Bacteriostatic Water for Injection 30mL (USP)

Bacteriostatic Water for Injection 30mL is a sterile, nonpyrogenic diluent containing Water for Injection with 0.9% benzyl alcohol (9mg/mL) as a bacteriostatic preservative. It is supplied in a 30mL multiple-dose vial and is intended for parenteral use only after adding a compatible injectable drug that requires dilution or dissolution in an aqueous vehicle.

The product is commonly searched for as Bacteriostatic Water for Injection, Bacteriostatic Water 30mL, BAC Water 30mL, BAC Water for Injection, and Bacteriostatic Water USP.

 

Product Information

• Product Name: Bacteriostatic Water for Injection
• Common Name: Bacteriostatic Water / BAC Water
• Strength: 30mL
• Dosage Form: Sterile injectable solution
• Active Component: Water for Injection
• Preservative: Benzyl Alcohol 0.9% (9mg/mL)
• Container: Multiple-dose vial
• Intended Function: Diluent / solvent for compatible injectable medicines
• Route: Parenteral use after addition of an appropriate drug
• Prescription Status: Rx only in the cited U.S. labeling
• USP: Bacteriostatic Water for Injection, USP
• DEA Schedule: None
• Neonatal Use: Not for use in neonates

What Is Bacteriostatic Water for Injection 30mL Used For?

Bacteriostatic Water for Injection is used as a diluent or solvent when an injectable medicine requires dilution or dissolution before administration.

Its purpose is therefore different from that of an active medication. Bacteriostatic Water does not provide the therapeutic effect of the medicine being reconstituted or diluted.

The required volume and compatibility depend on the specific injectable medication and its manufacturer’s instructions.

What Is BAC Water?

BAC Water is a commonly used informal abbreviation for bacteriostatic water.

In the pharmaceutical context, Bacteriostatic Water for Injection contains sterile Water for Injection plus a bacteriostatic preservative. For the 30mL U.S. presentation referenced here, the preservative is 0.9% benzyl alcohol.

“BAC Water” should not be confused with ordinary sterile water or non-sterile water. Products intended for injection must meet the applicable pharmaceutical quality and sterility requirements.

Bacteriostatic Water vs Sterile Water for Injection

Bacteriostatic Water for Injection and Sterile Water for Injection are not interchangeable products in every situation.

Bacteriostatic Water for Injection contains a preservative, typically benzyl alcohol, and is supplied in a multi-dose container.

Sterile Water for Injection does not contain a bacteriostatic preservative and is generally supplied for single-dose use.

The appropriate diluent depends on the specific injectable medicine. The drug manufacturer’s labeling should be followed to determine which diluent is compatible.

Bacteriostatic Water 30mL and Benzyl Alcohol

The cited 30mL product contains 9mg/mL benzyl alcohol, equivalent to 0.9%, as its bacteriostatic preservative.

Benzyl alcohol is important to the product’s bacteriostatic formulation but also explains why the product carries a warning against neonatal use. Bacteriostatic Water for Injection should not be used in neonates.

Important Safety Information

Bacteriostatic Water for Injection is intended only as a diluent or solvent for compatible injectable drugs. It should not be regarded as a standalone treatment.

Important considerations include:

• Verify compatibility with the injectable medicine before use.
• Follow the injectable medicine manufacturer’s instructions concerning dilution and reconstitution.
• Do not use in neonates because of the benzyl alcohol preservative.
• Inspect the solution for particulate matter or discoloration when the container and solution permit.
• Use appropriate sterile technique for preparation and administration.
• Do not use a vial if its integrity, sterility, or labeling is questionable.
• The product should only be used for the route and purpose permitted by the applicable product labeling.

Storage

The cited U.S. 30mL product labeling specifies storage at 20–25°C (68–77°F), consistent with controlled room temperature.

Storage and handling after first access should follow the manufacturer’s labeling and applicable institutional procedures.

Bacteriostatic Water 30mL Multi-Dose Vial

The 30mL presentation is supplied as a multiple-dose vial, allowing repeated withdrawals when handled according to appropriate sterile procedures. Current DailyMed labeling identifies a 30mL plastic flip-top vial containing 0.9% benzyl alcohol.

Specific packaging, manufacturer, NDC, and regulatory status can differ between markets.

Availability & Ordering

Commercial searches for this product commonly include Bacteriostatic Water for Injection 30mL, BAC Water 30mL, Bacteriostatic Water 30mL USP, Bacteriostatic Water Injection, Bacteriostatic Water multi-dose vial, and Bacteriostatic Water online pharmacy.

Availability and prescription requirements vary by country. Buyers should verify that the product is appropriately authorized for sale and intended for the required medical use in their jurisdiction.

Frequently Asked Questions

What is Bacteriostatic Water for Injection 30mL?

It is a sterile, nonpyrogenic preparation of Water for Injection containing 0.9% benzyl alcohol as a bacteriostatic preservative, supplied in a 30mL multi-dose vial.

What is BAC Water?

BAC Water is a common abbreviation for bacteriostatic water. In this pharmaceutical context, it refers to sterile Water for Injection containing a bacteriostatic preservative.

What is Bacteriostatic Water 30mL used for?

It is used as a diluent or solvent for compatible injectable medicines that require dilution or dissolution before administration.

Does Bacteriostatic Water contain benzyl alcohol?

Yes. The referenced 30mL formulation contains 0.9% benzyl alcohol, equivalent to 9mg/mL.

Is Bacteriostatic Water the same as Sterile Water for Injection?

No. Bacteriostatic Water contains a preservative, whereas Sterile Water for Injection does not. The appropriate product depends on the injectable medicine being prepared.

Can Bacteriostatic Water be used for every injectable medicine?

No. Compatibility depends on the specific medicine. The manufacturer’s prescribing or preparation instructions should identify the appropriate diluent.

Is Bacteriostatic Water for Injection prescription-only?

The cited U.S. formulation is labeled Rx only. Prescription and supply requirements can vary between countries.

Can Bacteriostatic Water be used in neonates?

No. The cited product labeling specifically states “Not for use in neonates.”

Is Bacteriostatic Water 30mL available as a multi-dose vial?

Yes. Current U.S. labeling identifies a 30mL multiple-dose vial presentation.

What is the difference between BAC Water 30mL and Bacteriostatic Water 30mL?

They are commonly used names for the same type of pharmaceutical product. “BAC Water” is an informal abbreviation, while “Bacteriostatic Water for Injection” is the formal product description.

Is Bacteriostatic Water an active medication?

No. Its primary pharmaceutical function is as a diluent or solvent for compatible injectable medicines.

Last Updated: September 16, 2026 | Medically Reviewed By: Licensed Pharmacist

Medical Disclaimer: This information is provided for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Bacteriostatic Water for Injection is intended for appropriate pharmaceutical use as a diluent or solvent. Always follow the labeling of the injectable medicine being prepared and consult a qualified healthcare professional when necessary.