The inspection before a cycle decides whether the load that comes out is usable. Most failed loads — wet packs, popped seals, unchanged indicators — trace back to problems that existed before the chamber started. This five-part checklist mirrors the routine Canadian dental clinics build around CSA Z314.8 and AAMI ST79.
1. Instrument Preparation: Clean Before Anything Else
Steam only sterilizes the surfaces it can reach. Dried soil shields microbes from direct steam contact, so cleaning comes first, inspection second.
- Check every surface for visible soil, especially hinges, serrations, and box locks. If you can see residue, the cycle will not remove it — reclean the item.
- Open hinged instruments (scissors, forceps) before packaging — a closed hinge blocks steam.
- Dry lumens and cannulas with forced air. Residual water blocks steam contact and leaves a wet pack.
- Log the cleaning method and operator; inspectors usually ask for cleaning records first.
2. Packaging: A Barrier Is Only as Strong as Its Seal
Packaging admits steam during the cycle and keeps everything out afterward. A pinhole or a weak seal fails the second job even when the cycle ran well.
- Match the pouch to the instrument so contents never stress the seal line. CliniEco’s sterilization pouches with Class 4 dual indicators come in assorted sizes so the packaging fits the load.
- Keep the seal zone clean and dry. Moisture, powder, or a fold creates a false seal that can open weeks later on the shelf.
- Leave the internal indicator visible through the film so results are read without opening the pack.
- Secure wrapped cassettes with autoclave indicator tape, never office tape. Autoclave indicator tape changes colour with heat exposure, signalling the wrap went through the chamber — it documents exposure, not sterility.
3. Loading: Steam Needs a Pathway
How items sit in the chamber decides how evenly steam reaches them and how well they dry. Overloading is a common cause of wet packs and incomplete indicator change.
- Do not overload. Leave clear space between pouches and trays; rated capacity is not an invitation to fill every gap.
- Do not stack pouches flat. Stand them on edge, paper-to-paper and plastic-to-plastic, so air escapes and condensate drains. If a pouch lies flat, keep the paper side up so steam enters through the paper.
- Keep paper away from the chamber walls. Contact with a wet metal wall wicks moisture into the pack.
4. Machine Checks: Door, Water, Drain, and the First Cycle
The sterilizer deserves the same few minutes as the instruments, and pre-vacuum machines need an empty-chamber test before the first load.
- Inspect the door gasket for cracks, tears, or debris. A damaged gasket lets air in, so the chamber cannot hold the vacuum pre-vacuum cycles depend on.
- Refill with distilled water only. Tap-water minerals form scale on the steam generator and can deposit on packs; CSA Z314.8 treats water quality as a factor in steam quality.
- Clean the drain screen or filter on the schedule in your sterilizer manual. A blocked drain is a frequent cause of wet loads.
- Run a Bowie-Dick test pack in an empty chamber after warm-up, before the first load. It challenges the vacuum system’s air removal: if steam cannot penetrate the sheet evenly, the colour change is blotchy and the sterilizer stays out of service until the test passes. CSA Z314.8 and AAMI ST79 describe this as the daily first-cycle check for vacuum-assisted sterilizers.
5. Records: Write It Down Before the Load Runs
A cycle without a record is treated as one that did not happen. Fill in the load sheet before you press start, not from memory at day’s end.
What the load sheet should carry
- Cycle number, date, operator, and load contents.
- Exposure parameters — temperature, time, and pressure — noted when the cycle finishes.
- Monitoring results: the Bowie-Dick outcome, chemical indicator results from the load, and the biological indicator result when due.
Keep the three monitors straight: the Bowie-Dick test asks whether air is removed; chemical indicators ask whether the right conditions reached the pack; biological indicators ask whether spores were killed. In Ontario, the RCDSO requires a biological indicator for each sterilizer on every day that it is used — daily monitoring, not weekly. The weekly baseline is the CDC / AAMI ST79 standard in most US states.
FAQ
Q: What should be checked before running an autoclave?
A: Five areas: instrument cleanliness (hinges, lumens, no visible soil), packaging integrity (correct size, clean and dry seal zone, visible indicator), loading (spacing, no stacking), machine condition (door gasket, distilled water, drain filter), and the load sheet with monitoring planned.
Q: How full can an autoclave load be?
A: There is no fixed number; steam must circulate around every item. Leave gaps between pouches and trays, stand pouches on edge, and respect the limits in your sterilizer manual. A crowded chamber is the usual prelude to wet packs and incomplete indicator change.
Q: Why is a Bowie-Dick test done first in the day?
A: Because it tests the vacuum system before any instrument is at risk. Pre-vacuum sterilizers remove air before steam enters, and a leak or weak vacuum leaves air pockets that block steam penetration. Run the pack in an empty chamber after warm-up: an even colour change means air removal is working. If the sheet is blotchy, do not use the sterilizer until the fault is found and the test passes.
Related reading: explore our sterilization compliance hub for every industry that sterilizes.
start with our pillar guide on sterility assurance level (SAL) and what 10⁻⁶ really means.
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