Hi Nat
Very Nice. Some points; there are some very minor errors in punctuation, so another really good proof-read would be handy.
You mention vacuuming carpets and mopping floors, but not sweeping/vacuuming floors.
You mention PAT testing 'all' your machinery; First of all i am not sure why you say this anyway, and secondly only the electrical machinery can be tested, therefore not 'all' machinery is tested. Thirdly, although there is no legal obligation to PAT test, if you have it documented that you are going to do so, you are then obliged to follow it through 110%. Given that a lot of small business you clean won't bother with PAT testing themseleves, it's not much of a selling point for you IMHO. The fact that you have a correct H&S policy should be all the public needs to know.
But as before, i like your site