Will the health and safety personnel will be needed in the future after all workers have cultivated a safety culture relating to their respective job?

Ask yourself, do we need a Police if the country is safe from Crime.

Well, it is mandatory to deploy safety personnel even though any organisation has maintain good safety culture. Safety is something like proactive approach and continually improving process to achieve the organisation objectives, goals in terms of developing well structured Safety Management System (SMS). Safety is not the role but it is a responsibility for the organisation strive to achieve their commitment.

well. I think so. You cannot eliminate the role of production supervisor even though all workers have cultivated a production culture. Safety is continuous improvement process and the role of safety personnel is to basically facilitate. designated safety personnel can keep an close eye on all the safety matters & in absence of such personnel, it is very likely that entire safety system may collapse very quickly.