Testing requirements

The testing protocols for washer disinfectors are very similar to those required for ultrasonic baths as highlighted in last month’s article. They fall into three main categories; weekly, quarterly and annual tests.

A weekly protein residue test should be carried out on one of the instruments that has been through the washer disinfector cycle. However, unlike with ultrasonic baths, instruments don’t normally need to be rinsed with RO (reverse osmosis) or distilled water, because the washer disinfector will incorporate this as part of the rinse cycle as standard. HTM01-05 recommends the use of a rinse aid in order to help reduce water spotting on stainless steel instruments, which can cause rusting and inhibits the lubrication of joints - this is a particular concern in the case of forceps.

If an instrument fails the protein residue test, firstly, double-check that the washer disinfector is not displaying any visible error codes and that it contains detergent. Then run another cycle. If the test is failed again an engineer should be consulted, as this could be indicative of a problem with the washer disinfector itself.