30 CFR § 57.22102
Smoking (I-C mines)
July 29, 2020
(a) Persons shall not smoke or carry smoking materials, matches, or lighters underground or within 50 feet of a mine opening. The operator shall institute a reasonable program to assure that persons entering the mine do not carry such items.
(b) Smoking is prohibited in surface milling facilities except in designated, dust-free smoking areas.