true
Probable cause is not needed to obtain an administrative search warrant.
a.True
b.False
conduction
Heat transfer to another body or within a body by direct contact is called:
a.Conduction.
b.Convection.
c.Radiation.
d.Pyrolysis.
true
Fuses and circuit breakers provide protection against electrical short circuits, ground/earth faults,and load currents that might be damaging (i.e. overloads) to the building electrical system.Properly functioning circuit protection may allow the elimination of the buildings wiring system as a potential cause of the fire.
a.True
b.False
false
In pre-flashover conditions the primary heat transfer mechanism for fire spread through a
compartment is radiation.
a.True
b.False
false
In a compartment, flashover occurs because convective heat energy raises combustible to their auto-ignition temperature.
a.True
b.False
true
Combustion may continue with available oxygen concentrations lower than 1 percent.
a.True
b.False
true
The way structures react in a fire often influence how the fire grows and spreads as well as how theymaintain their structural integrity during the fire. Therefore, the fire investigator should considerthe type of structure and method of construction when completing the analysis of fire growth and spread as a part of their fire investigation.
a.True
b.False
false
Materials which have been properly treated with flame-retardants will not undergo pyrolysis andfor this reason will not ignite.
a.True
b.False
empirical
Data that is based on observation or experience and can be verified is called:
a.Anecdotal data
b.Empirical data
c.Qualitative data
d.Categorical data
true
Inductive reasoning is when all available empirical data is analyzed using the investigator’s experience, training, knowledge and expertise.
a.True
b.False
deductive reasoning
Testing of a hypothesis by comparing the investigators hypothesis to all known facts is using____________ reasoning.
a.Deductive
b.Inductive
c.Both A and B
d.Neither A or B
all of the above
Which of the following can be defined as a fuel gas?
a.Natural gas
b.Liquefied petroleum gas
c.Manufactured gases
d. all of the above
all of the above
Prior to conducting an on scene investigation many things should be identified, including:
a.Date and time of incident
b.Size and complexity of the incident
c.Purpose of the investigation
d.All of the above
true
Luminescent flame temperatures are dependant on the fuel to oxygen ratio.
a.True
b.False
timeline
The investigative tool used to graphically or in a narrative manner depict events relating to a fire or explosion in chronological order is called:
a.Timeline
b.Systems analysis
c.Fault tree
d.Computer modeling
Fault tree
A diagram that places, in a logical sequence, the conditions and chains of events that are necessaryfor a fire or explosion to occur is called:
a.Timeline
b.Systems analysis
c.Fault tree
d.Computer modeling
true
Protected areas result from an object or item prohibiting the products of combustion from depositingon materials which the object protects.
a.True
b.False
backdraft
A deflagration resulting from the sudden introduction of air into a confined space containing oxygendeficient products of incomplete combustion.
a.Flashover
b.Flameover
c.Smoke Explosion
d.Backdraft
the geometric shape of the pattern
What does the “V” in V-pattern represent?
a.Vector – pattern
b.Virtual – pattern
c.The geometric shape of the pattern
d.Represents the name of the first individual who recognized the pattern
There is a gasoline pattern found on the premises
Which of the following is NOT one of the three elements of arson?
a.There has been burning of property
b.The burning is incendiary in origin
c.The burning is shown to be started with malice with the intent of destroying property
d.There is a gasoline can found on the premises
false
A BLEVE is a type of explosion involving the ignition of a dispersed vapor cloud?
a.True
b.False
true
Adequate debris removal is essential in an origin investigation?
a.True
b.False
true
The court usually permits the fire and explosion investigator to refresh his memory from his noteswhile testifying in a deposition or trial?
a.True
b.False
false
In a fire, the human body is completely consumed?
a.True
b.False
all of the above
Fire deaths can occur from:
a.Inhalation of hot gases
b.Inhalation of toxic gases
c.Thermal Burns
d.All of the Above
The basic methodology of the fire investigation should rely on the use of a __________ and attention to all relevant details.
a. systematic approach
b. approximation approach
c. methodology approach
d. general approach
a. systematic approach
With few exceptions, the proper methodolgy for a fire or explosion investigation is to first _________ then investigate the cause, circumstances, conditions, or agencies that brought the ignition source, fuel, and oxidant together.
a. determine responsibility
b. determine and establish origin(s)
c. determine if it is a criminal action
d. all of the above
b. determine and establish origin(s)
The process of determining the origin, cause, development, and responsibility as well as the failure analysis of a fire or explosion is the definition of _____________.
a. fire investigation
b. fire scene reconstruction
c. fire evaluation
d. fire analysis
d. fire analysis
The process of determining the origin, cause, and responsibility for a fire or explosion is _______________.
a. fire analysis
b. fire investigation
c. fire scene survey
d. fire evaluation
b. fire investigation
The _________ is the systematic pursite of knowledge involving the recognition and formulation of a problem, the collection of data through observation and experiment, and the formulation and testing of a hypothesis.
a. scientific method
b. scientific examination
c. scientific survey
d. scientific theory
a. scientific method
________ are the visible or measurable physical effects that remain after a fire. These include thermal effects on materials, such as charring, oxidation, consumption of combustibles, smoke and soot deposits, distortion, melting, color changes, changes in character of materials, structural collapse, and other effects.
a. Fire arrows
b. Fire pointers
c. Fire patterns
d. Flammable patterns
c. Fire patterns
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 is called ____.
a. broken
b. distorted
c. failure
d. faulty
c. failure
Vehicle fire inspections may present many other situations that pose safety hazards to the investigator. These can include:
a. fuel leaks
b. expelled lubricants
c. electrical energy stored in the battery
d. all of the above
d. all of the above
The burn or damage patterns remaining on the body panels and in the interior of the vehicle are primarily used to locate the __________.
a. origin of the fire
b. potential ignition sources
c. fuel loads
d. all of the above
d. all of the above
A wide variety of materials and substances may serve as the first materials ignited in motor vehicle fires. These include engine fuels; transmission,·power steering, and brake fluids; coolants; lubricants; and the vehicle interior materials or cargo. Once a fire is started, any of these materials may contribute as a secondary fuel, affecting the fire growth rate and the ultimate damage sustained.
a. True
b. False
a. True
Solid fuels are less common than liquids and gasses as the first materials ignited in motor vehicle fires. The exception would be scenarios where overloaded wiring or smoking materials are possible ignition sources or where the vehicle is subject to an exposure fire.
a. True
b. False
a. True
In most instances, the sources of ignition energy in motor vehicle fires are the same as those associated with structural fires, arcs, overloaded wiring, open flames, and smoking materials. There are, however, some unique sources that should be considered, such as the hot surfaces of the:
a. catalytic converter
b. turbocharger
c. manifold
d. all of the above
d. all of the above
When the engine is not running, the primary source of electrical energy in a motor vehicle is the _________.
a. alternator
b. distributor
c. battery
d. fuel pump
c. battery (can also be other components)
- When the ignition is off and the vehicle is not running, vehicle circuits having a+ 12 volt potential will still supply current from __ to __.
a. battery to starter
b. battery to alternator
c. battery to ignition
d. all of the above
d. all of the above
When the ignition is off and the vehicle is not running, vehicle circuits will still supply current to _.
a. clock
b. lights
c. power door locks
d. all of the above
d. all of the above (clock is not listed)
Protection of electrical circuits in motor vehicles is provided by:
a. fuses
b. circuitbreakers
c. fusible links
d. all of the above
d. all of the above
Electrical problems in circuits protected by fuses cannot start a fire.
a. True
b. False
b. False
The most common open flame in a carburated vehicle fire is:
a. lighted match
b. pilot flames or operating burners
c. catalytic converter
d. a backfire through the carburator
d. a backfire through the carburetor (bad question)
There are two basic fuel systems used in gasoline powered motor vehicles:
a. vacuum/low pressure carbureted system
b. high pressure fuel injected system
c. both a & b
d. neither a or b
c. both a & b
The flash point of gasoline is approximately _.
a. 100* F
b. 212* F
c. -45* F
d. 25* F
c. -45* F
Compared to gasoline, brake fluid is a higher flash point liquid.
a. True
b. False
a. True
Gasoline will normally not ignite on a hot surface but requires a(n) __ for ignition.
a. arc
b. spark
c. open flame
d. any of the above
d. any of the above
In high-pressured fuel injected systems, the fuel is typically pumped from a storage tank under pressure of:
a. 10-15 PSI
b. 20-25 PSI
c. 35-70 PSI
d. 110-160 PSI
c. 35-70 PSI (answer sheet says C or D)
The fuel pump will run when the ignition key is in the _ position.
a. accessory
b. off
c. run
d. all of the above
c. run
Leaks that develop on the supply side of the fuel lines system may present operational problems that should be noticed by the operator whereas on the return side of the system may __.
a. cause the engine to stall
b. go undetected by the operator
c. appear as warning lights
d. cause the engine to race
b. go undetected by the operator
In a vehicle equipped with a fuel injection system; if a fuel leak was to occur on the supply side, there is sufficient pressure to project a small fuel stream several feet in distance.
a. True
b. False
a. True
The pressure from the mechanical fuel pump to the carburetor system is typically in the rate of _ PSI.
a. 3-5
b. 10-20
c. 32
d. 32-70
a. 3-5
When exposed to heat energy from a fire, the rate of vaporization of the gasoline in the fuel tank will increase significantly.
a. True
b. Fals
a. True
Sparks, as a possible source of ignition energy, especially for gasses, vapors or liquid vapors in a spray or mist form may reach temperatures as high as _ in a vehicle traveling less than 5 mph.
a. 110* F
b. 560* F
c. 600* F
d. 1400* F
d. 1400* F
The major components of the emission control system are:
a. the exhaust gas re-circulation valve.
b. charcoal canister
c. variety of rubber vacuum hoses and sensors
d. all of the above
d. all of the above
The decoding of a vehicle identification number (VIN) will provide the investigator with information regarding:
a. manufacturer
b. engine type
c. year of manufacture
d. all of the above
d. all of the above
Federal Motor Vehicle Safety Standard 301 is intended specifically to reduce the fire hazard resulting from __.
a. transmission fluid
b. motor oil
c. brake fluids
d. motor fuel
d. motor fuel
The lamp filaments of broken bulbs area source of ignition energy since the filament has a temperature in the order of _.
a. 36* F
b. 100* F
c. 1000* F
d. 2550 * F
d. 2550* F
Federal Motor Vehicle Safety Standard (FMVSS) for vehicle interior materials flammability is _.
a. FMVSS 208
b. FMVSS 210
c. FMVSS 301
d. FMVSS 302
d. FMVSS 302
Modern upholstery, fabrics and materials in vehicles by their chemical nature are generally easy to ignite with a cigarette.
a. True
b. False
b. False
The urethane foam seating materials will not burn once ignited by a name and does not substantially intensify a vehicle fire.
a. True
b. False
b. False
Rapid-fire growth and extensive damage are proof of an incendiary fire.
a. True
b. False
b. False
The external temperatures of catalytic converters in automobiles can reach temperatures high enough to ignite ordinary combustibles under normal operating conditions and can become higher when ventilation and air circulation are restricted.
a. True
b. False
a. True
The vehicle identification number of a vehicle may be found on the ____.
a. dash of the vehicle
b. Federal Theft Prevention Standard label
c. Federal Emissions Certification label
d. all of the above
a. dash of the vehicle
Documentation of the vehicle fire incident can be accomplished through ________.
a. photographs
b. written notes
c. diagrams
d. all of the above
d all of the above
___ are common sources of ignition for fires in vehicles.
a. Electrical arcs
b. Hot surfaces
c. Open flames
d. All of the above
d. All of the above
The area of greatest destruction is always the area of origin.
a. True
b. False
b. False
Which of the following can affect the flash point of lubricating oils?
a. contamination of the lubricating oil
b. the age (length of service) of the oil
c. the chemical composition
d. all of the above
d. all of the above
Evidence of a mechanical failure in an engine or transmission is proof of a motive for vehicle arson.
a. True
b. False
b. False
A dragging or improperly adjusted brake can overheat to the point a fire can occur.
a. True
b. False
a. True
Many modern vehicles use plastic materials in the engine compartments, increasing the fuel load.
a. True
b. False
a. True
Corrosion of electrical wiring and components can present a fire hazard.
a. True
b. False
a. True
The positions of the power door locks in a vehicle that has been involved in a fire can be reliably used to determine its pre-fire positions.
a. True
b. False
b. False
The surface temperature of engine components increase during the heat (hot) soak period, rendering it a more competent ignition source for fugitive engine fluids.
a. True
b. False
a. True
Electrical arcs may normally occur in which component?
a. Relays
b. Electrical motors
c. Alternators
d. All of the above
d. All of the above
Heat energy produced as a result or friction from a failed bearing may serve as a competent ignition source.
a. True
b. False
a. True
A lit cigarette can be a competent ignition source for __.
a. gasoline vapors.
b. diesel fuel vapors.
c. transmission fluid vapors.
d. paper debris
d. paper debris
A momentary electrical arc or spark can be considered as a competent ignition source for Diesel fuel at room temperatures.
a. True
b. False
b. False
Factors to be considered when investigating a motor vehicle fire include:
a. prevailing winds.
b. vehicle orientation.
c. air temperature.
d. all of the above
d. all of the above
Vapors of ignitable liquids are heavier than air at 72 F.
a. True
b. False
a. True
Any liquid or the liquid phase of any material that is capable of fueling a fire, including a flammable liquid, combustible liquid, or any other material that can be liquefied and burned is the definition for ___________.
a. accelerants
b. melted thermoplastics
c. ignitable liquid
d. ignitable vapors
c. ignitable liquid
When investigating a vehicle fire, information regarding safety recalls can be obtained from the _____________.
a. National Highway Traffic Safely Administration (NHTSA).
b. National Safety Council.
c. National Transportation Safety Board.
d. All of the above.
a. National Highway Traffic Safely Administration (NHTSA).
Properly tightened steel fuel line connections may loosen significantly merely from the heat of a vehicle fire.
a. True
b. False
a. True
In order to comply with FMVSS Standard 302 burning rate of the tested material must be less than
a. 2 inches per minute.
b. 4 inches per minute.
c. 6 inches per minute.
d. 14 inches perminute.
b. 4 inches per minute.
FMVSS 302 requires compliance for
a. present in the passenger compartment of the vehicle.
b. present in the passenger, engine and trunk of the vehicle.
c. all materials within .5 inches of the air space of the passenger compartment.
d. all materials in the vehicle.
c. all materials within .5 inches of the air space of the passenger compartment.
FMVSS 301 does not apply to:
a. motorcycles.
b. commercial passenger vehicles.
c. trucks with gross weights less that I 0,000 pounds.
d. passenger cars.
a. motorcycles.
Factors influencing motor vehicle safety are the _________.
a. Vehicle’s design
b. Vehicle’s construction
c. Vehicle’s materials
d. All of the above
d. All of the above
During a vehicle fire, electrical components such as the horn and the wipers can suddenly operate due to fire damage.
a. True
b. False
a. True
Evidence of electrical wire separation and the formation of a bead are always indicative that it was the source of ignition for the fire.
a. True
b. False
b. False
Gasoline has the highest ignition temperature of any of the liquids normally found in the engine compartment.
a. True
b. False
a. True
It is always possible to determine whether the crash or the resulting fire caused a death.
a. True
b. False
b. False
The development of fire patterns on and in a motor vehicle may be affected by:
a. airflow caused by vehicle movement.
b. distribution of fuel loads.
c. breaches in compartments.
d. all of the above
d. all of the above
During the refueling of a motor vehicle the flow of gasoline may result in the production, accumulation and discharge of a static electrical discharge.
a. True
b. False
a. True
An overheated automatic transmission may result in transmission fluid being expelled from the transmission dipstick presenting a fire hazard if it comes in contact with a hot surface capable of raising the transmission fluid to its ignition temperature.
a. True
b. False
a. True
The continuous fuel flow from a compromised fuel line unaided by mechanical or electrical pumps is the definition of “fuel system siphoning” in motor vehicles.
a. True
b. False
a. True
The post collision failure of a vehicle’s fuel tank can be caused by being compromised:
a. due to collision forces and crush.
b. as a result of exposure to fire.
c. due to a mis-assembly and defective components.
d. all of the above.
d. all of the above.
When evaluating the involvement of the fuel system, the fuel tank should be inspected for
a. presence of gasoline
b. punctures
c. condition of fuel filler pipe
d. all of the above
d. all of the above
When inspecting a metallic fuel tank for damage, the liquid level may be determined by a line of demarcation caused by the heat capacity of the fuel and the resulting cooling of the fuel tank.
a. True
b. False
a. True
Post collision analysis of a crash data retrieval unit (black box) may provide the investigator with data relative to
a. location of electrical failure.
b. occupant interior temperatures.
c. engine RPM.
d. brake pressure.
c and d
Fire spread form the engine compartment to the passenger compartment is limited but not prevented by the presence of the bulkhead (front of dash panel).
a. True
b. False
a. True
What is the melting temperature of die cast zinc which is used to construct the typical ignition lock cylinder?
a. 240-500F b. 560-750F
c. 800-1200F d. 1250-1500F
b. 560-750*F
What is the melting temperature of the lock wafers which are typically made of brass that are located in the ignition lock cylinder?
A. 240-500 degrees F
B. 560-750 degrees F
C. 1710-1825 degrees F
D. 1250-1500 degrees F
C. 1710-1825 degrees F
In recreational vehicles, what are the type of energy sources that you may encounter during an investigation?
A. 12 V DC
B. 120/240V AC
C. Generator
D. All of the above
D. All of the above
Heavy equipment is subject to the same failure modes as ordinary vehicles, but also susceptible to failure due to which of the following?
A. Failure of the hydraulics
B. Bearing Failures
C. Ignition of the material being handled.
D. All of the above
D. All of the above
The location of the fire and the way that the windshield reacts to it may allow a determination of the compartment of origin?
A. True
B. False
A. True
A passenger compartment fire will frequently cause failure at the bottom of the windshield?
A. True
B. False
B. False
Undeployed supplemental restraint systems (Airbags) in vehicles can pose a hazard to the investigator if not rendered safe prior to examining the vehicle.
A. True
B. False
A. True
Melted metals in a vehicle do not indicate which of the following?
A. Fluid line failure
B. Electrical Failure
C. Ignitable liquid as an accelerant
D. None of the above
C. Ignitable liquid as an accelerant
In addition to providing electrical energy, the lead-acid battery can also be a source of fire in the form of what type of gas? Section 27.5.3.2
A. Oxygen
B. Carbon Dioxide
C. Hydrogen
D. Other acidic gasses
C. Hydrogen
In motor vehicles, the entire frame, body and engine may be used as the ground path?
A. True
B. False
A. True
Event Data Recorders record the vehicles parameters before and just after a crash, which of the following does it not record?
A. Vehicle speed
B. Airbag deployment
C. Electrical failure
D. Engine RPM
C. Electrical failure
Engine Control Modules are generally found on which of the following vehicles?
A. Fleet Trucks
B. Busses
C. Passenger cars
D. Both A and B
D. Both A and B
Evidence – Demonstrative
Tangible items; see, touch, smell, hear.
Evidence – Documentary
Written form; business records, banking, calendars, phone records, fire reports, etc…
Evidence – Testimonial
Competent live witness speaking under oath; two types; fact and expert
Evidence – illustrative
Photos, sketches, maps, diagrams. Modes are frequently used at trial.
Evidence – illustravtive
Photos and Videos; what, why, how, when
Evidence collection
Document in place, document the collection, use proper container, (flag, bag, & tag)
Evidence – collection
Fuel gas powered tools outside the perimeter. Find out where tools were refuels.
Heat transfer
Conduction, convection, radiation
Interviews
Purpose of the interview; prepare for the interview, document the interview
Vehicle Fires
Sparks from an aluminum wheel are not a competent ignition source.
Vehicle Fires
The most common source of an open flame in a vehicle is an exhaust system backfire out of a carburetor.
Vehicle Fires
Carburetor backfire leaves a distinct pattern on the hood.
Vehicle Fires
Two basic fuel systems: vacuum/low pressure carbureted system, and high-pressure, fuel injected system.
Vehicle Fires
Loose battery connections; not over-current protected; loose connections can result in intermittent arcing.
Vehicle Fires
Power steering fluid: Flashpoint 347-356F, autoignition 680-720F.
Vehicle Fires
Automatic Transmission Fluid: Flashpoint 302-536F, autoignition 626-716F.
Vehicle Fires
Overcharging a battery does not cause it to explode.
Explosions
Low order damage: characterized by walls bulge out or laid down, virtually intact, next to the structure. roofs slightly left.
Explosions
High order damage: shattering of the structure, producing small debris pieces.
Explosions
Post blast effects: burned debris away-fire preceded, unburned the debris away-no fire.
Explosions
Dust explosions: most often occur in confined areas of relatively wide dispersal.
Explosions
Search 1.5 times further than the farthest piece of debris.
Fire effects/ fire patterns
Char shrinks as it forms. More reliable for evaluating fire spread, deduce the direction based on depth, large shiny blisters (alligatoring) is not evidence of the use of an accelerant.
Fire effects/fire patterns
Spalling: loss of surface material due to cracking, breaking, chipping, breakdown in surface tensile strength, moisture present in the concrete, may appear lighter in color.
Fire effects/fire patterns
Crazed glass: caused by rapid cooling.
Fire effects/fire patterns
Light bulbs 25W or more “pull” (gases expand and bubble out); 25W or less contain a vacuum and can pull in.
Fire effects/fire patterns
Annealing (softening) of springs may provide clues concerning direction, duration, and intensity.
Fire effects/fire patterns
Saddle burns – A U-shaped burn pattern found on the top of floor joists, caused by fire burning down through the floor. Often, a saddle burn is caused by a burning liquid on the floor or radiant heat from a material close to the floor. Saddle burns display deep charring.
Fire effects/fire patterns
Inverted cone burns are indicative of the vertical flame plume not reaching the ceiling, short-lived fires with a low HRR
Fire effects/fire patterns
Melting Temperatures: Copper 1981F; Aluminum 1220F; Steel 2760*F
Heat Sources
Mechanical: converted to heat when two materials rub against each other and create friction.
Chemical: chemical reaction; exothermic and endothermic.
Electrical: Converted to heat energy; flowing through a conductor.
Nuclear: splitting the nucleus of an atom into two smaller nuclei (nuclear fission)
Electrical
Resistance Heating: properly installed, produces low resistance.
Loose connections: high resistance with increased heating at the contact.
Electrical
Ground Fault: the purpose if grounding an electrical system is to make sure that any housings or exposed metal in the system or connected to it cannot become electrically charged.
Electrical
Sleeving: the softening and sagging of thermoplastic conductor insulation due to the heating of the conductor.
Electrical
Lightning: a form of static electricity, a polarized electrostatic charge in the clouds.
Electrical
9.2.2.2.2: the unit of measurement of potential difference or voltage is usually volts.
Electrical
9.2.2.3: the rate of charge flow is called electrical current, and current is measured in amperes.
Electrical
9.2.6.1: power – the rate at which energy is used.
Electrical
9.3.3: the cables of a service drop go into a weather-head, which is designed to keep water from entering the system, and then down a service raceway to a meter base.
Electrical
9.6.2.1: fuses are basically non-mechanical devices with a fusible element in a small enclosure.
Electrical
9.6.3.1: a circuit breaker is a switch that opens either automatically with over-current or manually by pushing a handle.
Electrical
9.7: Branch Circuits: the individual circuits that feed lighting, receptacles, and various appliances are the branch circuits.
Electrical
9.9.4.1: Arc: is a high temperature luminous electric discharge across a gap or through a medium such as charred insulation.
Electrical
9.10.3: Arcing through a carbonized path due to thermal means (arcing through char), insulation on conductors, when exposed to direct flame or radiant heat, may be charred before being melted. That char is conductive enough to allow sporadic arcing through the char.
Fatalities
Charred bones are an indication of fire intensity and duration
Fatalities
The Pugilistic posture is as a result of the muscle dehydrating and shrinking, shrinkage causes flexion
Fatalities
Humans do not spontaneously combust
Miscellaneous
Hire a FPE to examine a flow valve, EE for a toaster, Mechanical Engineer for a furnace and a metallurgist for metal issues
Miscellaneous
Do not put field notes in the investigative report
Miscellaneous
Polyethylene chair has a higher HRR than a pool of gasoline or a Christmas tree
Miscellaneous
A pathologist should exam a fractured skull
Miscellaneous
Main breaker is the safest way to de-energize a house
Miscellaneous
Fill the evidence can only 2/3 full
Miscellaneous
Annealed (softening) springs can indicate duration and intensity
Miscellaneous
An autopsy should always be performed
Miscellaneous
Witnesses can only testify to facts observed
Miscellaneous
Identify interview question types according to the priority that they should be asked
Miscellaneous
Vapor density of <.6 will rise to the ceiling and accumulate
Miscellaneous
Oxidation is the basic chemical reaction associated with combustion
Miscellaneous
Add more oxygen and expect color change and change of texture
Thermal Inertia
Thermal conductivity(k), density(p), heat capacity (c)
Latent heat of vaporization
The heat absorbed when a substance changes phase from a liquid to a gas. No change in chemical structure of the material
Flameover
Unburned fuel from the originating fire accumulates in the ceiling layer to sufficient concentration that it ignites
Flashover
A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach ignition temperature more or less simultaneously
Backdraft
A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion
Boiling Point
Temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
Burning Point
The lowest temperature at which a volatile oil in an open vessel will continue to burn when ignited by a flame held close to its surface; used to test safety of kerosene and other illuminating oils.
Clean Burn
A distinct and visible fire effect generally apparent on non-combustible surfaces after combustible layers (soot, paper, paint)have burned away
Combustion
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
Calcination
A fire effect realized in gypsum products, including wallboard, as a result of exposure to heat that drives off free and chemically bound water
Fire
A rapid oxidation process, which is a chemical reaction resulting in the evolution of light and heat in varying intensities
Fire Plume
Creation of hot gases by fire; the hot gases rise above the fire itself
Flame Spread
Classified as concurrent or counterflow: concurrent-(wide-aided flame spread) occurs when flame spread direction is the same as the gas flow or wind direction; counterflow-(opposed flame spread) occurs where the flame spread direction is counter to or opposed to the gas flow
Heat
a form of energy characterized by vibration of molecules and capable of initiating and supporting chemical changes and changes of state
Ignition Temperature
Minimum temperature a substance should attain in order to ignite under specific test conditions
Lower Explosive Limit (LEL)
The minimum percentage of fuel in air (by volume) in which combustion can occur
Upper Explosive Limit
The maximum percentage of fuel in air in which combustion can occur
Melting Point
Phase change; the material changes from a solid to a liquid with no change in the chemical structure of the material (melting candle wax)
Pyrolysis
A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion
Specific Gravity (Vapor Density)
The ratio of the average molecular weight of a gas or vapor to the average molecular weight of air
Specific Gravity
The ratio of the mass of a given volume of a substance to the mass of an equal volume of water at a temperature of 4*C
Combustible Liquid
Flash Point @ or above 100°F
Flammable Liquid
Flash Point less than 100°F
Ignitable Liquid
Both combustible and flammable liquids are ignitable liquids.
Flash Point
Momentary Flame; the lowest temperature at which vapors will ignite. Measuring a flash point requires an ignition source. At the flash point, the vapor may cease to burn when the ignition source is removed.
Accelerant
Can be any material to spread fire; usually gasoline.
Origin Determination
- Witness Information
- Fire Patterns
- Arc Mapping
- Fire Dynamics
Ceiling Jet
Obstruction to plume at ceiling level creates ceiling jets.
Thermal Inertia
The degree of slowness with which the temperature of a body approaches that of its surroundings and which is dependent upon its absorptivity, its specific heat, its thermal conductivity, its dimensions, and other factors
High Order Explosion
A high order explosion describes an explosive event where the blast pressure front moves rapidly, shattering objects in its path. High order damage: shattering of the structure, producing small debris pieces.
High Explosive
A high explosive is a material that has an explosion velocity of greater than 1000 m/s, or a material capable of sustaining a detonation
Low Order Explosion
A low order explosion describes an explosive event where the blast pressure front moves slowly, displacing or heaving (rather than shattering) objects in its path. Low order damage: characterized by walls bulge out or laid down, virtually intact, next to the structure. roofs slightly left.
Low Explosive
A low explosive is a material that has an explosion velocity of less than 1000 m/s.
True – Administrative Warrant
Probably cause IS NOT NEEDED to obtain an ADMINISTRATIVE search warrant.
Conduction
Heat transfer to another body or within a body by DIRECT contact.
Pre-Flashover conditions
In pre-flashover conditions, the primary heat transfer mechanism for fire spread through a compartment is conduction.
Conduction Heat Transfer
Conduction is the form of heat transfer that takes place within solids when one portion of an object is heated. Energy is transferred from the heated area to the unheated area at a rate dependent on the difference in temperature and the physical properties of the material.
Convection Heat Transfer
Convection is the transfer of heat energy by the movement of heated liquids or gases from the source of heat to a cooler part of the environment.
Heat is transferred by convection to a solid when hot gases pass over cooler surfaces. The rate of heat transfer to the solid is a function of the temperature difference, the surface area exposed to the hot gas, and the velocity of the hot gas. The higher the velocity of the gas, the greater the rate of convective transfer.
Radiation Heat Transfer
Radiation is the transfer of heat energy from a hot surface to a cooler surface by electromagnetic waves without an intervening medium. For example, the heat energy from the sun is radiated to earth through the vacuum of space. Radiant energy can be transferred only by line-of-sight and will be reduced or blocked by intervening materials. Intervening materials do not necessarily block all radiant heat. For example, radiant heat is reduced on the order of 50 percent by some glazing materials.
Pyrolysis
A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone; pyrolysis often precedes combustion
Combustion
Combustion may continue with available oxygen concentrations lower than 1 percent.
Empirical Data
Data that is based on observation or experience and can be verified.
Inductive Reasoning
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.
Deductive Reasoning
Test the Hypothesis with deductive reasoning. The process by which conclusions
are drawn by logical inference from given premises. Testing of the hypothesis is done by the principle of deductive reasoning, in which the investigator compares the hypothesis to all the known facts as well as the body
of scientific knowledge associated with the phenomena relevant
to the specific incident.
Fault Tree
Fault trees can be used to test the possibility of a hypothesized fire cause. Fault trees are developed by
breaking down an event into causal component parts. These
components are then placed in a logical sequence of events or
conditions necessary to produce the event. If the conditions or
sequence are not present then the hypothesis is disproved.
Time Lines
In the context of testing a cause hypothesis, the time frame may be a discriminator for determining if an ignition scenario is consistent with the available data as it related to time frames.
“V” Pattern
The geometric shape of the pattern.
Arson
The crime of maliciously and intentionally, or recklessly, starting a fire or causing an explosion.
Arc
A high-temperature luminous electric discharge
across a gap or through a medium such as charred insulation.
Cause
The circumstances, conditions, or agencies that brought about or resulted in the fire or explosion incident, damage to property resulting from the fire or explosion incident, or bodily injury or loss of life resulting from the fire or explosion incident.
Combustion
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.
Fire
A rapid oxidation process, which is a chemical
reaction resulting in the evolution of light and heat in varying intensities.
Drop Down / Fall Down
The spread of fire by the dropping or falling of burning materials. Synonymous with “fall down.”
Conduction
Heat transfer to another body or within a body by direct contact.
Convection
Heat transfer by circulation within a medium such as a gas or a liquid.
Competent Ignition Source
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.
Detonation
Propagation of a combustion zone at a velocity greater than the speed of sound in the unreacted medium.
Forensic (Forensic Science)
The application of science
to answer questions of interest to the legal system.
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.
Scientific Method
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 a hypothesis; and, when possible, the selection of a final
hypothesis.
Systematic Approach
The systematic approach recommended is based on the scientific method, which is used in the physical sciences. This method provides an organizational and analytical process that is desirable and necessary in a successful
fire investigation
The Scientific Method
Recognize the Need (identify the problem)
Define the problem
Collect Data
Analyze the Data
Develop a Hypothesis
Test the Hypothesis (if fail, go back to collect data)
Select the Hypothesis
The Scientific Method – Recognize the need.
First, one should determine that a problem exists. In this case, a fire or explosion has occurred and the cause should be determined and listed so that future,
similar incidents can be prevented.
The Scientific Method – Define the Problem
Having determined that a problem exists, the investigator or analyst should define the manner in
which the problem can be solved. In this case, a proper origin and cause investigation should be conducted. This is done by an examination of the scene and by a combination of other data collection methods, such as the review of previously conducted
investigations of the incident, the interviewing of witnesses
or other knowledgeable persons, and the results of scientific testing.
The Scientific Method – Collect Data
Facts about the fire incident are now collected by observation, experiment, or other direct datagathering
means. The data collected is called empirical data because it is based on observation or experience and is capable
of being verified or known to be true.
The Scientific Method – Analyze the Data
The scientific method requires that all data collected be analyzed. This is an essential step that must take place before the formation of the final hypothesis. The identification, gathering, and cataloging of data does not
equate to data analysis. Analysis of the data is based on the knowledge, training, experience, and expertise of the individual doing the analysis. If the investigator lacks expertise to properly attribute meaning to a piece of data, then assistance
should be sought. Understanding the meaning of the data will enable the investigator to form hypotheses based on the evidence, rather than on speculation.
The Scientific Method – Develop a Hypothesis (Inductive Reasoning)
(Inductive Reasoning). Based on the data analysis, the investigator produces a hypothesis, or hypotheses, to explain the phenomena, whether it be the nature
of fire patterns, fire spread, identification of the origin,
the ignition sequence, the fire cause, or the causes of damage or responsibility for the fire or explosion incident. This process is referred to as inductive reasoning. These hypotheses should be based solely on the empirical data that the investigator has collected through observation and then developed into explanations for the event, which are based upon the
investigator’s knowledge, training, experience, and expertise.
The Scientific Method –
Test the Hypothesis (Deductive Reasoning)
(Deductive Reasoning). The investigator does not have a valid or reliable conclusion unless the hypothesis can stand the test of careful and serious challenge. Testing of the hypothesis is done by the principle of deductive reasoning, in which the investigator compares the hypothesis to all known facts as well as the body of scientific knowledge
associated with the phenomena relevant to the specific incident. A hypothesis can be tested physically by conducting experiments,
analytically by applying accepted scientific principles,
or by referring to scientific research. When relying on
the research of others, the investigator or analyst must ensure that the conditions, circumstances, and variables of the research and those of the hypothesis are sufficiently similar.
Whenever the investigator relies on research as a means of hypothesis testing, references to the research relied upon should be acknowledged and cited. If the hypothesis is refuted or not supported, it should be discarded and alternate hypotheses should be developed and tested. This may require the collection of new data or the reanalysis of existing data. The testing process needs to be continued until all feasible hypotheses
have been tested and one is determined to be uniquely
consistent with the facts and with the principles of science. If no hypothesis can withstand an examination by deductive reasoning, the issue should be considered undetermined.
The Scientific Method – Testing the hypothesis
Any hypothesis that is incapable of being tested either physically or analytically, is an invalid hypothesis. A hypothesis
developed based on the absence of data is an example of a hypothesis that is incapable of being tested. The inability to refute a hypothesis does not mean that the hypothesis is true.
Expectation Bias
Expectation bias is a well-established phenomenon that occurs in scientific analysis when investigator(s) reach a premature conclusion without having examined or considered all of the relevant data. Instead of collecting
and examining all of the data in a logical and unbiased
manner to reach a scientifically reliable conclusion, the investigator(s) uses the premature determination to dictate investigative processes, analyses, and, ultimately, conclusions, in a
way that is not scientifically valid. The introduction of expectation bias into the investigation results in the use of only that data that supports this previously formed conclusion and often
results in the misinterpretation and/or the discarding of data that does not support the original opinion. Investigators are strongly cautioned to avoid expectation bias through
proper use of the scientific method.
Confirmation Bias
Different hypotheses may be compatible with the same data. When using the scientific method, testing of hypotheses should be designed to disprove the hypothesis
(falsification of the hypothesis). Confirmation bias
occurs when the investigator instead tries to prove the hypothesis. This can result in failure to consider alternate hypotheses, or prematurely discounting seemingly contradictory data without an appropriate assessment. A hypothesis can be said to
be valid only when rigorous testing has failed to disprove the hypothesis.
Administrative Review
An administrative review is one typically carried out within an organization to ensure that the investigator’s work product meets the organization’s quality
assurance requirements. An administrative reviewer will determine whether all of the steps outlined in an organization’s procedure manual, or required by agency policy, have been followed and whether all of the appropriate documentation is present in the file, and may check for typographical or grammatical
errors.
Technical Review
A technical review can have multiple facets. If a technical reviewer has been asked to critique all aspects of the investigator’s work product, then the technical reviewer should be qualified and familiar with all aspects of
proper fire investigation and should, at a minimum, have access to all of the documentation available to the investigator whose work is being reviewed. If a technical reviewer has been asked to critique only specific aspects of the investigator’s work product, then the technical reviewer should be qualified
and familiar with those specific aspects and, at a minimum, have access to all documentation relevant to those aspects. A technical review can serve as an additional test of the various
aspects of the investigator’s work product.
Peer Review
Peer review is a formal procedure generally
employed in prepublication review of scientific or technical
documents and screening of grant applications by
research-sponsoring agencies. Peer review carries with it connotations of both independence and objectivity. Peer reviewers should not have any interest in the outcome of the review.
The author does not select the reviewers, and reviews are often conducted anonymously. As such, the term “peer review”
should not be applied to reviews of an investigator’s work by coworkers, supervisors, or investigators from agencies conducting
investigations of the same incident. Such reviews are
more appropriately characterized as “technical reviews,” as described
above.
Thermal Inertia
During transient heating, a more common condition, the result is changing rates of heat transfer and temperature. During this period, all three properties—thermal
conductivity (k), density (ρ), and heat capacity (c) — play a role. Multiplied together as a mathematical product, these properties are called the thermal inertia, kρc, of a material. The thermal inertia
of a material is a measure of how easily the surface temperature of the material will increase when heat flows into the material. Low-density materials like polyurethane foam have a low thermal inertia and the surface temperature will increase quickly upon exposure to a heat flux. Conversely, metals have a high thermal inertia due to their high thermal conductivity and high
density. As such, when exposed to a flame, the surface temperature
of a metal object increases relatively slowly compared to the surface temperature of a plastic or wood object. Table 5.5.2.3 provides data for some common materials at room temperature. Thermal properties are generally a function of temperature.
Saddle Burns
A U-shaped burn pattern found on the top of floor joists, caused by fire burning down through the floor. Often, a saddle burn is caused by a burning liquid on the floor or radiant heat from a material close to the floor. Saddle burns display deep charring.