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Questions and Answers
Most building codes rate construction types according to:
Most building codes rate construction types according to:
To ensure that the decay stage of a ventilation-limited fire is the fire's final stage, firefighters must provide a controlled transition of a fire in the decay stage from ventilation-limited to fuel-limited, by:
To ensure that the decay stage of a ventilation-limited fire is the fire's final stage, firefighters must provide a controlled transition of a fire in the decay stage from ventilation-limited to fuel-limited, by:
What provides the best indicators of structural integrity?
What provides the best indicators of structural integrity?
Fire spreading from a wall to a nearby couch due to radiant heat transfer is an example of:
Fire spreading from a wall to a nearby couch due to radiant heat transfer is an example of:
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Which element of the fire tetrahedron is included to explain flaming (gas-phase) combustion?
Which element of the fire tetrahedron is included to explain flaming (gas-phase) combustion?
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When a structural member such as a window, roof, or doorway fails, introducing a new source of oxygen to a fire, _____ ventilation has occurred.
When a structural member such as a window, roof, or doorway fails, introducing a new source of oxygen to a fire, _____ ventilation has occurred.
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The _____ stage of fire development occurs when the heat release rate of the fire has reached its peak.
The _____ stage of fire development occurs when the heat release rate of the fire has reached its peak.
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The use of engineered or lightweight construction and trussed support systems pose a danger to firefighters because engineered trusses:
The use of engineered or lightweight construction and trussed support systems pose a danger to firefighters because engineered trusses:
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A collapsed storage shed that is fully involved in flames would be an example of a:
A collapsed storage shed that is fully involved in flames would be an example of a:
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Where might firefighters be MOST likely to encounter inoperative standpipes and sprinkler systems?
Where might firefighters be MOST likely to encounter inoperative standpipes and sprinkler systems?
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When solid fuels are heated, they begin to _____ and release fuel gases and vapors.
When solid fuels are heated, they begin to _____ and release fuel gases and vapors.
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Heat that is radiated to the insulating air layer between PPE and your body:
Heat that is radiated to the insulating air layer between PPE and your body:
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How does a compartment fire affect pressure in and around gases in the compartment?
How does a compartment fire affect pressure in and around gases in the compartment?
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What factor helps determine the flow path in a structure fire?
What factor helps determine the flow path in a structure fire?
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Combustion can occur within a range of concentration of fuel vapor and air; this range is referred to as the:
Combustion can occur within a range of concentration of fuel vapor and air; this range is referred to as the:
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What occurs when a mixture of unburned fuel gases and oxygen come in contact with an ignition source?
What occurs when a mixture of unburned fuel gases and oxygen come in contact with an ignition source?
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How does the self-sustained chemical reaction influence the oxidation reaction in flaming combustion?
How does the self-sustained chemical reaction influence the oxidation reaction in flaming combustion?
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A compartment is any:
A compartment is any:
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An extinguishing agent, such as dry chemical or Halon-replacement agent, terminates the combustion reaction by:
An extinguishing agent, such as dry chemical or Halon-replacement agent, terminates the combustion reaction by:
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What is the cause of most fire deaths?
What is the cause of most fire deaths?
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A fuel's chemical content influences its heat release rate and its:
A fuel's chemical content influences its heat release rate and its:
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The minimum temperature at which a fuel in the air must be heated in order to start self-sustained combustion is known as the:
The minimum temperature at which a fuel in the air must be heated in order to start self-sustained combustion is known as the:
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What may occur if water is added to a burning liquid that is less dense than water?
What may occur if water is added to a burning liquid that is less dense than water?
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Hydrogen cyanide (HCN) is a product of combustion that:
Hydrogen cyanide (HCN) is a product of combustion that:
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Which type of electrical heating occurs when the current flowing through a conductor exceeds its design limits?
Which type of electrical heating occurs when the current flowing through a conductor exceeds its design limits?
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What is the most effective means of establishing awareness of hazards in commercial, industrial, and storage facilities with large fuel loads?
What is the most effective means of establishing awareness of hazards in commercial, industrial, and storage facilities with large fuel loads?
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Which statement about the dangers of products of combustion is accurate?
Which statement about the dangers of products of combustion is accurate?
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In a ventilation-limited compartment fire that has a large volume of flammable gases, opening a door or window could result in:
In a ventilation-limited compartment fire that has a large volume of flammable gases, opening a door or window could result in:
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In a compartment fire, smoke flashover indicators include rapidly increasing volume, turbulence, optical density, and:
In a compartment fire, smoke flashover indicators include rapidly increasing volume, turbulence, optical density, and:
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What causes flaming combustion to occur?
What causes flaming combustion to occur?
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Which type of phenomenon occurs when the fire rapidly transitions from the growth stage to the fully developed stage?
Which type of phenomenon occurs when the fire rapidly transitions from the growth stage to the fully developed stage?
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A fire is said to be in the _____ stage when it runs out of either available fuel or available oxygen.
A fire is said to be in the _____ stage when it runs out of either available fuel or available oxygen.
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The transfer of heat through and between solids is known as:
The transfer of heat through and between solids is known as:
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Which product of combustion acts as a chemical asphyxiant by excluding oxygen from the blood, leading to hypoxia of the brain and tissues?
Which product of combustion acts as a chemical asphyxiant by excluding oxygen from the blood, leading to hypoxia of the brain and tissues?
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What is often the most readily available fuel source and significantly influences fire development in a compartment fire?
What is often the most readily available fuel source and significantly influences fire development in a compartment fire?
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What will a liquid with a specific gravity of less than one do when combined with water?
What will a liquid with a specific gravity of less than one do when combined with water?
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Which type of buildings are subject to rapid fire spread because many of the protective features such as gypsum wallboard and automatic fire suppression systems are not in place?
Which type of buildings are subject to rapid fire spread because many of the protective features such as gypsum wallboard and automatic fire suppression systems are not in place?
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What will establish new flow paths between the fire compartment and exterior vents of the building?
What will establish new flow paths between the fire compartment and exterior vents of the building?
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Which statement about energy and combustion is accurate?
Which statement about energy and combustion is accurate?
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Which means of influencing fire dynamics is typically a tactic in wildland fires or liquid and gas fires?
Which means of influencing fire dynamics is typically a tactic in wildland fires or liquid and gas fires?
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Why must firefighters use tactics that control the oxygen available to the fire when they advance a hoseline through a door or ventilate windows?
Why must firefighters use tactics that control the oxygen available to the fire when they advance a hoseline through a door or ventilate windows?
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Firefighters working in the exhaust portion of the flow path will:
Firefighters working in the exhaust portion of the flow path will:
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Using extinguishing agents other than water and foam to interrupt the combustion reaction is referred to as:
Using extinguishing agents other than water and foam to interrupt the combustion reaction is referred to as:
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Which statement describes a fire in the incipient stage?
Which statement describes a fire in the incipient stage?
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When a substance changes from one type of matter into another, such as two or more substances combining to form compounds, the substance undergoes a:
When a substance changes from one type of matter into another, such as two or more substances combining to form compounds, the substance undergoes a:
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In a compartment fire, the interface between the hot gas layers and cooler layer of air is commonly referred to as the:
In a compartment fire, the interface between the hot gas layers and cooler layer of air is commonly referred to as the:
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By which mechanism of heat transfer does heat travel in a straight line at the speed of light, allowing heat to travel through vacuums and air spaces?
By which mechanism of heat transfer does heat travel in a straight line at the speed of light, allowing heat to travel through vacuums and air spaces?
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The minimum temperature at which a liquid gives off sufficient vapors to ignite, but not sustain combustion, is its:
The minimum temperature at which a liquid gives off sufficient vapors to ignite, but not sustain combustion, is its:
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Which action will transition a compartment fire in a modern structure from ventilation-limited to fuel-limited?
Which action will transition a compartment fire in a modern structure from ventilation-limited to fuel-limited?
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The flow path of a structure fire is comprised of two regions: the ambient air flow in and the:
The flow path of a structure fire is comprised of two regions: the ambient air flow in and the:
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Which statement BEST describes a fire in a large compartment or a compartment with a high ceiling?
Which statement BEST describes a fire in a large compartment or a compartment with a high ceiling?
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Which statement about ventilation and wind considerations is MOST accurate?
Which statement about ventilation and wind considerations is MOST accurate?
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What is the likely result if additional air is allowed into an already-ventilated compartment fire?
What is the likely result if additional air is allowed into an already-ventilated compartment fire?
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Materials that burn at normal oxygen levels will burn more intensely in _____ atmospheres.
Materials that burn at normal oxygen levels will burn more intensely in _____ atmospheres.
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Gaseous fuels can be the most dangerous of all fuel types because they:
Gaseous fuels can be the most dangerous of all fuel types because they:
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During the _____ stage of fire development, the three elements of the fire triangle come together and the combustion process begins.
During the _____ stage of fire development, the three elements of the fire triangle come together and the combustion process begins.
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Which is an indicator for potential backdraft?
Which is an indicator for potential backdraft?
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What is the MOST common source of heat in combustion reactions?
What is the MOST common source of heat in combustion reactions?
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In addition to structural members, what can be a significant factor influencing fire spread and loss of lives in fires?
In addition to structural members, what can be a significant factor influencing fire spread and loss of lives in fires?
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Which statement describes the factor that MOST influences compartment fire development?
Which statement describes the factor that MOST influences compartment fire development?
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Which measurement is often used to measure how long PPE will protect a firefighter in an interior fire environment?
Which measurement is often used to measure how long PPE will protect a firefighter in an interior fire environment?
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In most compartment fires, the energy release in fire is directly proportional to the:
In most compartment fires, the energy release in fire is directly proportional to the:
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Sawdust ignites more easily than a log because the sawdust has a higher:
Sawdust ignites more easily than a log because the sawdust has a higher:
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Fires involve a heat producing chemical reaction between fuel and:
Fires involve a heat producing chemical reaction between fuel and:
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What occurs when a gas is compressed?
What occurs when a gas is compressed?
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Which heat transfer mechanism is dependent on several factors including the turbulence and velocity of moving gases?
Which heat transfer mechanism is dependent on several factors including the turbulence and velocity of moving gases?
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In the fire environment, convection usually involves the transfer of heat through:
In the fire environment, convection usually involves the transfer of heat through:
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What will occur if firefighters begin an attack on a ventilation-limited structure fire with ventilation alone?
What will occur if firefighters begin an attack on a ventilation-limited structure fire with ventilation alone?
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What occurs during flashover?
What occurs during flashover?
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What is the measurement of the average kinetic energy in the particles of a sample of matter?
What is the measurement of the average kinetic energy in the particles of a sample of matter?
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What construction features tend to contain fires for a longer period of time, thus creating fuel-rich, ventilation-limited environments?
What construction features tend to contain fires for a longer period of time, thus creating fuel-rich, ventilation-limited environments?
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What occurs when a mixture of fuel and oxygen encounters an external heat source with sufficient heat or thermal energy to start the combustion reaction?
What occurs when a mixture of fuel and oxygen encounters an external heat source with sufficient heat or thermal energy to start the combustion reaction?
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Fires develop through four stages: incipient, growth, _____, and decay.
Fires develop through four stages: incipient, growth, _____, and decay.
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What may occur in an oxidation reaction when the heat generated exceeds the heat being lost?
What may occur in an oxidation reaction when the heat generated exceeds the heat being lost?
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Observed from the exterior, a high neutral plane may indicate that the fire is in the early stages of development, or could indicate:
Observed from the exterior, a high neutral plane may indicate that the fire is in the early stages of development, or could indicate:
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Study Notes
Electrical Heating
- Overcurrent or overload happens when current exceeds design limits in a conductor.
Hazard Awareness
- Preincident surveys are crucial for identifying hazards in facilities with large fuel loads.
Products of Combustion
- Low oxygen concentrations can cause hypoxia, leading to death.
Ventilation-Limited Fires
- Opening a door or window in a ventilation-limited fire may lead to backdraft, a sudden increase of flame.
Smoke Flashover Indicators
- Indicators of smoke flashover include increasing volume, turbulence, optical density, and darkening color.
Flaming Combustion
- Flaming combustion occurs when gaseous fuel mixes with sufficient oxygen and reaches ignition temperature.
Fire Growth Stages
- Flashover is the rapid transition from the growth stage to fully developed stage of fire.
Fire Decay Stage
- A fire is in the decay stage when it runs out of available fuel or oxygen.
Heat Transfer Mechanisms
- Conduction refers to heat transfer through solids, while convection involves the movement of warm gases.
Chemical Asphyxiant
- Carbon monoxide (CO) is a chemical asphyxiant that prevents oxygen from reaching the brain and tissues.
Fuel Sources in Fires
- Contents within a structure often provide the most significant fuel source influencing fire development.
Liquid Specific Gravity
- A liquid with a specific gravity less than one will float when placed in water.
Rapid Fire Spread Buildings
- Buildings under construction are at higher risk for rapid fire spread due to fewer protective features.
New Flow Paths
- Firefighters creating openings in a building establish new flow paths between compartments and outside.
Energy and Combustion
- Combustion releases kinetic energy from a fuel's stored chemical potential energy.
Fire Dynamics in Wildland Fires
- Fuel removal is a tactic commonly employed in wildland and liquid/gas fire scenarios.
Controlling Fire Spread
- Firefighters must control oxygen availability when venting to prevent unwanted fire spread.
Flow Path Temperature
- In the exhaust portion of a flow path, firefighters will sense rising temperatures due to increasing velocity and turbulence.
Interrupting Combustion
- Chemical flame inhibition involves using agents other than water and foam to interrupt combustion processes.
Incipient Stage of Fire
- In the incipient stage, temperatures are only slightly above ambient levels at affected fire areas.
Chemical Reaction Definition
- A chemical reaction occurs when substances combine to form new compounds.
Neutral Plane Definition
- The interface between hot gas layers and cooler air is known as the neutral plane in fire dynamics.
Radiation Mechanism
- Radiation allows heat to travel through vacuums and air spaces without direct contact.
Flash Point
- The flash point is the minimum temperature at which a liquid can emit sufficient vapors to ignite.
Transitioning Fire Dynamics
- Extinguishing some fuel can change a compartment fire from ventilation-limited to fuel-limited.
Flow Path Characteristics
- The flow path consists of ambient air flowing in and hot exhaust gases flowing out.
Compartment Fire Development
- Large compartments can alter fire behavior; gases can accumulate at ceiling level, affecting conditions at the floor.
Wind and Ventilation
- Wind can increase pressure within a structure, potentially forcing smoke and flames toward unburned areas.
Compartment Fire Changes
- Introducing fresh air into a ventilated compartment can increase the fire's heat release rate.
Combustion Intensification
- Materials burn more intensely in oxygen-enriched atmospheres.
Gaseous Fuels
- Gaseous fuels pose a significant risk due to their state being primed for ignition.
Stages of Fire Development
- The four stages of fire include incipient, growth, fully-developed, and decay.
Backdraft Risk Indicators
- Pulsing smoke movement in small openings can signal potential backdraft conditions.
Heat Source in Combustion
- Chemical energy is the most common source of heat in combustion reactions.
Fire Spread Factors
- Combustible interior finishes significantly contribute to fire spread and loss of life during incidents.
Fuel-Limited vs. Ventilation-Limited Fires
- Fire behavior is highly influenced by whether the fire is fuel-limited or ventilation-limited.
PPE Heat Protection Measurement
- Heat flux to PPE is measured to determine the protection duration for firefighters in interior fire conditions.
Oxygen Availability
- The amount of oxygen available directly correlates with energy release in fire scenarios.
Sawdust Ignition
- Sawdust ignites more easily than less fragmented timber due to its higher surface-to-mass ratio.
Oxidizer in Fire Reactions
- Fires result from the chemical reaction between fuel and an oxidizer.
Gas Compression
- Compressing a gas generates heat, raising its temperature.
Convection Factors
- Convection heat transfer is affected by factors like turbulence and velocity of gases.
Fire Environment Dynamics
- Inenviroment, convection generally involves the transfer of heat from moving hot gases.
Ventilation in Structure Fires
- Ventilating a structure fire can lead to increased heat release rates and fire spread if mismanaged.
Flashover Definition
- Flashover occurs when burning gases fill the entire compartment volume, extending beyond openings.
Kinetic Energy Measurement
- Temperature measures the average kinetic energy of particles in a substance.
Construction Feature Impacts
- Energy-efficient designs can lead to prolonged fire containment, fostering dangerous fire conditions.
Piloted Ignition Process
- Piloted ignition occurs when a fuel-oxygen mixture encounters sufficient external heat to initiate combustion.
Stages Summary
- Fire progression involves four stages: incipient, growth, fully-developed, and decay.
Oxidation Reaction Outcomes
- Excess heat generation in an oxidation reaction can lead to spontaneous ignition.
High Neutral Plane Indicator
- A high neutral plane may indicate a developing fire in upper areas of a structure.
Building Code Ratings
- Construction types are rated by their ability to maintain structural integrity over time.
Managing Decay Stage Fires
- Proper cooling of hot gases is critical to ensuring the fire remains in a controlled decay stage.
Structural Integrity Indicators
- Information gathered from the scene gives the best indicators of structural integrity during a fire.
Heat Transfer Examples
- Radiant heat transfer can cause nearby materials to ignite, as seen with fire spreading from walls to furniture.
Chemical Chain Reaction Component
- The fire tetrahedron includes the chemical chain reaction necessary for sustaining flaming combustion.
Unplanned Ventilation
- Unplanned ventilation occurs when openings or failures inadvertently introduce fresh oxygen to an existing fire.### Fire Stages and Development
- The fully-developed stage of fire development occurs when the heat release rate has peaked.
- A collapsed storage shed engulfed in flames exemplifies a fully-developed fuel-limited fire.
Structural Hazards
- Engineered trusses can fail in 5 to 10 minutes of exposure to fire, posing risks for firefighters.
- Inoperative standpipes and sprinkler systems are more likely found in buildings under demolition.
Fuel Behavior and Combustion
- Solid fuels pyrolize when heated, releasing fuel gases and vapors.
- The flammable (explosive) range defines the concentration limits of fuel vapor and air for combustion.
- Smoke explosions occur when unburned fuel gases mix with oxygen and contact an ignition source.
Fire Dynamics
- A fire increases the pressure of surrounding gases in a compartment.
- The floor plan and openings within a structure significantly influence the flow path in a fire.
- The self-sustained chemical reaction in flaming combustion speeds up the oxidation reaction.
Extinguishing Methods
- An extinguishing agent disrupts the chemical chain reaction to terminate combustion.
- Adding water to burning liquids that are less dense can cause the water to disperse the fuel instead of extinguishing it.
Toxicity and Hazards
- Most fire-related deaths result from exposure to toxic gases in smoke, notably due to the lack of oxygen.
- Hydrogen cyanide (HCN) is a highly toxic product of combustion that targets the brain.
Fire Behavior and Safety
- A fuel's chemical composition impacts its heat release rate and heat of combustion.
- Autoignition temperature (AIT) is the minimum temperature required to initiate self-sustained combustion in the presence of air.
Studying That Suits You
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Description
Test your knowledge with these flashcards based on Chapter 4 of the IFSTA materials. This quiz covers important concepts such as electrical heating types and hazard awareness in facilities. Perfect for those studying for firefighting and safety certifications.
