The main thing is the Risk Assessment here I think. As Ajax said
, it's you as an employee of yourself and/or others that has to be responsible for the health and safety of you and/or your staff. There is a lot of info online (Liz linked to a bit of it
) on this. Generally large companies if they haven't got internal advisers on this then they'd seek external advice when it comes to the risk assessment but then have somebody responsible for managing that. Though a small company, especially self-employed are always responsible themselves directly of everything, obviously.
So I'd say if the terms to work on a site is to carry out crazy tasks such as wearing wellies instead of toe-caped boots, wearing a harness attached to a secure point when on the second step of a ladder, is what you need to do to get paid. Do it, but factor the extra time and expense in your pricing.
On site, unless you run it, there will always be guidelines (or strict
rules more like) given to you. Though on domestics or jobs where you're the one sticking the invoice in, you need to make sure you, anybody you employ, and in some strange cases those you even sub other parts of the job to you could actually be responsible for.
There are a lot of firms out there that can provide more accurate advice on this, and I'm only saying this as this is your health and safety here.
So please do take all the advice given as a general view from those within the trade.