The following definitions apply in this subpart.
Attended. Presence of an individual or continuous monitoring to prevent unauthorized entry or access. In addition, areas containing explosive material at underground areas of a mine can be considered attended when all access to the underground areas of the mine is secured from unauthorized entry. Vertical shafts shall be considered secure. Inclined shafts or adits shall be considered secure when locked at the surface. Barrier. A material object, or objects that separates, keeps apart, or demarcates in a conspicuous manner such as cones, a warning sign, or tape.
Blast area. The area in which concussion (shock wave), flying material, or gases from an explosion may cause injury to persons. In determining the blast area, the following factors shall be considered:
(1) Geology or material to be blasted.
(2) Blast pattern.
(3) Burden, depth, diameter, and angle of the holes.
(4) Blasting experience of the mine.
(5) Delay system, powder factor, and pounds per delay.
(6) Type and amount of explosive material.
(7) Type and amount of stemming.
Blast site. The area where explosive material is handled during loading, including the perimeter formed by the loaded blastholes and 50 feet (15.2 meters) in all directions from loaded holes. A minimum distance of 30 feet (9.1 meters) may replace the 50-foot (15.2-meter) requirement if the perimeter of loaded holes is demarcated with a barrier. The 50-foot (15.2-meter) and alternative 30-foot (9.1-meter) requirements also apply in all directions along the full depth of the hole. In underground mines, at least 15 feet (4.6 meters) of solid rib, pillar, or broken rock can be substituted for the 50-foot (15.2-meter) distance. In underground mines utilizing a block-caving system or similar system, at least 6 feet (1.8 meters) of solid rib or pillar, including concrete reinforcement of at least 10 inches (254 millimeters), with overall dimensions of not less than 6 feet (1.8 meters), may be substituted for the 50-foot (15.2-meter) distance requirement.
Blasting agent. Any substance classified as a blasting agent by the Department of Transportation in 49 CFR 173.114a(a). This document is available at any MSHA Metal and Nonmetal Safety and Health district office.
Detonating cord. A flexible cord containing a center core of high explosives which may be used to initiate other explosives.
Detonator. Any device containing a detonating charge used to initiate an explosive. These devices include electric or nonelectric instantaneous or delay blasting caps, and delay connectors. The term "detonator" does not include detonating cord. Detonators may be either "Class A" detonators or "Class C" detonators, as classified by the Department of Transportation in 49 CFR 173.53, and 173.100. This document is available at any MSHA Metal and Nonmetal Safety and Health district office.
Emulsion. An explosive material containing substantial amounts of oxidizers dissolved in water droplets, surrounded by an immiscible fuel.
Explosive. Any substance classified as an explosive by the Department of Transportation in 49 CFR 173.53, 173.88, and 173.100. This document is available at any MSHA Metal and Nonmetal Safety and Health district office.
Explosive material. Explosives, blasting agents, and detonators.
Flash point. The minimum temperature at which sufficient vapor is released by a liquid to form a flammable vapor-air mixture near the surface of the liquid.
Igniter cord. A fuse that burns progressively along its length with an external flame at the zone of burning, used for lighting a series of safety fuses in a desired sequence.
Laminated partition. A partition composed of the following material and minimum nominal dimensions: 1/2-inch-thick plywood, 1/2-inch-thick gypsum wallboard, 1/8-inch-thick low carbon steel, and 1/4-inch-thick plywood, bonded together in that order. Other combinations of materials may be used, such as plywood, wood or gypsum wallboard as insulators, and steel or wood as structural elements, provided that the partition is equivalent to a laminated partition for both insulation and structural purposes as determined by appropriate testing. The Institute of Makers of Explosives (IME) 22 container or compartment, described in IME Safety Library Publication 22 (Jan. 1985), meets the criteria of a laminated partition. This document is available at any MSHA Metal and Nonmetal Safety and Health district office.
Loading. Placing explosive material either in a blasthole or against the material to be blasted.
Magazine. A bullet-resistant, theft-resistant, fire-resistant, weather-resistant, ventilated facility for the storage of explosives and detonators (BATF Type 1 or Type 2 facility).
Misfire. The complete or partial failure of explosive material to detonate as planned. The term also is used to describe the explosive material itself that has failed to detonate.
Multipurpose dry-chemical fire extinguisher. An extinguisher having a rating of at least 2-A:10-B:C and containing a nominal 4.5 pounds or more of dry-chemical agent.
Primer. A unit, package, or cartridge of explosives which contains a detonator and is used to initiate other explosives or blasting agents.
Safety switch. A switch that provides shunt protection in blasting circuits between the blast site and the switch used to connect a power source to the blasting circuit.
Slurry. An explosive material containing substantial portions of a liquid, oxidizers, and fuel, plus a thickener.
Storage facility. The entire class of structures used to store explosive materials. A "storage facility" used to store blasting agents corresponds to a BATF Type 4 or 5 storage facility.
Water gel. An explosive material containing substantial portions of water, oxidizers, and fuel, plus a cross-linking agent.
STORAGE-SURFACE AND UNDERGROUND
053-3 Wyo. Code R. § 57.6000