Sterilisation is the silent guardian of patient safety. It doesn’t get the spotlight like surgery or diagnosis, but it’s every bit as critical. Whether you’re running a dental clinic, tattoo studio or medical lab, one thing remains universal — you need your autoclaves to work flawlessly. The trouble is, many practices are making preventable mistakes that quietly undermine the entire process.
Here’s what you need to know about the most common autoclave slip-ups and how they might be putting patients, staff and compliance standards at risk.
Using the Wrong Sterilisation Method for the Load
Not all sterilisation is created equal. One of the most fundamental mistakes is assuming that anything hot and pressurised will do the trick. Some clinics still use dry heat or even household devices thinking they’re sufficient for certain tools. But there’s a reason why autoclaves are stronger at sterilising than microwaves or other substitutes — they offer uniform temperature and validated cycle control that basic equipment simply can’t replicate.
Mismatching the sterilisation method with the type of item — like using steam sterilisation for heat-sensitive plastics — doesn’t just affect effectiveness. It could damage the instrument and lead to incomplete decontamination. Every material has a threshold, and every cycle should be matched accordingly.
To avoid this, staff must be trained not just in operating autoclaves but also in choosing the right cycle for each load type. Your machine can only do so much if it’s being fed the wrong input from the get-go.
Inconsistent Load Configuration
Ever played Tetris in a rush? That’s what some autoclave chambers look like at the end of a long day. Overloading the chamber or stacking instruments too tightly is one of the easiest ways to compromise a cycle.
Steam needs space to move. It must contact every surface evenly to sterilise effectively. When pouches are packed shoulder-to-shoulder or stacked on top of one another, steam distribution becomes patchy. You might end up with pockets of under-sterilised gear — which defeats the whole point.
Make sure instruments are spaced apart, pouches are arranged vertically when required and hollow items are positioned to allow internal steam entry. Cycle validation strips or biological indicators can help test whether your configuration is actually working as intended.
Understanding and applying essential autoclave safety protocols is key here. Correct loading is just as important as cycle selection.
Placing Incompatible Materials in the Chamber
You’d be surprised what finds its way into autoclaves. From acrylic handles to rubber tubing to electronics, it’s not uncommon to see materials inside that were never meant to be steam-sterilised. This doesn’t just damage the items — it can lead to chamber contamination, cycle failure or even dangerous pressure build-up.
Autoclave compatibility isn’t guesswork. It requires checking the manufacturer’s guidelines for every tool or accessory you intend to sterilise. Just because something looks heat-tolerant doesn’t mean it is.
One dental clinic faced ongoing spore test failures and couldn’t figure out why. Turns out, they were including plastic cassettes that warped slightly with each cycle, trapping moisture and blocking steam. Knowing what materials should never go inside an autoclave helps eliminate one of the easiest-to-avoid risks in the entire process.
Skipping Maintenance and Calibration
Autoclaves aren’t set-and-forget machines. Like any piece of precision equipment, they require regular calibration, servicing and cleaning. Yet many facilities only address them when something goes wrong — like a failed spore test or an unusual noise.
When valves get clogged, gaskets degrade or heating elements weaken, your cycles start to drift. Temperatures might not hold, pressures might fluctuate, and you’ll never know unless you’re testing and maintaining regularly.
A robust maintenance routine includes:
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Weekly chamber cleaning
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Gasket inspection
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Water reservoir flushing
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Annual professional calibration and validation
Neglecting these basics isn’t just poor practice — it could lead to false cycle completions and non-sterile equipment being used on actual patients.
Ignoring Chemical and Biological Indicators
It’s easy to treat indicators like an afterthought. They’re just little strips or tubes, right? But these are your proof that the cycle actually did its job. Ignoring them — or worse, not using them — is a massive liability.
Chemical indicators confirm that time, temperature and steam were present during the cycle. Biological indicators (like spore tests) confirm that all microbial life was destroyed.
Some facilities only test weekly, which leaves room for undetected failures to creep in. A best practice is to include a chemical indicator in every load and perform biological testing regularly based on usage volume and regulations.
Even when time is tight, skipping these checks is a shortcut to disaster.
Rushing the Drying Phase
After a successful sterilisation cycle, it’s tempting to open the door, grab the load and get back to work. But opening the chamber too early — or skipping the drying phase entirely — can result in moisture recontaminating the load.
Moisture allows bacteria to migrate. Even if a load is technically sterile, contact with a wet pouch or surface could nullify that status in seconds. That’s why autoclaves include drying phases.
Always wait for the full cycle to complete, including drying. If time pressure is a regular issue, consider upgrading to a faster cycle model or adjusting your workflow to prevent overlap.
Failing to Quarantine Failed Loads
When a cycle fails — especially a spore test — there’s a tendency to repeat the cycle and move on. But if you don’t quarantine the items from that failed load, you risk using contaminated tools unknowingly.
Every failed sterilisation must be documented, investigated and followed up with a clear plan:
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Retest with new indicators
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Inspect the unit for malfunction
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Reprocess or discard compromised instruments
Failing to do this can breach infection control standards, damage your reputation and put patients at serious risk.
Undertraining Staff
Technology can only go so far. The most advanced autoclave in the world is useless in the hands of someone who doesn’t know how to load it properly, select the right cycle or interpret the indicators.
Undertraining is rampant in smaller facilities and among casual staff who ‘just help out’. While it might seem like common sense, proper sterilisation technique needs formal training, supervision and regular refreshers.
This isn’t just about compliance — it’s about culture. When staff value sterilisation as much as clinical work, safety becomes a team priority.
FAQs
1) What happens if an autoclave fails to reach proper temperature?
If your autoclave doesn’t hit the required temperature — usually between 121°C and 134°C — then full sterilisation isn’t achieved. Some bacteria, viruses and especially spores can survive lower temperatures. This leads to ineffective sterilisation and increases the risk of cross-contamination or infection. The most common causes are worn heating elements, incorrect cycle selection or chamber overloads. It’s vital to stop using the machine, document the failure and run diagnostic checks. Regular maintenance and proper cycle validation help catch this before it becomes a threat.
2) Can I sterilise everything together in one load?
Not always. Different instruments require different cycles based on their material, design and level of contamination. For example, solid metal tools can usually be processed together, but porous or hollow instruments might need specialised vacuum cycles. If you throw everything in together, some items might not be fully sterilised — even if the cycle finishes successfully. It’s best to group items by type and packaging method, then select cycles that match those categories. Always consult your autoclave manual and follow industry-specific sterilisation protocols.
3) How do I know if a sterilisation cycle actually worked?
The best way to confirm a successful cycle is to use both chemical and biological indicators. Chemical strips change colour when exposed to the right combination of steam, temperature and time. Biological indicators contain resistant spores that should be destroyed during sterilisation — if they survive, the cycle has failed. Many autoclaves now offer built-in printouts or digital logs that also confirm parameters were met. Relying on machine beeps alone isn’t enough. Regular indicator testing ensures you’re not just hoping your instruments are sterile — you know they are.
4) Is pre-cleaning really that important?
Yes, and here’s why: sterilisation doesn’t clean, it decontaminates. If instruments are still covered in organic material (blood, tissue, debris), that residue can shield microorganisms from the sterilising steam. In fact, leftover debris is one of the most common causes of sterilisation failure. Pre-cleaning — whether manual or ultrasonic — ensures that sterilisation can reach all surfaces evenly. Skipping this step is like painting over rust. It might look fine on the surface, but the danger is still there underneath.
5)Should I replace my autoclave after a certain number of years?
Autoclaves don’t last forever. Even with top-notch care, wear and tear eventually take their toll. Most units have a functional lifespan of 7 to 10 years, depending on usage. If you’re dealing with frequent breakdowns, failed spore tests or outdated software, it might be time for an upgrade. Newer models come with better cycle control, energy efficiency and smart diagnostics. Plus, as compliance standards evolve, older machines may no longer meet regulatory requirements. If your autoclave is more trouble than it’s worth, it’s probably time to invest in something more reliable.
Trust Your Tools — and Your Process — with MES Australia
Autoclave mistakes don’t always scream for attention, but the impact can be loud when things go wrong. Patient safety, compliance and professional credibility all ride on the consistency of your sterilisation routine.
Take the time to double-check your cycles, retrain your team and rethink your equipment if it’s no longer pulling its weight. Safe instruments aren’t just about good gear — they’re about good habits. Explore autoclaves designed to support your high standards and visit MES Australia for machines you can depend on every cycle.
For all your autoclave requirements, please call us today on 1300 342 013 or leave an enquiry.
