Bacteriostatic Water is a sterile, non-pyrogenic aqueous solution containing a low concentration of benzyl alcohol used in laboratory and pharmaceutical research to investigate reconstitution of lyophilised materials and compounds

Bacteriostatic Water

Synonyms / Designations: Bacteriostatic Water for Injection (research use) Sterile Water with Benzyl Alcohol
CAS Number: 7732-18-5 (water) 100-51-6 (benzyl alcohol component)
Molecular Formula: H2O (with 0.9% benzyl alcohol, w/v)
Molar Mass 18.02 g/mol (water)
Composition: Sterile water for injection containing 0.9% benzyl alcohol as a bacteriostatic preservative
Product Classification Sterile aqueous diluent; bacteriostatic solvent
Purity: Manufactured to pharmacopeial specification (USP/Ph. Eur. grade components)
Appearance: Clear, colourless, sterile solution
Pack Size: 3 mL
Storage: Store in a cool dark place. Discard 30 DAYS after opening.
Solubility: Fully miscible with water and aqueous buffers

Description & Mechanism

Bacteriostatic Water is a sterile aqueous solution containing a low concentration of benzyl alcohol, formulated to inhibit microbial growth during repeated vial access. It is widely used in laboratory, pharmaceutical, and formulation research as a diluent for the reconstitution and dilution of injectable-grade compounds under controlled experimental conditions.

In biochemical and cellular research systems, Bacteriostatic Water is employed to evaluate compound solubility, stability following reconstitution, and short-term storage behaviour. The presence of benzyl alcohol provides bacteriostatic activity by disrupting microbial cell membranes, thereby reducing contamination risk during multi-use experimental workflows.