Direct comparison
Bac Water vs Sodium Chloride: Label Differences
Bac water vs sodium chloride compared on two FDA labels: sodium chloride content, benzyl alcohol, pH, tonicity and warnings, plus CDC multi-dose rules.
Written and maintained by CASRAI Editorial Board
Last updated
How do Bacteriostatic water for injection and Bacteriostatic 0.9% sodium chloride injection compare side by side?
The table below compares Bacteriostatic water for injection and Bacteriostatic 0.9% sodium chloride injection across 11 dimensions, from what the label says it is to which one to use.
Side-by-side comparison
| Dimension | Bacteriostatic water for injection | Bacteriostatic 0.9% sodium chloride injection |
|---|---|---|
| What the label says it is | A sterile, nonpyrogenic preparation of water for injection with benzyl alcohol added as a bacteriostatic preservative. | A sterile, nonpyrogenic, isotonic solution of sodium chloride in water for injection, with benzyl alcohol added as a bacteriostatic preservative. |
| Sodium chloride | None listed. The label refers to it as a preparation "without a solute". | 9 mg per mL (0.9%). |
| Benzyl alcohol (preservative) | 0.9% (9 mg/mL) or 1.1% (11 mg/mL), depending on the product. | 0.9% (9 mg/mL). |
| pH on the label | 5.7 (range 4.5 to 7.0). | 5.0 (range 4.5 to 7.0). May contain hydrochloric acid for pH adjustment. |
| Tonicity and intravenous warning | Solute-free. The label warns that intravenous administration without a solute may result in hemolysis, and says not to use it for intravenous injection unless the additives make an approximately isotonic admixture. | Labeled isotonic. |
| Container | Multiple-dose container; repeated withdrawals may be made. | Multiple-dose vial; repeated withdrawals may be made. |
| Stated purpose | To dilute or dissolve drugs for injection. The overdosage section says "Use only as a diluent or solvent." | Parenteral use only after addition of drugs that require dilution or must be dissolved in an aqueous vehicle. Carton: "FOR DRUG DILUENT USE ONLY". The label says it should not be used for fluid or sodium chloride replacement. |
| Neonates | Contraindicated: solutions containing benzyl alcohol must not be used in neonates because of potential toxicity. | Same contraindication. Carton: "WARNING: NOT FOR USE IN NEONATES". |
| Other carton wording on the sodium chloride label | Not part of this comparison. | "Rx only" and "NOT FOR INHALATION". |
| Opened multi-dose vial handling (CDC) | CDC guidance for any opened multi-dose vial: date it and discard within 28 days unless the manufacturer specifies otherwise; the beyond-use date should never exceed the manufacturer's original expiration date; assign multi-dose vials to a single patient whenever possible. | CDC guidance for any opened multi-dose vial: date it and discard within 28 days unless the manufacturer specifies otherwise; the beyond-use date should never exceed the manufacturer's original expiration date; assign multi-dose vials to a single patient whenever possible. |
| Which one to use | Only the one the drug's own labeling names as its diluent. The water label itself says to consult the manufacturer's instructions for the choice of vehicle. | Only the one the drug's own labeling names as its diluent. It is a diluent product, not a substitute for plain saline used as a fluid. |
Sources
- Bacteriostatic Water for Injection, USP label (Henry Schein, DailyMed set ID a833502e-a622-4e81-8c58-cef6ccb6c4c9), read 2026-11-01
- CDC Injection Safety, clinical safety guidance for healthcare providers, read 2026-11-01
- Bacteriostatic 0.9% Sodium Chloride Injection, USP label (Hospira, DailyMed set ID 376093e7-e09e-4a57-3199-195e45251866), read 2026-11-01
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Common questions
Common questions about Bacteriostatic water for injection vs Bacteriostatic 0.9% sodium chloride injection
Is bacteriostatic water the same as sodium chloride?
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No. On the labels read here, bacteriostatic water for injection is water with benzyl alcohol and no solute, while bacteriostatic 0.9% sodium chloride injection is an isotonic solution containing sodium chloride at 9 mg/mL plus benzyl alcohol. Both are multiple-dose diluents.
Is bacteriostatic water the same as normal saline?
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No. Normal saline is 0.9% sodium chloride (9 mg/mL). The bacteriostatic sodium chloride product on the Hospira label is that strength with 0.9% benzyl alcohol added, supplied as a multiple-dose drug diluent. Bacteriostatic water contains no sodium chloride.
What is the difference between bac water and saline?
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Saline contains sodium chloride and bac water does not. Both bacteriostatic products on the labels read contain benzyl alcohol, are for drug diluent use, and carry a neonate contraindication. The water label adds a hemolysis warning for intravenous use without a solute.
Is bacteriostatic sodium chloride the same as bacteriostatic water?
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No. The composition difference on the two labels is sodium chloride: 9 mg/mL in the sodium chloride injection, none in the water. That changes tonicity, which is why the water label carries a hemolysis warning and the sodium chloride label says isotonic.
Going deeper
