Could any of my esteemed colleagues enlighten me please? In the case of a childminder looking after children in her own home but as a business concern does the HASAWA apply to the domestic property in the context of "others who may be affected by the undertaking" or is there some other legislation?

The childminder is (or should be) either self-employed or a company. Therefore an employer dutyholder under HASAWA etc. As already said, it would be the S3 duty of this 'not to create risk' to others of most relevance. The 'domestic premise' becomes a 'workplace' by definition during work activities (even tho childminding may not feel like work, and the house reverts to home again at end of day). That extends to any activities outside the premises as part of the undertaking, such as walks in park etc. Pragmatically, the standards set by the early years framework (overseen by Ofsted) will be the key reference point.

You`re right AUD what threw me was the enforcement, would the HSE really go and check peoples houses, so in those circumstances its not reasonable to check every childminders house prior to becoming registered and using a persons personal integrity would be a green light to malcontents. So although HASWA applies it is not enforced by HSE but by ofsted who are the final arbiters but through other agencies