Ch 5-6 Flashcards
(112 cards)
1
Q
The four essential elements necessary for fire are
A
Fuel
Oxidizing agent
Heat
Uninhibited chemical chain reaction
2
Q
The three methods of heat transfer:
A
Conduction – direct contact
Convection – heat circulated through a gas or liquid
Radiation – electromagnetic waves
3
Q
Auto ignition is the phenomenon when:
A
Large quantities of radiation are applied to a combustible material, causing it to spontaneously ignite unpiloted
4
Q
The term used when the vertical spread of fire on the exterior of a multistory building spread from a floor to the floor above
A
Autoexposure.
Can be through a combination of radiation and convection
5
Q
A compartment fire that is not ventilation limited will pass through 4 stages:
A
Incipient
Free burning
Flashover – all exposed surfaces ignite simultaneously
Smoldering/decay – glowing combustion without flame
6
Q
There are several terms that describe the various elements of a compartment fire. These include:
A
The fire plume – a column of flames
Smoke and heated gases
The ceiling layer – hot buoyant gases
The neutral plane – interface layer between the ceiling layer and the cooler air. This contains the by-directional flow.
7
Q
Entrainment is the term known for the process of:
A
Fresh cooler air drawing into the fire from an opening such as a door or window
8
Q
The primary factor influencing a fire burning in a single compartment is
A
The oxygen supply.
9
Q
Examples of construction factors that may influence fire behavior are:
A
Combustible interior walls or finishes
Vertical openings and penetrations
The height of the fire room
The proximity of walls to each other
HVAC system systems
10
Q
The first thing to fail in many construction types, including lightweight members, such as wooden trusses are the:
A
The connections within the members
11
Q
The temperature at which aluminum begins to melt is:
And aluminum also anneals at:
A
Aluminum melts about 1200°F
Aluminum will anneal when exposed to prolonged heat of 350°F or more
The degradation of construction materials is significantly affected by fire duration and size
12
Q
A flow path is known as the movement of hot fire gases and smoke from
A
Areas of high pressure to areas of low pressure, and are created with ventilation openings.
These can be intentional or unintentional openings.
13
Q
3 hazards facing firefighters in a burning structure besides building collapse are
A
Flashover
Backdraft
Concealed space fire or explosion
14
Q
flame spread or fire growth, a particularly hazardous phenomenon, wasn’t recognized until about three generations ago.
Whether or not a compartment goes to flashover is greatly influenced by:
A
Building construction, specifically materials lining the walls and ceilings of the space.
15
Q
Paper vapor seal on the back of batt-insulation is very combustible.
Foamed plastic insulation in walls and ceilings should be protected from flame exposure with
A
1/2” gypsum wallboard covering
16
Q
There are 3 ways in which interior finishes may increase the fire hazard:
A
They may increase fire extension by surface flame spread
They may generate smoke and toxic gases
They may add fuel to the fire, contributing to flashover
17
Q
Celotex, or low density, fiber board used for sheathing and soundproofing, conceal in walls, can be ignited by
A
Plumbers torches
18
Q
Combustible acoustical tile is made from
A
Fiber board with holes punched.
19
Q
High density fiber board, when punched with holes is known as
A
Pegboard. Commonly made by the masonite corporation.
20
Q
Robertson protected metal is the name of:
A
Asphalt coated steel.
May be be used for walls and roofs.
21
Q
Carpeting not only on floors, but also on the walls has become common place in these occupancies:
A
Daycare centers
this is a very dangerous practice. unless the carpeting achieved an appropriate interior finish fire rating it should be removed
22
Q
One hazard in remodeling buildings is when codes require the installation of a ceiling that meets flame spread requirements, but the codes do not require…
A
The removal of the old ceiling.
The dangerous combustible ceiling is left along with the concealed space
23
Q
Restrictions on flames spread in codes are typically strictest for ??
This creates a problem for modern open plan offices.
A
Strictest for corridors and less strict for rooms.
Open plan offices are vague on where the corridor begins and ends
24
Q
The most significant factor in deaths from fire are exposure to
A
Smoke and toxic gases.
Not the thermal exposure.
25
Definition – the generic term used to describe the airborne solid and liquid particles and gas produced by a fire.
Smoke.
Carbon give smoke it’s opaqueness.
Liquid particulars include acrolein and halogen acids
Gases include CO, HCN, and CO2
26
The most prevalent toxic fire gas is:
CO.
HCN is next and maybe just as dangerous.
Habers rule determines concentration and exposure time
27
The toxic effect of materials is a product of concentration and exposure time.
Habers rule states that:
Any exposure equal to 33,000 is dangerous.
This is calculated by (ppm X exposure minutes) >=33,000
28
In regards to CO, the book states exposures of
3500 PPM over 10 minutes is possibly incapacitating
12,500 PPM may be nearly instantly fatal.
29
CO can ignite or be explosive with sufficient oxygen.
When combined with flames appearing in clouds of dark black smoke pouring from windows, this could mean
This could be a sign that flashover is imminent
30
Ventilation of the building did not prevent a CO explosion. Because.
The gas:air mixture can still pocket in enclosed locations
31
When considering the most expensive byproduct of fire, suppression, water damage is second to
Smoke damage especially where delicate equipment is involved or health contamination such as food spoilage
32
Polychlorinated biphenyl (PCB) or were you active material can be mixed with smoke causing extremely high cleanup costs.
Fire problems associated with radioactive material can damage…
Can damage living tissue, and might require abandonment of the property for the safety of personnel.
PCBs are used as non-flammable coolant in transformers. Leaks can cause serious contamination incidents.
33
Plastics containing halogens, such as chlorine, chlorine, bromine, or iodine can form corrosive acids when combined with:
When combined with hydrogen and oxygen or moisture in the air.
This corrosion can damage delicate equipment, as well as brickwork and concrete
34
Regarding magnesium fires, water can be dangerous and cause violent reactions. But under certain circumstances…
Water should be used from a safe distance with a master stream. It will cause the magnesium to burn up at a faster rate.
35
Booker gear, according to the book can we stand temperatures above?
Above 220°F.
36
The trade-off to protecting the thermal balance and neutral plane in the fire compartment is due to the heat release rate of synthetic fuels and plastics.
The best tactic is
Protect the neutral plane if you can ventilate.
If ventilation cannot be done, you must cool the ceiling fire gases to below their ignition temperatures with water.
If you don’t prevent flashover, the neutral plane doesn’t matter
37
Last ditch unorthodox effort to apply water to upper floors of high rises is to
Deploy portable ground monitors from the windows of adjacent buildings
38
PPV can be used to locate hidden fires by:
By pressurizing the space and accelerating the burn with oxygen rich air. Hoseline should be ready along with tools to open walls or ceilings
39
When using gas PPV fans to ventilate for smoke and CO conditions, you should monitor the air for:
For CO to ensure that levels are below 35PPM
40
Another unorthodox method of extinguishing insulation fires is to use:
To use piercing nozzles with Class A foam.
41
An activated sprinkler hood is basically an:
An indirect offensive attack.
42
“ flowing the floor” is a term that means
Flowing water on the floor of the level above the fire. If the fuels are moved away from the exterior walls and the floor has standing water, it cannot burn.
43
Effective PPV ventilation can make the fire behave. This means that, especially in vertical ventilation, you should be able to.
Control the flow path, and force the heat and smoke to follow the path of least resistance into the vent exits
44
By-directional flow is the movement of air by:
Allowing the cooler air to entrain in the lower portion of an opening while the hot fire gases are exiting through the upper portion of the same opening
45
Ceilings made of embossed, steel and wooden boards are referred to as
Matchboarding
46
Limiting the spread of fire with a building contribute to life safety. This is achieved through:
Fire rated floors
Protection of vertical openings
Compartmentation - using firewalls and fire partitions
Fire resistive construction
The use of fire protection systems - sprinkler systems and alarm systems
47
Life safety for building occupants as a primary concern and fire protection.
The most important elements of life safety include:
Proper means of egress
Partition against hazards (based on occupancy)
48
Lots of words in terms in fire protection are ambiguous and inexact. For instance, inflammability and combustibility, non-combustibility means.
Some buildings are described as non-combustible. Non-combust ability refers to certain components, but a non-combustible building can contain significant combustible components.
49
The resistance of a structural member to collapse by fire because of the nature of material or assembly is referred to as
Inherent fire resistance. This applies to structural members. Not to the fire resistance of a structure.
This is associated with a fire resistance rating, subscribed to a component or assembly.
50
Generally speaking, combustible structures are protected with
Gypsum wall board and Wood assemblies that have passed the standard fire resistance test.
51
The three main groups that developed standards for fire resistance that came out of the national bureau of standards are the
NIST
UL
NFPA
52
In regards to fire resistance, testing assemblies, the standard time-temperature curve is listed in:
This curve has remained unchanged for more than 100 years
Originally in NFPA 251 up to 2006;
Similar standards are currently UL 263 and ASTM E-119
Minimum test sizes and max temps for specimens are:
9’ columns/1100°F
12’ beam and girders
100’ sq walls and partitions/250°F
180’ sq floors and roofs/250°F
53
In fire resistance tests of assemblies, assemblies that pass the test are rated in units of hours, such as
One, two, or three hours, depending on how long it survived the fire
54
Fire resistance protection for the main floor assemblies is supposed to provide:
Fire resistance of:
Columns is to resist collapse
Floors is to resist the passage of fire and collapse
Walls to resist the passage of fire and collapse
Fire doors is to resist the passage of fire
55
Fire resistance does not provide protections for these factors:
Fire resistance is not specifically:
Directed at ensuring life safety
Intended to provide smoke control
Concerned with the dollar loss due to fire
56
The difference between fire resistance, ratings, and flame spread ratings are important. These two are not interchangeable.
The flame spread rating means:
The rate at which fire spreads over the surface of a material, the smoke develops, and the fuel contributes to the fire.
Fire resistance is based on the length of time an assembly will continue perform it structural or barrier function when assaulted by fire
57
The Steiner Tunnel Test evaluates flame spread over10 minutes on a scale of 0 (cement board) to 100 (red oak).
This classifies surface materials as:
Class A 0-25
Class B 26-75
Class C 76-200
These tests are also known as:
NFPA 255
UL 723
ASTM E-84
58
The Steiner Tunnel Test is also used for smoke developed ratings when tested at underwriters laboratories (UL 723).
The same materials are tested compared to the same reference, cement board and red oak. The rated score is based on.
0-300
Using a photoelectric cell and measuring light obscuration in the smoke stack.
No toxicity or irritation is measured in this test.
59
Roofing material tests are made through ASTM E-108 or UL 790 to test the resistance to an external fire, fire spread of the roofing surface itself, and propensity to generate brands. A wind of 12 mph is applied during the test.
The results provide three ratings:
Based on the spread of fire,
Class A is rated for severe fire exposures
Class B is rated for moderate fire exposures
Class C is rated for light fire exposures
60
The radiant panel test, ASTM E162 is not
Used for compliance with a code or evidence of a prosecution. Results may be correlated, but not directly related to the Steiner test.
61
Some other tests that are typically not developed used widely include
The radiant panel test
Modern flame spread test
Carpet tests for floors, NFPA 253
Carpet test for walls NFPA 265 and ASTM E84
Critical radiant, flux of floor covering test, NFPA 253
62
Critical radiant flux or CRF is the amount of external radiant heat energy…
The amount of external radiant heat energy below which a flame front will cease to propagate
The higher, the CRF number, the less flammable the carpeting
Rated as class I and class II
Class I is less flammable
63
As a result of the World Trade Center collapse on 911, a few changes are made to fire protection in life safety, including
Improvements to sprayed on fireproofing
Wider stairs and high rises
Separate firefighters stairwells
Improved firefighter elevator access
Requirement for radio signal amplification in buildings
Additionally, hardening of elevators and shafts for civilian egress
64
A new tool to help determine roof conditions is called the health of burning structure panel or HOBS. This uses:
Vibration analysis to monitor vibrations in a structure that might be a pre-cursor to collapse.
65
In the hierarchy of fire, resistive assemblies, the following assemblies are rated as
1. Fire walls are typically 2 to 4 hour resistance, rated and used to separate buildings
2. Fire partitions are typically one hour resistance rated and used to create corridors or separate tenant spaces.
3. Fire barriers are typically one to two hour resistance rated, and are used to enclose shafts, exit stairwells and passageways, and horizontal exits
66
Openings in fire resistive assemblies for the HVAC system must include
Fire dampers, which are mechanically operated using a feasible link, or pneumatic or electric activation
Smoke dampers are also available for smoke partitions
67
Fire doors are required to retain their ability to close and latch closed.
Fire doors can have a protection rating ranging from 20 min - 3 hours.
Three types of fire doors are:
Swinging, the most common choice used in poor doors and stairwell openings
Sliding, typically found across openings in elevator, shafts or stairwells in old factories
Rolling, used in large openings, found in modern factories and warehouses
Fire shutters may also be used such as a ticket booth window.
68
There are two types of fire door closures:
Self closing – an automatic door closer that closes the door after it’s been opened. May also use a fusible link.
Automatic closures – normally open, but held in place by a feasible link and close with gravity, or pulled by a weight
69
Some fire doors are released by smoke detectors. These are typically held open with.
Electromagnets or mechanical latches if they’re too heavy for magnets
70
Horizontal exits are used to reduce travel distances and subdivide or compartmentalize floors.
They usually have ?? rated walls and doors?
2 hour rated walls with rated fire doors
71
Smoke barriers are typically one hour fire rated, including door sweeps, and smoke dampers. These are typically used in:
Healthcare facilities to move non-ambulatory patients horizontally
72
Horizontal or vertical penetrations in fire rated assemblies should be protected by:
Using a special fire resistant putty, or a combination of putty with a metal sleeve inserted into the opening.
73
In regards to escalators, one way to protect these is the use of
Draft curtains 3-4 feet deep, with sprinklers. This does not prevent smoke or fire gas movement.
Draft curtains may be either gypsum or glass
74
The book references, smoky ejectors and large exhaust fans, being used, generally during overhaul. The problem was prevention of outside air from entering into the air stream and deluding the flow for combustion products. The solution was:
The use of positive pressure of ventilation PPV
75
NFPA 13 references sprinkler systems. What are the additional sprinkler system standards for specific occupancies?
NFPA 13D – 1 to 2 family Dwellings
NFPA 13R – low Rise, occupancies, (less than 4- stories or 60 feet)
76
The four major classifications of automatic sprinkler systems are:
Wet pipe Systems – contains water under pressure
Dry pipe systems – contains air or nitrogen under pressure
Pre-action systems – contains air not under pressure and require requires a supplemental fire detecting device
Deluge Systems – sprinkler heads are open all the time, contains air, requires a fire detecting device.
77
Pre-action and deluge systems, typically protect:
Pre-action systems are usually used in areas with easily damaged contents such as data centers
Deluge systems are typically used in highly flammable areas such as flammable liquid operations
78
When talking about sprinkler systems, hydraulically designed systems mean:
That the system and pipe sizes are based on the necessary, flow and pressure for the contents being protected
79
Specific terms of fire flow in sprinkler systems are density of water and demand area. These mean:
Density of water is measured in GPM per square foot of coverage area
Demand area references, the overall size of the fire with all sprinklers operating.
The demand is based on occupancy, hazard classifications
80
NFPA 13 defines demand based on the type of hazard presented in the occupancy classifications.
there are 5 classifications:
Light hazard
Ordinary hazard group 1
Ordinary hazard group 2
Extra hazard group 1
Extra hazard group 2
81
The key to essential sprinkler system operations is that the sprinklers will
Pre-wet the exposed contents. This is designed to First slow, and then stop the advancement of fire through pre-wetting
82
Arguments against sprinkler systems typically failed because
Sprinkler systems are tested to 200 psi
Smoke and fire did more damagethan water
There’s no record of a multiple death of fire in a completely sprinkler building when the system was working correctly
Most people don’t understand how they work
83
Misconceptions and truths about sprinkler system use
The fire department should support sprinkler systems with higher pressures as soon as possible
Sprinkler systems should not be shut down as long as hot water is still falling and vision is obscured
Residential sprinklers are designed to limit flashover and hold a content fire during occupant escape.
84
When the sprinkler system is pronounced at a service, the degree of impairment should be given, such as:
FDC can still be used
Technicians on the way
The system is completely unavailable
The second floor is out of service
Etc
85
86
In a sprinkler protected building, where concessions or trade-offs were made for code modifications, in the event of sprinkler out of service, what should the fire department do?
Do not hesitate to shut down the business until the life safety concern is satisfied. This may be presented to the city attorney.
87
The fire department should have a formal policy on the subject with sprinkler systems out of service.
The policy should cover:
Fire department notifications
Formal legal action
Informal actions
Authority to modify requirements
Formal personnel instructions 
88
The fundamental purpose of a sprinkler system is to
Hit the incipient fire with enough water to control it.
89
Regarding sprinkler valves, there are rules and policies that should be followed, including
Sprinkler valves should be chained and/or locked and should include a tampering alarm
Sprinkler valves may be located in another location such as an adjacent store
90
For special situations involving flammable liquids, sprinklers need special considerations. Be aware of:
Flammable liquids float on water, sprinklers may be ineffective
Sprinklers may cause runoff and contamination problems
Sprinklers should keep containers from overheating or BLEVE
Foam sprinklers are better option than water
91
A separate type of sprinkler designed to suppress a fire with as much as 100 GPM is known as:
Early suppression/fast response or ESFR sprinkle
They typically dump water directly on the Target fire
92
In regards to sprinkler system design, a single riser can cover
An area up to about 52,000 ft.², or 40,000 ft.² for high piled or extra hazard occupancies
93
According to the book, in firefighting considerations for sprinkler operations, you should not
Do not close the valve until the fire is controlled
Do not replace sprinkler heads or reset dry pipe valves. These are contractor jobs.
94
Standpipe Systems are governed by NFPA 14. The classes of standpipes are:
Class 1 system, 2.5 inch hose connections and 100 psi and 250 GPM
Class 2 system, 1.5. inch connections and 65 psi and 100 GPM for building occupants. Aka houseline
Class 3 system, both 1.5 and 2.5 inch connections, up to 100 psi and 250 GPM
95
Standpipe systems are also classified by the water supply provided to the system. These are (4):
Automatic wet – has a water supply capable of supplying the system demand automatically
Semi automatic dry – dry system that requires the use of a preaction device such as a deluge valve
Manual dry – no permanent water supply
Manual wet – has a small water supply to maintain water in the system. May also share water supply with an automatic sprinkler system. Requires support.
96
If the FDC is blocked, clogged, or broken, you should
Pump into the second floor hose valve in the stairwell.
97
Initiating devices for fire alarm systems include:
Pull stations
Spot – type smoke detectors; photoelectric, and ionization
Line – type smoke detectors; projected beams
Duct detectors
Heat detectors
Gas detectors
Flame detectors; ultraviolet, or infrared
Water flow switches
Water pressure switches
Supervisory/tamper switches
98
Indicating devices/signaling device devices in fire alarm systems include
Strobes, horns, buzzers, sirens, speakers, lamps, lights and any combination of these
99
100
As a general rule, when investigating automatic alarms, follow these few guidelines:
Don’t reset the alarm until it’s been investigated. Use the silence switch.
Smoke alarms should have a solid red light to indicate activation
Water flow switches are more indicative than smoke detectors for actual locations
101
102
NFPA 72 defines an unwanted alarm as
Any alarm that occurs that is not the result of a potentially hazardous condition.
103
The smoke management system is possibly the most difficult to navigate.
4 categories of systems are:
Smoke control – such as a stairwell pressurization system
Purge – venting of smoke
Zoned smoke control – combination of pressurization and venting, typically between floors
Airflow – high air velocity to stop smoke movement
104
105
Smoke control systems are managed by criteria from which NFPA standard
NFPA 92, standard for smoke control systems
106
Smoke control systems may be automatic, manual, or both.
Activation devices include
Spot type detectors, poor initiating devices
Water flow switches are better
Projected beam detectors are better, specifically in atriums
107
And smoke management systems, several concerns and considerations for use are:
If the system is not working properly, should it be shut down?
When manually activating a system, communicate this to firefighter personnel
Leave someone at the control to ensure a quick activation or shut down if necessary
108
The two most common types of hazard specific fire protection systems are
Dry chemical systems- paint spray booths and gas station pumps
Wet chemical systems- primarily used in cooking hoods in restaurants
Water spray Systems- for LPG tanks and electrical transformers
Foam systems – for flammable and combustible liquid facilities
CO2 systems- for contents that may be damaged by water
Halon Systems – records, storage facilities, and museums
Clean Agent systems – replacement for Halon Systems, non ozone damaging
Water mist systems – lucky sprinkler system, but 1000 µm or less water mist
109
110
In high rise fires, a realistic estimate between the alarm time and the start of extinguishment is
20 minutes
111
The incident of arson related fires in libraries is about
85% of labor fires are arson
112
According to the book, when flowing to standpipes, you should add how much pressure?
25 psi for the standpipe and 5 psi for each floor, in addition to normal friction laws
