SI 2015/1583 The Health and Safety at Work etc. Act 1974 (General Duties of Self-Employed Persons) (Prescribed Undertakings) Regulations 2015 (link)
These Regulations specify the circumstances in which self-employed persons will be required to comply with their duty under section 3(2) of the Health and Safety at Work etc. Act 1974 (link) to conduct their undertakings in such a way as to ensure, so far as reasonably practicable, that they themselves and other persons (not being their employees) who may be affected by their work activities are not exposed to risks to their health and safety.
Source: HMSO