NFPA 921 FINAL PAPER 2025 QUESTIONS AND ANSWERS
RATED A+
✔✔Drop Down or "fall down." - ✔✔The spread of fire by the dropping or falling of
burning materials.
✔✔Effective Fire Temperatures - ✔✔Temperatures reached in fires that produce
physical effects that can be related to specific temperature ranges.
✔✔Spark - ✔✔A small, incandescent particle created by some arcs.
✔✔Empirical Data. - ✔✔Factual data that is based on actual measurement, observation
or direct sensory experience rather than on theory.
✔✔Energy - ✔✔A property of matter manifested as an ability to perform work, either by
moving an object against a force or by transferring heat.
✔✔Entrainment - ✔✔The process of air or gases being drawn into a fire, plume, or jet.
✔✔Explosible - ✔✔A material with a pressure ratio (maximum pressure/pressure at
ignition, in absolute units) equal to or greater than 2.0 in any test when tested using the
explosibility or Go/No-Go screening test described in Section 13 of ASTM E1226,
Standard Test Method for Explosibility of Dust Clouds.
✔✔Explosion Dynamics. - ✔✔Study of how chemistry, physics, fire science, engineering
disciplines of fluid and solid mechanics, and heat transfer interact to influence explosion
behavior.
✔✔Explosion - ✔✔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. These high-pressure gases then do mechanical work
such as moving, changing, or shattering nearby materials.
✔✔Explosive Material - ✔✔Any material that can act as fuel for an explosion.
✔✔Explosive - ✔✔Any chemical compound, mixture, or device that functions by
explosion.
✔✔Exposed Surface - ✔✔The side of a structural assembly or object that is directly
exposed to the fire.
✔✔Failure - ✔✔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 Analysis. - ✔✔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.
✔✔Finish Rating. - ✔✔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.
✔✔Fire - ✔✔A rapid oxidation process, which is a chemical reaction resulting in the
evolution of light and heat in varying intensities.
✔✔Fire Analysis - ✔✔The process of determining the origin, cause, development,
responsibility, and, when required, a fail‐ ure analysis of a fire or explosion.
✔✔Fire Area - ✔✔The boundary of fire effects within a scene in which the area of origin
will be located. The _____ 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 Cause - ✔✔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 Dynamics. - ✔✔The detailed study of how chemistry, fire science, and the
engineering disciplines of fluid mechanics and heat transfer interact to influence fire
behavior.
✔✔Fire Effects - ✔✔The observable or measurable changes in or on a material as a
result of a fire.
✔✔Fire Hazard. - ✔✔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 Patterns. - ✔✔The visible or measurable physical changes, or identifiable
shapes, formed by a fire effect or group of fire effects.
✔✔Fire investigtion - ✔✔The process of determining the origin, cause, and
development of a fire or explosion.
, ✔✔Fire Scene Reconstruction. - ✔✔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 Science. - ✔✔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 Spread aka fire propagation - ✔✔The movement of fire from one place to
another
✔✔First Fuel Ignited. - ✔✔That which first sustains combustion beyond the ignition
source.
✔✔Flame - ✔✔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.
✔✔Flame Front. - ✔✔The flaming leading edge of a propagating combustion reaction
zone.
✔✔Data - ✔✔evidence; information gathered from observations
✔✔Exothermic - ✔✔Releases heat (energy)
✔✔NTP - ✔✔Normal Temperature and Pressure: 20 deg C (68°F), 1 atmosphere (14.7
psi or 101.6 kPa) (5.1.5.1)
✔✔stoichiometric ratio - ✔✔The optimum ratio of fuel air mixture where combustion is
most efficient (5.1.5.2.2)
✔✔Rollover - ✔✔The condition where unburned fuel (pyrolysate) from the originating
fire has accumulated in the ceiling layer to a sufficient concentration (i.e., at or above
the lower flammable limit) that it ignites and burns; can occur without ignition of, or prior
to, the ignition of other fuels separate from the origin.
✔✔Scientific Method - ✔✔The systematic pursuit of knowledge invo1ving 1) the
recognition and definition of a problem; 2) the collection of data through observation and
experimentation; 3) analysis of the data; 4) the formulation, evaluation and testing of
hypotheses; and, where possible, 5) the selection of a final hypothesis.
RATED A+
✔✔Drop Down or "fall down." - ✔✔The spread of fire by the dropping or falling of
burning materials.
✔✔Effective Fire Temperatures - ✔✔Temperatures reached in fires that produce
physical effects that can be related to specific temperature ranges.
✔✔Spark - ✔✔A small, incandescent particle created by some arcs.
✔✔Empirical Data. - ✔✔Factual data that is based on actual measurement, observation
or direct sensory experience rather than on theory.
✔✔Energy - ✔✔A property of matter manifested as an ability to perform work, either by
moving an object against a force or by transferring heat.
✔✔Entrainment - ✔✔The process of air or gases being drawn into a fire, plume, or jet.
✔✔Explosible - ✔✔A material with a pressure ratio (maximum pressure/pressure at
ignition, in absolute units) equal to or greater than 2.0 in any test when tested using the
explosibility or Go/No-Go screening test described in Section 13 of ASTM E1226,
Standard Test Method for Explosibility of Dust Clouds.
✔✔Explosion Dynamics. - ✔✔Study of how chemistry, physics, fire science, engineering
disciplines of fluid and solid mechanics, and heat transfer interact to influence explosion
behavior.
✔✔Explosion - ✔✔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. These high-pressure gases then do mechanical work
such as moving, changing, or shattering nearby materials.
✔✔Explosive Material - ✔✔Any material that can act as fuel for an explosion.
✔✔Explosive - ✔✔Any chemical compound, mixture, or device that functions by
explosion.
✔✔Exposed Surface - ✔✔The side of a structural assembly or object that is directly
exposed to the fire.
✔✔Failure - ✔✔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 Analysis. - ✔✔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.
✔✔Finish Rating. - ✔✔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.
✔✔Fire - ✔✔A rapid oxidation process, which is a chemical reaction resulting in the
evolution of light and heat in varying intensities.
✔✔Fire Analysis - ✔✔The process of determining the origin, cause, development,
responsibility, and, when required, a fail‐ ure analysis of a fire or explosion.
✔✔Fire Area - ✔✔The boundary of fire effects within a scene in which the area of origin
will be located. The _____ 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 Cause - ✔✔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 Dynamics. - ✔✔The detailed study of how chemistry, fire science, and the
engineering disciplines of fluid mechanics and heat transfer interact to influence fire
behavior.
✔✔Fire Effects - ✔✔The observable or measurable changes in or on a material as a
result of a fire.
✔✔Fire Hazard. - ✔✔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 Patterns. - ✔✔The visible or measurable physical changes, or identifiable
shapes, formed by a fire effect or group of fire effects.
✔✔Fire investigtion - ✔✔The process of determining the origin, cause, and
development of a fire or explosion.
, ✔✔Fire Scene Reconstruction. - ✔✔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 Science. - ✔✔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 Spread aka fire propagation - ✔✔The movement of fire from one place to
another
✔✔First Fuel Ignited. - ✔✔That which first sustains combustion beyond the ignition
source.
✔✔Flame - ✔✔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.
✔✔Flame Front. - ✔✔The flaming leading edge of a propagating combustion reaction
zone.
✔✔Data - ✔✔evidence; information gathered from observations
✔✔Exothermic - ✔✔Releases heat (energy)
✔✔NTP - ✔✔Normal Temperature and Pressure: 20 deg C (68°F), 1 atmosphere (14.7
psi or 101.6 kPa) (5.1.5.1)
✔✔stoichiometric ratio - ✔✔The optimum ratio of fuel air mixture where combustion is
most efficient (5.1.5.2.2)
✔✔Rollover - ✔✔The condition where unburned fuel (pyrolysate) from the originating
fire has accumulated in the ceiling layer to a sufficient concentration (i.e., at or above
the lower flammable limit) that it ignites and burns; can occur without ignition of, or prior
to, the ignition of other fuels separate from the origin.
✔✔Scientific Method - ✔✔The systematic pursuit of knowledge invo1ving 1) the
recognition and definition of a problem; 2) the collection of data through observation and
experimentation; 3) analysis of the data; 4) the formulation, evaluation and testing of
hypotheses; and, where possible, 5) the selection of a final hypothesis.
