If an employer in their dress policy insist that certain shoes have to be worn because of health and safety, are they liable for meeting some or all of the cost?
It depends- if for example they say "wear proper shoes not flip flops" then I don't think you can expect them to pay.
But if they specify a particular type of boot that may be different
I am a staff nurse and our uniform policy states that for Health and Safety reasons shoes must have an enclosed heel, and it is because H&S is explicitly stated as the reason that I asked the question.
no in the NHS there is no requirement for them to provide you with suitable shoes. Saying it must have an enclosed heel for health and safety reasons does NOT make it PPE. Check with the tax office though, when I worked in the NHS (now retired) there was a tax rebate on clothing bought specifically for work requirements.