921 Definitions Flashcards
A rapid oxidation process, which is an exothermic chemical reaction, resulting in the evolution of light and heat in varying intensities
Fire
The flow of electric charge
Current.
the tendency of a material to move or deform permanently to relieve stresses.
Creep
Heat transfer to another body or within a body by direct contact
Conduction
An ignition source that has sufficient energy and is capable of transferring that energy to the fuel long enough to raise the fuel to its ignition temperature.
Competent Ignition Source
The heat, gases, volatilized liquids and solids, particulate matter, and ash generated by combustion
Combustion Products
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
a liquid that has a closed-cup flash point at or above 37.8°C (100°F).
Combustible Liquid
An instrument that samples air and indicates whether there are ignitible vapors or gases present
Combustible Gas Indicator.
Capable of undergoing combustion
Combustible
A distinct and visible fire effect generally apparent on noncombustible surfaces after combustible layer(s) (such as soot, paint, and paper) have been burned away
Clean Burn
Convex segments of carbonized material separated by cracks or crevasses that form on the surface of char, forming on materials such as wood as the result of pyrolysis or burning
Char Blisters
Carbonaceous material that has been burned or pyrolyzed and has a blackened appearance
Char
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
The circumstances, conditions, or agencies that brought about or resulted in the fire or explosion incident, damage to property, bodily injury, or loss of life.
Cause
The amount of heat necessary to raise 1 gram of water 1°C at the pressure of 1 atmosphere and temperature of 15°C
Calorie
A fire effect realized in gypsum products, including wallboard, as a result of exposure to heat that drives off free and chemically bound water
Calcination of Gypsum
The quantity of heat required to raise the temperature of one pound of water 1°F at the pressure of 1 atmosphere and temperature of 60°F
British Thermal Unit (Btu)
The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed
Bonding
Boiling liquid expanding vapor explosion
BLEVE
The expanding leading edge of an explosion reaction that separates a major difference in pressure between normal ambient pressure ahead of the front and potentially damaging high pressure at and behind the front
Blast Pressure Front
A rounded mass of resolidified metal on the end of the remains of an electrical conductor or conductors that was caused by arcing and is characterized by a sharp line of demarcation between the melted and unmelted conductor surfaces
Bead
A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion
Backdraft.
The lowest temperature at which a combustible material ignites in air without a spark or flame
Autoignition Temperature
Initiation of combustion by heat but without a spark or flame
Autoignition
the crime of maliciously and intentionally, or recklessly, starting a fire or causing an explosion
Arson.
A fire pattern displayed on the cross-section of a burned wooden structural member.
Arrow Pattern
A structure, part of a structure, or general geographic location within a fire scene, in which the “point of origin” of a fire or explosion is reasonably believed to be located.
Area of Origin
Arcing associated with a matrix of charred material (e.g., charred conductor insulation) that acts as a semiconductive medium
Arcing Through Char
The location on a conductor with localized damage that resulted from an electrical arc
Arc Site.
Melting of conductors and conducting surfaces as a result of electrical arcing. see 9.11.1.1
Arc Melting
Identifying and documenting a fire pattern derived from the identification of arc sites used to aid in determining the area of fire origin or spread.
Arc Mapping.
A high-temperature luminous electric discharge across a gap or through a medium such as charred insulation.
Arc.
The unit of electric current that is equivalent to a flow of one coulomb per second; one coulomb is defined as 6.24 × 1018 electrons.
Ampere.
The maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating. [70, Article 100]
Ampacity.
Someone’s or something’s surroundings, especially as they pertain to the local environment; for example, air and/or temperature.
Ambient
A system that uses moving mechanical or electrical parts to achieve a fire protection goal.
Active Fire Protection System
An unplanned event that interrupts an activity and sometimes causes injury or damage or a chance occurrence arising from unknown causes; an unexpected happening due to carelessness, ignorance, and the like.
Accident
A fuel or oxidizer, often an ignitible liquid, intentionally used to initiate a fire or increase the rate of growth or spread of fire.
Accelerant
A temperature (scale) measured in Kelvins (K) or Rankines (R)
Absolute Temperature.
Standard, code, recommended practice, or guide?
the main text of which contains only mandatory provisions using the word “shall” to indicate requirements and that is in a form generally suitable for mandatory reference by another standard or code or for adoption into law.
Standard.
A document that is similar in content and structure to a code or standard but that contains only nonmandatory provisions using the word “should” to indicate recommendations in the body of the text.
Recommended Practice.
A document that is advisory or informative in nature and that contains only nonmandatory provisions, but the document as a whole is not suitable for adoption into law.
Guide
A standard that is an extensive compilation of provisions covering broad subject matter or that is suitable for adoption into law independently of other codes and standards.
Code
The process of systematically utilizing logical techniques to dissect, reorder, evaluate, and interpret data.
Data Analysis
The process by which conclusions are drawn by logical inference from given premises
Deductive Reasoning
Propagation of a combustion zone at a velocity that is less than the speed of sound in the unreacted medium
Deflagration
The mass of a substance per unit volume, usually specified at standard temperature and pressure.
Density
1) Sensing the existence of a fire, especially by a detector from one or more products of the fire, such as smoke, heat, infrared radiation, and the like. (2) The act or process of discovering and locating a fire
Detection
Propagation of a combustion zone at a velocity greater than the speed of sound in the unreacted medium
Detonation
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 flame in which fuel and air mix or diffuse together at the region of combustion
Diffusion Flame
The spread of fire by the dropping or falling of burning materials. Synonymous with “fall down.”
Drop Down.
Temperatures reached in fires that produce physical effects that can be related to specific temperature ranges
Effective Fire Temperatures
A small, incandescent particle created by some arcs.
Electric Spark.
A broad concept that includes public or private information stored in an electronic or digital medium,
Electronically Stored Information (ESI).
Factual data that is based on actual measurement, observation or direct sensory experience rather than on theory.
Empirical Data.
A property of matter manifested as an ability to perform work, either by moving an object against a force or by transferring heat.
Energy
The process of air or gases being drawn into a fire, plume, or jet.
Entrainment.
The sudden conversion of potential energy (chemical or mechanical) into kinetic energy with the production and release of gases under pressure, or the release of gas under pressure.
Explosion
Study of how chemistry, physics, fire science, engineering disciplines of fluid and solid mechanics, and heat transfer interact to influence explosion behavior
Explosion Dynamics.
Any chemical compound, mixture, or device that functions by explosion.
Explosive
Any material that can act as fuel for an explosion.
Explosive Material.
The side of a structural assembly or object that is directly exposed to the fire.
Exposed Surface.
To cause to cease burning
Extinguish
Distortion, breakage, deterioration, or other fault in an item, component, system, assembly, or structure that results in unsatisfactory performance of the function for which it was designed
Failure
A logical, systematic examination of an item, component, assembly, or structure and its place and function within a system, conducted in order to identify and analyze the probability, causes, and consequences of potential and real failures
Failure Analysis
The time in minutes, determined under specific laboratory conditions, at which the stud or joist in contact with the exposed protective membrane in a protected combustible assembly reaches an average temperature rise of 121°C (250°F) or an individual temperature rise of 163°C (325°F) as measured behind the protective membrane nearest the fire on the plane of the wood.
finish rating
The process of determining the origin, cause, development, responsibility, and, when required, a failure analysis of a fire or explosion.
fire analysis
The boundary of fire effects within a scene in which the area of origin will be located. The fire area is characterized by identifying the border between damaged and undamaged areas, which are distinguishable by fire effects and patterns created by flame, heat, and smoke.
fire area
The circumstances, conditions, or agencies that bring together a fuel, ignition source, and oxidizer (such as air or oxygen) resulting in a fire or a combustion explosion.
fire cause
The study of chemical processes that occur in fires including changes of state, decomposition, and combustion.
fire chemistry
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
The observable or measurable changes in or on a material as a result of a fire.
fire effects
Any situation, process, material, or condition that can cause a fire or explosion or that can provide a ready fuel supply to augment the spread or intensity of a fire or explosion, all of which pose a threat to life or property.
fire hazard
The process of determining the origin, cause, and development of a fire or explosion
fire investigation
An individual who has demonstrated the skills and knowledge necessary to conduct, coordinate, and complete a fire investigation. [1033, 2014]
fire investigator
The physical changes, or identifiable shapes, formed by a fire effect or group of fire effects
fire patterns
The process of recreating the physical scene during fire scene analysis investigation or through the removal of debris and the placement of contents or structural elements in their pre-fire positions.
fire scene reconstruction
the body of knowledge concerning the study of fire and related subjects (such as combustion, flame, products of combustion, heat release, heat transfer, fire and explosion chemistry, fire and explosion dynamics, thermodynamics, kinetics, fluid mechanics, fire safety) and their interaction with people, structures, and the environment.
fire science
The movement of fire from one place to another.
fire spread
The first fuel ignited is that which first sustains combustion beyond the ignition source.
First Fuel Ignited.
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. In most cases, some portion of the emitted radiant energy is visible to the human eye. [72, 2019]
flame
The flaming leading edge of a propagating combustion reaction zone.
flame
The condition where unburned fuel (pyrolysate) from the originating fire has accumulated in the upper layer to a sufficient concentration (i.e., at or above the lower flammable limit) that it ignites and burns. This can occur without ignition of, or prior to the ignition of, other fuels separate from the origin.
flameover
Capable of burning with a flame.
flammable
The upper or lower concentration limit at a specified temperature and pressure of a flammable gas or a vapor of an ignitible liquid and air, expressed as a percentage of fuel by volume that can be ignited.
flammable limit
A liquid that has a closed-cup flash point that is below 37.8°C (100°F) and a maximum vapor pressure of 2068 mm Hg (40 psia) at 37.8°C (100°F).
flammable liquid
The range of concentrations between the lower and upper flammable limits.
flammable range
A fire that spreads by means of a flame front rapidly through a diffuse fuel, such as dust, gas, or the vapors of an ignitible liquid, without the production of damaging pressure.
flash fire
The lowest temperature of a liquid, as determined by specific laboratory tests, at which the liquid gives off vapors at a sufficient rate to support a momentary flame across its surface.
flash point of a liquid
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, given sufficient availability of oxygen, fire spreads rapidly throughout the space, resulting in full room involvement or total involvement of the compartment or enclosed space.
flashover
The application of science to answer questions of interest to the legal system.
forensic science
A material that will maintain combustion under specified environmental conditions.
fuel
Natural gas, manufactured gas, LP-Gas, and similar gases commonly used for commercial or residential purposes such as heating, cooling, or cooking.
fuel gas
The total quantity of combustible contents of a building, space, or fire area, including interior finish and trim, expressed in heat units or the equivalent weight in wood.
fuel load
A fire in which the heat release rate and growth rate are controlled by the characteristics of the fuel, such as quantity and geometry, and in which adequate air for combustion is available
fuel-controlled fire
Condition in a compartment fire in which the entire volume is involved in combustion of varying intensities.
Full Room Involvement.
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and earth or to some conducting body that serves in place of the earth.
Ground
A current that flows outside the normal circuit path, such as (1) through the equipment grounding conductor; (2) through conductive material in contact with lower potential (such as earth), other than the electrical system ground (metal water or plumbing pipes, etc.); or (3) through a combination of these ground return paths.
ground fault
A substance (solid, liquid, or gas) that when released is capable of creating harm to people, the environment, and property.
Hazardous Material
A form of energy characterized by vibration of molecules and capable of initiating and supporting chemical changes and changes of state.
Heat.
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 heat energy that brings about ignition
heat of ignition
the rate at which heat energy is generated by burning
heat release rate (HRR)
the exchange of thermal energy between materials through conduction, convection, and or radiation
heat transfer
A material that is capable of sustaining a reaction front that moves through the unreacted material at a speed equal to or greater than that of sound in that medium [typically 1000 m/sec (3000 ft/sec)]; a material capable of sustaining a detonation.
high explosive
a term describing any combustible or flammable liquid
ignitible liquid
the process of initiating self-sustained combustion
ignition
the quantity of heat energy that should be absobed by a substance to ignite and burn
ignition energy
the minimum temperature a substance should attain in order to ignite under specific test conditions
ignition temperature
the time between the applicatiopn of an ignition source to a material and the onset of self-sustained combustion
igniton time
a fire that is intentionally ignited in an area or under circumstances where and when there should not be a fire
incendiary fire
The process by which a person starts from a particular experience and proceeds to generalizations. The process by which hypotheses are developed based upon observable or known facts and the training, experience, knowledge, and expertise of the observer
inductive reasoning
Any person, entity, or organization, including their representatives, with statutory obligations or whose legal rights or interests may be affected by the investigation of a specific incident.
Interested Party
A group of individuals working on behalf of an interested party to conduct an investigation into the incident.
Investigative Team.
The preferred SI unit of heat, energy, or work.
Joule
a measurement of energy release rate
kilowatt
the systematic process of removing debris from the top down and observing the relative location of artifacts at the fire scene
layering
the borders defining the differences in fire effects on materials between the affected area and adjacent, less-affected areas
lines of demarcation
the term to discribe the fuel that is first set on fire by the heat of ignition; to be meaningful, both a type of material and a form of material should be identified.
material first ignited
the SI unit of electrical impedance or, in the direct current case, electrical resistance.
ohm
the general location where a fire or explosion began
origin
Any current in excess of the rated current of equipment or the ampacity of a conductor; it may result from an overload (see 3.3.143), short circuit (3.3.175), or ground fault
Overcurrent
Operation of equipment in excess of normal, full-load rating or of a conductor in excess of rated ampacity that, where it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.
overload
The column of hot gases, flames, and smoke rising above a fire; also called convection column, thermal updraft, or thermal column.
plume
The physical location within the area of origin where a heat source, a fuel, and an oxidizing agent first interact, resulting in a fire or explosion
the point of origin
A property of a process, such as fire, which describes the amount of energy that is emitted, transferred, or received per unit time and is measured in joules per second (J/s) or watts (W).
power
The cause that directly produces the effect without the intervention of any other cause.
proximate cause
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
Electromagnetic transmission of heat energy; increases the sensible temperature of any substance capable of absorbing the radiation, especially solid and opaque objects.
radiant heat
Heat transfer by way of electromagnetic waves that are longer than visible light waves and shorter than radio waves.
radiation
A return to flaming combustion after apparent but incomplete extinguishment.
rekindle
The accountability of a person or other entity for the event or sequence of events that caused the fire or explosion, spread of the fire, bodily injuries, loss of life, or property damage.
responsibility
The systematic pursuit of knowledge involving the recognition and definition of a problem; the collection of data through observation and experimentation; analysis of the data; the formulation, evaluation and testing of hypotheses; and, where possible, the selection of a final hypothesis.
scientific method
The result of exothermic reactions, occurring spontaneously in some materials under certain conditions, whereby heat is generated at a rate sufficient to raise the temperature of the material.
self-heating
Ignition resulting from self-heating, synonymous with spontaneous ignition.
self-ignition
The minimum temperature at which the self-heating properties of a material lead to ignition.
self-ignition tempature
An arc site where one or more of the circuit conductors were physically severed by the arcing event at that location.
sever arc
An abnormal connection of low resistance between normal circuit conductors where the resistance is normally much greater; this is an overcurrent situation but it is not an overload
short circuit
The airborne solid and liquid particulates and gases evolved when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass.
smoke
The condensed residue of suspended vapors and liquid products of incomplete combustion.
smoke condensate
Black particles of carbon produced in a flame.
soot
A moving particle of solid material that emits radiant energy due either to its temperature or the process of combustion on its surface.
spark
Process whereby a material increases in temperature without drawing heat from its surroundings.
spontaneous heating
Initiation of combustion of a material by an internal chemical or biological reaction that has produced sufficient heat to ignite the material.
Spontaneous Ignition
The degree of sensible heat of a body as measured by a thermometer or similar instrument.
temperture
The degree of sensible heat of a body as measured by a thermometer or similar instrument.
thermal inertia
The branch of physics that deals with the relationship between heat and other forms of energy.
thermodynamics
The study of the science, methodology, and practice of temperature measurement.
thermomentry
Plastic materials that soften and melt under exposure to heat and can reach a flowable state
thermoplastic
Plastic materials that are hardened into a permanent shape in the manufacturing process and are not commonly subject to softening when heated; typically form char in a fire. Will become brittle when heated.
Thermoset Plastics.
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
Solid or liquid fuel used to intentionally spread or accelerate the spread of a fire from one area to another.
trailer
A buoyant layer of hot gases and smoke produced by a fire in a compartment.
upper layer
he movement of gases within, into, or from any compartment or space or the firefighting operation of removing smoke and heat from the structure by opening windows and doors or making holes in the roof.
ventilation
A fire in which the heat release rate or growth is controlled by the amount of air available to the fire.
Ventilation-Controlled Fire.
The unit of electrical pressure (electromotive force) represented by the symbol “E”; the difference in potential required to make a current of one ampere flow through a resistance of one ohm
volt
Unit of power, or rate of work, equal to one joule per second, or the rate of work represented by a current of one ampere under the potential of one volt.
watt
Operational usage: A dog’s olfactory ability to distinguish between various odors.
Scent Discrimination.
