Chapter 6

Question 1

Fire is a combustion process that can be self sustaining reaction. This chemical process is ___ in that two fo the products of fire are heat and light.

Answer 1

Exothermic

Question 2

Oxygen is found in normal breathing air in the atmosphere at a volume of ___%. The rest of the air is mostly nitrogen, an inert chemical.

Answer 2

21%

Question 3

Heat and light are released an energy form we refer to as a ___ or ___.

Answer 3

Flame or fire

Question 4

A more complete explanation of the fire process involves the fire tetrahedron. This concept was developed in the early ___ by ___.

Answer 4

1950’s by Walter Haessler

Question 5

The fire tetrahedron joins a fourth component, an ___.

Answer 5

Uninhibited chain reaction

Question 6

Walter Haessler was interested in finding out why the chemical ___ was so effective as a fire extinguishing agent.

Answer 6

Ammonium phosphate

Question 7

Fire tetrahedron… The fourth component deals with ___.

Answer 7

Free chain reactions

Question 8

Fire tetrahedron… The fuel is considered a ___.

Answer 8

Reducing agent

Question 9

Fire tetrahedron… In the fire process known as ___, the tetrahedron better describes the reaction taking place.

Answer 9

Flaming combustion

Question 10

Five classes of fire.

Answer 10

Class A - Ordinary Combustibles
Class B - Flammable petroleum products
Class C - Electrically energized equipment
Class D - Combustible metals, end in IUM
Class K - Combustible cooking fuels such as veg oil or animal oils or fats.

Question 11

Class ___; similar to class B fuels but involve very high temps and require wet chemicals to extinguish.

Answer 11

Class K

Question 12

This is an ___ reaction, meaning it absorbs thermal energy from its surroundings.

Answer 12

Endothermic

Question 13

Class A fires burning produce ___, ___, and ___.

Answer 13

Carbon dioxide
Carbon monoxide
Water

Question 14

Plastics are considered to be hydrocarbon based. They produce heavy black smoke and high levels of ___, ___, ___, and ___.

Answer 14

Carbon monoxide
Carbon dioxide
Hydrogen cyanide
Hydrogen chloride

Question 15

The most abundant gas produced at any fire is ___.

Answer 15

Carbon monoxide

Question 16

Heat and gas carry CO in ___ throughout the structure.

Answer 16

Convection currents

Question 17

CO poisoning is the cause of death in more than ___ of all fire fatalities.

Answer 17

50%

Question 18

When fires involve natural and synthetic material that contain nitrogen, the materials release ___.

Answer 18

Hydrogen cyanide

Question 19

___, a very potent irritant, is released from burning polyethylene.

Answer 19

Acrolein

Question 20

___, a deadly gas released from polyvinyl chloride, is irritating to the eyes and upper respiratory tract.

Answer 20

Hydrogen chloride

Question 21

The greater the supply of oxygen, the ___ gasses produced.

Answer 21

Fewer

Question 22

4 phases of fire:

Answer 22

Incipient
Free-burning
Flashover
Smoldering decay

Question 23

Fire growth depends on:

Answer 23

Type of fuel (combustible or flammable)
Physical property of the fuel (solid, liquid, vapor, or gas)
Surface to mass ratio (ex 4x4, wood shavings, or dust)
Arrangement of the fuel (tightly packed or spaces betwn)
Adequate ventilation (nat ventilation or airtight room)

Question 24

Flame itself can produce a flame temp of ___ to ___, but the room temperature may not change significantly.

Answer 24

800°f to 1000°f

Question 25

4 principle means of fire spread:

Answer 25

Convection
Radiation
Conduction
Direct flame impingement (sometimes considered a form of radiation)

Question 26

The travel of ___ can be affected by air currents and ventilation systems.

Answer 26

Convection currents

Question 27

Convection… Because of rapid smoke and fire spread, the greatest dangers exist on the ___, the ___ the fire, and the ___ of the building. The priority of search should be set in this order.

Answer 27

Fire floor
Floor immediately above
Top floor

Question 28

MGM Grand Hotel Fire… Fire in the casino area burned at a rate of approx ___ - ___ feet per second.

Answer 28

15 - 19

Question 29

___: Flames from the fire produce heat waves that move in a straight line form the fire.

Answer 29

Radiation

Question 30

Radiant heat moves ___ from the fire, this heating everyone it can reach.

Answer 30

equally in all directions

Question 31

Radiation… It is a ___ energy, thus can move through glass and water, that does not become thermal energy until it strikes an object and exited the molecules.

Answer 31

Electromagnetic energy

Question 32

In the 1800’s, ___ defunded the law of heat and conduction as, the heat transfer in a. stationary medium(solids, liquids, and gases)

Answer 32

Joseph Fourier

Question 33

There is no heat conduction through ___.

Answer 33

A perfect vacuum

Question 34

Conduction… The rate of heat flow is directly proportional to temperature differences. The heat transfers from the point of heat ___ toward the colder areas.

Answer 34

Outward

Question 35

The spread of fire through ___ is similar to that of radiant heat spread.

Answer 35

Direct flame impingement

Question 36

Direct flame impingement is sometimes considered a form of ___.

Answer 36

Radiation

Question 37

Heating process that contributes to flashover.

Answer 37

Thermal radiation feedback

Question 38

Flashover… The combination of ___ and ___ are now bringing all things in the room to their ignition point.

Answer 38

radiant and convected heat

Question 39

Flashover… ___ of fire across the ceiling is one of the first signs that flashover is imminent.

Answer 39

Rollover

Question 40

___ feet into the room where flashover has occurred is commonly known as the point of no return.

Answer 40

5 feet

Question 41

Flashover… The ___ in the room determines the fire temperature and the pressure generated by the expanding heat and gases of the self sustaining chemical process.

Answer 41

Fire load

Question 42

The key to recognizing flashover is ___ and ___.

Answer 42

smoke movement and fire growth

Question 43

Indicators of impending flashover:

Answer 43

Room size
Extreme, unbearable heat that drives you to the floor
Rollover

Question 44

High ceilings can reach ___ feet, as typical in a warehouse, mask the signs of flashover due to the low heat at the floor level.

Answer 44

20 feet

Question 45

When an oxygen starved fire in an enclosed compartment suddenly gets a fresh supply of air, it will ignite with explosive force. This is known as ___.

Answer 45

Backdraft

Question 46

Backdraft… This phenomenon can occur from premature ___.

Answer 46

Horizontal ventilation

Question 47

Indicators of backdraft:

Answer 47

Thick smoke pushing out opening under pressure
Heavy smoke appears with no visible fire
Dark yellowish-brown smoke seeping form tight building
Smoke is pushed out and drawn back in
Windows stained black and are hot
There is little or no visible flame
The building is tightly closed or contained

Question 48

The use of insulation in ___ has severely limited natural airflow in modern buildings.

Answer 48

Thermal pane windows

Question 49

The oxygen and CO mixture ignites at approximately ___.

Answer 49

1100°f

Question 50

___ are common locations for backdraft.

Answer 50

Commercial occupancies

Question 51

Smoke contains particles of ___, ___, and multiple ___.

Answer 51

Tar
Water
Gases

Question 52

Dark black smoke is typical of ___ based fires, such as plastics and foams.

Answer 52

Hydrocarbon

Question 53

___ smoke indicates and oxygen starved fire.

Answer 53

Dirty brown

Question 54

Lighter smoke is more indicative of Class ___ fires.

Answer 54

A

Question 55

___: A process by which the walls and furnishings in a compartment heat as heat is transferred within the compartment; this heat then feeds back and further heats the compartment.

Answer 55

Thermal radiation feedback