Does Bacteriostatic Water Need to Be Refrigerated?

Short answer

• Unopened: room temperature, 20 to 25 C (68 to 77 F). That is what the label says.
• Opened: the label still gives only room temperature. The CDC and USP add a 28-day limit after first puncture.
• Fridge: the label does not specify refrigeration. A fridge does not add days to the 28-day limit.

What the label says

The bacteriostatic water label on DailyMed has one storage line. It says to store at 20 to 25 C (68 to 77 F). It points to the USP term "controlled room temperature."

That is all the label says about storage. It does not say to refrigerate, it gives no 28-day limit, and it does not mention freezing. You can read the full bacteriostatic water label yourself.

Some pages quote a wider range, such as 15 to 30 C, but that range is not on this label, which says 20 to 25 C.

Storage table: label vs CDC and USP

Each column is a different source. They are kept apart on purpose, so you can see who says what.

Neither the label nor the CDC text specifies refrigeration. No label we read requires a fridge.

The 28-day rule after first puncture

The 28-day limit does not come from the label. It comes from health guidelines:

• The CDC says to date an opened multiple-dose vial and throw it out within 28 days, unless the maker gives a different date.
• USP chapter 797 sets the same 28 days for an opened multiple-dose container with a preservative.

The clock starts the day the first needle goes through the stopper, not the day you buy the vial. A written date matters more than where the vial sits. In one hospital survey, half of the opened vials had no opening date at all (Mattner and Gastmeier, 2004).

To find your date, add 28 days to the first puncture date. If the vial opens on June 1, the discard date is June 29. If the printed expiry comes sooner, use that date instead. For a full timeline, see how long bacteriostatic water lasts.

Should you refrigerate an opened vial?

The label does not specify refrigeration, and the CDC page does not ask for it either. So two things are true:

• A fridge does not stretch the 28 days. The CDC and USP limit stays the same.
• The label's own range is 20 to 25 C. A fridge is outside that range.

If your product's label gives its own storage rule, follow that. A pharmacist can help with your own case.

How to store it

• Keep it at room temperature, 20 to 25 C (68 to 77 F), as the label says.
• Keep it away from heat that would take it above that range.
• Keep the vial sealed until you need it.
• Write the first puncture date on the vial.
• Use clean technique each time you enter the vial. The label asks for this.

The label gives only a storage range. It says nothing about shipping, and nothing on it calls for a cold pack.

Signs a vial should not be used

The label says do not use it unless the solution is clear and the seal is intact. It also says to look for particles and color change. Do not use a vial if:

• The water is cloudy or has bits in it.
• The color has changed.
• The seal or stopper is broken.
• It is past 28 days from first puncture.
• It is past the printed expiry date.

Bacteriostatic water vs sterile water storage

The two labels give the same storage range, 20 to 25 C (68 to 77 F), and neither one says to refrigerate.

The big difference is reuse. Sterile water has no preservative and comes in single-dose vials. Its label says do not reuse it and throw out what is left, so the 28-day rule does not come into play. See bacteriostatic water vs sterile water for the full side-by-side table.

One more label fact: bacteriostatic water is not for use in newborns. The label says to use only preservative-free sterile water when mixing drugs for a newborn.