GroundRules
30 CFR 57.22221: Overcast and undercast construction (I-A, II-A, III, and V-A mines).
Where this section sits in the code
- Title 30—Mineral Resources
- CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR
- SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH
- PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
- Subpart T—Safety Standards for Methane in Metal and Nonmetal Mines
Overcasts and undercasts shall be—
(a) Of substantial construction;
(b)(1) Constructed of noncombustible materials; or
(2) Where constructed of combustible materials, the outside surfaces shall be coated with at least one inch of construction plaster containing perlite and gypsum; at least one inch of expanded vermiculite, Portland cement and limestone; or other coatings with equivalent fire resistance;
(c) Kept clear of obstructions.
Collected 2026-08-27T02:25:24Z. Source file · JSON