When it comes to infection control, nothing quite matches the power and reliability of autoclaves. These mighty machines are the backbone of sterilisation in clinics, labs, salons and more. But what happens when they stumble? More specifically, what should you do when your autoclave fails a spore test? This isn’t just a minor inconvenience — it’s a red flag that could signal significant risks to patient safety, regulatory compliance, and operational integrity.
Let’s break down what a failed spore test really means, why it matters, and the steps you must take to fix it, fast.
Why Spore Testing Matters
Spore testing (or biological monitoring) is the gold standard for ensuring sterilisation effectiveness. It’s designed to challenge your autoclave with highly resistant bacterial spores, like Geobacillus stearothermophilus, that only truly effective sterilisation can destroy.
When your spore test comes back positive, it means those resilient spores survived the cycle. That’s a big deal. It suggests your autoclave might not be killing all microbes, putting tools and instruments at risk of contamination.
So, where do you go from here?
Isolate and Identify the Problem Immediately
First things first — stop using the autoclave immediately. Take any loads processed after the failed test out of service. Do not use any of those items until you can confirm they’ve been properly reprocessed.
Next, document the failed test and isolate any instruments that could’ve been exposed. You’ll need this for regulatory reporting and internal audits.
Start by reviewing your logs and test results. Were the test indicators in the right spot? Was the pack loaded correctly? Were cycle parameters met? These clues help pinpoint whether the failure was user error, mechanical, or environmental.
Having a solid understanding of the principles of steam sterilisation helps make sense of what went wrong and prevents knee-jerk decisions that miss the root cause.
Re-Test Immediately With a New Spore Strip
One failed spore test doesn’t always mean your autoclave is completely out of commission. Run a second biological indicator test using a new test pack. Make sure everything is loaded precisely as per manufacturer specifications.
While you wait for the results — which could take up to 48 hours depending on the system — your facility should have a backup sterilisation method ready to go. If you’re running a solo setup, you might need to delay non-critical procedures until you have a resolution.
It’s also a good idea to perform chemical indicator testing and a physical parameter check (like temperature and pressure) to give you a more immediate sense of whether something’s off.
If your second spore test also fails, it confirms a systemic problem. That’s when it’s time to escalate. You’ll want to consider these common problems when using an autoclave and rule them out one by one.
Inspect Critical Autoclave Components
Failed spore tests are often tied to problems with key autoclave components. Start with the basics:
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Heating element – If your autoclave isn’t reaching the necessary temperature, sterilisation won’t happen.
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Door gasket – A damaged or worn seal can lead to steam leaks, which compromise pressure.
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Air removal valve or vacuum pump – Incomplete air removal prevents steam from penetrating instruments.
Use your operator’s manual to run diagnostic checks. Clean the chamber and filters if they haven’t been serviced in a while. And always check for software errors if your autoclave has digital controls.
Even newer models can fail if preventative maintenance gets neglected. If you’re unsure, it’s worth testing your autoclave’s heating elements as a logical first step.
Involve Your Equipment Supplier or Manufacturer
If you can’t identify the problem internally, contact your supplier or the autoclave manufacturer. Many offer remote diagnostics or local technicians who can quickly evaluate performance.
Make sure to provide them with your service logs, test results and photos of any obvious wear or damage. The more context you give, the faster the resolution.
Some autoclaves may be under warranty, which could cover parts or labour. Even if they’re not, timely servicing can help avoid bigger costs down the road — especially if compliance issues trigger penalties.
Implement a Preventative Maintenance Plan
An autoclave failure is often a symptom of a deeper issue — like lax servicing or inconsistent test schedules. Once the issue is resolved, build a proactive maintenance calendar:
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Weekly chamber cleaning
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Monthly gasket inspections
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Quarterly validation cycles
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Annual professional servicing
Make spore testing a non-negotiable part of your schedule. In Australia, industry bodies like AS/NZS 4187 recommend weekly biological monitoring — or more frequently in high-risk environments.
This isn’t just about ticking a compliance box. It’s about creating a culture of safety and accountability.
Educate Staff and Review Sterilisation SOPs
Autoclave errors often trace back to human error. Was the chamber overloaded? Were pouches sealed incorrectly? Was the load wet at the end?
Now’s the time to sit down with your staff, review your sterilisation SOPs, and re-train if needed. Use real examples to reinforce why cutting corners — even unintentionally — can have serious consequences.
Create visual guides or short videos showing correct loading techniques. Post them near the autoclave as quick reminders.
Document Everything for Audit Compliance
In Australia, practices are legally required to keep detailed sterilisation records. If your facility is accredited, this documentation is even more critical.
Make sure you log:
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The date and result of the failed spore test
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Any corrective action taken
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The results of follow-up tests
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Communications with your service provider
If an external audit or patient complaint ever arises, this paper trail protects your practice and shows you acted promptly and responsibly.
Know When to Replace the Unit
If your autoclave is older than 10 years, you might be dealing with diminishing returns. Multiple component failures or repeated spore test issues could indicate it’s nearing the end of its lifecycle.
Investing in a modern autoclave with features like automated test reminders, digital tracking, and improved energy efficiency can save time, improve compliance, and reduce human error.
Think of it as insurance — for your reputation, your clients, and your business.
FAQs
1) What causes a spore test to fail?
A spore test usually fails when the autoclave doesn’t reach or maintain the conditions needed to kill highly resistant bacterial spores. This could be due to a range of issues like mechanical faults (e.g. a faulty heating element), user error (like overloading or incorrect packaging), or even poor maintenance (such as a dirty chamber or worn gaskets). Sometimes, the biological indicator itself might’ve been mishandled or expired. It’s important to evaluate all aspects — equipment, staff, and materials — when troubleshooting a failed test. Start with a fresh biological indicator, double-check cycle settings, and assess physical parameters like temperature and pressure to rule out the obvious.
2) Can you still use instruments after a failed spore test?
No, you shouldn’t use any instruments that were sterilised during or after the failed spore test until they’ve been reprocessed successfully. Using them could risk patient or client safety, especially in clinical settings. Regulatory bodies will expect you to quarantine those items, document everything, and confirm proper re-sterilisation before they’re used again. It might cause delays, but the consequences of using potentially non-sterile equipment are far worse. Always err on the side of caution and treat those instruments as compromised.
3) How often should you run spore tests?
In Australia, the standard recommendation is to perform spore testing at least weekly. However, depending on the type of practice and the frequency of autoclave use, some facilities opt to do it more often — even daily in high-risk environments like surgical centres. It’s also advisable to perform a spore test after any repair or major maintenance. This keeps your sterilisation process transparent, traceable, and compliant. A reliable schedule not only helps avoid issues but also reinforces the accountability culture within your team.
4) What’s the difference between a chemical and a biological indicator?
Chemical indicators are visual cues (like colour-changing strips) that react to one or more conditions of the sterilisation cycle — temperature, time, or steam presence. While useful, they don’t confirm sterility. Biological indicators are more robust — they use live spores to test whether the autoclave truly kills microorganisms. A pass means those tough spores were destroyed. Both have their place, but biological indicators are considered the definitive standard for validation. If you want peace of mind, spore testing is the way to go.
5) Should I repair or replace a faulty autoclave?
This depends on a few factors — the age of your unit, how often it’s breaking down, the cost of parts, and how critical it is to your operations. If you’ve had two or more spore test failures in a short period and repairs are stacking up, it might be time to bite the bullet and invest in a new unit. Look at the warranty status, the availability of support from the manufacturer, and the performance history of your autoclave. If you can’t rely on it to protect patients and meet regulations, it’s probably not worth the risk.
Stay One Step Ahead with MES Australia
When sterilisation slips, so does safety. A failed spore test isn’t just a technical hiccup — it’s a chance to improve, reset standards, and protect what matters most. From recognising the first signs of failure to understanding the lifecycle of your equipment, staying informed puts you back in control.
If you’re in the market for reliable, high-performance sterilisation equipment, check out our extensive range of autoclaves. Our team is here to support your practice with dependable solutions that meet Australian standards. Visit MES Australia and make sure your next sterilisation cycle is one you can trust.
For all your autoclave requirements, please call us today on 1300 342 013 or leave an enquiry.
