How to Store Bacteriostatic Water Safely Confused about whether BAC water needs refrigeration after opening? According to USP standards and Pfizer's own guidance, both room temp (2025C) and refrigeration are acceptable Do you guys refrigerate your bac water after first use? : r Peptides MUST READ , You can only use bac water to mix peptides no exceptions, You must put it in the refrigerator immediately and keep it there only time you take it out is when you are using it and Bacteriostatic Water 101: Comprehensive Guide to Its Uses and Storage SyringesNeedlesDepot