Bacteriostatic Water Bac Water by Hospira Mountainside Medical Bacteriostatic Water for Injection with Preservative by Hospira Pfizer DID YOU KNOW? Bacteriostatic Water contains 0.9% benzyl alcohol, which prevents bacteria from growing after the vial is opened. This makes it safe to use for up to 28 days once punctured 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 Bac Water (Hospira) 30ml Novara Peptides