30 CFR § 57.22602 - Blasting from the surface (I-C mines).
§ 57.22602 Blasting from the surface (I-C mines).
(a) All blasting shall be initiated from the surface after all persons are out of the mine and any connecting mines.
(b) Persons shall not enter the mine until a competent person has examined the blast sites and methane concentrations are less than 0.5 percent.