053-3 Wyo. Code R. § 57.4000
The following definitions apply in this subpart.
Booster fan. A fan installed in the main airstream or a split of the main airstream to increase airflow through a section or sections of a mine.
Combustible liquids. Liquids having a flash point at or above 100 oF (37.8 oC). They are divided into the following classes:
Class II liquids-those having flash points at or above 100 oF (37.8 oC) and below 140 oF (60 oC).
Class IIIA liquids-those having flash points at or above 140 oF (60 oC) and below 200 oF (93.4 oC).
Class IIIB liquids-those having flash points at or above 200 oF (93.4 oC).
Combustible material. A material that, in the form in which it is used and under the conditions anticipated, will ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat. Wood, paper, rubber, and plastics are examples of combustible materials.
Escapeway. A designated passageway by which persons can leave an underground mine.
Fire resistance rating. The time, in minutes or hours, that an assembly of materials will retain its protective characteristics or structural integrity upon exposure to fire.
Flame spread rating. The numerical designation that indicates the extent flame will spread over the surface of a material during a specified period of time.
Flammable gas. A gas that will burn in the normal concentrations of oxygen in the air.
Flammable liquid. A liquid that has a flash point below 100 oF (37.8 oC), a vapor pressure not exceeding 40 pounds per square inch (absolute) at 100 oF (37.8 oC), and is known as a Class I liquid.
Flash 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.
Main 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.
Mine opening. Any opening or entrance from the surface into an underground mine.
Multipurpose dry-chemical fire extinguisher. An extinguisher having a rating of at least 2-A:10-B:C and containing a nominal 4.5 pounds or more of dry-chemical agent.
Noncombustible material. A material that, in the form in which it is used and under the conditions anticipated, will not ignite, burn, support combustion, or release flammable vapors when subjected to fire or heat. Concrete, masonry block, brick, and steel are examples of noncombustible materials.
Safety 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.
Storage tank. A container exceeding 60 gallons in capacity used for the storage of flammable or combustible liquids.
053-3 Wyo. Code R. § 57.4000