[Code of Federal Regulations]

[Title 30, Volume 1]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 30CFR75.1316]



[Page 574]

 

                       TITLE 30--MINERAL RESOURCES

 

  CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR

 

PART 75_MANDATORY SAFETY STANDARDS_UNDERGROUND COAL MINES--Table of 

Contents

 

                    Subpart N_Explosives and Blasting

 

Sec.  75.1316  Preparation before blasting.



    (a)(1) All nonbattery-powered electric equipment, including cables, 

located within 50 feet from boreholes to be loaded with explosives or 

the sites where sheathed explosive units are to be placed and fired 

shall be deenergized or removed to at least 50 feet from these locations 

before priming of explosives. Battery-powered equipment shall be removed 

to at least 50 feet from these locations before priming of explosives.

    (2) As an alternative to paragraph (a)(1) of this section, electric 

equipment, including cables, need not be deenergized or removed if 

located at least 25 feet from these locations provided stray current 

tests conducted prior to priming the explosives detect stray currents of 

0.05 ampere or less through a 1-ohm resistor.

    (i) Tests shall be made at floor locations on the perimeter, on 

energized equipment frames and on repaired areas of energized cables 

within the area between 25 to 50 feet from the locations where the 

explosives are to be primed.

    (ii) Tests shall be conducted using a blasting multimeter or other 

instrument specifically designed for such use.

    (3) The blasting cable or detonator circuitry shall not come in 

contact with energized electric equipment, including cables.

    (b) Before loading boreholes with explosives, each borehole shall be 

cleared and its depth and direction determined.

    (c) No borehole drilled beyond the depth of cut coal shall be loaded 

with explosives unless that portion of the borehole deeper than the cut 

is tamped with noncombustible material.

    (d) When two working faces are approaching each other, cutting, 

drilling and blasting shall be done at only one working face at a time 

if the two faces are within 25 feet of each other.



[35 FR 17890, Nov. 20, 1970, as amended at 56 FR 51616, Oct. 11, 1991]