30 CFR § 57.22205 - Doors on main fans (I-A, II-A, III, and V-A mines).

---
identifier: "/us/cfr/t30/s57.22205"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 57.22205 - Doors on main fans (I-A, II-A, III, and V-A mines)."
title_number: 30
title_name: "Mineral Resources"
section_number: "57.22205"
section_name: "Doors on main fans (I-A, II-A, III, and V-A mines)."
chapter_name: "MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR"
subchapter_number: "K"
subchapter_name: "METAL AND NONMETAL MINE SAFETY AND HEALTH"
part_number: "57"
part_name: "SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "30 U.S.C. 811."
regulatory_source: "50 FR 4082, Jan. 29, 1985, unless otherwise noted."
cfr_part: "57"
---


# 57.22205 Doors on main fans (I-A, II-A, III, and V-A mines).

In mines ventilated by multiple main fans, each main fan installation shall be equipped with noncombustible doors. Such doors shall automatically close to prevent air reversal through the fan. The doors shall be located so that they are not in direct line with explosive forces which could come out of the mine.