StacksVerified U.S. regulatory reference

30 CFR §77.212

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
When fans are used to ventilate draw-off tunnels the fans shall be:
  1. (a)Installed on the surface;
  2. (b)Installed in fireproof housings and connected to the tunnel openings with fireproof air ducts; and,
  3. (c)Offset from the tunnel opening.