Bacteriostatic water, sealed at ten millilitres.

Sterile water containing 0.9% benzyl alcohol as a bacteriostatic preservative. The preservative inhibits the growth of bacteria in the vial, which is what allows a single vial to be entered more than once.

Sterile water contains no preservative. Bacteriostatic water contains 0.9% benzyl alcohol, and that preservative is the whole difference: it is what makes this a multi-dose vial rather than a single-use one.

It is the bacteriostatic preservative. At 0.9% it inhibits bacterial growth inside the vial after it has been entered.

No. The benzyl alcohol inhibits the growth of bacteria inside the vial; it does not sterilise the contents, and it does not make a contaminated vial safe to use. It is a preservative, not a steriliser.

A sterile diluent and solvent, used to reconstitute or dilute substances for laboratory and research purposes. It is a diluent, not a product with any activity of its own.

It is sold as a diluent for laboratory and research purposes.

Each vial holds 10ml and is sealed. How many times it can be drawn from depends entirely on the volume taken each time — a 10ml vial gives ten 1ml draws, or five 2ml draws.

Store the sealed vial as stated on its label. Once it has been entered, the limit is 28 days from first puncture.

28 days from first puncture. Write the date on the vial the first time you draw from it, and discard it once that period is up. The benzyl alcohol inhibits bacterial growth in the vial between draws — it does not sterilise the contents, so the limit applies however much liquid is left.

0.9% w/v, which is 9 mg/mL — so a 10ml vial contains 90 mg of benzyl alcohol in total.

An unopened vial with its seal intact can be returned within 14 days of delivery for a full refund. A vial that has been opened or unsealed cannot be — it is sealed for hygiene reasons, and regulation 28(3) of the Consumer Contracts Regulations 2013 excludes it. Anything faulty, damaged or not as described is refunded whether or not it was opened. Full terms are on the returns and refunds page.

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Stripe emails a payment receipt for every order automatically.

The largest bundle on this page is 100 vials, and you can order up to 10 of any bundle in a single order. For anything larger, get in touch at [email protected].

Picking, packing and posting one order costs the same whether it contains one vial or ten, so a larger order carries less of that cost per vial. The saving on each bundle is shown next to it.