{"data":{"id":"us/30-cfr-57.4000","jurisdiction":"us","citation":"30 CFR 57.4000","heading":"Definitions.","body":"The following definitions apply in this subpart.\nCombustible liquids. Liquids having a flash point at or above 100 °F (37.8 °C). They are divided into the following classes:\nClass II liquids—those having flash points at or above 100 °F (37.8 °C) and below 140 °F (60 °C).\nClass IIIA liquids—those having flash points at or above 140 °F (60 °C) and below 200 °F (93.4 °C).\nClass IIIB liquids—those having flash points at or above 200 °F (93.4 °C).\nEscapeway. A designated passageway by which persons can leave an underground mine.\nFlash point. The minimum temperature at which sufficient vapor is released by a liquid to form a flammable vapor-air mixture near the surface of the liquid.\nMain fan. A fan that controls the entire airflow of an underground mine or the airflow of one of the major air circuits of the mine.\nMine opening. Any opening or entrance from the surface into an underground mine.\nSafety can. A container of not over five gallons capacity that is designed to safely relieve internal pressure when exposed to heat and has a spring-closing lid and spout cover.","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 C—Fire Prevention and Control"],"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":"19a6da9855e4ad874632337d8ab978cd0afa31c600b0823fa23dce2913a95fee","source_id":"us-cfr","stale":true,"prev":"us/30-cfr-57.3461","next":"us/30-cfr-57.4011"},"notice":"GroundRules: Original legal text. Not legal advice."}