Fire Behavior and Combustion Science Flashcards

What three elements make up the fire triangle?

Answer: Fuel, oxygen, and heat

The fire triangle consists of fuel, oxygen, and heat — all three must be present simultaneously for fire to exist and sustain itself.

Which class of fire involves ordinary combustibles such as wood, paper, and cloth?

Answer: Class A

Class A fires involve ordinary solid combustibles like wood, paper, cloth, and most plastics, and are the most common type found in homes and offices.

What is the autoignition temperature of a material?

Answer: The minimum temperature at which it will ignite without any external ignition source

Autoignition temperature is the minimum temperature at which a material spontaneously ignites without any external spark or flame present.

What is flashover in the context of fire development?

Answer: The sudden, simultaneous ignition of all combustible materials in a room

Flashover occurs when all combustibles in a room reach their ignition temperature simultaneously, resulting in near-instantaneous full-room fire involvement.

Which combustion gas is responsible for the majority of fire-related fatalities in the United States?

Answer: Carbon monoxide (CO)

Carbon monoxide is the leading cause of fire deaths because it is colorless, odorless, and rapidly incapacitates victims before they can escape.

How does the 'fire tetrahedron' differ from the older 'fire triangle' model?

Answer: It adds the uninhibited chemical chain reaction as a fourth element

The fire tetrahedron adds the uninhibited chemical chain reaction as a fourth element, explaining how chemical suppression agents extinguish fires without removing heat, fuel, or oxygen.

Which class of fire involves flammable liquids such as gasoline and oil?

Answer: Class B

Class B fires involve flammable and combustible liquids (gasoline, oil, paint) and flammable gases, and require smothering or chemical suppression rather than water.