Which component is not part of the fire triangle?

Which component is not part of the fire triangle?

• A. Heat
• B. Fuel
• C. Oxygen
• D. Nitrogen

Answer: (D)

Fire requires three elements to sustain combustion: heat to reach ignition, fuel to feed the flame, and oxygen to support the chemical reaction. The fire triangle shows these three essential components. Nitrogen, though it makes up most of the air, does not participate in the combustion process and is largely inert in ordinary fires; it also helps dilute oxygen. Because it does not contribute to burning, nitrogen is not part of the fire triangle.

Fire requires three elements to sustain combustion: heat to reach ignition, fuel to feed the flame, and oxygen to support the chemical reaction. The fire triangle shows these three essential components. Nitrogen, though it makes up most of the air, does not participate in the combustion process and is largely inert in ordinary fires; it also helps dilute oxygen. Because it does not contribute to burning, nitrogen is not part of the fire triangle.