Definitions Flashcards
NFPA 1700 addresses fire control within a structure by establishing a basic understanding of fire science and fire dynamics.
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NFPA 921, Guide for Fire and Explosion investigations, served as a model for how to translate fire dynamics understanding in practicable, applicable ways
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The pressure of the weight of air on the surface of the earth, approximately 14.7 pounds per square inch at sea level.
Atmospheric pressure
A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion.
Backdraft
A building opening that serves as both an intake and exhaust vent of a flow path at the same time.
Bidirectional Vent
A coordinated fire attack from the exterior with a master stream (300+gpm).
Blitz Attack
The quantity of heat required to raise the temperature of one pound of water 1F at the pressure of 1 atmosphere and temperature of 60F.
British Thermal Unit
British thermal unit is equal to 1055 joules, 1.055 kilojoules, and 252.15 calories.
BTU
The amount of heat necessary to raise 1 gram of water 1C at the pressure of 1 atmosphere and temperature of 15C.
Calorie
A calorie is 4.184 joules, and there are 252.15 calories in a BTU.
Calorie
A relatively thin layer of flowing hot gases that develops under a horizontal surface as a result of plume impingement and the flowing gas being forced to move horizontally.
Ceiling Jet
A buoyant layer of hot gases and smoke produced by a fire in a compartment.
Ceiling Layer
A chemical process of oxidation that occurs at a rate fast enough to produce heat and usually light in the form of either a glow or flame.
Combustion
Heat transfer to another body or within a body by direct contact.
Conduction
Heat transfer by circulation within a medium such as a gas or liquid.
Convection
The stage of fire development within a structure characterized by either a decrease in the fuel load or available oxygen to support combustion resulting in lower temperatures and lower pressure in the fire area.
Decay stage
The initial phase of the decontamination process during which the amount of surface contaminant is significantly reduced by removing bulk contaminants and substances from the surface of the equipment or tools using some form of brushing, wetting agent, and or detergents.
Gross decontamination
Propagation of a combustion zone at a velocity that is less than the speed of sound in the unreacted medium.
Deflagration
The density of air is approximately 1.275 grams per cubic meter.
Density
Propagation of combustion zone at a velocity greater than the speed of sound in the unreacted medium.
Detonation
The difference between pressures at different points along flow path that creates a flow of gases or fluids from an area of higher pressure to an area of lower pressure.
Differential Pressure
A gas, vapor, dust, particulate, aerosol, mist, fog, or hybrid mixture of these, suspended in the atmosphere, which is capable of being ignited and propagating a flame front.
Diffuse fuel
A unidirectional or bidirectional flow of smoke/air that presents irregular stratification and shape or alternates in direction.
Dynamic flow
The sudden conversion of potential energy into kinetic energy with the production and release of gases under pressure, or the release of gas under pressure.
Explosion
The detailed study of how chemistry fire science, and the engineering disciplines of fluid mechanics and heat transfer interact to influence fire behavior.
Fire dynamics
A body or stream of gaseous material involved in the combustion process and emitting radiant energy at specific wavelength bands determined by the combustion chemistry of the fuel.
Flame
The flaming leading edge of a propagation combustion reaction zone.
Flame Front
The condition where unburned fuel from a fire has accumulated in the ceiling layer to a sufficient concentration that it ignites and burns.
Flameover
A 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.
Flash Fire
A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach ignition temperature more or less simultaneously and fire spreads rapidly throughout the space, resulting in full room involvement or total involvement of the compartment or enclosed space.
Flashover
The tactic of controlling or closing ventilation points to limit additional oxygen into the space thereby limiting fire development, heat release rate, and smoke production, and to control the movement of the heat and smoke conditions out of the fire area to the exterior and to other areas within the building.
Flow path control
The stage of fire development where heat release rate has reached its peak within a compartment based on available fuel or ventilation.
Fully developed stage
Luminous burning of solid material without a visible flame.
Glowing combustion
The stage of fire development where the heat release rate from an incipient fire has increased to the point where heat transferred from the fire and the combustion products are pyrolyzing adjacent fuel sources and the fire begins to spread across the ceiling of the fire compartment.
Growth stage
An arrow used in a fire scene drawing to show the direction of heat, smoke, or flame flow.
Heat and Flame Vector
The measure of the rate of heat transfer to a surface or an area, typically expressed in kW/m2, or W/cm2.
Heat flux
The total amount of thermal energy that could be generated by a fuel if it were to burn completely and which is typically measured in kilojoules per gram or mega joules per kilogram.
Heat of combustion
The early stage of fire development where the fire’s progression is limited to a fuel source and the thermal hazard is localized to the area of the burning material.
Incipient stage
Firefighting operations involving the application of extinguishing agents to reduce the buildup of heat released from a fire with the intention of suppressing the fire without applying the agent directly onto the burning surface.
Indirect Attack
The energy that causes a change in state of matter of an object.
Latent heat
Any liquid that has a closed-cup flash point at or above 100*F, as determined by the test procedures and apparatus set forth in section 4.4 of NFPA 30.
Combustible liquid
Combustible liquids are classified according to Section 4.3 of NFPA 30
Combustible liquid
Any liquid that has a closed-cup flash point below 100*F as determined by the test procedures and apparatus set forth in section 4.4 of NFPA 30 and a Reid vapor pressure that does not exceed an absolute pressure of 40psi.
Flammable Liquid
An explosive that has a reaction velocity of less than 1000 m/sec.
Low explosive
A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone, pyrolysis often precedes combustion.
Pyrolysis
Heat energy carried by electromagnetic waves that are longer than light waves and shorter than radio waves, radiant heat increases the temperature of any substance capable of absorbing the radiation, especially solid and opaque objects.
Radiant heat
A transient phase in fire behavior accompanied by a rapid increase in heat release rate of the fire and temperature in the environment, sometimes accompanied by the generation of over pressure.
Rapid fire development
A dedicated crew of at least one officer and three members, positioned outside the IDLH, trained and equipped as specified in NFPA 1407, who are assigned for rapid deployment to rescue lost or trapped members
Rapid Intervention Crew (RIC)
The energy that causes a change in the temperature of an object.
Sensible heat
A rapid-fire development that occurs when a smoke-air mixture falls within its flammable range, either external or internal to the room of origin, and is ignited, resulting in a significant pressure front.
Smoke explosion
The ignition of the product of pyrolysis and incomplete combustion interior or exterior to the fire compartment due to the accumulated smoke layer falling within its flammability range and either autoigniting or igniting due to an ignition source.
Smoke ignition
The vertical airflow within buildings caused by the temperature created density differences between the building interior and exterior or between two interior spaces.
Stack effect
A fuel that is subject to ignition by thermal radiation such as from a flame or a hot gas layer.
Target fuel
A fire scene where a fire continued to burn until most combustibles were consumed and the fire self-extinguished due to a lack of fuel or was extinguished when the fuel load was reduced by burning and there was sufficient suppression agent application to extinguish the fire.
Total burn
The application of a fire stream from the exterior of a structure to improve conditions prior to interior fire control.
Transitional attack
A building opening that serves as either an intake and exhaust vent of a flow path at a given time.
Unidirectional Vent
A flame in which fuel and air mix or diffuse together at the region of combustion.
Diffusion flame
The body of knowledge concerning the study of fire and related subjects and their interaction with people, structures, and environment.
Fire Science
The exchange of thermal energy from the source to the fuel by the mechanisms of conduction, convection, or radiation, or all three.
Heat transfer
The increase in length, volume, or surface area of a body with rise in temperature.
Thermal expansion
