A service established in or near a place of employment for the purposes of: (a) protecting the workers against any health hazard which may arise out of their work or the conditions in which it is carried out; (b) contributing towards the workers physical and mental adjustment, in particular by the adaptation of the work to the workers and their assignment to jobs for which they are suited; and (c) contributing to the establishment and maintenance of the highest possible degree of physical and mental well-being of the workers