milk Storage Bags 25 Count, Polyethylene, Leak Proof, Pre-sterilized. Lansinoh Breast Milk Storage Bags have been developed specifically for the freezer, and can also be used to store your breast milk in the fridge. Our manufacturing process enables us to produce these medical grade bags without using plasticisers, so substances that could be harmful to your baby will not leach into your breast milk. Leak proof. Pre-sterilised. Double zipper for a secure seal. Convenient write-on tab above fill area to eliminate potential puncture. Made from food safe polyethylene (PE). Tissue pack dispenser for easy access and storage. Easy to pour. Gusseted bottom to allow for expansion. Breast Milk storage guidelines included.