“BAC water” is shorthand for bacteriostatic water. The abbreviation is informal: it is not a chemical formula, a brand or a grade, and it does not appear on manufacturer labels, which always spell out “Bacteriostatic Water”. The product itself is sterile WFI-grade water containing 0.9% benzyl alcohol as a preservative, supplied in vials of 3 mL, 10 mL or 30 mL. See what is bacteriostatic water?
Where the abbreviation comes from
“Bacteriostatic” means that the preservative stops bacteria from multiplying without necessarily killing them, and the first three letters became the everyday name in laboratories and in search queries. It is the same product whether it is called BAC water, bac water, bacteriostatic water or BW; the label is the only authority on what is in the vial. See what does bacteriostatic mean?
What it is not
- It is not “bacterial” water or water containing bacteria; the opposite is true. The sealed product is sterile. See is bacteriostatic water sterile?
- It is not the same as plain sterile water, which contains no preservative. See is bacteriostatic water the same as sterile water?
- It is not bacteriostatic sodium chloride (bacteriostatic saline), which also contains 0.9% salt. See does bacteriostatic water contain salt?
- It is not a bacteriostatic agent in its own right: only the 0.9% benzyl alcohol is. See what is benzyl alcohol used for?
Reading the label
A vial of BAC water reads “Bacteriostatic Water” (with “USP” where the manufacturer states monograph compliance), lists 0.9% benzyl alcohol as the sole additive, and gives the volume, lot number, expiration date and storage conditions. Anything else on the composition line means it is a different product. See bacteriostatic water ingredients and what USP means on the label.
Related
Bacteriostatic water FAQ · Glossary · All packs
All BAC Water Supply products are supplied for laboratory research use only and are not for human or veterinary use.