Certified Fire Investigator Practice Exam

What is known as the "Ignition Temperature"?

1. The lowest temperature for flame propagation

2. The maximum temperature to ignite a substance

3. The temperature at which a fire extinguishes

4. The average temperature of flames in a fire

The correct answer is: The maximum temperature to ignite a substance

The term "Ignition Temperature" refers specifically to the minimum temperature required to initiate combustion in a substance without an external ignition source. This is the point at which the heat energy supplied to the material can overcome the material's heat of combustion, causing it to catch fire. The reasoning behind the selection of this definition is based on its practical implications in fire investigation and safety. Understanding ignition temperature is crucial for identifying the conditions that could lead to a fire starting in any given environment. The first option discusses flame propagation, which does not accurately define ignition temperature, focusing instead on the spread of fire rather than its initiation. The choice related to a fire extinguishing addresses a completely different aspect of fire behavior and is not relevant to ignition. Lastly, the average temperature of flames during a fire is also unrelated, as it does not pertain to the specific starting point of combustion but rather describes the conditions during an active fire.