NFPA 921 Fire Investigation Flashcards

According to NFPA 921, what is the primary purpose of fire pattern analysis?

Answer: To identify the origin and direction of fire travel

NFPA 921 defines fire pattern analysis as the process used to identify origin and direction of fire travel based on physical evidence.

In fire investigation, 'arc mapping' is used primarily to:

Answer: Locate electrical arc damage to determine fire spread direction

Arc mapping identifies electrical arcing locations to help determine the sequence of events and fire progression through a structure.

Which of the following best describes a 'V-pattern' in fire investigation?

Answer: A char pattern on walls indicating upward fire spread from a low point

V-patterns appear on walls when fire burns upward and outward from a point of origin, with the narrow base pointing toward the heat source.

Per NFPA 921, which type of evidence should be collected first at a fire scene?

Answer: Transient and perishable evidence

NFPA 921 instructs investigators to prioritize transient and perishable evidence because it is most easily lost or destroyed.

What does the term 'fire spread' refer to in NFPA 921?

Answer: The movement of fire from its origin to other locations

Fire spread describes how fire moves from the point of origin to adjacent areas, driven by heat transfer mechanisms.

According to NFPA 921, which heat transfer mechanism is most responsible for spreading fire through open spaces?

Answer: Convection

Convection moves heated gases and flames through open spaces, making it the dominant heat transfer mechanism for fire spread in open areas.

In the context of NFPA 921, what is 'flashover'?

Answer: The rapid transition from a growing fire to full room involvement

Flashover is the near-simultaneous ignition of all combustible materials in a compartment, marking the transition to full room involvement.