How often do they need to be maintained and who does it?

The maintenance programme should be as specified by the manufacturer. If this is not available, a Maintenance Person can devise a suitable programme in consultation with an Authorising Engineer (Decontamination). All maintenance should be carried out by a suitably qualified Maintenance Person. The Maintenance Person can be an employee of the equipment manufacturer or supplier or an independent contractor. This is currently under review but archived documents can be foundĀ here.