Melissa's CommentsThis bags are really secure- seriously, they don't leak so you don't have to worry. Even if you're transporting in a diaper bag, the seal is VERY strong and secure.
The Lansinoh Breastmilk Storage Bags - 50 Count (20450) are built to be strong, with a double-zipper seal that prevents milk leakage, plus double-reinforced side seams for ultimate protection. Store, freeze, and protect breastmilk safely in these presterilized bags that are BPA- and BPS-free. They�re easy to use, and you can save time by pumping directly into the bag. The bottom is designed to sit on flat surfaces to prevent spills.