Summary

Bacteriostatic water with benzyl alcohol (commonly called "BAC water") is a sterile, non-pyrogenic water solution containing 0.9% benzyl alcohol as a preservative. The benzyl alcohol acts as a bacteriostatic agent, meaning it inhibits the growth and reproduction of bacteria in the solution without killing them. This property allows BAC water to remain sterile and safe for repeated withdrawals from the same vial over a period of up to 28 days, distinguishing it from plain sterile water which is intended for single-use only. For research use only—not for human consumption.

Usage

BAC water is primarily used to reconstitute and dilute injectable medications, such as peptides, hormones, and some antibiotics, to the desired concentration prior to administration by intravenous, subcutaneous, or intramuscular injection. Its bacteriostatic property makes it ideal for multi-dose vials in both clinical and research settings, greatly reducing the risk of bacterial contamination when accessing the vial multiple times.

The typical shelf life after first use is up to 28 days when stored properly (typically between 2–20°C in a dry place away from direct sunlight, heat sources, and moisture), allowing safer, flexible multi-dose preparation in both clinical and home injection protocols.