Classes of Fire
The components that constitute a fire are fuel, oxygen, heat, and chemical chain reaction. Based on the type of fuel, fires are categorized into the following classes as per the OSHA Standard:
Fire resulting due to solid organic materials such as paper, wood, coal or textiles.
Fire resulting due to flammable liquids and gases such as petrol, diesel, propane, solvents etc.
Fire resulting due to energized/live electrical equipment such as computers, circuit breakers, machinery, appliances etc.
Fire resulting due to metals such as aluminum, magnesium, etc.
Fire resulting due to cooking oils and fats.
As per European Standard, the classification is slightly different, wherein fires resulting due to flammable gases are considered Class C, and there is no class for electrical fires.