Biological Indicator Shelf Life and Storage in Canadian Clinics: What to Check
A box of spore tests that has sat in a cupboard since last winter still looks fine. The lot number and the expiry date are what tell you whether it is.
Biological indicators (BIs) are living products. Each vial or strip carries a defined population of Geobacillus stearothermophilus spores, and and that population is held to the printed expiry date when the product is stored the way the maker states. Two checks catch most of the problems a clinic meets: the date on the box, and the record that ties each test to the load it monitored.
What does the expiry date on a biological indicator mean?
The expiry date is the last day the stated spore population and the stated readout performance are assured. Past that date the population can fall below the level the test depends on, and a passing result proves less than it appears to. Storage conditions matter as much as the date. Heat, direct sunlight and damp are the three that shorten usable life, and a cupboard above a sterilizer is the wrong place for a box of spore tests. ISO 11138-1 sets the general requirements for how a biological indicator is made and performs; what a clinic adds is a storage habit and a record.
How should biological indicators be stored in a clinic?
Store the box sealed, at room temperature, away from the sterilizer and away from a sink. Do not refrigerate or freeze a spore test. Keep the box in its outer packaging so the lot number and expiry stay readable, rotate stock so the oldest lot is used first, and write the date the box was opened on the side. A small stock ordered more often is easier to keep in date than a year of supply in one cupboard.
| Storage check | What it means in practice |
|---|---|
| Keep the box sealed | Store in the outer packaging so the lot number and expiry stay readable |
| Room temperature | Away from heat, direct sunlight and damp, and out of a cold room |
| Away from the sterilizer | A cupboard above an autoclave runs hot and shortens usable life |
| Rotate by lot | Oldest lot used first, so nothing drifts past its printed date |
| Record lot and expiry | Written into the sterilization log beside the cycle it monitored |
What should you check before you use a spore test?
Three things, every time: the expiry date on the vial or strip, the lot number, and where the box has been stored. Then run the test the way the cycle requires, with a control alongside each batch and the incubation temperature the maker states. The lot number and expiry date belong in the sterilization log next to the cycle they monitored, because that pair is what an inspector asks for when a result is questioned.
How long do you keep biological indicator records?
Ontario's dental infection control standard expects the sterilizer log to be maintained for at least ten years from the date of the last entry, which is what makes the lot and expiry fields worth filling in at the time rather than rebuilding later. A log that records the cycle, the indicator lot, the expiry date and the result answers the question without pulling the original box out of a cupboard.
A clinic that wants one fast window and one low-cost window can run the 1-hour rapid-readout indicator beside the 24-hour self-contained vial, with a 5-pack biological indicator trial to test the workflow before committing to a case. The 24-well dry-block incubator holds a full day of tubes. The sterilization monitoring collection groups the formats by readout window, and the sterilization compliance hub collects the records Canadian clinics are asked to keep.
Ordering for a clinic, lab or care home? Wholesale and multi-site ordering covers case pricing and account setup, and the B2B wholesale collection lists the lines stocked for institutional buyers.
References
- Royal College of Dental Surgeons of Ontario, Infection prevention and control (checked 29 September 2026)
- Public Health Ontario, Sterilization monitoring log for tabletop sterilizers (checked 29 September 2026)
- Biological indicators, general requirements, ISO 11138-1 (checked 29 September 2026)
Related Reading
- Do you need to record biological indicator lot numbers and expiry dates
- How do Canadian clinics dispose of expired biological indicators
- Buying autoclave tape, chemical indicators and biological indicators in bulk
Frequently Asked Questions
What is the shelf life of a biological indicator?
The maker sets it. The expiry date on the box is the last day the stated spore population and readout performance are assured under the stated storage conditions.
Should biological indicators be refrigerated?
No. Store spore tests sealed at room temperature, away from heat, direct sunlight and damp, and away from the sterilizer itself.
What should you record when you run a spore test?
The cycle it monitored, the indicator lot number, the expiry date and the result, written into the sterilization log at the time of the test.
How long are sterilization records kept in Ontario?
Ontario's dental infection control standard expects the sterilizer log to be maintained for at least ten years from the date of the last entry.
Last updated: September 2026. CliniEco Medical is a licensed medical device establishment (MDEL #35334).
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