Fire is not quite fire
The control of fire by early humans was a turning point in the cultural aspect of human evolution that allowed humans to cook food and obtain warmth and protection. Making fire also allowed the expansion of human activity into the dark and colder hours of the night, and provided protection from predators and insects. The earliest definitive evidence of the human control of fire dates back to 200.000 to 700.000 years before our time, showing the use of ordinary combustibles such as firewood.
Along with the evolution of our race and the technological advancements by now, today fire may occur from various sources and for various reasons. Experts classify fires in five different categories today:
Class A fires
CLASS A fires are fires in ordinary combustibles, such as wood, paper, cloth, trash, and plastics.
In order to put out such fires the following extinguishing substances can be used: water, foam, dry powder and wet chemical. CO2 must not be used, however.
Class B fires
CLASS B fires are fires in flammable liquids such as gasoline, petroleum oil and paint. Class B fires also include flammable gases such as propane and butane. Class B fires do not include fires involving cooking oils and grease.
Use foam, dry powder and CO2 to fight these fires, not water or wet chemicals.
Class C fires
CLASS C fires are fires involving energized electical equipment such as motors, transformers, and appliances. Remove the power and the Class C fire becomes one of the other classes of fire.
Fight them with dry powder or CO2 only !
Class D fires
CLASS D fires are fires in combustible metals such as potassium, sodium, aluminum, and magnesium.
Only dry powder may be used against this type of fires !
Class K fires
CLASS K fires are fires in cooking oils and greases such as animals fats and vegetable fats.
Only wet chemicals are effective against these fires; frying pans on fire shall be covered with a wet kitchen cloth.
Or, in other words...
Sounds complicated ? Don't worry - here is an easy way to remember:
Class A fires leave ASH
Class B fires BOIL
Class C fires have CURRENT
Class D has DENSE METAL, and of course...
Class K stands for KITCHEN !
See ? Not so difficult after all !
Pair up the labels so that you get four correct sentences !
Class A fires......leave an ash.
Class K fires......may involve cooking oils and vegetable fats.
Class D fires......are fires of combustible metals.
Class B fires......may involve combustible liquids.
Class X fires......do not exist
Tick the correct answers !
- Burning cooking oil can best be put out by pouring water on it.
- For burning eletrical equipment, CO2 must be used as extinguisher.
- Flammable metals can be extinguished by dry powder.
- Class A fires may be put out with any extinguishing substance, even CO2.