Ch.6 Flashcards
Fire is a _______, ________, _______, and _______-
- Exothermic reaction
- Oxidation Process
- Combustion process
- Chemical process
Fire is a chemical process in which ______, ______, and _______ come together in an uninhibited chain reaction.
- heat
- fuel
- oxygen
Fire produces an _________, releasing heat, light, smoke, toxic gases, and other products of incomplete combustion.
exothermic reaction
Fire is a ________ that can be self-sustaining reaction.
combustion process
Fuel for fire can be in any form of the three physical properties of matter: _____, _____, ______
- solid
- liquid
- gas
The fire triangle consists of ______, ______, and _____
- Fuel
- Heat
- Oxygen
The first component of the fire triangle is _______
Fuel
Fuel must be a ______ or _______ material
combustible or flammable
The fuel is most likely composed of ______ and ______ that can be oxidized.
-carbon and hydrogen atoms
The second component of the fire triangle is ________
Oxygen
What is the most common oxidizing material in the atmosphere?
Oxygen
Oxygen is found in normal breathing air in the atmosphere at a volume of _______ percent
21%
The rest of air is mostly _______, an inert chemical.
Nitrogen
The third component of the triangle is _________
heat energy
Water is an effective firefighting agent because it ________ and because it is readily available.
It can also be used to ____________ by submerging some fuels.
- absorbs heat, thus cooling the fuel
- smother flames
A more complete explanation of the fire process involves the _____________
Fire Tetrahedron
The Fire Tetrahedron was developed in the 1950’s by ___________
Walter Haessler
Walter Haessler was interested in finding out why ____________ was so effective as a fire-extinguishing agent.
the dry chemical ammonium phosphate
In the 4 sided Fire Tetrahedron, there is a fourth component:
uninhibited chain reaction
In the fire process known as ________, the tetrahedron better describes the reaction taking place.
flaming combustion
The fuel in the fire tetrahedron is considered a _________
reducing agent
What are the 5 classes of fires:
Class A: Ordinary Combustibles
Class B: Flammable Petroleum products
Class C: Electrically energized equipment
Class D: Combustible Metals
Class K: Cooking Fuels, Vegetable or animal oils and fats
In Class C fire, the fuel itself can be either class ____, ____ or _____
Class A
Class B
Class D
Combustible metal fires are more common in _________
manufacturing areas
Firefighters must avoid bringing water into contact with ___________
Class D: Combustible Metal fires
Class K fires are technically a subclass of the ______________
Class B- flammable liquid/gas class
The extinguishing agent rapidly converts the burning substance to a noncombustible soap:
Saponification
Saponification is a ___________
Endothermic reaction
Meaning it absorbs thermal energy from its surroundings:
Endothermic reaction
When a Class A fire burns, they produce ______, ______, and ________
- Carbon Dioxide CO2
- Carbon Monoxide CO
- Water
Plastics are hydrocarbon-based and produce heavy black smoke and high levels of _______, ______, and _______
- Carbon Monoxide
- Carbon Dioxide
- Hydrogen Cyanide
- Hydrogen Chloride
Most fire deaths result from the ___________
Toxicity of the smoke
The most abundant gas produced at any fire is __________
Carbon Monoxide
*This gas has killed the most people
Carbon monoxide poisoning is the cause of death in more than _______ percent of all fire fatalities.
50%
When fires involve natural and synthetic materials that contain nitrogen, such as wool, silk, acrylonitrile, polyurethane, melamine, and nylons, the materials release _________
Hydrogen Cyanide
________ and ________ are associated with morbidity and mortality
Hydrogen Cyanide and Carbon Monoxide
Automobile fires have sickened firefighters from gases released from __________
polyurethane foam rubber seats
_______ is a very potent irritant, released from burning polyethylene
Acrolein
_________ is a deadly gas released from polyvinyl chloride (PVC)
Hydrogen Chloride
The fires progress depends on _______, _____, and ______
- fuel load
- combustibility of fuel
- intensity of heat produced
4 phases of fire:
- Incipient stage
- Free-burning stage
- Flashover
- Smoldering decay stage
The ______ is the actual ignition stage. The fire involves only the original material ignited and produces some heat and smoke.
incipient phase
The flame itself may produce a flame temperature of _____ to _____
800 to 1000 degrees
- Fire preheats surrounding materials
- Fire spreads vertically as a thermal convection current
- Thermal column meets resistance of ceiling and spreads out horizontally.
- Room is heated from top down
Free-basing phase
Fire spreads in all directions through ______ heat waves
radiant
During the smoldering phase the temperature can reach ________ or more.
1000 degrees
Fire can spread by 4 principal means:
- convection
- radiation
- conduction
- direct flame impingement
Direct flame impingement is sometimes considered a form of ___________
radiation
When the lighter gases stay near the top floors of structure while the flames and heavy gases spread throughout the lower areas of the structure.
stratify
MGM Grand Hotel Fire:
- November 21, 1980
- 85 people died
- burning 15 to 19 feet per second
The priority of search should be set at:
- fire floor
- floor immediately above fire
- top floor of building
Flames from a fire produce heat waves that move in a _____ from the fire.
straight line
______ are an invisible movement of heat that can penetrate windows and unprotected openings.
Heat waves
Radiant heat moves ____________, heating everything it can reach.
equally in all directions from fire
Radiant Heat is _________
electromagnetic heat waves
Water curtains are of little use in stopping __________
radiant heat
Who defined the law of heat of Conduction in the 1800’s:
Joseph Fourier
The most important physical properties fro Heat conduction are:
- thermal conductivity
- density
- specific heat
The point in the progression of a room fire when all the combustibles in the room have ignited:
Flashover
*Temp can exceed 1000 deg
The heating process during Flashover is caused by:
Thermal Radiation Feedback
_______is one of the first signs that flashover is imminent.
Rollover
_____ feet into room where flashover has occurred is commonly known as “the point of no return”
5
The key to recognizing flashover is the ______ and _______
- smoke movement
- fire growth
Ceilings, which can be nearly ___ feet high can mask the amount of heat at the ceiling level.
20 feet
Indicators of impending Flashover:
- Roomsize
- Extreme Heat
- Rollover
Backdraft can occur from _________
premature horizontal ventilation
Indicators of impending backdraft include:
- thick smoke pushing out windows
- Dark, yellowish-brown smoke seeping
- smoke out then back in
- windows stained black
- condensation streaks running down inside window
The Oxygen and Carbon Monoxide mixture ignites at approximately ________
1100 degrees
Backdrafts can be fairly common in:
- taxpayers
- strip shopping centers
- row houses
- garden apartments
With todays ______ and _____ it is not uncommon to have a backdraft in single-famiily dwelling.
- environmental consciousness
- energy saving ideas
________ has a training center where it can simulate backdraft explosions.
U.S. Navy
In U.S Navy backdraft Training, it has concluded that that fire must draw air into it for _____ seconds before ignition occurred.
few seconds
_______ is produced from the incomplete combustion of the fuel
smoke
Smoke contains:
- tar
- water
- multiple gases
At the very least the Incident Commander should obtain a view of _____ sides
at least 3 sides
Dark, Black smoke is indicative of __________
hydrocarbon-based fires (plastics and foams)
Dirty, Brown smoke indicates __________
oxygen-strarved fire
Lighter smoke is more indicative of _______
Class A fire
In very cold weather all smoke can look white because _______________
water condensation due to heat of fire
The chemical process of fire is exothermic in that 2 of the products of the fire are _____ and _______
heat and light
A method of heat transfer through a medium:
Conduction
A method of heat transfer by which air currents are the means of travel:
Convection
An artificial face or front to a building:
facade
2 or 3 story apartment building with common entryways and floor layouts, often with porches, patios, and greenery around the building:
Garden apartment
Where mercantile occupancy is on the first floor and living area occupy the floors above.
Taxpayer
Process by which walls and furnishings in a compartment heat as heat is transferred within the compartment, this heat then feeds back and further heats the compartment:
Thermal radiation feedback
