30 CFR Part 23 — Telephones and Signaling Devices
- § 23.1— Purpose.
- § 23.2— Definitions.
- § 23.3— Application procedures and requirements.
- § 23.5— Conditions governing investigations.
- § 23.6— General requirements for approval.
- § 23.7— Specific requirements for approval.
- § 23.8— Inspection and tests.
- § 23.9— Special requirements for complete devices.
- § 23.10— Material required for MSHA records.
- § 23.11— How approvals are granted.
- § 23.12— Wording, purpose, and use of approval plate.
- § 23.13— Withdrawal of approval.
- § 23.14— Instructions for handling future changes in design.