Subjgrp 176. Underground Only
- § 57.8520 - Ventilation plan.
- § 57.8525 - Main fan maintenance.
- § 57.8527 - Oxygen-deficiency testing.
- § 57.8528 - Unventilated areas.
- § 57.8529 - Auxiliary fan systems.
- § 57.8531 - Construction and maintenance of ventilation doors.
- § 57.8532 - Opening and closing ventilation doors.
- § 57.8534 - Shutdown or failure of auxiliary fans.
- § 57.8535 - Seals.