There is a problem with this ! There are situations where a "low" risk piece of equipment (such as an electrical suction machine, for instance, although some people class this as "medium" !) may actually pose a "high" risk because of either the location it is being used in, or the patient it is being used on.
We had a case where a suction machine refused to suck because the hydrophobic filter was dirty. The patient had a very severe chest problem - but also a fairly serious heart problem. He was being nursed in a side ward where there was no piped vacuum, so when they needed to suck him out and couldn't, he nearly died of a heart attack brought on by the fact he couldn't breathe !
I'm sure there are lots of similar examples - which make it difficult to classify what appear to be quite straight forward items. So far we've only decided on the "high" risk category - such things as anaesthetic machines and patient ventilators - which seem to be fairly obvious. Where to put the other items is the subject of ongoing discussions !