{"data":{"id":"us/30-cfr-57.8529","jurisdiction":"us","citation":"30 CFR 57.8529","heading":"Auxiliary fan systems.","body":"When auxiliary fan systems are used, such systems shall minimize recirculation and be maintained to provide ventilation air that effectively sweeps the working places.","path":["Title 30—Mineral Resources","CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR","SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH","PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES","Subpart G—Ventilation"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-30.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:24Z","sha256":"263523cf14b8bd8bddf82a0ac0b9c920c12b1f1e727f62d820b378407533894a","source_id":"us-cfr","stale":true,"prev":"us/30-cfr-57.8528","next":"us/30-cfr-57.8531"},"notice":"GroundRules: Original legal text. Not legal advice."}