StacksVerified U.S. regulatory reference

30 CFR §57.22104

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)Open flames, including cutting and welding, shall not be used underground.
  2. (b)Welding and cutting shall not be done within 50 feet of a mine opening unless all persons are out of the mine and the mine opening is covered. The cover shall be a substantial material, such as metal or wood, topped with a layer of wetted material to prevent sparks and flames from entering the mine opening.