Bacteriostatic Water for Injection (Bac Water) is a sterile solution used to dilute or dissolve powdered medications for injection. It contains a small percentage of benzyl alcohol, typically 0.9%, which acts as a bacteriostatic agent to inhibit the growth of most contaminating bacteria. This preservative allows a single vial to be entered multiple times, making it suitable for multi-dose applications. Understanding the correct storage and handling protocols is necessary to maintain the integrity of the water and the safety of the medication it reconstitutes.
Storing Sealed Vials
Vials of Bacteriostatic Water that have not been punctured should be stored according to the manufacturer’s specific instructions printed on the label. Unopened vials generally remain stable for an extended period, often two to three years from the manufacturing date, so the printed expiration date is the primary guideline for shelf life. Storage conditions typically involve keeping the vial at a controlled room temperature, usually between 68°F and 77°F (20°C to 25°C).
The sealed containers must be protected from direct sunlight, excessive heat, and moisture. Exposure to light can cause the benzyl alcohol preservative to break down prematurely, compromising the bacteriostatic properties of the solution. Extreme temperatures, including freezing, should be avoided as they can degrade the water’s quality or damage the sterile integrity of the container.
Post-Opening Storage Rules
Once a vial of Bacteriostatic Water has been punctured, a strict time limit for use begins due to the preservation mechanism. The most important rule for post-opening storage is the 28-day guideline, which dictates that the vial must be discarded 28 days after the first needle puncture, regardless of the remaining volume. This time limit is mandated by health guidelines because the efficacy of the benzyl alcohol preservative gradually declines after the seal is broken and the solution is exposed to air and repeated withdrawals.
The 28-day window overrides the original manufacturer’s expiration date once the vial has been entered. While the water itself is stable at controlled room temperature, refrigeration, typically between 36°F and 46°F (2°C to 8°C), is often recommended for opened vials to further inhibit microbial growth during the 28-day usage period.
After opening, clearly label the vial with the date of the first puncture. This ensures compliance with the 28-day rule. If the water is refrigerated, it should be allowed to warm back toward room temperature before reconstitution to ensure the powdered medication dissolves properly and to prevent discomfort during injection.
Safe Handling and Disposal Procedures
Maintaining sterility during the 28-day period depends on meticulous handling procedures. Before drawing any liquid, the rubber stopper on the vial must be thoroughly cleaned by swabbing it vigorously with a fresh alcohol wipe and allowing it to air-dry completely. A new, sterile needle and syringe must be used for each withdrawal to prevent the introduction of bacteria into the multi-dose vial.
When extracting the water, the needle should be gently inserted and removed to avoid coring the rubber stopper, which can introduce pieces of rubber into the solution. After the necessary volume has been withdrawn, the stopper must be securely resealed to prevent airborne contaminants from entering the vial.
Disposal is necessary once the 28-day period has passed, even if the water appears clear. Immediate disposal is also required if any signs of contamination are noticed before the time limit. Signs that necessitate immediate disposal include cloudiness, discoloration, the presence of floating particles, or a broken seal on the vial. Contaminated or expired water should be discarded by following local regulations for medical waste, which often involves placing the entire vial into a designated sharps or biohazard container.