Five Hazardous Characteristics:

(3) Fire Hazard. Includes combustibles, flammables, oxidizers, and pyrophorics as defined under 1910.1200 of Title 29 of the Code of Federal Regulations (CFR):

"Combustible liquid" means any liquid having a flash point at or above 1000F (37.80C), but below 2000F (93.30C).

"Flammable" means a chemical that falls into one of the following categories:

"Aerosol, flammable" means an aerosol that yields a flame projection exceeding 18 inches or a flashback (a flame extending back to the valve).
"Gas, flammable" means a gas that forms a flammable mixture with air.
"Liquid, flammable" means any liquid having a flash point below 1000F (37.80C).
"Solid, flammable" means a solid that is liable to cause fire through friction, absorption of moisture, spontaneous chemical change, retained heat, or which when ignited burns vigorously and persistently.
"Oxidizer" means a chemical that initiates or promotes combustion in other materials thereby causing a fire.
"Pyrophoric" means a chemical that will ignite spontaneously in air at a temperature of 1300F (54.40C) or below.