California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 17 - Mine Safety Orders
Article 31 - Air Quality, Radiation, and Ventilation
Underground
Section 7096 - (5-1). Dust, Smoke, and Gases from Secondary Blasting

(a) In order to protect employees from harmful dust, smoke, and gases from secondary blasting, such blasting shall not be done unnecessarily during the working shift.

(b) At permanent locations, such as bulldozing chambers, main grizzlies, draw points, and other control points where blasting is done throughout the working shift in the regular course of the work, employees shall be protected by one or more of the following, as necessary:

(c) When blasting a chute that is equipped with water sprays, it is recommended that the sprays be turned on before the shot is fired.

(d) After a secondary blast has been fired, employees shall not be required or permitted to return to the blast area until the atmosphere is reasonably free of dust, smoke, and gases from the blast.

(e) If the amount of explosive used or the frequency of secondary blasting is such that serious contamination of active working places is apt to occur, employees in such places shall be removed to the fresh air side of the blast area.

Such employees shall not be required or permitted to return to their working places until the atmosphere is reasonably free of dust, smoke, or gases.