BAC Water, commonly referred to as Bacteriostatic Water for Injection, is a sterile, nonpyrogenic preparation containing water for injection and a small amount of benzyl alcohol as a bacteriostatic preservative. FDA-listed formulations commonly contain 0.9% benzyl alcohol (9 mg/mL) and are supplied in multi-dose containers.

Bacteriostatic Water is intended specifically as a diluent or solvent for compatible injectable drugs that require dilution or reconstitution before administration. The appropriate diluent, volume, concentration, and handling requirements depend on the specific drug manufacturer’s instructions and applicable labeling.

Because formulations can differ, product specifications such as preservative concentration, container size, labeling, and regulatory status should always be verified against the specific product documentation.