Firefighting Knowledge Flashcards
7 cards from real NFSI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Firefighting Knowledge flashcards as text
What is the primary hazard associated with a backdraft condition?
Answer: Explosive ignition when oxygen is suddenly introduced to an oxygen-starved fire
Backdraft is a deflagration explosion triggered when oxygen is introduced to a superheated, oxygen-depleted compartment containing unburned combustible gases.
Which fuel property describes how easily a material releases vapors that can ignite?
Answer: Flash point
The flash point is the lowest temperature at which a liquid produces enough vapor to ignite momentarily when exposed to an ignition source.
When using a straight stream from a nozzle, what is the primary tactical advantage over a fog pattern?
Answer: It reaches deeper into a fire compartment with less steam conversion
A straight stream penetrates farther and generates less steam that could obscure vision or cause burns to firefighters in an enclosed space.
What is the purpose of the incident command system (ICS) span of control guideline?
Answer: To ensure no supervisor is responsible for more than 3–7 personnel
ICS span of control (3–7 people per supervisor, optimal 5) prevents supervisors from being overwhelmed and ensures effective coordination.
Which of the following best describes a 'two-in, two-out' rule?
Answer: At least two firefighters must be outside and ready to assist any time two or more are inside an IDLH atmosphere
The two-in, two-out rule (OSHA 29 CFR 1910.134) requires a standby rescue team outside whenever firefighters are operating in an immediately dangerous to life or health atmosphere.
What does 'laminar flow' indicate about smoke movement in a building?
Answer: Smoke is moving in a smooth, layered pattern, often signaling a lower-heat fire
Laminar (smooth, layered) smoke movement typically indicates a cooler, lower-energy fire, while turbulent or pulsing smoke signals high heat and potential flashover conditions.
What is the main reason firefighters use thermal imaging cameras (TICs) during overhaul?
Answer: To locate hidden hot spots and smoldering materials that could rekindle
TICs detect heat signatures through walls and debris, allowing firefighters to find concealed smoldering materials that could cause re-ignition after apparent suppression.