Quality and documentation
What is published for this product, what a certificate of analysis actually records, and what each test on one does and does not demonstrate. Read it before you ask a supplier for paperwork, so you know what to ask for.
Specification
The confirmed properties of the product as sold. A property that is batch-specific, or that we have not confirmed from the label or the supplier’s specification, is left out rather than estimated.
| Product | Bacteriostatic Water, 10ml vial |
|---|---|
| Composition | Sterile water with a bacteriostatic preservative, in a sealed multi-dose vial. |
| Appearance | Clear, colourless liquid, free of visible particles |
| Fill volume | 10ml |
| CAS number (water) | 7732-18-5 |
| EC number (water) | 231-791-2 |
| Molecular formula (water) | H₂O |
| Molecular weight (water) | 18.015 g/mol |
| Storage | 2–8°C, as printed on the label |
| In-use limit once opened | 28 days from first puncture |
| Hazard classification | Not classified as hazardous under the GB CLP Regulation |
The unopened expiry is batch-specific and printed on the vial, so it is not stated here as a single figure. Read it from the label of the vial you have.
How to read a certificate of analysis
A certificate of analysis records what was measured on one specific batch, by whom, against which limits. Three things make one useful: a batch identifier you can match to the vial in your hand, a date, and stated limits rather than the word “pass” on its own. A document with none of those describes nothing you can check.
- Appearance
- A visual check against a stated description, under defined lighting. What it does not show: It detects gross contamination, particulates and discolouration. It says nothing about sterility or about anything dissolved in the water.
- pH
- The acidity of the solution, measured with a calibrated meter. What it does not show: It confirms the solution sits in its specified range. It is a property of the batch as tested, not a guarantee of compatibility with anything you add to it.
- Sterility
- A culture-based test showing no microbial growth in the sample under the conditions of the method. What it does not show: It applies to the sealed vial as manufactured. Once the stopper is punctured the result no longer describes the contents — that is what the in-use limit exists for.
- Preservative content
- An assay confirming the bacteriostatic preservative is present at the specified level. What it does not show: It shows the preservative is within specification for that batch. It does not extend the in-use limit or make the vial suitable for any use beyond the one it is sold for.
- Container closure integrity
- A check that the seal holds, so the sealed contents stay sealed. What it does not show: It describes the container as tested. A vial that arrives with a damaged seal or a lifted cap should not be used regardless of what the batch record says.
Published documentation
The safety data sheet is the full sixteen-section SDS for this product, version 1.0, revised 2026-09-08. It covers hazard classification, composition, first aid, handling, storage, disposal and transport. Storage and the in-use limit are also stated on the product page, and how to store it and how long a vial lasts work through what those two figures mean in practice.