West Virginia Code Chapter 22A. Miners' Health, Safety and Training § 22A-2-32. Underground storage of explosives

Explosives and detonators stored underground shall be kept in section boxes or magazines of substantial construction with no metal exposed on the inside, and be located at least fifteen feet from roadways and power wires in a well rock-dusted location, protected from falls of roof. If not kept in separate boxes or magazines not less than five feet apart, they may be kept in the same box or magazine if separated by at least a four-inch hardwood partition or the equivalent. Not more than a forty-eight hour supply of explosives or detonators shall be stored underground in section boxes or magazines. These boxes or magazines shall be kept at least one hundred feet from the faces and out of the direct line of blasting.