What’s the Difference?

The main difference between bacteriostatic water and sterile water lies in their composition and intended use:

1. Bacteriostatic Water:
   • Composition: It is water that contains an antimicrobial agent (often benzyl alcohol) that prevents the growth and reproduction of bacteria.
   • Purpose: The antimicrobial agent makes bacteriostatic water suitable for multi-dose vials, as it inhibits bacterial growth, allowing the water to be used for several injections or purposes over time without the risk of contamination. It’s commonly used to dilute or dissolve peptides or drugs for research or injection.
   • Storage: Because it contains an antimicrobial agent, it is typically used within a specific time frame after opening to prevent any risks associated with contamination.
   • Usage: Bacteriostatic water is generally not intended for newborns or infants, as certain antimicrobial agents like benzyl alcohol can be harmful to them.
2. Sterile Water:
   • Composition: It is simply purified water that has been sterilized to ensure it is free of microorganisms. It does not contain any additives.
   • Purpose: Sterile water is used when a substance needs to be diluted or dissolved for injection, or for cleaning purposes, where no antimicrobial action is needed. It is typically used in single-dose vials because there are no preservatives or bacteriostatic agents.
   • Storage: Sterile water, once opened, should not be reused and typically should be disposed of after a single dose.
   • Usage: Sterile water is safe for use in all populations, including infants and newborns, since it contains no potentially harmful preservatives.

Key Differences:

• Additives: Bacteriostatic water contains an antimicrobial agent, while sterile water contains no additives.
• Use: Bacteriostatic water is used for multi-dose situations, while sterile water is generally for single-dose applications.
• Safety for Newborns: Bacteriostatic water is not safe for newborns, whereas sterile water is.