During the approach and progress of an electrical storm—

(a) Surface blasting operations shall be suspended and persons withdrawn from the blast area or to a safe location; or

(b) Underground electronic or electrical blasting operations that are capable of being initiated by lightning shall be suspended and all persons withdrawn from the blast area or to a safe location.

[61 FR 36801, July 12, 1996, as amended at 85 FR 2027, Jan. 14, 2020]