NFST Fire Behavior and Science Flashcards
6 cards from real NFST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 NFST Fire Behavior and Science flashcards as text
Which extinguishing agent is most effective on a Class A fire involving ordinary combustibles like wood and paper?
Answer: Water
Water is the primary and most effective agent for Class A fires because it cools burning material below ignition temperature.
What term describes the lowest temperature at which a liquid fuel produces enough vapor to ignite?
Answer: Flash point
Flash point is the minimum temperature at which a liquid gives off enough vapor to form an ignitable mixture near its surface.
Smoke rising quickly and freely from a building generally indicates what about the fire conditions inside?
Answer: There is adequate ventilation and the fire is oxygen-rich
Smoke that rises quickly and freely indicates the fire has a good oxygen supply and is burning in a well-ventilated space.
What is the primary purpose of ventilation during a structure fire?
Answer: To remove heat, smoke, and gases to improve visibility and reduce fire spread
Ventilation removes heat, smoke, and toxic gases from a structure, improving conditions for search and rescue and suppression efforts.
Which phase of fire development is characterized by limited fuel and plentiful oxygen?
Answer: Incipient (growth) phase
During the incipient or growth phase, the fire is small, fuel is abundant but consumption is low, and oxygen is plentiful.
What phenomenon occurs when burning liquid fuel floats on water and spreads, potentially worsening a flammable liquid fire?
Answer: Boilover
Boilover occurs when water beneath a burning oil layer turns to steam, causing a violent eruption that spreads burning fuel.