​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:

• Class A:

Fire resulting due to solid organic materials such as paper, wood, coal or textiles.

• Class B:

Fire resulting due to flammable liquids and gases such as petrol, diesel, propane, solvents etc.

• Class C:

Fire resulting due to energized/live electrical equipment such as computers, circuit breakers, machinery, appliances etc.

• Class D:

Fire resulting due to metals such as aluminum, magnesium, etc.

• Class K:

Fire resulting due to cooking oils and fats.

Note:

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.