For spore testing, dental offices should test each sterilizer at least once a week, and test every load that contains an implantable device. That is CDC's recommendation, and some states, including California, make weekly testing law.
If a spore test is positive, take the sterilizer out of service and repeat the test right away using the same cycle. Log every result with its lot number, and keep the log as long as your state requires (12 months in California).
What a spore test is
A spore test (also called a biological indicator) is a strip or vial of highly resistant bacterial spores that you run through a normal sterilizer cycle. If the cycle worked, the spores are killed and the test reads negative. CDC calls it the only check that "assesses the sterilization process directly."
It is one of three checks CDC recommends:
| Check | What it is | How often |
|---|---|---|
| Mechanical | Read the gauges, display or printout: time, temperature, pressure | Every load |
| Chemical | An indicator inside every package that changes color | Every package |
| Biological (spore test) | Spores run through a cycle, then incubated | At least weekly per sterilizer, and every implant load |
The mechanical and chemical checks tell you a load looks right. Only the spore test shows the sterilizer actually killed microorganisms.
How often to spore test an autoclave
- At least weekly, for each sterilizer. If you have two autoclaves, you run two spore tests a week. CDC does not set a lighter schedule for a sterilizer you rarely use.
- Every load with an implantable device. CDC says implants should ideally not be used until the spore test for their load comes back negative.
- Your state may require more. Spore testing is not an OSHA rule. It becomes law through state dental board infection control rules. California's 16 CCR 1005(b)(17) requires weekly testing of every sterilization device and says results "shall be documented and maintained for 12 months." Check your state's rule.
For testing a new sterilizer or one that was just repaired, follow the manufacturer's instructions and your state's rule.
How to run a weekly spore test
- Pick the same day each week, for example Monday's first full load, so the test isn't missed.
- Place the spore strip or vial where the test kit's instructions say, usually in a pouch in the middle of a normal load.
- Run the cycle as usual and log it in your cycle log.
- Keep a control from the same lot that has not been through the sterilizer. CDC says to use a matching control (same lot number as the test).
- Send both to the lab (mail-in) or incubate them in the office, following the kit's instructions.
- Log the result when it comes back: date run, sterilizer, test and control lot numbers, result and initials.
Mail-in or in-office testing
CDC doesn't prefer one over the other. With a mail-in service, a lab incubates the strip and reports the result to you. With in-office incubation, you read the result yourself after the time the kit states. The schedule and the steps after a positive result are the same either way.
Failed spore test protocol
CDC's steps after a positive spore test:
- Take the sterilizer out of service.
- Review how it was loaded and run, and check the mechanical and chemical results for the failed load.
- Recall and quarantine any implantable items from the load. Don't use them until they are shown to be sterile. Other items don't necessarily need to be recalled.
- Repeat the spore test right away, using the same cycle that produced the positive result.
- If the repeat test is negative and the sterilizer was run correctly, put it back into service.
- If the repeat test is positive, keep the sterilizer out of service until it is inspected or repaired and passes spore tests in three consecutive fully loaded cycles. When possible, recall, rewrap and re-sterilize items processed since the last negative test.
Write each step in the "Action if positive" column of your spore log, with the date. An inspector will look for that record.
Spore test log sheet
Our free autoclave log sheet includes a weekly spore test log, along with a cycle log and a maintenance log. Use one log per sterilizer.
Weekly spore test log
complyday.com| Date run | Cycle or load no. | Spore test lot no. | Control lot no. | Mail-in or in-office | Date of result | Test result (neg/pos) | Control result | Initials | Action if positive |
|---|---|---|---|---|---|---|---|---|---|
Run a spore test at least weekly on each sterilizer, and on every load with an implantable device. If a test is positive, take the sterilizer out of service and repeat the test right away on the same cycle. Source: CDC.
Open the printable spore test log or download the PDF from the autoclave log sheet page.
Where spore testing fits with the rest of your compliance
Spore testing is part of your infection control program, next to dental waterline testing and instrument processing. Its rules come from CDC and your state dental board, not OSHA. The dental OSHA compliance checklist covers the OSHA side. For the yearly training your team needs, see OSHA and HIPAA training for dental offices.