CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH (parts 56 to 58) > PART 56—SAFETY AND HEALTH STANDARDS—SURFACE METAL AND NONMETAL MINES > SUBPART E—Explosives (§56.6000 to §56.6905) > 56.6304—Primer protection.

56.6304—Primer protection.

(a) Tamping shall not be done directly on a primer.
(b) Rigid cartridges of explosives or blasting agents that are 4 inches (100 millimeters) in diameter or larger shall not be dropped on the primer except where the blasthole contains sufficient depth of water to protect the primer from impact. Slit packages of prill, water gel, or emulsions are not considered rigid cartridges and may be drop loaded.