Buy bacteriostatic water: which size and pack to get

Q: Where should I buy it?

That's a separate question — see our where to buy bac water guide for pharmacies vs online and how to verify a seller.

Before you buy bacteriostatic water, two choices decide most of it: which vial size (3, 10, or 30 mL) and how many vials. Everything else is verifying you're getting genuine USP-grade product from a named manufacturer, with a readable lot number and expiry date on a sealed vial.¹

This is a buying guide, not a retailer roundup — if you're comparing where to shop, see where to buy bac water. Here we help you pick the right size and pack, then check what matters before you order.

Written by bacwaterstar editorial team Reviewed by Jaspal Mann, Superintendent Pharmacist Last reviewed: September 5, 2026

Which size to buy

All three sizes are the same USP product with the same 0.9% benzyl alcohol preservative; they differ only in volume.¹ Pick by how much you'll use before the vial's in-use window is up.

Choosing a vial size.

Size	Best for
3 mL	Small or occasional use; often sold in multipacks
10 mL	Moderate use; a middle-ground size
30 mL	Regular use; usually the lowest cost per mL

Single vial, multipack, or bulk

Single vials suit a one-time need. Multipacks lower the per-vial cost and are common for the smaller sizes. Bulk packs exist for high-volume buyers. Buy the quantity you'll realistically use while each opened vial is still within its in-use window, rather than over-buying vials that expire unopened.

What to verify before you order

The name on the bottle matters less than the specification. Before you buy, confirm:

It's labeled USP grade with a named manufacturer, not a vague "premium" claim
The preservative is stated: 0.9% (9 mg/mL) benzyl alcohol¹
The seller provides a per-lot certificate of analysis
Vials arrive sealed, with a readable lot number and expiry
The solution is clear and the seal is intact on arrival²

Ready to buy

Pick your size to see the product detail and check current availability.

Buy 30 mL Buy 10 mL Buy 3 mL Hospira brand

Common questions

What's the best size to buy?

For regular use, the 30 mL vial is usually the lowest cost per mL. For occasional use, a 3 or 10 mL vial avoids waste.¹

Where should I buy it?

That's a separate question — see where to buy bac water for pharmacies vs online and how to verify a seller.

How do I know it's genuine USP-grade?

Check the label for the named manufacturer and 0.9% benzyl alcohol, and ask for the per-lot certificate of analysis.¹

Sources

Bacteriostatic Water for Injection, USP — Description. DailyMed, U.S. National Library of Medicine. View label.
Bacteriostatic Water for Injection, USP — Directions (clear & seal intact). DailyMed. View label.