Answers 100% Correct!
The fire tetrahedron components are: - ANSWERSfuel, oxygen, heat, chemical reaction.
If you remove one side, the fire goes out
Theory of Fire - ANSWERSfire is a rapid self sustaining oxidation accompanied by heat
& light of varying intensities
gases produced by combustion - ANSWERScarbon monoxide, carbon dioxide, sulfur
dioxide
how much oxygen must make up in atmosphere to burn - ANSWERSat least 16% (12%
for smoldering fire)
Fire classes; A, B C, and D - ANSWERSA: ordinary combustible materials, wood,
paper, cloth
B: flammable & combustable liquids, gases, greases
C: live electrical fires
D: combustable metals such as magnesium or sodium
Fire classes extinguished by - ANSWERSA: cooling (water or multi purpose dry
chemical)
B: smothering, cooling, stopping chain reaction (CO2 extinguisher, dry chemical
extinguisher, foam, halon)
C: turn off all electrical or powered equipment then fight fire as A or B fires (CO2, dry
chemical, or halon)
D: chemical powders
Flashpoint - ANSWERSLowest temperature at which a fuel gives off flammable vapors
in sufficient quantity to ignite & flash across the surface of the fuel
Flashpoint of different fuels - ANSWERSgasoline (-45 F)
diesel (110 F)
What burns? - ANSWERSvapor - not fuel
Conduction - ANSWERSThe direct transfer of heat from one substance to another
substance that it is touching.
Prevent by removing or cooling combustibles
Convection - ANSWERSThe transfer of heat by the movement of a heated air or liquid
Prevent by closing ventilation, ladder wells, doors
, Radiation - ANSWERSThe transfer of energy by electromagnetic waves without an
intervening medium
Prevent by putting a barrier between the fire and combustibles (water, doors, fog, etc)
Direct flame contact - ANSWERScombination of heat transfer by convection & radiation
at close range
Phases of fire development - ANSWERSignition
growth
flashover
fully developed fire
Smoldering or decay
ignition - ANSWERS4 elements of fire tetrahedron come together and flaming
combustion begins
growth - ANSWERSa fire plume begins to form above burning fuel. Air drawn into plume
and convection causes heated gases to rise - continues of enough fuel and oxygen are
available
flashover - ANSWERSA rapid transition from the growth stage to the fully developed
stage.
Occurs at 1000F-1500F
Signs of Flashover - ANSWERSif heat is hot enough to make you drop to your knees or
rollover which is small flashes of flame appear at ceiling level or smoke pouring out of
top of window or doorway
fully developed fire - ANSWERSall combustible materials in compartment are involved
in fire - burning fuels are releasing maximum amount of heat possible and produces
large amounts of unburned fire gases
Temperature of a normal fire - ANSWERScoal burns at 3,590F
wood burns at 300F but can reach as high as 1600 F
hydrocarbon generates 1832 F within 10 minutes of ignition
most combustable metals in fire produce 5000F-8,500F
Backdraft - ANSWERSInstantaneous explosion or rapid burning of superheated gases
that occurs when oxygen is introduced into an oxygen-depleted confined space. The
stalled combustion resumes with explosive force; may occur because of inadequate or
improper ventilation procedures.
Signs of Backdraft - ANSWERSBlack smoke becoming dense gray yellow
Pressurized smoke exiting small openings
Confinement and excessive heat