Phx Fire Vol 2 (Deck 2) Flashcards
201.01A
1
Q
Describe the purpose of the In-Transit procedure.
A
Establish a standard deployment approach to communicating company arrival to assigned work areas and to define On-Deck deployment and Company Recycling.
2
Q
Define On-Deck.
A
Tactical function within a Sector for layering of resources in forward positions, supervised by the Sector Officer or Company Officer, and remaining On-Deck until assigned by the IC or Sector Officer.
3
Q
How does the In-Transit time vary?
A
Due to the distance between staging and the incident, the size of the incident perimeter, and the amount of equipment the company needs to assemble.
4
Q
Do On-Deck crews have specific likely assignments?
A
Yes, Including rapid intervention crew, reinforcing a position within an assigned sector, crew relief within an assigned sector, and any other tactical position assigned by the IC.
5
Q
Describe the responsibility of the Company Officer during the In-Transit phase.
A
Must monitor the tactical radio channel while In Transit and provide a radio announcement to the IC or report face-to-face with the Sector Officer upon arrival to the assignment area, confirming the company is intact and in the assigned area.
6
Q
Describe how assigning On-Deck crews is done according to the standard operating procedures.
A
Contacting a staged company and directing them to go On-Deck in a specific Sector, providing accountability location and sector assignment.
7
Q
What are the responsibilities of an On-Deck crew upon arrival at their assigned location?
A
Must contact the IC or their Sector Officer, remain intact and in a ready state, monitor the tactical channel, and size up the area they are assigned to.
8
Q
Define company recycling.
A
A timely and efficient means of air replacement and re-hydration of companies while maintaining their sector assignment, without necessitating communication with the IC.
9
Q
How is the transfer of information conducted when an On-Deck crew is used as a relief crew?
A
The Company Officer should do a face-to-face transfer of information with the exiting Company Officer, including interior conditions, routing instructions, obstructions, tools/resources required, and sector objectives.
10
Q
Describe the responsibilities of Sector and Company Officers in monitoring the welfare of their personnel during a fire incident.
A
Determining if sector recycling or formal rehab is appropriate, and for forecasting the length of time their personnel will be working in an assigned sector.
11
Q
Define the purpose of a Utility Company on the fireground and how it helps expedite the recycle of companies within a sector.
A
Assigned to geographic areas on the fireground to help expedite the recycle of companies within the sector, and it assists in bringing spare air cylinders if necessary.
12
Q
How does the establishment of a Rehab Sector at large scale incidents impact the fireground operations?
A
May create the potential for command losing direct accountability of companies in transit to rehab and difficulty reassembling and reassigning crews in a timely manner from rehab.
13
Q
What specific directions may the IC provide to On-Deck Companies when assigning them?
A
May direct the On-Deck Company to spot on a hydrant, lay a second supply line, or focus their efforts specifically on operating as a Rapid Intervention Crew for the assigned Sector.
14
Q
Do On-Deck companies act as one-entity for the purposes of emergency service delivery, and how does this impact their actions during a fire incident?
A
Yes, They may receive specific directions from the IC, such as focusing their efforts on operating as a Rapid Intervention Crew for the assigned Sector.
15
Q
201.01A
A
In-Transit, On-Deck, Company Recycle
16
Q
What situation does Vol 2 empower the Sector Officer to do?
A
To manage the resolution of a Mayday situation within their sector.
17
Q
Describe the definition of a Mayday situation.
A
Any situation where a firefighter is unable to safely exit the hazard zone or an event that cannot be resolved by that individual within 30 seconds.
18
Q
How is a Mayday initiated?
A
A Mayday is initiated by any member communicating ‘Mayday, Mayday, Mayday’ via portable radio.
19
Q
Define Mayday readiness.
A
Ability to don, doff and manipulate the SCBA in zero visibility while wearing firefighting gloves, as well as maintaining a high level of readiness at all times.
20
Q
What is the Rule of Mayday Readiness?
A
It is every individual FF’s responsibility to maintain a high level of Mayday readiness at all times, including everyday preparation and prevention as well as the practiced ability to communicate and respond to a Mayday scenario.
21
Q
Describe the factors for Mayday prevention.
A
Working within an Incident Command System/Risk Management System, working within the IAP, and always being prepared for potential Mayday situations.
22
Q
Describe the two components of Mayday readiness.
A
Prevention and Response.
23
Q
What are the individual firefighter responsibilities for Mayday prevention?
A
Maintaining SCBA proficiency, practicing individual air management, using and caring for personal protective equipment, portable radio proficiency and use, practiced crew communications, and roving/replacement firefighter integration into crew.
24
Q
What are the Company Officer responsibilities for Mayday prevention?
A
Integrating a daily SCBA check into the crew routine, practicing crew communication in the hazard zone, rover integration into crew, maintaining knowledge of portable radios and practicing their use, ensuring Company Officer responsibilities and expectations are clear to the entire crew, practicing and maintaining crew integrity/accountability, and instilling the standard that firefighters should always stay on a hoseline.
25
How can effective Mayday readiness be established?
By recognizing that Mayday readiness has two components: Prevention and Response, and by actively and routinely preparing for the prevention of Mayday situations and the response to Mayday situations.
26
What does B.O.A. stand for in the context of Mayday response?
Breath, Organize, and Act; the steps to be taken once a Mayday situation is recognized and reported.
27
Define the tactical level of Mayday readiness and response.
Actively and routinely working toward Mayday prevention and preparedness, managed by the Battalion Chief and F.I.T. or I.S.O. tandem.
28
How should the Mayday situation be initially managed at the company level?
By the affected FF: maintaining prep & reaction skills, early communication, controlling emotional response, remember BOA, IAFF Fire Ground Survival Training.
29
What are the responsibilities of the tactical level in Mayday readiness and response?
The responsibilities of the tactical level include working within the overall incident action plan, continual assessment of the decision-making model, and management of tactical objectives for the sector.
30
Describe the responsibilities of the Sector Officer in managing a Mayday situation.
The Sector Officer takes responsibility for resolving the Mayday situation, managing communications with the down firefighter, overseeing search and rescue efforts, and increasing and maintaining resources assigned to the sector.
31
What are the key components of maintaining effective and appropriate communications with Command during a Mayday situation?
Sector C.A.N. reports, requesting or de-committing resources, and managing the logistical support.
32
How can the survivability of a Mayday situation be increased through sector operations?
Pessimistically projecting resource requirements, responding to the Mayday from the inside out, managing communications with the down firefighter, and improving ventilation are ways to increase survivability.
33
Define the term 'work/rest cycles' in the context of sector level air management during a Mayday situation.
Managing the time firefighters spend working and resting, ensuring they have adequate rest periods to prevent fatigue and maintain effectiveness.
34
What are the responsibilities of the IC in supporting the Mayday Sector Officer during a Mayday situation?
Must provide appropriate and adequate resources to manage the Mayday, reinforce surrounding geographical and/or functional sectors, and pessimistically project resource requirements for sector operations.
35
Do you know what 'TAG hose lines' means in the context of maintaining accountability during a Mayday situation?
Maintain adequate resources assigned to the sector, ensuring layered resources are in position to manage tactical objectives and respond in the event of a Mayday.
36
Describe the responsibilities of the Incident Command Team in responding to a Mayday situation.
Responsible for actively and continually providing for the prevention and response to a Mayday situation.
37
What are the strategic level responsibilities for the prevention and response to a Mayday situation?
Continually reassessing the incident, considering critical fireground factors, evaluating the IAP, planning for communications challenges, and considering remaining on-scene firefighters' welfare.
38
How should surrounding sectors not involved in the Mayday respond?
Continue the firefight in support of the Mayday, actively account for all members assigned to the sector, report P.A.R.'s to the Incident Commander as required, and maintain accountability of crews working to resolve the Mayday.
39
What communication route may be the best for maintaining accountability regarding crews working to resolve the Mayday?
Utilizing the Safety Channel .
40
Define the Risk Management System and its importance during a Mayday event.
A clear and concise utilization of strategies to assess and mitigate risks. It is crucial during a Mayday event to prevent creating further Mayday situations when resolving an existing one and to communicate deteriorating conditions to the IC.
41
Describe the strategic level communications once a Mayday is initiated.
All sectors should manage their communications to critical messages only over the radio, manage communications pace and tone, and ensure that incident and Mayday always remain on the same tactical channel.
42
What are the critical points that have to be confirmed prior to giving the benchmark of 'Mayday resolved?'
The individuals experiencing the Mayday situation are removed from the hazard zone.
43
Define tactical benchmarks in the context of Mayday readiness and response.
Refer to the end point of a Mayday, which is Mayday resolved
44
How should the overall incident organization be maintained during a Mayday situation at the strategic level?
Ensuring Battalion Chiefs are assigned to all critical tactical level positions, managing resource deployment, controlling access to the hazard zone through the Sector Officers, and supporting tactical level considerations such as improving access to the building and addressing the fire when conditions allow.
45
Describe the responsibilities of the Officer of the individual sector in which the Mayday occurred.
The Officer is responsible for notifying command of the completion of the rescue and ensuring all members involved are out of the hazard zone.
46
What are the responsibilities of the tactical radio operator in a Mayday response?
Initiating the emergency traffic tone, voicing the Mayday message on the tactical channel, maintaining communication with the Mayday initiator, and providing redundant monitoring of the Mayday radio traffic.
47
Define Mayday in the context of hazard zones.
Mayday is not just a fireground term; it can be used in any hazard zone and is initiated by a member in the field communicating 'Mayday, Mayday, Mayday' on the radio.
48
How does the dispatch center assist with a Mayday incident?
Provides redundant monitoring of the Mayday radio traffic and automatic activation of processes, including providing additional resources and upgrading the incident using the Mayday nature code.
49
Do all responding units need to be aware of the Mayday?
Yes, the tactical radio operator ensures all responding units are aware of the Mayday and upgrades the assignment to a Mayday nature code.
50
Key points of the Mayday Readiness and Response standard operating procedures.
Emphasizes the responsibility of all FFs to maintain preparedness for a Mayday situation, the importance of preventing Mayday situations, the need for action at all levels of an incident command system, and remembering BOA.
51
What is the ultimate goal for any Mayday response?
To successfully resolve the Mayday situation while not creating any further Mayday situations.
52
Define Mayday prevention and preparedness.
Requires action at all levels of an incident command system.
53
What emotional impact does a Mayday situation have according to the standard operating procedures?
A Mayday situation elevates emotional levels and tests the command system, requiring members to maintain composure and follow the B.O.A. approach.
54
Describe the purpose of the Regional Operating Procedure regarding risk assessment and safety management of emergency incidents.
Provide the safest possible work environment for members operating at emergency incidents and to ensure effective accountability and coordination of action.
55
What are the three levels of risk that the members are expected to operate under according to the Risk Management Plan?
1. Risking lives a lot to save savable lives.
2. Risking lives a little to save savable property.
3. Not risking lives at all for lives or property that are already lost.
56
How are actions expected to be taken in a calculated manner during emergency operations?
Require continual use of the Strategic Decision Making Model, establishment of Incident Command, proper PPE, an accountability system, safety procedures, continuous risk assessment, and uninterrupted communications.
57
Define the position in the risk management plan and its significance.
Represents the 'why' behind taking risks at the incident, and it must be clear to all companies working at all levels of the incident command system that the incident strategy and plans are focused on either savable lives or savable property.
58
3 Questions necessary to determine the level of risk for potential rescue situations at an incident.
1. Is it reasonable to believe that there are savable lives present at this incident?
2. Are there any survivable environments or compartments at this incident?
3. Do we have the resources and ability to affect a rescue and survive to complete it?
59
Define the defensive strategy in the context of risk management for fire incidents.
If the incident size-up has determined that neither savable lives nor savable property are present because of the conditions, no or very limited risk shall be taken within a defensive strategy.
60
Ideally, what would be the most advantageous risk mitigation scenario?
Quick overwhelming attack on the fire, mitigating significant risk, and allowing opportunity for rescue & FF survivability.
61
Describe the types of incidents for which the risk management plan is effective and necessary.
All types of hazards and incidents, including large scale medical incidents, hazardous materials incidents, technical rescue incidents, and violent incidents.
62
Describe the purpose of the fire behavior glossary and reference procedures.
To ensure fundamental knowledge and understanding of fire behavior and dynamics for professional fire suppression and life safety protection services.
63
201.01D
Fire Behavior Glossary & Reference
64
201.01C
Risk Management & Safety
65
201.01B
Mayday Readiness & Response
66
Define fire and combustion in the context of fire behavior.
Fire is a rapid oxidation process resulting in the evolution of light and heat, while combustion is a chemical process of oxidation that produces heat and usually light.
67
How are fire and combustion related, and what distinguishes them?
Though similar conditions, combustion can occur without fire.
68
What is meant by modes of combustion in the context of fire behavior?
Two conditions of combustion: non-flaming and flaming, where combustion can occur with or without the presence of fire.
69
Explain the significance of understanding fire behavior and dynamics.
Crucial for the safety and longevity of FFs, as well as for carrying out the mission of saving lives and property in the community.
70
Describe non-flaming combustion.
Occurs more slowly and at a lower temperature, producing a smoldering glow in the material’s surface without flames.
71
Define flaming combustion.
Commonly referred to as fire because it produces a visible flame above the material’s surface.
72
How is the fire triangle used to explain combustion?
Illustrates the 3 elements necessary for combustion to occur: fuel, oxygen, and heat. Removing any one of these elements will cease combustion.
73
Do all states of matter serve as fuel for fire?
Fuel may be found in any of 3 states of matter: solid, liquid, or gas. Only gases burn, while solids and liquids must be converted into a gas to burn.
74
Describe pyrolysis.
The chemical decomposition of a solid material caused by the absorption of heat, releasing gas from the solid material. It often precedes combustion.
75
Describe the concept of Surface to Mass Ratio in relation to the ease of ignition of solid fuels.
It significantly affects the ease of ignition of solid fuels.
76
What is vaporization and how does it occur?
Process of converting liquids into gas, which occurs when heat causes the liquid to turn into its gaseous state.
77
Define Heat Energy and its characteristics.
A form of energy characterized by the vibration of molecules and is capable of initiating and supporting chemical changes and changes of state.
78
How is temperature measured and what does it indicate?
In degrees Fahrenheit or degrees Celsius and indicates the degree of molecular activity of a material compared to a reference point.
79
Explain the concept of Heat Release Rate (HRR) and its measurement.
The rate at which fire releases energy and is measured in units of Watts (W), which is an International System unit equal to one Joule per second.
80
Describe the relationship between Surface to Volume Ratio and the ease of ignition of liquid fuels.
Greater surface area compared to volume leading to faster vaporization of the liquid.
81
What is the difference between the heat release rate of one candle and ten candles with the same flame temperature?
The heat release rate, where one candle produces ~80 W HRR and ten candles produce ~800 W HRR despite having the same flame temperature.
82
Explain the focus of UL-FSRI in the concept of Heat Release Rate vs Temperature.
Understanding the basics of the relationship between Heat Release Rate and Temperature in fire behavior.
83
Describe the behavior of gaseous fuels in a fire.
Can be the most dangerous as they are already in the natural state required for ignition, requiring no pyrolysis or vaporization to ready the fuel. They are also the most difficult to contain.
84
Define the role of oxygen in fire combustion.
Primary oxidizing agent in most fires, with materials able to ignite and burn at oxygen concentrations as low as 15 percent. Combustion can continue in the non-flaming mode below 15%, producing heat and dense, fuel-rich smoke.
85
How do materials behave in oxygen-enriched atmospheres?
Materials that burn at normal oxygen levels will burn more intensely in. Many materials that do not burn at all in normal oxygen levels may burn readily.
86
Describe the Law of Heat Flow in heat transfer.
Specifies that heat always flows from a hot substance to a cold substance, with the colder of two objects in contact with each other absorbing heat until both objects are at the same temperature.
87
Describe conduction as a heat transfer mechanism in the context of fire behavior.
Transfer of heat from one body to another through direct contact or a heat-conducting medium, such as when a cellar fire heats pipes enough to ignite wood inside walls.
88
Explain how convection contributes to the spread of fire in a building.
Transfer of heat by the movement of air or liquid. Heated air in a building expands, creating pressure and rising, leading to fire spread mostly in an upward direction.
89
Define convection and provide an example of its impact on fire behavior.
Transfer of heat by the movement of air or liquid. An example of its impact on fire behavior is the spread of fire through corridors, up stairwells, and elevator shafts, mostly caused by the convection of heat currents.
90
How does conduction differ from convection in terms of heat transfer during a fire?
Conduction involves the direct transfer of heat from one object to another, while convection is the transfer of heat by the movement of air or liquid, leading to upward fire spread and heat movement in any direction.
91
Describe radiation in the context of fire behavior.
Heat transfer through the movement of heat waves, causing radiated heat to travel through a space until it reaches an object.
92
What is the role of radiated heat in fire spread to exposures?
One of the major sources of fire spread to exposures and is also a major cause of firefighter burn injuries and flashover in a compartment fire.
93
Define uninhibited chemical chain reaction in the context of fire behavior.
Self-sustained reaction involved in flaming combustion, occurring when fuels are broken down by heat and causing the fire to continue burning until the fuel or oxygen is exhausted or an extinguishing agent is applied.
94
How is the extinguishment of fire carried out according to extinguishment theory?
By limiting or removing one or more of the essential elements in the combustion process, such as removing one of the sides of the fire triangle (fuel, heat, oxygen).
95
Describe the process of heat reduction as a method of extinguishing a fire.
Reducing the temperature of the fuel to a point where it does not produce sufficient vapor to burn, often accomplished by the application of water.
96
How can fuel removal effectively extinguish a fire?
Achieved by stopping the flow of liquid or gaseous fuel, removing solid fuel in the path of the fire, or allowing the fire to burn until the fuel is consumed.
97
Define extinguishment by oxygen reduction and provide examples of how it can be achieved.
Reducing the oxygen content in an area, which can be done by flooding an area with an inert gas like carbon dioxide, or by separating the fuel from the air by blanketing it with foam or placing a cover on a pot.
98
What is chemical flame inhibition and how does it work as a method of extinguishment?
Interrupting the flame-producing chemical reaction and stopping flaming, often achieved by extinguishing agents like dry chemical (sodium bicarbonate) and older systems such as Halon (halogenated hydrocarbons). This method is effective on gas and liquid fuels.
99
Describe why cooling is the preferred way to extinguish a smoldering fire.
Non-flaming combustion does not require the presence of the chemical chain reaction present in flaming combustion, making chemical flame inhibition less effective. Smoldering fires are best extinguished by reducing the temperature.
100
Describe the process of solid fuel combustion.
Solid fuels absorb heat, increase in temperature, decompose, and release gas, which ignites during flaming combustion.
101
How do liquid fuels burn?
Release vapors and mix with air to reach the explosive/flammable range, and when heat is added to the fuel vapor within this range, ignition can occur.
102
Define vapor pressure in the context of liquid fuel combustion.
Amount of fuel vapor generated by a liquid fuel, with higher vapor pressure liquids producing more fuel vapor than those with lower vapor pressure.
103
Describe the difference between a flammable liquid and a combustible liquid based on their flash points.
A flammable liquid has a flash point below 100°F, while a combustible liquid has a flash point equal to or greater than 100°F.
104
Define fire point.
Fire point is the lowest temperature at which a liquid will ignite and achieve sustained burning.
105
Describe the concept of vapor density and its implications in fire behavior.
Vapor density refers to the density of a gas compared to air. Gases with a vapor density around 1 mix evenly with air, while those with a vapor density greater than 1 are heavier than air and will sink to low areas.
106
Explain the conditions required for flaming combustion to begin and continue in a fire.
Concentration of fuel vapor in the burning mixture (air and fuel) must be between the upper and lower explosive limits for that fuel.
107
What is the lower explosive limit (LEL) and how is it relevant in fire safety?
Lowest concentration by volume of flammable gas in air that will support flame propagation. It determines the potential for ignition and fire hazards.
108
Define the upper explosive limit (UEL) and its significance in fire behavior.
Highest concentration by volume of flammable gas in air that will support flame propagation. It is significant in understanding the upper threshold for flammable gas concentrations.
109
What is the explosive range (flammable range) and why is it important in fire safety?
Range of gas to air mixtures in which ignition can occur, existing between the lower explosive limit and the upper explosive limit. It is important in assessing the potential for ignition and fire hazards.
110
Four different stages of compartment fire development.
Incipient stage, growth stage, fully developed stage, and decay stage.
111
How does the incipient stage of a fire begin?
Begins with the actual ignition, and the fire is generally small during this stage.
112
What happens as the plume of hot gases and flame rises from the fire in the incipient stage?
The plume reaches the ceiling and hot gases begin to spread horizontally across the ceiling.
113
Do incipient fires have plenty of oxygen and fuel available to burn?
Yes, oxygen levels in the air have not been significantly reduced by the fire.
114
Define pyrolysis in the context of fire development.
Process where radiant heat warms the adjacent fuels and increases the volume of fire.
115
Transition from an incipient fire into the growth stage?
Can occur quickly, sometimes in seconds, depending on the type and configuration of fuel involved.
116
How can incipient fires be extinguished?
Incipient fires can be readily extinguished with the use of the proper fire extinguisher.
117
Describe the growth stage of a fire.
When the original fire spreads to additional materials and may involve heat transfer, direct flame impingement, or burning liquid igniting secondary items.
118
What occurs during the fully developed stage of a fire?
Burning fuels release the maximum amount of heat possible, producing large volumes of fire gases that may travel throughout the building and impact survivability.
119
Define rollover and flashover in the context of fire development.
Occur during the growth stage of a fire, where rollover is the ignition of unburned fire gases while flashover is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area.
120
How does the presence of heated air contribute to fire development during the growth stage?
Causes the temperature to rise in the area, potentially leading to rapid fire development and flame spread if left unchecked.
121
Describe the impact of the fully developed stage on building survivability.
Large volume of fire and smoke produced can impact survivability even in remote areas of the building, and flammable products of combustion are likely to flow into adjacent rooms or out through openings to the exterior of the building.
122
What factors contribute to the spread of fire during the growth stage?
Through any combination of heat transfer (conduction, convection, or radiation), direct flame impingement, or burning liquid igniting secondary items.
123
Do foams or plastic materials play a role in fire spread during the growth stage?
Yes, they can melt and drip liquid, which can ignite secondary items and contribute to fire spread.
124
Describe the decay stage of a fire.
When all available fuel is consumed or when the oxygen concentration falls below 15%, resulting in diminished flaming combustion.
125
Fuel limited,
There is adequate ventilation, but the fire consumes all available fuel in the compartment, causing the heat release rate to decline.
126
Ventilation limited.
There is adequate fuel available, but the fire consumes enough of the available oxygen in the compartment, causing the heat release rate to decline.
127
How does thermal layering affect the behavior of gases in a fire?
Causes gases to form into layers according to temperature, with the hottest gases near the top and cooler ones below.
128
What are the potential consequences of introducing oxygen to a fire in the decay stage due to reduced oxygen concentration?
Potentially leading to rapid fire development and/or backdraft.
129
Describe the upper layer in a compartment fire.
Hot fire gases and buoyant smoke collected by the ceiling and walls of an enclosure, forming a relatively uniform layer of heated smoke and gases throughout.
130
What happens as a fire develops in a compartment in relation to the upper layer?
Hot rising smoke and fire gases spread across the ceiling and mushroom down into the room, collecting in a thick, relatively uniformed layer of hot gases throughout.
131
How can decreasing the heat of the fire within the enclosure affect the upper layer?
Will decrease the temperature and formation of hot gases in the upper layer, potentially causing the upper layer to lift.
132
Lower layer in a compartment fire.
Zone beneath the upper layer, consisting primarily of ambient air that is drawn into the fire through ventilation openings in the enclosure.
133
Interface height.
Vertical distance from the floor of the enclosure to the thermal interface.
134
Neutral plane.
Flow of smoke and fire gases through an opening, which can be either unidirectional or bidirectional.
135
How is unidirectional flow different from bidirectional flow?
Unidirectional flow occurs when the flow through an opening moves in one direction only, while bidirectional flow occurs when an opening acts as both an inlet and an outlet for flows at the same time.
136
What determines the pressure distribution in a compartment?
The volume of hot smoke generated by the fire.
137
Define the thermal interface in the context of fire behavior.
Boundary between the hot upper layer and the cooler lower layer of a compartment fire.
138
How can the position of the neutral plane be observed during a fire?
Above the flow will be outwards, below the flow will be inwards.
139
How does the neutral plane differ from the thermal interface?
The neutral plane occurs at a ventilation opening and indicates pressure differences, while the thermal interface occurs within a compartment and is the boundary between the hot upper layer and the cooler lower layer of a compartment fire.
140
Describe thermal interface and interface height in a compartment fire.
The separation between the hot upper layer and the cool lower layer, indicating heat differences and the potential for flashover.
141
What are two of the most toxic gases present in smoke, and what are their effects?
Carbon monoxide and hydrogen cyanide act as chemical asphyxiants, posing a significant threat to human life and being responsible for many fire deaths.
142
How does smoke contribute to rapid fire development, and how should firefighters consider it?
The combination of fire gases in smoke is flammable and contributes to rapid fire development. Firefighters should consider smoke as additional fuel.
143
Define the buoyancy of hot air and its role in smoke movement during a fire.
When air is heated, it becomes more buoyant, causing hot air to rise. This buoyancy, along with the expansion of nitrogen due to fire energy, can push significant volumes of smoke through openings and indicate the rising hot air and expanding nitrogen.
144
Five characteristics of smoke?
Volume, velocity, density, color, and stratification.
145
Significance of smoke volume.
Indicate the size, location, and stage of the fire within a structure, serving as a visible indicator of the fire.
146
Smoke velocity & relation to heat.
Indicator of the pressure built up within a structure due to buoyancy and expansion from the heat released by the fire.
147
How does the expansion of nitrogen contribute to smoke movement?
Driving a significant increase in the volume of the air, which can push significant volumes of smoke through openings.
148
Difference between turbulent smoke and laminar smoke.
Turbulent smoke indicates extreme heat closer to the fire, while laminar smoke indicates low heat, either from a small fire or because the smoke is remote from the fire and has cooled.
149
Smoke density and its significance.
Apparent thickness of smoke and can indicate the efficiency of the combustion process. It is lower in early fuel-limited stages and higher in ventilation-limited stages.
150
Black smoke indicates?
Dark smoke often indicates fuel-rich conditions due to restricted air supply (ventilation limited). It can result from the release of carbon in the fuel as soot in the smoke, especially when the air supply is restricted.
151
Brown smoke indicates?
Early stages of the pyrolysis of timber products. In a wood-framed building, the presence of brown smoke may indicate that the structure is involved in the fire.
152
Grey smoke indicates?
Presence of at least some flaming or smoldering combustion. Dark smoke that has traveled some distance can cool, and large carbon particles suspended in the smoke can adhere to surfaces.
153
Dense smoke.
Indicates that the fire is ventilation-limited. A severely ventilation-limited fire will produce large volumes of thick, dense smoke.
154
Suspended fuel in thick dark smoke...
Can ignite.
155
Rate of smoke production changes in early stages & later stages?
Early: plenty of oxygen, rate of smoke production is lower.
Later: smoke production increases.
156
White smoke.
Application of water to a fire, progress in extinguishment, or the release of volatile components from certain fuels. It can also represent a significant danger if it has a high fuel content.
157
Smoke stratification and its importance in fire assessment.
Layering of smoke in a fire-affected area.
158
Flow path contribution to fire travel and firefighting operations?
Movement of smoke and flame away from the fire and the corresponding flow of air into the fire. Understanding the flow path is crucial for predicting fire behavior and implementing effective firefighting strategies.
159
Potential dangers associated with white smoke.
Can have a very high fuel content, representing a significant danger. When mixed with oxygen and an ignition source, it has the potential for a sudden and powerful ignition, posing a serious threat to firefighters and occupants.
160
Flow path management.
Reducing the rate of fire growth by closing or restricting inlet(s) and/or outlet(s) and purposefully managing the flow path to increase firefighter safety during operations.
161
What are the characteristics of unidirectional flow?
Smoke, flame, or air moving in a single direction across the full area of the opening, and it can exist as either an exhaust or an inlet.
162
How can velocity and direction of air movement indicate potential fire development?
A sudden inward movement of the air track could indicate the potential for rapid fire development, causing the fire to intensify and be followed by an outward rush of smoke and/or flame.
163
Bidirectional flow.
Smoke/air flow moving in opposing directions within the same openings.
164
Dynamic flow in the context of fire behavior.
Unidirectional or bidirectional flow of smoke/air that presents irregular stratification and shape, or alternates in direction (pulsates).
165
Rollover in a developing compartment fire.
Occurs when unburned fire gases at the top of a compartment ignite and flames travel through the hot gas layer across the ceiling.
166
Difference between rollover and flashover.
Primarily involves the burning of gases, while flashover involves the ignition of the entire contents of the room.
167
Ventilation-induced flashover.
Dangerous fire event where the introduction of fresh air causes a rapid transition to flashover conditions.
168
How does the presence of rollover indicate an imminent flashover?
The significant radiant heat added to the room during a rollover event usually leads to flashover occurring within seconds, indicating that flashover is imminent.
169
Flashover.
Simultaneous ignition of all combustible materials and gases in a compartment due to surfaces exposed to thermal radiation reaching ignition temperatures.
170
Temperature typically exceeded during flashover?
1100°F.
171
How does the environment of the room change during flashover?
From a two-layer condition to a single well-mixed, untenable hot gas condition from floor to ceiling.
172
What stage of fire does flashover occur in?
During the growth stage of a fire, and once it has occurred, the fire is in the Fully Developed Stage.
173
Impact of room geometry on flashover.
The size, shape, and volume affect the formation of the upper layer and thus the heat transfer within a given fire compartment. Rooms with peaked or cathedral ceilings may experience delayed flashover due to difficulty in upper layer formation.
174
Transition period between pre-flashover fire conditions to post-flashover like?
Can occur rapidly, and during flashover, the volume of fire will increase to fill the entire volume of space in the room, with fire and burning gases likely extending out of any openings in the room with substantial velocity.
175
Ventilation-induced flashover.
Initiated by introducing oxygen into a pre-heated, fuel-rich, and oxygen-deficient area, often occurring in modern content fires.
176
Conditions favorable for ventilation-induced flashover to occur?
Modern content fires rapidly consume more oxygen within the fire compartment.
177
Fully developed stage.
Once ventilation-induced flashover occurs.
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How is ventilation-induced flashover different from a backdraft?
Ventilation-induced flashover is similar to a backdraft but involves less pressure, whereas a backdraft involves significantly more pressure, causing an explosion.
179
Do all ventilation openings have the same impact on the fire?
No, while all ventilation openings may have an impact on the fire, taking a window of a fire room in the oxygen-deficient early decay stage will have more immediate effect on fire regrowth than opening the fire apartment door down the hall.
180
What happens if water is not applied to the seat of the fire soon after ventilation occurs?
Temporary improvement period may be followed by a rapid deterioration of conditions, potentially leading to flashover.
181
Temporary improvement period in oxygen-depleted environments during a fire.
Lasting for an unspecified amount of time, influenced by factors such as fire size, ventilation, and building dynamics.
182
Black Fire.
Thick, superheated, fuel-rich black smoke is heated beyond its ignition point but is too rich in gases to burn, resulting in no visible flames but extremely hot and destructive conditions.
183
How can FFs extend the temporary improvement period during a fire?
By coordinating ventilation with fire attack.
184
Characteristics of Black Fire.
Absence of visible flames, thick black superheated turbulent smoke, extreme heat, and destructive potential, often leading to severe burns.
185
Dealing with Black Fire.
Treat the black fire smoke as if it were flames, immediately flowing water into the smoke layer with a hoseline to aggressively cool the area.
186
Smoke explosion and provide an example of when it can occur.
Smoke-air mixture falls within its flammable range and is ignited, resulting in a significant pressure front. An example is when smoke migrates and accumulates in hidden areas such as rooms remote from the fire area or void spaces, then mixes with air to fall within its flammable range and encounters an ignition source.
187
How can a smoke explosion lead to structural damage and potential harm?
If ignition occurs in a relatively confined space or if obstacles promote turbulence, the flame front may accelerate, leading to an overpressure situation that may result in structural damage and/or injury or death.
188
Backdraft.
Introduction of oxygen to a compartment that has been pressurized by the smoke and fire causing a sudden explosion .
189
Vent point ignition.
Smoke ignites as it is released from a window or door and mixes with air in the atmosphere.
190
Behavior of a backdraft.
During a backdraft, the ignition pushes unburned fuel-rich gases ahead of the burning smoke-air mixture as it expands, resulting in a large fireball as the burning flammable and smoke-air mixture is forced, under pressure, from the compartment.
191
Indicators of a potential backdraft.
No visible/active flaming within the compartment, extremely limited or no ventilation of the fire compartment, pulsating smoke, and grey-yellow smoke seeping out from around closed and intact doors and windows.
192
Flash fire.
Fire that spreads by means of a flame front rapidly through a diffuse fuel, such as dust, gas, or the vapors of an ignitable liquid, without the production of damaging pressure.
193
How do backdrafts and smoke explosions differ in terms of ventilation?
Backdrafts occur immediately following ventilation of the affected compartment, while a smoke explosion occurs without immediate and direct ventilation of the affected area.
194
What risks do backdrafts pose?
Damage to the structure, extension of the fire beyond the compartment, and pose several risks to FFs who are in its path due to over-pressurization and dramatic fireballs produced during the event.
195
BLEVE and explain the conditions that lead to its occurrence.
Boiling Liquid Expanding Vapor Explosion, caused by the rupture of a vessel containing a pressurized liquid that has reached temperatures above its boiling point.
196
Conditions leading to BLEVE
Occurs when the liquid in a pressurized vessel is heated to a temperature exceeding its boiling point and the container ruptures due to excessive pressure build-up or mechanical/thermal damage.
197
Describe a boilover in the context of burning combustible liquids in an open-top tank.
Event in the burning of certain combustible liquids in an open-top tank when, after a long period of quiescent burning, there is a sudden increase in fire intensity associated with the expulsion of burning oil from the tank.
198
Boilover.
Water is added to a grease/oil fire, causing the fuel to be expelled upward and ignite, resulting in a large plume of burning liquid outside the container.
199
Stack effect in the context of building air movement.
Movement of air throughout a building due to temperature differences between the interior and exterior; vertical air movement & horizontal air movement.
200
How does the stack effect impact air movement in a building?
Two ways: vertically, affecting the movement of smoke throughout the building, and horizontally, influencing the exchange of air between the interior and exterior, as well as between floors and vertical shafts.
201
Stack effect neutral pressure zone.
In the center of the building, there exists an area that experiences no horizontal air movement.
202
Stack Effect.
In a building, refers to the vertical movement of air due to temperature differentials, where warmer air rises and escapes from upper openings while cooler air is drawn in from lower openings.
203
Magnitude of the Stack Effect?
Determined by the temperature differential between the interior and exterior of the building, as well as the building's height.
204
Positive Stack Effect.
Occurring in winter, when the interior of a building is warmer than the external environment, causing air to move upwards and escape from upper openings.
205
Factors contributing to a more powerful Stack Effect?
Taller buildings experience it powerfully due to the increased air movement over a longer distance inside the building and the presence of large vertical shafts such as stairways, elevators, and compactors.
206
Negative stack effect.
In hot weather, the air inside occupied buildings is cooler than the air outside due to internal air conditioning systems, causing air inside the building to travel downwards via vertical shafts and attempt to exit the building via available openings near the bottom.
207
Upper floor effects in the positive stack effect (winter) situation?
Tend to want to vent out of the windows.
208
Lower floor effects in the negative stack effect (summer) situation?
Tend to want to vent out of the windows.
209
Reverse Stack Effect.
The negative stack effect in summer.
210
Do fires on lower floors experience similar conditions in both positive and negative stack effects?
Yes, lower floors tend to want to vent out of the windows in both situations.
