Electrical equipment - Test and Tag
With any equipment Sandra, accurately determining what the risk that damage might occur between one inspection and the next can be trying and somewhat inconsistent.
By this I mean an extension lead that is sitting protected in a tray, plugged into a wall outlet and supplying a large printer could quite reasonably tested (properly) and tagged for retest in five years time, The same lead, laying on a floor, moved, unplugged and plugged back in several times a week, used to supply a variety of different items could be tested yearly. If it was used for commercial cleaning equipment then six monthly. Assuming it was a heavy duty lead, take it on a building site and three months may not be frequent enough.
The thing is, it is up to the person responsible for the equipment, in conjunction with the person testing to determine a suitable retest period with regard to the specific environment it's being used in.