Who is the Responsible Person ?

In the majority of premises the responsible person will be the employer, the emphasis being on who has control of the premises. 

Responsible Person - Article 3

(a) in relation to a workplace, the employer, if the workplace is to any extent under his control;

(b) in relation to any premises not falling within paragraph (a)—

(i) the person who has control of the premises (as occupier or otherwise) in connection with the carrying on by him of a trade, business or other undertaking (for profit or not); or