USP injection grade Bacteriostatic water for injection, USP, 30 mL multi-dose vial, 0.9% benzyl alcohol
Bacteriostatic water for injection, USP — sterile, non-pyrogenic, 0.9% benzyl alcohol, multi-dose vial.

Bacteriostatic water for injection, USP

★★★★★ Pharmacist-reviewed · USP injection grade

Bacteriostatic water for injection, USP is a sterile, non-pyrogenic preparation with 0.9% (9 mg/mL) benzyl alcohol in a multiple-dose vial for repeated withdrawals to dilute or dissolve drugs.1

$17.85
Per vial. Secure checkout by private order link.

Purchase option

One-time purchaseShips when in stock
Subscribe & saveDelivery monthly · cancel anytime
All sizes
  • USP injection grade — sterile, non-pyrogenic1
  • 0.9% benzyl alcohol — multi-dose vial
  • Per-lot certificate of analysis
  • Ships across the US — controlled room temperature3
Reviewed by Jaspal Mann, Superintendent Pharmacist Last reviewed: September 6, 2026

Check availability

Full USP specification

Bacteriostatic water for injection, USP. Source: official label (DailyMed / Hospira) and RxList (FDA drug information).
GradeWater for Injection, USP1
PreservativeBenzyl alcohol 0.9% (9 mg/mL)1
SterilitySterile, non-pyrogenic1
pH5.7 (range 4.5 to 7.0)1
ContainerMultiple-dose vial, repeated withdrawals1
Common presentation30 mL plastic flip-top vial, not pressurized2
Storage20–25 °C (68–77 °F)3

What "for injection" means here

"For injection" signals the grade: this is water manufactured to the USP standard for parenteral preparations, sterile and non-pyrogenic, intended to be added to drugs that are then injected.2 It is a diluent, indicated only for diluting or dissolving drugs for intravenous, intramuscular, or subcutaneous injection, per the instructions of the drug's manufacturer.2

Safety points from the label

Used as a diluent, it has few side effects of its own; reactions usually relate to the drug added or injection technique.4 The label is clear on a few points worth knowing.

Diluent Use & Reconstitution Acknowledgement. bacwaterstar cannot determine the cause of cloudiness, clumping, precipitation, discoloration, or failed reconstitution after this diluent has been mixed with any third-party peptide, compound, powder, vial, or other material. bacwaterstar does not manufacture, test, authenticate, or guarantee the quality or compatibility of any third-party compound used with our products.

From the label: for drug-diluent use only; not for use in neonates (benzyl alcohol toxicity); must be made approximately isotonic before use; not for epidural or spinal anesthesia; IV use without a solute may cause hemolysis.2,4

Common questions

Is bacteriostatic water for injection the same as bac water?

Yes. "Bac water" is the short name for bacteriostatic water for injection, USP.1 See our complete guide.

What size does it come in?

The common presentation is a 30 mL multiple-dose vial; a 10 mL size is also available.2

How is it stored?

At controlled room temperature, 20 to 25 °C (68 to 77 °F).3

30 mL vial 10 mL vial Complete guide

Sources
  1. Bacteriostatic Water for Injection, USP — Description. DailyMed, U.S. National Library of Medicine. View label.
  2. Bacteriostatic Water for Injection, USP — Uses, Directions, Warnings & Precautions. DailyMed. View label.
  3. Bacteriostatic Water for Injection, USP — Storage, 20–25 °C (Hospira, Inc.). DailyMed. View document.
  4. Bacteriostatic Water for Injection — Side effects and warnings. RxList (FDA drug information). View monograph.