StacksVerified U.S. regulatory reference

30 CFR §23.6

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Telephones and signaling devices shall be durable in construction, practical in operation, and suitable for conditions of underground service. They shall offer no probable explosion hazard under normal operation if use in gassy or dusty mine atmospheres.