Simple answer "Health and Safety Policy" it doesn't have to make sense, there just has to be a policy.
I'm sorry to have to say that a lot of things are done in the name of "Health and Safety Policy" when the real reason is that it's the fear of being sued American style.
Insurance companies are also one of the driving forces behind the seemingly stupid things done in the name of "Health and Safety"
As part of my working life has been spent as a Health and Safety inspector I can vouch that it is not the Legislation that is responsible
for banning or prohibiting certain activities, but the fear of litigation