30 C.F.R. § 57.20011 Barricades and warning signs.
Title 30 - Mineral Resources
Areas where health or safety hazards exist that are not immediately obvious to employees shall be barricaded, or warning signs shall be posted at all approaches. Warning signs shall be readily visible, legible, and display the nature of the hazard and any protective action required.
Title 30: Mineral Resources
PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES
Subpart S—Miscellaneous
§ 57.20011 Barricades and warning signs.

