Bacterostatic Water BAC Bacteriostatic Water vs. Sterile Water: What's the Difference? Wittmer Rejuvenation Clinic What is Bac Water? Bacteriostatic Water (BAC Water) is sterile water that contains 0.9% benzyl alcohol, which helps prevent bacterial growth. Used in research and laboratory settings for reconstitution and dilution. Visit Bacteriostatic Water 20 ml Sterile Solution PRG Pfizer Bacteriostatic Sterile Water for Injection USP 30 ml vial 25 Box Med Supplies