Within Control – Infection Prevention & Training
Your Shield Against Infection
Sterilisation failure is one of those situations every dental practice hopes will never happen.
But a strong infection prevention and control system is not built on the assumption that equipment and processes will never fail. It is built around the ability to recognise a failure, contain it, investigate it, document it and respond appropriately before patient safety is compromised.
This is particularly important under AS/NZS 5369:2023, incorporating Amendment No. 1 (January 2026), the current Australian/New Zealand standard addressing the reprocessing of reusable medical devices (RMDs). The Standard covers effective and safe reprocessing, storage, handling and transportation of reusable devices.
For dental practices, the important message is simple:
A steriliser completing its cycle does not, by itself, prove that every RMD in that load is sterile.
Sterilisation assurance comes from a system of controls.
What do we mean by a “sterilisation failure”?
A sterilisation failure or non-conformance occurs when there is evidence—or reasonable doubt—that the required sterilisation process or established release criteria have not been achieved.
Some failures are obvious.
The steriliser may display an error message or terminate the cycle.
Others can be much quieter.
The machine may display “Cycle Complete”, but review of the cycle parameters, chemical indicators, packaging or processed load identifies something that does not meet the required criteria.
This is why staff competency is so important.
The ADA’s current IPC guidance, which applies AS/NZS 5369:2023, specifically highlights that staff inspecting sterilised RMDs need to understand the requirements for passing a load and what to do when those requirements are not met.
Where can sterilisation failures occur?
Sterilisation does not begin when the autoclave door closes.
The complete reprocessing pathway matters:
Point of use → Transport → Cleaning → Rinsing → Drying → Inspection → Packaging → Loading → Sterilisation → Monitoring → Load release → Storage → Traceability
A problem at an earlier stage can undermine what happens later.
For example, an instrument that has not been adequately cleaned should not simply be considered acceptable because it subsequently went through a sterilisation cycle.
This reflects a fundamental principle of AS/NZS 5369: reprocessing is an interconnected, controlled process rather than a single piece of equipment. Standards Australia describes the Standard as covering the steps needed to ensure RMDs are effectively cleaned, disinfected and sterilised, with particular emphasis on validation and monitoring.
🚨 Warning signs of a potential sterilisation failure
Dental teams should be trained to recognise situations that require investigation.
These can include:
1. Physical cycle parameters outside the established criteria
Review the steriliser’s cycle record.
The relevant physical parameters include:
TIME + TEMPERATURE + PRESSURE
If the required cycle conditions have not been achieved, the load should not simply be released because the machine reached the end of its program.
Current ADA guidance requires practices to have a risk-management process for parametric release and specifically refers to checking time, temperature and pressure.
2. Failed chemical indicators
Chemical indicators provide information about the conditions achieved at the location where the indicator was placed.
But not all indicators provide the same information.
For example:
Class 1 indicators primarily demonstrate exposure to the process. They respond to heat and do not establish that adequate steam conditions were achieved inside a package.
Classes 4, 5 and 6 provide progressively more specific information about critical sterilisation variables, depending on the indicator type.
A colour change on the outside of a pouch therefore does not equal proof of sterility.
This is an important staff-training point:
PROCESS INDICATOR CHANGED COLOUR ≠ITEM PROVEN STERILE
3. Failed air removal and steam penetration testing
Effective steam sterilisation requires steam to contact the surfaces being sterilised.
Air can interfere with steam penetration, particularly with challenging loads and hollow RMDs.
The January 2026 amendment to AS/NZS 5369 updated terminology around this area. References for small steam sterilisers now use Air Removal and Steam Penetration Test (ARSPT) terminology, and load-monitoring PCD requirements were clarified.
For Type B and some Type S small steam sterilisers, load-monitoring PCDs are required to conform to ISO 11140-6.
This matters in dentistry because many RMDs present challenging geometries.
A Helix-style device should therefore not be selected simply because something marketed as a “Helix test” is available.
ADA NSW warned practices in April 2026 that not all commercially available Helix devices meet the required international standard and specifically highlighted the requirement for compliant ISO 11140-6 devices.
4. Wet packs đź’§
The steriliser has finished.
The parameters appear acceptable.
The pouch indicator has changed.
But when the door opens, you find a wet pack.
Do not dismiss this as:
“It’s only a little bit of water.”
Packaging is part of maintaining the processed RMD in its required state until use.
A wet or compromised package is therefore a non-conforming item that requires appropriate management, rather than something to be routinely released into storage.
The question should not be:
“Did the steriliser finish?”
It should be:
“Does this RMD meet all of our established release criteria?”
5. Torn, damaged or opened packaging
Packaging should be inspected before release and again as appropriate before clinical use.
Look for:
- Tears;
- Punctures;
- Damaged seals;
- Open seams;
- Moisture;
- Contamination;
- Compromised packaging;
- Other evidence that package integrity has been lost.
If package integrity cannot be assured, neither can the maintained condition of the packaged RMD.
6. Incorrect loading or overloading
Loading is not about fitting as much as possible into the steriliser.
The load configuration can influence:
- air removal;
- steam penetration;
- condensate removal;
- drying;
- overall process effectiveness.
AS/NZS 5369 places considerable emphasis on validation, product families and challenging load configurations.
Performance qualification assesses whether defined load configurations can be processed effectively, including evaluation of the most challenging devices within relevant product families.
So a validated process should not quietly become:
“There’s still a little room—put another ten pouches in.”
Routine processing needs to remain consistent with the established and validated process.
7. Cycle interruption, alarm or steriliser fault
An alarm is not an inconvenience to be cleared so staff can continue working.
It is information.
If a cycle is interrupted or an error occurs:
Do not automatically release the load.
The operator should determine:
- What happened;
- When it happened;
- Which cycle phase was affected;
- Whether required parameters were achieved;
- What the manufacturer’s instructions specify;
- Whether the affected load can meet release criteria;
- Whether technical assessment is required.
Repeated failures deserve particular attention.
Resetting an alarm repeatedly without investigating its cause is not a quality-assurance system.
8. Missing cycle documentation
Another form of failure is not necessarily a mechanical failure at all.
Imagine this:
The steriliser appears to have worked.
The packs are dry.
The indicators appear satisfactory.
But there is no adequate cycle record.
How will you demonstrate that the required process occurred?
How will you link the load to your sterilisation records?
How will you investigate the cycle later if a problem is discovered?
Documentation provides evidence that monitoring and release actually occurred.
Current ADA guidance recommends that steriliser cycle data remain stored and accessible for at least seven years, while noting that longer retention requirements can apply in some circumstances.
The biggest mistake: simply running the instruments again
When something fails, the instinct can be:
“Just put them through another cycle.”
That may completely miss the cause of the failure.
Suppose the problem was:
- Inadequate cleaning;
- Incorrect packaging;
- Overloaded chamber;
- Equipment malfunction;
- Failed steam penetration;
- Incorrect cycle selection;
- Damaged packaging.
Another cycle does not necessarily correct the underlying problem.
Instead, the failure needs to be investigated and appropriately managed.
A practical response to sterilisation failure
I teach teams a simple six-stage framework:
🛑 STOP → 📦 QUARANTINE → 🔍 INVESTIGATE → 📝 DOCUMENT → 🛠️ CORRECT → ✅ VERIFY
Let’s look at each step.
🛑 STEP 1 — STOP
If there is evidence that the release criteria have not been met:
DO NOT RELEASE THE AFFECTED RMDs FOR CLINICAL USE.
Prevent the potentially affected items from entering normal sterile storage or being distributed for patient care.
The purpose is containment.
Do not allow uncertainty to become exposure.
📦 STEP 2 — QUARANTINE
Identify and control the affected RMDs or loads in accordance with your facility’s procedures.
They should not become mixed with items that have already satisfied release criteria.
Depending on the circumstances, this may require determining:
- Which steriliser was involved;
- Affected cycle/load number;
- Time and date;
- RMDs in the load;
- Whether previous or subsequent cycles could be affected;
- Whether any affected RMDs remain in storage;
- Whether anything has already been released.
This is where traceability becomes extremely valuable.
A good tracking system is not merely paperwork for an audit.
When something goes wrong, it helps answer:
What was processed, when was it processed, where did it go and who or what may be affected?
🔍 STEP 3 — INVESTIGATE
Now determine why the failure occurred.
Review the entire process rather than immediately blaming the steriliser.
Consider:
Equipment
Was there a fault or alarm?
Physical monitoring
Were the required time, temperature and pressure parameters achieved?
Cycle selection
Was the correct validated program selected?
Loading
Was the chamber loaded according to the established configuration and manufacturer’s instructions?
Packaging
Were appropriate materials used and correctly sealed?
Chemical indicators
Were the correct indicators used and were their results acceptable?
Air removal and steam penetration
Were required routine tests satisfactory?
Cleaning
Were RMDs adequately cleaned before packaging?
Drying
Was residual moisture present?
Operator process
Was the documented procedure followed?
Maintenance and validation
Is the steriliser within its required servicing, calibration, qualification and validation requirements?
Investigation should identify the cause, not merely describe the symptom.
📝 STEP 4 — DOCUMENT
A failure should leave a record.
Depending on the event, documentation may include:
- Date and time;
- Steriliser ID;
- Cycle/load number;
- Affected RMDs;
- Cycle parameters;
- Indicator results;
- Error or fault displayed;
- Nature of the non-conformance;
- Immediate containment;
- Investigation undertaken;
- Person responsible;
- Corrective action;
- Technical/service involvement;
- Reprocessing undertaken;
- Verification results;
- Final outcome.
Documentation turns an incident into something the organisation can trace, investigate and learn from.
🛠️ STEP 5 — CORRECT
Correct the actual problem.
The corrective action will depend on what the investigation identifies.
It could involve:
Operator issue → retraining
Incorrect loading → correct load configuration
Packaging problem → correct packaging/sealing process
Failed monitoring device → investigate test/device/process
Equipment fault → remove equipment from use and obtain appropriate technical assessment
Cleaning failure → recommence the required reprocessing pathway
The objective is not simply to make the alarm disappear.
It is to restore a controlled and effective process.
✅ STEP 6 — VERIFY
Before returning an affected process or piece of equipment to normal operation, establish that it is functioning correctly.
The level of verification required will depend on the nature of the failure and applicable manufacturer, validation and organisational requirements.
This is another reason that validation and routine monitoring are central to AS/NZS 5369.
The Standard emphasises validation and monitoring because a reprocessing system should be able to demonstrate that it can consistently produce the intended result.
What if instruments from the affected load have already been used?
This changes the situation significantly.
The issue is no longer limited to the sterilisation room.
The organisation may need to establish:
Which RMDs were involved?
Which loads were affected?
When did the problem begin?
Which patients may have been exposed?
What exactly failed?
What is the clinical/infection risk?
This is where traceability, incident management, risk assessment and appropriate escalation become critical.
The response should be based on the circumstances and applicable regulatory/public-health requirements rather than staff making an informal decision about whether the incident “looks serious.”
Biological indicators are not a substitute for the entire monitoring system
Another misconception is:
“Our biological indicator passed, so everything is fine.”
Biological, chemical and physical monitoring provide different information.
They should not be treated as interchangeable.
Current ADA guidance describes routine steam-sterilisation monitoring as using physical monitoring, such as cycle-parameter records, in combination with chemical indicators. It also explains the different functions and precision of the chemical-indicator classes.
Sterilisation assurance therefore comes from multiple controls, not one test result.
Competency is one of your most important controls
A sophisticated steriliser cannot compensate for staff who have never been taught how to interpret its results.
The person checking and releasing loads needs to know:
- What normal looks like;
- What the cycle parameters mean;
- How to interpret applicable indicators;
- What acceptable packaging looks like;
- How to recognise wet or damaged packs;
- What monitoring is required;
- What constitutes a non-conformance;
- When not to release a load;
- How to escalate a problem.
Current ADA guidance explicitly states that the staff member undertaking steriliser load checking must be competent, with the necessary knowledge and skill obtained through education, training, qualification, experience or a combination of these.
Competency therefore goes beyond:
“I know how to start the autoclave.”
Build a system that expects problems to be detected
A strong IPC system should make the correct action easy.
Your sterilisation area should have documented processes covering:
Routine monitoring → Load checking → Release criteria → Non-conformance → Quarantine → Investigation → Corrective action → Verification → Documentation
And every team member involved in reprocessing should know where those procedures are located and what their responsibilities are.
A procedure sitting unread in a folder does not create safety.
A procedure understood and consistently followed by competent staff does.
The key message
Sterilisation failure does not always arrive with a flashing red alarm.
Sometimes it looks like:
đź’§ One wet pouch.
📉 One unusual parameter.
🧪 One unexpected indicator result.
📦 One damaged seal.
⚠️ One error that someone decides to ignore.
đź“„ One missing cycle record.
Or one staff member saying:
“It’s probably fine.”
That is why sterilisation assurance depends on systems rather than assumptions.
Remember:
STOP
Don’t release questionable RMDs.
QUARANTINE
Control potentially affected items.
INVESTIGATE
Find out what happened.
DOCUMENT
Create a traceable record.
CORRECT
Address the actual cause.
VERIFY
Demonstrate that the process is operating correctly.
Sterilisation is a process—not an autoclave
A steriliser is one component of a much larger infection-prevention system.
Safe reprocessing depends on:
- Correct cleaning.
- Correct inspection.
- Correct packaging.
- Correct loading.
- Validated processes.
- Appropriate monitoring.
- Competent staff.
- Documented load release.
- Traceability.
- And a clear response when something goes wrong.
The most concerning sterilisation failure isn’t necessarily the one that triggers an alarm.
It is the one that happens—and nobody recognises it.
At Within Control – Infection Prevention & Training, our focus is helping dental teams move beyond simply following steps to understanding the systems behind safe reprocessing.
Because a strong IPC program doesn’t only teach staff how to sterilise instruments.
It teaches them how to recognise when something hasn’t gone according to plan—and exactly what to do next.