Bacteriostatic water is commonly used in order to dilute or dissolve substances such as reconstituting powdered substances for injection purposes. Bacteriostatic water is sterile water that contains 0.9% benzyl alcohol to prevent it from being contaminated by potential bacteria.
The antibacterial properties of the benzyl alcohol allow the bottle to be drawn from several times with a sterile needle. As a result of the addition of benzyl alcohol, the water is considered "static" because of the stability of the solution and unchanging bacteria content.
Bacteriostatic water can be used intravenously, intramuscularly, and subcutaneously depending on what the water is mixed with.
Despite being bacteria-free, bacteriostatic water is different from sterile, purified water since sterile, purified water has no additives. Bacteriostatic water is typically preferred by researchers over simply using an antibacterial agent because the addition of benzyl alcohol doesn’t just kill bacteria but prevents growth from happening long before it is used for research purposes. Other antibacterial agents can also react with medications potentially causing negative side effects or adverse reactions.
However, bacteriostatic water isn’t the primary choice in a few specific cases. For example, bacteriostatic water should not be used to treat newborns or pregnant women because the toxicity from the benzyl alcohol could potentially affect the fetus or baby. Bacteriostatic water should also not be used for hydration or any form of spinal anesthesia like an epidural. Bacteriostatic water shouldn’t be used on its own without an isotonic medication added because this can cause hemolysis.