I could be wrong about this, as I'm still learning, but anyway...

The last time we went to get some timber from a merchant, the timber was too long to go in our van. The man in the warehouse had to cut them all to length with a handsaw as he said the health and safety executive had confiscated their power mitre saw.

I believe it's like this: these saws have insufficient guarding and are causeing a disproportionate number of workplace injuries. HSE have decided that for management to provide one of these in a workplace is an offence, and the saw itself is evidence of the offence and is to be treated accordingly. If the management objects HSE can just serve a prohibition notice on the works.