Instrument reprocessing:
the cleaning step decides everything after it
You cannot sterilise a dirty instrument. Every standard says it, and the cleaning stage is where most non-conformances are actually found.
If you reprocess reusable instruments in Australia, the standard governing you changed. This page covers what changed, and why the ultrasonic stage carries more weight than most people give it.
The standard changed — check which one you are working to
The change that matters most commercially: AS 5369 explicitly reaches beyond hospitals. It applies to health settings and non-health settings alike — dental practices, veterinary clinics, and non-medical facilities including beauty salons and tattoo studios. A great many premises that never considered themselves subject to a reprocessing standard now are.
The standard classifies devices by the risk of the procedure they are used in — critical (must be sterilised), semi-critical (sterilised or high-level disinfected) and non-critical (cleaned and low-level disinfected) — and introduces product families and validation testing to confirm the process actually works.
This page is an orientation, not compliance advice. Obtain the current standard and confirm your obligations with your accrediting body — transition arrangements differ by facility type.
Why cleaning is the step that decides the outcome
Sterilisation does not penetrate soil. Protein, tissue and dried blood shield micro-organisms from steam and from chemical sterilants, so an instrument that goes into the steriliser dirty comes out contaminated and carrying a sterility label. That is the failure mode the whole standard exists to prevent.
Cleaning is therefore a critical stage of reprocessing, and the process must deliver results that are both verifiable and repeatable.
Standing time: the cheapest control you have
The time between using an instrument and cleaning it is the single biggest determinant of how hard it will be to clean. Blood and protein dry, adhere and become dramatically harder to remove — and if they are then exposed to heat, they coagulate onto the surface permanently.
What good practice looks like
- Point-of-use treatment — keep instruments moist from the moment of use with a spray, gel or damp cover so soil never dries in transit.
- Move them promptly — the longer the delay, the worse the outcome, and long delays should be a documented exception rather than routine.
- Open the hinges and box locks before soaking. Closed instruments protect their own soil.
- Never a hot pre-soak — heat sets protein. Cool or ambient, always.
- Disassemble what is designed to come apart. An assembled instrument has interfaces nothing reaches.
Where ultrasonics fits in the sequence
Manual brushing cannot reach a box lock, a serration, a cannula or a lumen. Cavitation can, because it works wherever the liquid goes. The normal sequence is:
- Point-of-use moisture control
- Gross soil removal — manual, cool water
- Ultrasonic clean in a near-neutral enzymatic solution at 38–54 °C
- Thorough rinse — see water quality, because rinse water quality shows up on the instrument
- Dry, inspect, then package and sterilise
Two operational points that get missed. Degas the bath after every fresh fill or the first load of the day is cleaned in a gassy tank that is not cavitating properly — see degassing. And change the solution on a rule: an ultrasonic bath in a reprocessing setting accumulates bioburden, and a dirty bath re-deposits it on the next set.
Demonstrating it worked
"We ran it for ten minutes" is not evidence. What is defensible:
- Recorded cycle parameters — solution, concentration, temperature, time, per load.
- Routine function testing of the ultrasonic bath — see the foil test, plus commercial soil-test devices where your standard requires them.
- Cleaning verification on instruments, not just the machine — residual protein tests, and the methods in how do you prove a part is clean.
- Maintenance and calibration records for the equipment.
Equipment that suits the setting
Single practice or surgery — the PowerSonic benchtop range: listed pricing, lid, timer and heater, bought outright.
Higher volume or continuous duty — MSX 15 and MSX 30. The MSX 30 is the one built for reprocessing workflows: continuous duty, 316 stainless, condensate-deflector lid, LCD control with stored recipes so the cycle is set once and repeated, and load sensing so the delivered power does not change with the basket.
Where the sequence must be automated and recorded — UltraWash runs wash, rinse, hot-air and vacuum dry as one programmed sequence in a sealed chamber, and UltraKleen Pro runs it as a three-station line with a dedicated collection tank behind every wet tank. Both remove the operator variability that audits find.
What we can do
The cleaning process is matched to the instruments, contamination and applicable reprocessing standard, with the cycle parameters documented to provide a repeatable and verifiable process. If you are transitioning your procedures to AS 5369, we can specify the equipment that makes the cleaning step demonstrable rather than assumed.
Validating the process on your own parts
We assess each application. Where required, we validate the process through a controlled cleaning trial on the machine and chemistry we would specify, with the cycle and the result reported against your standard — ask us to scope it.