(a) In all mines where a fire boss is employed, all working places and worked-out places adjacent to working places shall be examined, when it can be done, at least once a day by a competent fire boss. It shall be his or her duty to enter a report of existing conditions of the working places and worked-out places in a well-bound book to be kept by him or her for that purpose.
(b) All dangerous places that are marked out shall be marked on a blackboard, furnished by the company, before any other employee enters the mine.