AAMI Standard ST46 makes clear, utilizing paper/poly pouches to separate small items in a wrapped or filtered instrument tray is forbidden. This is because the poly laminate is a barrier to sterilization and being water repellant may contribute to wet pack. These paper bags are the ideal and appropriate alternative. They are made of 100 percent medical grade paper, which are porous to sterilant. Further, the moisture absorbent paper helps to dissipate condensate, helping to fight wet pack.