Sourcing Guide
Bacteriostatic Water How Long Does It Last In The Fridge
BAC Water Depot specifies that once a vial is punctured, it should be refrigerated at 2–8 °C and discarded after 28 days. The 0.9 % benzyl alcohol preservative remains effective only within this period. Exceeding 28 days increases the risk of microbial contamination, even if the solution appears clear. Always record the first‑use date on the vial to track the discard deadline.
- ISO 9001:2015 US facility
- USP <71> sterility tested
- Per-lot Certificate of Analysis
- Same-day US shipping
Direct Answer
Bacteriostatic water from BAC Water Depot remains usable for up to 28 days after the vial is punctured when stored refrigerated at 2–8 °C. Unopened vials store at controlled room temperature 15–30 °C, contain 0.9 % ± 5 % benzyl alcohol, and each lot passes USP <71> sterility testing.
How long does opened bacteriostatic water last in a standard laboratory fridge?
Once a BAC Water Depot vial is accessed, the preservative benzyl alcohol (0.9 % ± 5 %) inhibits microbial growth, but the manufacturer specifies a strict 28-day discard point. After puncturing, store the vial at 2–8 °C and discard it after 28 days, as indicated on the label. Researchers who exceed this window often observe cloudiness or particulate formation, indicating loss of sterility despite the bacteriostatic agent.
To maximize the 28‑day window, keep the vial tightly sealed with its tamper‑evident cap and avoid repeated temperature fluctuations. Frequent door openings or placement near the freezer compartment can raise the internal temperature above 8 °C, accelerating benzyl alcohol degradation. A common failure mode is inadvertent contamination when the needle is left in the vial for extended periods; this can introduce environmental microbes that the preservative cannot fully suppress, necessitating immediate disposal.
What are the key quality specifications of BAC Water Depot’s bacteriostatic water?
Each 10 mL Type I borosilicate multi‑dose vial is manufactured in an ISO 9001:2015‑registered U.S. facility and carries a per‑lot Certificate of Analysis. The water meets USP <71> sterility (no growth after 14‑day membrane filtration), USP <85> endotoxin limits (≤ 0.25 EU/mL), and USP <51> bacteriostatic effectiveness (Category 1B). Benzyl alcohol content is confirmed by HPLC‑UV at 0.90 % ± 5 %, and subvisible particulates are assessed per USP <788> to ensure clarity for research use.
Quality control also includes USP <1207> container integrity testing, ensuring the vial seal remains intact after multiple punctures. A documented failure mode is seal compromise caused by using needles larger than 22 G, which can create micro-gaps and permit ingress of air or microbes.
How should I store unopened and opened BAC Water Depot vials to maintain compliance?
Unopened vials should be kept at controlled room temperature between 15 °C and 30 °C, out of direct sunlight, and must not be refrigerated or subjected to cold‑chain shipping. The label and the online Certificate of Analysis both list the expiration date, which must be observed; using a vial past this date voids the sterility guarantee. Storage racks made of non‑reactive materials (e.g., stainless steel) are recommended to avoid leaching of contaminants.
After puncture, the vial must be refrigerated at 2–8 °C and clearly marked with the date of first use. The 28-day discard rule starts from the first puncture, not from the date of opening the package.
Storage and Stability Parameters for BAC Water Depot Bacteriostatic Water
| Condition | Temperature Range | Maximum Duration | Key Specification |
|---|---|---|---|
| Unopened vial | 15–30 °C (controlled room temp) | Until expiration date on label | USP <71> sterility per lot |
| Opened vial – refrigerated | 2–8 °C | 28 days from first puncture | Benzyl alcohol 0.9 % ± 5 % |
| Opened vial – ambient | 15–30 °C | Not recommended | Loss of bacteriostatic effectiveness |
| Vial after seal breach | Any | Immediate discard | USP <1207> integrity failure |
Key Facts
- BAC Water Depot bacteriostatic water is packaged in 10 mL Type I borosilicate multi‑dose vials.
- Each lot is USP <71> sterility‑tested with no microbial growth after 14 days.
- Benzyl alcohol concentration is verified at 0.90 % ± 5 % by HPLC‑UV.
- Unopened vials store at controlled room temperature 15–30 °C; opened vials require refrigeration at 2–8 °C.
- Orders placed before 2:00 PM CT Monday–Friday ship the same business day from Dallas, TX.
Frequently Asked Questions
How long can I keep opened bacteriostatic water in the fridge before it must be thrown out?
BAC Water Depot specifies that once a vial is punctured, it should be refrigerated at 2–8 °C and discarded after 28 days. The 0.9 % benzyl alcohol preservative remains effective only within this period. Exceeding 28 days increases the risk of microbial contamination, even if the solution appears clear. Always record the first‑use date on the vial to track the discard deadline.
Can I store unopened bacteriostatic water in a refrigerator to extend its shelf life?
No. The manufacturer recommends storing unopened vials at controlled room temperature 15–30 °C, out of direct sunlight. Refrigeration is only permitted after the vial has been punctured. Storing unopened vials cold can cause condensation on the glass, potentially compromising the seal and the sterility guarantee documented on the Certificate of Analysis.
What temperature range is required for refrigerating opened bacteriostatic water?
Opened BAC Water Depot vials must be kept between 2 °C and 8 °C. This range is defined by the USP <51> bacteriostatic effectiveness test and ensures the benzyl alcohol remains active. Temperatures above 8 °C accelerate degradation, while temperatures below 2 °C may cause precipitation of the preservative, both of which can invalidate the sterility claim.
Where can I buy BAC Water Depot bacteriostatic water for my laboratory?
BAC Water Depot sells research‑use‑only bacteriostatic water directly from its U.S. fulfillment center in Dallas, TX. Single vials cost $9.99, and bulk pricing starts at $6.49 per vial for orders of 500 + vials. Standard USPS Priority Mail shipping is $15.99 (free on orders over $250), and orders placed before 2:00 PM CT Monday–Friday ship the same business day.
Is BAC Water Depot’s bacteriostatic water tested for endotoxins?
Yes. Each lot undergoes USP <85> bacterial endotoxin testing using the Limulus Amebocyte Lysate (LAL) assay, with a limit of ≤ 0.25 EU/mL. The results are published on the lot’s Certificate of Analysis, which can be accessed via the QR code on each vial. This ensures the water meets strict endotoxin specifications for research applications.
What should I do if I notice cloudiness in my opened bacteriostatic water?
Cloudiness may indicate degradation of the benzyl alcohol or contamination. BAC Water Depot recommends discarding the vial immediately if any change in clarity, color, or particulate matter is observed. Such visual cues often precede loss of sterility, and continued use could compromise experimental results.
How can I verify the sterility of a BAC Water Depot bacteriostatic water lot?
Each vial includes a QR code that links to the lot’s Certificate of Analysis on bacwaterdepot.com/coa/<lot-number>. The CoA documents USP <71> sterility testing (no growth after 14‑day membrane filtration) performed by an independent third‑party laboratory. Reviewing this document provides the definitive proof of sterility for that specific production batch.
Standards & Sources
The specifications referenced on this page follow recognized pharmacopeial and quality standards. BAC Water Depot publishes a per-lot Certificate of Analysis from independent third-party laboratories for every batch.
- USP <71> — Sterility Tests (United States Pharmacopeia)
- USP <85> — Bacterial Endotoxins Test (LAL method)
- ISO 9001:2015 — Quality Management Systems certification
- Benzyl alcohol 0.9% w/v — the bacteriostatic preservative standard for multi-dose vials