Fire is a phenomenon of combustion manifested in intense heat and light in the form of a glow or flames. The word fire when used with an indefinite article is commonly used to describe either a fuel in a state of combustion (such as a campfire or a fire in a fireplace or kitchen stove) or an instance of violent, destructive and uncontrolled burning (such as a wildfire and fires in buildings and vehicles).
Fire is not a state of matter: rather, it is an exothermic chemical reaction accompanied by intense heat released during a rapid oxidation of combustible material. Fire may be visible as the brilliant glow and flames and may produce smoke.
Fires start when a flammable or combustible material with adequate supply of oxygen or other oxidizer is subjected to enough heat. The common fire-causing sources of heat include a spark, another fire (such as an explosion, a fire in the oven or fireplace, or a lit match, lighter or cigarette) and sources of intense thermal radiation (such as sunlight, a flue, an incandescent light bulb or a radiant heater). Mechanical and electrical machinery may cause fire when combustible materials used on or located near the equipment are exposed to intense heat from Joule heating, friction or exhaust gas. Fires can sustain themselves by the further release of heat energy in the process of combustion and may propagate, provided there is continuous supply of oxygen and fuel. Fires may become uncontrolled and cause great damage to and destruction of human life, animals, plants and property.
Fire is extinguished when any of the elements of so-called fire triangle—heat, oxygen or fuel—is removed. The unburnable solid remains of fire are called ash.
- Oxyacetylene Flame (3000 C or above)(5432 F)
- Oxyhydrogen Flame (2000 C or above)(3632 F)
- Bunsen Burner Flame (Max. Setting) (1300 - 1600 C)(2372 - 2912 F)
- Candle Flame (1400 C)(2552 F)
- Blowtorch (1300 C)(2372 F)
- Log fire (1000 C ~)(1832 F)
- Heather Fire (500 1000 C~)(932 1832 F)
- Paper — (approximately 235 C)(455 F)
- Class A: Fires that involve flammable solids such as wood, cloth, rubber, paper, and some types of plastics.
- Class B: Fires that involve flammable liquids or liquifiable solids such as petrol/gasoline, oil, paint, some waxes & plastics, but not cooking fats or oils.
- Class C: Fires that involve flammable gases, such as natural gas, hydrogen, propane, butane.
- Class D: Fires that involve combustible metals, such as sodium, magnesium, and potassium.
- Shock Risk (formerly known as Class E): Fires that involve any of the materials found in Class A and B fires, but with the introduction of an electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire.
- Class F: Fires involving cooking fats and oils. The high temperature of the oils when on fire far exceeds that of other flammable liquids making normal extinguishing agents ineffective.
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