It depends which H&S legislation you are talking about. Sole trader = self-employed and therefore like anyone else a sole trader needs to consider the application of each piece of legislation having regard to the work they are doing.

For example from LOLER

"3) The requirements imposed by these Regulations on an employer shall also apply -
(a) to a self-employed person, in respect of lifting equipment he uses at work;"

The "Application" section of each set of Regs will tell you if they apply to the self-employed. Also be careful about assuming no risk assessments need be done - PUWER for example has an almost identical clause to the one quoted for LOLER above and this had the effect of applying the same duties to a self-employed person as to an employer with regard to work equipment that they use in their work.

i think what industry sector you are working in will have a massive effect on what you need to comply with. The more stringent the legislation you need to apply the more likely you won't be able due to cost restraints or will have to charge more to the customer to make a living. trouble is the customer wants all the h&S bells and whistles but doesn't want to pay for it, its a vicious circle.

Phil