Do you own a Class B Autoclave in your practice? If so, there are a number of requirements and considerations for your practice in order to meet National Safety and Quality Health Service (NSQHS) Standards.
Autoclaves
Class B Autoclaves are designed to meet the most rigorous standards, including Australian Standard AS 5369:2023, and are used to sterilise solid, hollow, porous and wrapped Reusable Medical Devices (RMDs).
These units are pre-vacuum autoclaves, which remove air from the chamber before the steam cycle begins, allowing the steam sterilant to reach every part of the instrument. They perform multiple vacuum (air removal) and steam pulses to ensure instruments are sterilised uniformly.
Whilst they are more expensive than Class S autoclaves, they are a more viable option as your range of instruments grows and offer greater flexibility in what can be sterilised, helping to future-proof your operations.
Used widely in medical clinics, dental practices, specialist clinics and anywhere that uses critical and semi-critical RMDs, Class B autoclaves are the autoclave of choice.
Class S autoclaves are less robust than Class B autoclaves and are typically used for unwrapped and solid instruments, although some models are validated for wrapped instruments. Some units do offer pre-vacuum cycles, but most offer a less intensive version and are commonly found in facilities with less demanding sterilisation needs, such as nail and beauty salons.
Frequently Asked Questions
1. What is the daily requirement for Class B autoclave owners in Australia?
A Bowie Dick Test must be performed on the day of use, prior to sterilisation. It is designed to ensure that vacuum-assisted steam sterilisers can effectively remove air from the chamber before the sterilisation cycle begins.
Air trapped in the steriliser chamber, known as non-condensable gases (NCGs), will act as a barrier, preventing the steam sterilant from contacting all surfaces of the instruments and therefore compromising sterilisation.
The Bowie Dick Test is mandatory as per Australian Standard AS 5369:2023 and is performed daily as part of routine monitoring.
2. How does a Bowie Dick Test work?
The test pack consists of a small bundle with a chemical indicator in the centre, or a plastic helix device with a chemical indicator strip. It is designed to simulate wrapped instruments and is placed over the steriliser chamber drain in an empty steriliser.
A Bowie Dick cycle is performed. This is a shorter cycle that focuses on air removal rather than a full sterilisation cycle.
After the cycle is complete, the chemical indicator card is checked and a pass or fail is determined based on the colour change of the indicator.
An uneven or incomplete colour change signals a failure to remove all air from the chamber and may be due to vacuum issues, excess NCGs, or leaks in the door gasket, valves or pipes.
3. What should I do if my Bowie Dick Test fails?
If the test card or helix strip records a fail, you must refer to the autoclave Manufacturer's Instructions for Use (MIU) and troubleshoot the unit.
This may include:
- Checking that the door gasket is clean and intact
- Clearing the chamber drain filters
- Inspecting the safety valve in the water tank for blockages
If the autoclave records another fail, contact the machine service provider for technical support. The gasket may need replacing, or the pressure sensors may need to be recalibrated.
4. Why can't autoclave printouts replace a Bowie Dick Test?
Autoclave machine printouts provide information on parameters only, including temperature, pressure and holding time. They cannot provide information about steam quality, which is essential for proper sterilisation.
The chemical indicators used in Bowie Dick testing specifically measure steam penetration and air removal, which are critical factors that machine printouts cannot assess.
5. Why is a maintenance schedule important?
A regular maintenance schedule can reduce the chances of cycle failures and may also extend your autoclave's lifespan from 8–10 years up to 12–15 years.
Daily maintenance should include cleaning the rubber door seal and internal chamber door with a damp, lint-free cloth when the autoclave is cold.
Weekly maintenance should involve cleaning the inner chamber, racks, drain filter and trays. You may also perform a Biological Indicator test, although this is not mandatory, to help ensure the sterilisation process is effective.
Monthly or quarterly maintenance may involve descaling. It is very important to always use distilled or demineralised water.
Annual professional servicing is mandatory to meet Australian Standard AS 5369:2023. This annual performance qualification helps ensure your autoclave is performing as intended and includes validation using Biological Indicators and data loggers, calibration, safety checks, and replacement of parts where required.
Independent validation tests are performed by AMA Medical Products' preferred partner, Proline Medical. For all your validation requirements, please call one of our friendly customer service team members on (08) 6489 1300.
6. Which Australian Standard governs the reprocessing of reusable medical devices?
In December 2023, Australian Standard AS 5369:2023 – Reprocessing of reusable medical devices and other devices in health and non-health related facilities superseded AS/NZS 4187:2014 and AS/NZS 4815:2006 Office-based health care facilities – Reprocessing of reusable medical and surgical instruments and equipment, and maintenance of the associated environment.
AS 5369:2023 specifies the requirements for the effective and safe reprocessing, storage, handling and transportation of reusable medical devices (RMDs) and other devices used in human healthcare facilities.
This includes office-based facilities such as medical clinics, dental practices and podiatry practices, which were previously covered under AS/NZS 4815:2006.
Implementation of AS 5369:2023 is required in healthcare settings as well as other non-healthcare settings where RMDs and other devices are in use in accordance with the National Safety and Quality Health Service (NSQHS) Standards.
7. What is SRACA and how can they help with sterilisation standards?
SRACA (Sterilising Research and Advisory Council of Australia) is a professional body that promotes high standards of practice in sterilising and disinfection services.
There are branches in each Australian state, with the common goal of maintaining industry standards and supporting professional development by running workshops and seminars to keep practitioners fully informed.