accelerant
A fuel (usually a flammable liquid) that is used to initiate or increase the intensity or speed of spread of fire.
adiabatic
Conditions of equilibrium of temperature and pressure
autoignition temperature
temperature at which a material will ignite in the absence of any external pilot source of heat; spontaneous ignition temperature.
Arrow Pattern
patterns with progressive destruction like a series of wall studs
BLEVE
Boiling-liquid, expanding-vapor explosion. A mechanical explosion caused by the heating of a liquid in a sealed vessel to a temperature far above its boiling point.
boiling point
The (pressure-dependent) temperature at which a liquid changes to its gas phase
combustible liquid
A liquid having a flash point at or above 38�C (100�F).
flame point
Temperature at which a flame is sustained by evaporation or pyrolysis of a fuel; fire point
flammable liquid
A liquid having a flash point below 38�C (100�F).
flash point
Temperature at which an ignitable vapor is first produced by a liquid fuel
ignitable liquid
Classification for liquid fuels including both flammable and combustible classes
ignition energy
The quantity of energy that must be transferred into a fuel/oxidizer combination to trigger a self-sustaining combustion
ignition temperature
The minimum temperature to which a substance must be heated in air to ignite independently of the heating source
olefinic
Hydrocarbons containing double carbon-carbon bonds (denoted C = C); nonsaturated hydrocarbons; alkenes
vapor density
The ratio of the weight of a given volume of gas or vapor to that of an equal volume of air
alligatoring
Rectangular patterns of char formed on burned wood
annealing
Loss of temper in metal caused by heating.
area of origin
The general locale in which a fire was ignited
calcination
Loss of water of crystallization caused by heating
chain of evidence (chain of custody)
Written documentation of possession of items of physical evidence from their recovery to their submission in court.
char depth
The measurement of pyrolytic or combustion damage to a wood surface compared with its original surface height.
clean burn
An area of wall or ceiling where the charred organic residues have been burned away by direct flame contact
crazing
Stress cracks in glass as the result of rapid cooling
dropdown
The collapse of burning material in a room that induces separate, low-level ignition
fire patterns
Indicators of damage (or relative lack of damage) created by a combination of smoke, flames, and heat effects
ghost marks
Stained outlines of floor tiles produced by the dissolution and combustion of tile adhesive
heat horizon
The demarcation (usually horizontal) of fire damage revealed by the charring, burning, or discoloration of paint or wall coverings
ignitable liquid
Classification for liquid fuels including both flammable and combustible classes
indicators
Observable (and usually measurable) changes in appearance caused by heat, flame, or smoke
overhaul
The firefighting operation of eliminating hidden flames, glowing embers, or sparks that may rekindle the fire, usually accompanied by
the removal of structural contents
salvage
Procedures to reduce incidental losses from smoke, water, and weather following fires, generally by removal or covering of contents
smoke horizon
Surface deposits that reveal the height at which smoke and soot stained the walls and windows of a room without thermal
damage.
spalling
Crumbling or fracturing of a concrete or brick surface as a result of exposure to thermal or mechanical stress
trailers
Long trails of fast-burning materials used to spread a fire throughout a structure
area of transition
Mixture of directional fire indicators in a wildlands fire
backing
Slow extension of a fire downslope or into wind in the opposite direction of its main spread
crowning
Rapid extension of fire through the porous array of leaves, needles, and fine fuels above 2m
flanking
Lateral spread of fire in a direction at right angles to the main direction of fire growth
hot set
Direct ignition of available fuels with an open flame (match or lighter).
ladder fuels
Intermediate-height fuels between the ground litter and the crowns of trees overhead
rekindle
Reignition of a fire due to latent heat, sparks, or embers
spot fires
Fires started by airborne embers some distance away from the main body of the fire
ampacity
Current-carrying capacity of electric conductors (expressed in amperes).
circuit breaker
A device designed to open a circuit automatically at a predetermined overcurrent without injury to itself when properly applied
within its ratings
conductor
Any material capable of permitting the flow of electrons
duty
Conditions of use in electrical service
eutectic
An alloy of two materials having special physical or chemical properties, typically having the lowest melting point of any combination
of the two
ground
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment, and the earth, or to some
conducting body that serves in place of the earth
open neutral
In an American single-phase, 120/240 V residential system, the neutral return leg is not connected to the service ground.
receptacle
A contact device installed as the outlet for the connection of an appliance by means of a plug
service conductors
The supply conductors that extend from the street main or transformer to the equipment of the premises served.
service drop
The overhead service conductors from the pole, transformer, or other aerial support to the service entrance equipment on the
structure, including any splices
thermal protector
A device against overheating that is responsive to temperature or current and will protect the equipment against overheating due to overload or failure to start
voltage, nominal
A value assigned to a circuit or system for the purpose of conveniently designating its voltage class (120/240, 480Y/277,
600, etc.)
arson set
Device, assembly, or contrivance used to ignite an incendiary fire
corpus delicti
Literally, the body of the crime. The fundamental facts necessary to prove the commission of a crime
fraud
Deception deliberately practiced in order to secure unfair or unlawful gain.
motive
Inner drive or impulse that causes a person to do something or act in a certain way.
pyromania
Uncontrollable psychological impulse to start fires.
torch
A professional fire setter
seat of explosion
The area of most intense physical damage caused by high explosive pressures and shock waves in the vicinity of a solid or
liquid explosive