Bacteriostatic water is sterile water that contains a small amount of benzyl alcohol (usually 0.9%), which acts as a preservative and helps limit bacterial growth after the vial has been opened.

It’s commonly used in clinical and laboratory settings as a diluent—meaning it can be used to dissolve or dilute certain compatible substances before use.

Key points:

• 💧 Sterile water with 0.9% benzyl alcohol

• 🦠 The preservative helps inhibit bacterial growth

• 🧪 Often used for reconstitution or dilution when specifically appropriate

• 🚫 It is not the same as plain sterile water

• ⚠️ It should only be used when the medication/product instructions specifically identify bacteriostatic water as a compatible diluent