30 CFR Part 57Public Domain
§ 57.11054 — Communication with refuge chambers
Subpart J — Travelways and Escapeways
Telephone or other voice communication shall be provided between the surface and refuge chambers and such systems shall be independent of the mine power supply.
Public Domain: 30 CFR Part 57 (MSHA Safety and Health Standards — Underground Metal and Nonmetal Mines) is a U.S. government publication and is not subject to copyright. Text extracted from the official source ↗. Figures are served from the eCFR; if one does not load, use the link in its place.