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BAC Water. How long is it good for after using it?

6 replies6 peopleDec 28, 2025☆ Follow
Summary

How long does opened bacteriostatic water stay usable for multiple vial reconstitutions?

Users report keeping one bottle for two to three months after first puncture while storing it in the fridge or a drawer, with some adding extra benzyl alcohol after a few months. One person noted redness at an injection site after two months of use. Opinions vary on whether room-temperature storage is acceptable once punctured and on the exact safe duration.

What this discussion establishesWhere people disagree

Whether opened BAC water remains safe past one month or can routinely be used for two to three months

Still open

Whether the reported redness was caused by the water age or by another factor

Nothing here is advice.

6 replies · 6 people
LevelLedger68archiveopening postDec 28, 2025

I've kept the same bottle for roughly two months and used it to reconstitute three vials so far. I'm wondering how long the water remains okay once I've started drawing from it with a syringe. It's sitting in the fridge right now. The question came up because I noticed redness around an injection site for the first time.

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RustBramble76archiveDec 28, 2025

I keep using the same bottle until it's gone, which usually takes me about two and a half months. I wouldn't personally push it past three months after opening, though everyone has their own comfort level with the risk.

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ClearBeacon24archiveDec 28, 2025

Usually i include some more benzyl alcohol once several months have gone by and there have never been any problems.

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ClearQuill21archiveJan 28
↳ replying to @ClearBeacon24

I wonder if storing it in darkness under typical conditions would be okay.

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GreenBeacon31archiveJan 28
↳ replying to @ClearQuill21

Without any puncture the seal stays intact so normal indoor temperature works fine for storage. After the first use I generally figure it stays usable around thirty days if kept cold. From what I know brightness or sunlight makes no difference to this water. Basically it's just purified liquid mixed with a small amount of alcohol.

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CopperAlder51archiveJan 28
↳ replying to @GreenBeacon31

Hospital settings suggest a one-month limit since staff access the vial repeatedly each day. In my case the same bottle has lasted past eight weeks without any trouble. It sits in a cabinet where I examine the liquid before each draw and clean the top with a wipe both before and after. Cold storage might let it go longer still but the shorter period still feels safest to me.

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ClearBeacon24archiveJan 29
↳ replying to @ClearQuill21

yes on room temp

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