NFPA Certified Fire And Explosion
Investigator (CFEI) Exam Questions And
Correct Answers With Rationales 2026
1. Which of the following is the first step in a systematic fire
investigation?
A. Collecting physical evidence
B. Interviewing witnesses
C. Identifying the area of origin
D. Reviewing insurance records
Rationale: Identifying the area of origin is critical because understanding
where the fire started allows investigators to focus their efforts and
determine potential causes.
, 2. A “flashover” occurs in a compartment fire when:
A. The fire spreads outside the building
B. A combustible vapor ignites
C. All combustible surfaces in a compartment ignite nearly
simultaneously
D. The fire is extinguished
Rationale: Flashover is the near-simultaneous ignition of all combustible
materials in an enclosed space due to high temperatures and radiant heat.
3. Which of the following accelerants is most commonly associated with
arson?
A. Water
B. Alcohol-based cleaners
C. Gasoline
D. Vegetable oil
Rationale: Gasoline is highly flammable, widely available, and commonly
misused as an accelerant in intentional fires.
4. In fire dynamics, the “heat release rate” refers to:
A. The temperature at which materials ignite
B. The time it takes for fire to spread
, C. The amount of energy released per unit time during combustion
D. The area of the fire’s origin
Rationale: Heat release rate is a key factor in fire growth and severity,
measuring the energy output during burning.
5. Which of the following best describes the role of an NFPA CFEI?
A. Extinguishing fires
B. Inspecting fire suppression systems
C. Investigating fire and explosion incidents to determine origin and
cause
D. Selling fire safety equipment
Rationale: A Certified Fire and Explosion Investigator systematically
examines fire scenes to determine how and why the fire or explosion
occurred.
6. The presence of “V-patterns” on walls in a fire scene typically
indicates:
A. Arson
B. The area of origin of the fire
C. Smoke behavior only
D. Flashover
, Rationale: V-patterns point toward the fire’s point of origin because the
flames travel upward and outward, leaving a V-shaped burn pattern.
7. Which method is commonly used to detect hydrocarbon-based
accelerants?
A. Gas chromatography-mass spectrometry (GC-MS)
B. Infrared spectroscopy
C. Both A and B
D. Ultraviolet light
Rationale: GC-MS and infrared spectroscopy are both reliable analytical
methods for identifying trace accelerants in fire debris.
8. Ignition temperature is defined as:
A. The minimum temperature at which a material will spontaneously
ignite without an external flame
B. The temperature a material reaches after flashover
C. The point at which materials melt
D. The temperature water boils
Rationale: Ignition temperature is the critical threshold for spontaneous
combustion without an external spark or flame.
Investigator (CFEI) Exam Questions And
Correct Answers With Rationales 2026
1. Which of the following is the first step in a systematic fire
investigation?
A. Collecting physical evidence
B. Interviewing witnesses
C. Identifying the area of origin
D. Reviewing insurance records
Rationale: Identifying the area of origin is critical because understanding
where the fire started allows investigators to focus their efforts and
determine potential causes.
, 2. A “flashover” occurs in a compartment fire when:
A. The fire spreads outside the building
B. A combustible vapor ignites
C. All combustible surfaces in a compartment ignite nearly
simultaneously
D. The fire is extinguished
Rationale: Flashover is the near-simultaneous ignition of all combustible
materials in an enclosed space due to high temperatures and radiant heat.
3. Which of the following accelerants is most commonly associated with
arson?
A. Water
B. Alcohol-based cleaners
C. Gasoline
D. Vegetable oil
Rationale: Gasoline is highly flammable, widely available, and commonly
misused as an accelerant in intentional fires.
4. In fire dynamics, the “heat release rate” refers to:
A. The temperature at which materials ignite
B. The time it takes for fire to spread
, C. The amount of energy released per unit time during combustion
D. The area of the fire’s origin
Rationale: Heat release rate is a key factor in fire growth and severity,
measuring the energy output during burning.
5. Which of the following best describes the role of an NFPA CFEI?
A. Extinguishing fires
B. Inspecting fire suppression systems
C. Investigating fire and explosion incidents to determine origin and
cause
D. Selling fire safety equipment
Rationale: A Certified Fire and Explosion Investigator systematically
examines fire scenes to determine how and why the fire or explosion
occurred.
6. The presence of “V-patterns” on walls in a fire scene typically
indicates:
A. Arson
B. The area of origin of the fire
C. Smoke behavior only
D. Flashover
, Rationale: V-patterns point toward the fire’s point of origin because the
flames travel upward and outward, leaving a V-shaped burn pattern.
7. Which method is commonly used to detect hydrocarbon-based
accelerants?
A. Gas chromatography-mass spectrometry (GC-MS)
B. Infrared spectroscopy
C. Both A and B
D. Ultraviolet light
Rationale: GC-MS and infrared spectroscopy are both reliable analytical
methods for identifying trace accelerants in fire debris.
8. Ignition temperature is defined as:
A. The minimum temperature at which a material will spontaneously
ignite without an external flame
B. The temperature a material reaches after flashover
C. The point at which materials melt
D. The temperature water boils
Rationale: Ignition temperature is the critical threshold for spontaneous
combustion without an external spark or flame.
