30 CFR 57.4361 - Underground evacuation drills.
(a) At least once every six months, mine evacuation drills shall be held to assess the ability of all persons underground to reach the surface or other designated points of safety within the time limits of the self-rescue devices that would be used during an actual emergency.
(b) The evacuation drills shall -
(1) Be held for each shift at some time other than a shift change and involve all persons underground;
(2) Involve activation of the fire alarm system; and
(3) Include evacuation of all persons from their work areas to the surface or to designated central evacuation points.
(c) At the completion of each drill, the mine operator shall certify the date and the time the evacuation began and ended. Certifications shall be retained for at least one year after each drill.