Bacteriostatic Water 30 mL: Who Makes It, the 20 mL Fill, and the 28-Day Math

1. The Short Answer

Bacteriostatic water 30ml is the largest vial the United States Pharmacopeia allows: the monograph limits Bacteriostatic Water for Injection to containers not larger than 30 mL.¹ The standard presentation is Hospira's 30 mL plastic multiple-dose vial with 0.9% benzyl alcohol, NDC 0409-3977-03, and several other companies sell 30 mL vials under their own NDCs.²

Whether a 30 mL vial makes sense for you comes down to one number. Once the stopper is punctured, the standard in-use limit is 28 days, so you have to draw about 1.07 mL a day to finish it. Below that rate, part of every vial goes in the trash.

2. Why 30 mL Is the Ceiling

The 30 mL cap is written into the USP monograph itself, alongside the endotoxin limit, the pH range and the “NOT FOR USE IN NEWBORNS” warning.¹ A product labeled “Bacteriostatic Water for Injection, USP” in a 50 mL or 100 mL bottle cannot be the monograph product, whatever else it is.

The monograph does not explain the number, but the approved label gives useful context. It notes that experimental studies suggest an estimated intravenous dose of up to 30 mL of 0.9% benzyl alcohol may be given to an adult without toxic effects, while about 9 mL given to a 6 kg infant may cause blood pressure changes.² A full 30 mL vial at 9 mg/mL holds 270 mg of benzyl alcohol. Capping the container keeps the total preservative that can come out of one vial inside a range the label treats as tolerable for adults.

3. Bacteriostatic Water 30 mL Vials: Who Makes and Labels Them

Hospira, a Pfizer company, lists two presentations that use a 30 mL vial.³ Other companies appear on DailyMed as the labeler for a 30 mL vial, each under its own NDC. These are the ones we could verify on DailyMed in September 2026:

Sources: Hospira label and Pfizer how-supplied page,²³ Henry Schein,⁴ HealthFirst,⁵ US MedSource,⁶ Medical Purchasing Solutions⁷ and ProPharma⁸ labels on DailyMed.

Read the table as one manufacturer and several labels, not six competing products. The HealthFirst label says the product is distributed by Hospira.⁵ The Medical Purchasing Solutions listing is marked as a repackaged label.⁷ The US MedSource vial shares the “3977” product digits and the same polyolefin vial description as Hospira's.⁶ Every one of the five non-Hospira labels in the table names 0409-3977 as its source NDC, the plastic 0.9% vial, and none names the glass 20 mL product.⁴⁸ The different company names mostly reflect who buys, repacks and resells the vial, which is covered in more depth in our brands guide.

One more 30 mL listing appeared in the same search and is left out of the table on purpose. Fujian Genohope Biotech lists a 30 mL multiple-dose vial, 25 per carton, under NDC 84502-115, but its marketing category is “unapproved drug other” and DailyMed shows FDA's notice that the labeling has not been approved.⁹ An NDC on a 30 mL vial does not by itself mean it is the FDA-approved product; the marketing category on its DailyMed page does.

What “Hospira bacteriostatic water 30ml” means on a listing

Hospira sells 0409-3977-03 as a tray of 25 vials. Individual vials on a retail site are usually split from a tray. Check that the vial itself shows the NDC, lot and expiry, because a loose vial has lost its carton. The product is labeled Rx only, and many medical suppliers ask for a license before selling it.² Our Hospira label guide walks through the rest of the label.

The 30 mL tray is the one on the shortage list

When we checked in September 2026, FDA's Drug Shortages database had no bacteriostatic water entry.¹⁰ ASHP's list did. Its bulletin, created July 15, 2025, names a single affected product, Pfizer's 30 mL vial in a tray of 25 (NDC 0409-3977-03), says there is insufficient supply for usual ordering, and says Pfizer has the 30 mL vials in limited supply.¹¹ The bulletin's stated reason:

That fits the table above. Every approved 30 mL vial traces back to one Hospira product, so a relabeler's stock cannot fill a gap at the source. If a seller cites a “nationwide shortage,” the ASHP bulletin is the record behind that claim; if a seller says there is no shortage, FDA's database is.

4. The 20 mL Fill in a 30 mL Vial

Searches for “bacteriostatic water 20ml” usually land on NDC 0409-1093-04. It is a glass vial with room for 30 mL that is filled with 20 mL, and it uses a stronger preservative concentration: 1.1% (11 mg/mL) benzyl alcohol instead of 0.9%.³

Two details are worth knowing. First, the extra headspace is intentional, not a short fill. Second, the 1.1% concentration exists because some drug labels call for it by name. The Herceptin label, for example, says to reconstitute the 420 mg multiple-dose vial with 20 mL of Bacteriostatic Water for Injection containing 1.1% benzyl alcohol, and to use preservative-free Sterile Water for Injection instead for patients with benzyl alcohol hypersensitivity.¹² When a drug label names a diluent this precisely, the 0.9% plastic vial is not a like-for-like swap.

5. The 28-Day Math: When a 30 mL Vial Is Worth It

Under USP <797>, an opened or needle-punctured multiple-dose container is discarded 28 days after first entry unless the manufacturer specifies a different date.¹³ That turns vial size into a simple rate problem: the vial's volume divided by 28 is the average amount you must use each day to finish it.

At 0.25 mL/day you use 7 mL in 28 days. Discarded volume = fill minus 7 mL.

When 30 mL fits

• High daily volume. A clinic or lab reconstituting several vials a day can empty 30 mL well inside 28 days.
• A drug label that calls for large diluent volumes. A 20 mL reconstitution, like the Herceptin example above, is a single large draw rather than weeks of small ones.
• Many users in a controlled setting. CDC advises that multiple-dose vials be dedicated to a single patient whenever possible, and that they be handled away from the immediate treatment area when shared.¹⁴ Outside that kind of setting, the case for a big shared vial is weak.

When 30 mL is the wrong call

A single user mixing one or two vials a month is the common case, and it is where a 30 mL vial wastes the most. More volume also means more punctures through the same stopper before the vial is empty. At 0.5 mL per draw, a 30 mL vial takes 60 entries to finish. Each one is a chance for contamination, which is why the clock exists. The 28-day rule guide covers how to date and track an opened vial.

6. What One FDA-Approved 30 mL Bottle Shows About the Math

The 28-day arithmetic above is ours, so here is a check from an FDA-approved label that ships a 30 mL bottle to a single patient. EGRIFTA WR (tesamorelin) comes in a package with four single-patient-use drug vials and one 30 mL multiple-dose bottle of Bacteriostatic Water for Injection, USP, plus a 28-day supply of syringes and needles.¹⁵

The label's instructions reconstitute one drug vial a week with 1.3 mL of the bacteriostatic water, and tell the user to throw away the water left in the bottle 28 days after first use.¹⁵ Four reconstitutions of 1.3 mL add up to 5.2 mL. That leaves 24.8 mL of a 30 mL bottle, about 83%, to be discarded by design. The kit pairs a 30 mL bottle with a 28-day discard date, so the clock, not the volume, ends the bottle's life.

FDA takes the same line. It generally recommends that vials holding multiple doses of sterile medication be used within 28 days after first use, and in its guidance on compounded GLP-1 vials it tells consumers to discard the vial within 28 days even if medication remains, even if the compounder's instructions say it can be used longer.¹⁶ The rule does not bend for a big vial, which is why a 30 mL vial is the right size only when the draw rate is high enough to empty it.

7. Sterile Water 30 mL Is a Different Product

“Sterile water 30ml” is often searched alongside bacteriostatic water, and the two are easy to confuse on a shelf. Sterile Water for Injection, USP contains no bacteriostat, antimicrobial agent or added buffer, and it is supplied only in single-dose containers. The label says not to reuse the container and to discard the unused portion.¹⁷

Because it has no preservative, sterile water is not bound by the 30 mL limit; Hospira's own sterile water label covers vials as large as 100 mL.¹⁷ A 30 mL bottle of sterile water is therefore meant to be entered once. Drawing from it over several days treats a single-dose product as if it were multiple-dose, which it is not designed for. Which diluent is correct depends on the drug's own instructions; the bacteriostatic vs sterile water guide compares them in detail.

8. Checking a 30 mL Vial Before You Use It

1. Match the NDC to DailyMed. The labeler, fill, container and benzyl alcohol strength on the vial should match one of the labels in the table above.
2. Use the container as a cross-check. For Hospira, plastic 30 mL means 0.9%; glass with a 20 mL fill means 1.1%.³ A glass vial labeled 30 mL and 0.9% under a Hospira NDC does not match either listing.
3. Look for the required wording. The monograph requires the benzyl alcohol proportion and the newborn warning on the label.¹
4. Write the first-puncture date on the vial. The 28 days start then, not at the printed expiry.¹³

For research use where a 30 mL vial is more than you need, our own PureBac water comes in 10 mL and 3 mL multiple-dose vials with 0.9% benzyl alcohol. It is research-grade, not an FDA-approved drug, and it has no NDC; its certificate of analysis is the document to check.

9. Summary

• 30 mL is the largest container the USP monograph allows for bacteriostatic water.
• Hospira makes a 30 mL plastic vial (0.9%) and a 20 mL fill in a 30 mL glass vial (1.1%).
• Henry Schein, HealthFirst, US MedSource, Medical Purchasing Solutions and ProPharma sell 30 mL vials under their own NDCs, all sourced from Hospira's 0409-3977.
• ASHP lists the 30 mL tray (0409-3977-03) as short since July 2025; FDA's shortage database had no entry in September 2026.
• Finishing 30 mL within 28 days takes about 1.07 mL a day; lighter users discard most of the vial, and even an approved kit label uses only 5.2 mL of its 30 mL bottle.
• Sterile water in a 30 mL bottle is single-dose and preservative-free, and it is not interchangeable.