Hi! This is my first posting on LACTNET, so I apologise if this question has been answered previously. I am a Nursing Mother Counselor, I manufacture the Invisible Nursing Pads and also have a rental station, My question is this: What is the maximum amount of time that Expressed Breastmilk can stay safely in the Playtex or Munchkin bags? (Does this differ from the Egnell or Medela freezer bags?) The storage times for EBM are widely published, however, I have heard that it may not be safe to store for extended lengths of time in these bags. Have ther been studies on this? Can someone direct me to the correct answer? Any guidance would be greatly appreciated.