{"data":{"id":"us-va/4vac25-40-5470","jurisdiction":"us-va","citation":"4VAC25-40-5470","heading":"Installation of air locks","body":"The main ventilation shall be so arranged by means of air locks, overcasts, or undercasts that the passage of trips or persons does not cause interruptions of air currents.  Where air locks are impractical, single doors may be used if they are attended constantly while the areas of the mine affected by the doors are being worked, unless they are operated mechanically or are self-closing.","path":["Title 4. Conservation And Natural Resources","Agency 25. Department of Energy","Chapter 40. Safety and Health Regulations for Mineral Mining","Part XV. Safety and Health Regulations—Underground Only","Article 11. Gassy Mines"],"source_url":"https://law.lis.virginia.gov/admincode/title4/agency25/chapter40/section5470/","current_through":"2026 Regular Session (effective July 1, 2026)","vintage":"","retrieved_at":"2026-09-14T04:46:11Z","sha256":"2a47f81c7beb85d6f59df8e8ce49a2f3c1a74dd31553c718d7ee82001a4545ee","source_id":"us-va-vac","stale":false,"prev":"us-va/4vac25-40-5460","next":"us-va/4vac25-40-5480"},"notice":"GroundRules: Original legal text. Not legal advice."}