30 CFR § 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines).

---
identifier: "/us/cfr/t30/s57.22217"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "30 CFR § 57.22217 - Seals and stoppings (I-A, I-B, and I-C mines)."
title_number: 30
title_name: "Mineral Resources"
section_number: "57.22217"
section_name: "Seals and stoppings (I-A, I-B, and I-C 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"
---


# 57.22217 Seals and stoppings (I-A, I-B, and I-C mines).

All seals, and those stoppings that separate main intake from main return airways, shall be of substantial construction and constructed of noncombustible materials, except that stoppings constructed of brattice materials may be used in face areas.