The vocabulary of bacteriostatic water is borrowed from pharmacopeial standards, analytical chemistry and packaging engineering. Here are the terms that appear on labels, certificates of analysis and in these guides, in alphabetical order.
- Accelerated stability
- Storage of samples at elevated temperature and humidity (typically 40 °C / 75% RH) to predict long-term stability quickly. See how expiration dates are set.
- Antimicrobial effectiveness test
- A challenge test in which a preserved product is inoculated with defined organisms to confirm the preservative inhibits their growth over 28 days.
- Aseptic technique
- Working practices that prevent introduction of microorganisms: clean surfaces, disinfected stoppers, sterile single-use devices, no open exposure.
- Assay
- A quantitative measurement of a component's content; for bacteriostatic water, the measurement of benzyl alcohol against the 0.9% label claim. See the benzyl alcohol assay.
- Bactericidal
- Kills bacteria. Contrast with bacteriostatic.
- Bacteriostatic
- Inhibits the growth and multiplication of bacteria without necessarily killing them.
- Bacteriostatic saline
- 0.9% sodium chloride solution with 0.9% benzyl alcohol; isotonic, unlike bacteriostatic water. See the comparison.
- Benzaldehyde
- The first oxidation product of benzyl alcohol; almond-like odor; a marker of preservative degradation.
- Benzoic acid
- The further oxidation product of benzaldehyde; lowers pH slightly as it forms.
- Benzyl alcohol
- C7H8O, the aromatic alcohol used at 0.9% as the preservative in bacteriostatic water. See the full guide.
- Certificate of analysis (COA)
- A lot-specific document reporting test results against specification. See how to read a COA.
- Container closure integrity (CCI)
- The ability of the vial, stopper and crimp to exclude microorganisms and prevent leakage through shelf life. See CCI testing.
- Controlled room temperature (CRT)
- 20 to 25 °C, with permitted excursions between 15 and 30 °C; the labeled storage condition.
- Crimp / ferrule
- The aluminum band crimped over the stopper and vial neck that forms the seal; cannot be reapplied once removed.
- Cytotoxic
- Toxic to cells; benzyl alcohol at preservative concentration is cytotoxic to cultured cells. See cell culture.
- Deionized (DI) water
- Water with ions removed by ion exchange; not sterile or endotoxin-controlled. See vs. deionized water.
- Discard date
- First-puncture date plus 28 days, by laboratory convention, for an opened multi-use vial.
- Distilled water
- Water purified by boiling and condensation; not sterile or endotoxin-controlled. See vs. distilled water.
- Endotoxin
- Lipopolysaccharide from Gram-negative bacterial cell walls; heat-stable; measured in EU/mL. See endotoxin testing.
- EU/mL
- Endotoxin units per millilitre; the limit for bacteriostatic water is 0.5 EU/mL.
- Excess volume / overfill
- The small volume above the labeled volume added so that the labeled volume can be withdrawn. See fill volume.
- Expiration date
- The last date through which a sealed vial stored as labeled is supported by stability data.
- Flip-off cap
- The plastic cap over the crimp that protects the stopper surface and provides tamper evidence.
- Headspace
- The gas space above the liquid in a sealed vial.
- Hydrolytic resistance
- A glass's resistance to releasing alkali into water; Type I borosilicate has the highest.
- Hypotonic
- Lower osmotic concentration than physiological fluids; bacteriostatic water is hypotonic because it contains no salts.
- LAL test
- Limulus amebocyte lysate test for bacterial endotoxins; gel-clot, turbidimetric or chromogenic.
- Light obscuration
- The instrumental method for counting sub-visible particles. See particulate testing.
- Lot / batch
- The set of vials filled from one bulk preparation in one operation, sharing a lot number and a COA. See lot traceability.
- Membrane filtration (sterility)
- The sterility test method in which sample is filtered, the membrane rinsed free of preservative, and cultured. See sterility testing.
- Multi-use vial
- A sealed vial designed to be entered more than once, made possible by a preservative; limited to 30 mL for bacteriostatic water.
- Nonpyrogenic
- Free of fever-producing substances, in practice meaning within the endotoxin limit.
- Particulate matter
- Visible or sub-visible particles in a solution; tested per USP <788>.
- pH
- Acidity/alkalinity; 4.5 to 7.0 for bacteriostatic water, typically ~5.7, unbuffered. See pH explained.
- Preservative
- An antimicrobial agent added to inhibit growth in a multi-use product.
- Purified Water
- The base pharmacopeial water grade with conductivity and TOC limits but no endotoxin or sterility requirement. See USP water grades.
- Research use only (RUO)
- A labeling designation limiting intended use to laboratory research. See what RUO means.
- Sterile
- Free of viable microorganisms; a property of the sealed container, verified by the sterility test.
- Stopper
- The elastomer (usually bromobutyl or chlorobutyl rubber) closure that is punctured for withdrawal and reseals.
- Type I borosilicate glass
- The glass type with the highest hydrolytic resistance, used for vials. See vials.
- WFI grade
- The pharmacopeial water grade with an endotoxin limit of 0.25 EU/mL, from which sterile and bacteriostatic waters are made.
All guides are indexed in the knowledge base.
All BAC Water Supply products are supplied for laboratory research use only and are not for human or veterinary use.