Recommendations for testing your autoclave - these will vary according to whether you are processing hollow or simple solid instruments and the frequency of use / number of cycles that you run:
- Class 4 Indicators - these are normally present on the bags / packaging that you wrap your instruments in or you can buy them as indicator strips. They change colour after going through a sterile cycle showing that your instruments have been processed, however it does not show the effectiveness of the cycle - whether it was run successfully or not.
- Vacuum Test - this test should be a part of the cycles that your autoclave can run, it should appear on the cycles menu. It will draw down and hold a vacuum for a period of time to confirm that there are no vacuum leaks present and will normally take about 20 minutes. Its run at the start of every day prior to commencing your sterilisation cycles.
- Class 6 Indicators - these are a step up form the class 4 indicators in that they only change colour when a time @ temperature has been achieved, typically 134 degrees for 4 minutes. You should have an indicator strip on each tray of each cycle.
- Helix Test Kit - these are sold as a Helix Test Device with 250 indicator strips. The Helix test is a steam penetration test, the indicator is placed inside the device and the steam penetrates through the device tubing to reach the indicator & change colour. The Helix test is only applicable if you are running a hollow instrument cycle and should be run daily.
- Spore Testing - commonly referred to as the "Gold Standard" spore testing involves processing a quantity of live bacteria spores through an autoclave cycle to test the lethality of the process. The spores are incubated after the sterilisation process and a colour change (positive result) will show whether each spore has been killed or not. Spore testing should be run periodically, the frequency will depend on how often the autoclave is used but the dental association recommend weekly spore testing.
- Cycle Recording - most autoclaves are equipped with a built in datalogger for cycle recording, this will normally download directly to your PC or to a USB stick. Ensure that these are reviewed periodically, that the download is working and any alarms or malfunctions have been investigated and resolved.
Your sterilisation process is only as good as the systems that you set up to monitor it, a simple yet robust & regular testing process goes a long way to avoiding any possibility of non sterile instruments re-entering your procedures.
