Fire Investigation 1A

Front 1

A flammable liquid is any liquid having

Back 1

a flashpoint below 100°F.
Exception: Any mixture having components with flashpoints of 100'F or higher, the total of which make up 99% or more of the total volume of the mixture.

Front 2

A combustible liquid is any liquid

Back 2

having a flashpoint at or above 100*F.

Front 3

The explosive concentration of vapors in air has a lower and upper limit.

Back 3

The Lower Explosive Limit (LEL) is the lowest concentration that will ignite.
-The Upper Explosive Limit (UEL) is the highest
concentration that will ignite. - If the vapor concentration is between the LEL
and UEL, there is serious risk of fire or
explosion.

Front 4

Define Heat

Back 4

a form of energy associated with the motion of atoms and molecules
Temperature-The quality of heat concentration
Heat of combustion- the amount of heat released during complete oxidation

Front 5

Oxidation Process

Back 5

• Normal air has 21% Oxygen(Nitrogen 78%)
• Instantaneous oxidation = Explosion
• Very Slow oxidation = Rust
• Rapid oxidation = Fire (Steady state, free burning, and smoldering fires)
• Self oxidation = Organic peroxide or any oxide or oxalate

Front 6

Define Conduction

Back 6

• Transfer of heat within a body or to another body by direct contact
• Occurs when a material is heated as a result of
direct contact with heat source Heat flow depends on several factors

Front 7

Define Convection

Back 7

• Transfer of heat energy from fluid to solid surface
• Transfer of heat through movement of hot smoke and fire gases
• Flow is from hot fire gases to cooler components

Front 8

Define Radiation

Back 8

Transmission of energy as electromagnetic wave without intervening medium

Front 9

Define Mechanical Heat Energy

Back 9

Generated by friction or compression
Movement of two surfaces against each other
creates heat of friction
Movement results in heat and/or sparks being
generated
Heat of compression generated when gas
compressed

Front 10

Define Electrical Heat Energy

Back 10

Can generate temperatures high enough to ignite any combustible materials near heated area
Can occur as
- Resistance
- Over current/overload -Arcing
- Sparking

Front 11

Define Chemical Heat Energy

Back 11

• Most common heat source in combustion reactions
• Oxidation almost always results in production of heat
• Self-heating

Front 12

Define Heat

Back 12

Heat the energy necessary to increase the temperature of the fuel to a point where sufficient vapors are given off for ignition to occur

Front 13

Define flame

Back 13

• Visible, luminous body of a burning gas
• Becomes hotter, less luminous when burning gas mixes with proper amounts of oxygen
• Loss of luminosity caused by more complete combustion of carbon
• Product of combustion

Front 14

Class A Fires

Back 14

• Involve ordinary combustible materials
• Primary mechanism of extinguishment is cooling to reduce temperature of fuel to slow or stop release of pyrolysis products

Front 15

Class B Fires

Back 15

Involve flammable and combustible liquids and gases
Those involving gases can be extinguished by cutting
off gas supply.
Can be extinguished with appropriately applied foam
and/or dry chemical agent

Front 16

Class C Fires

Back 16

Involve energized electrical equipment
Typical sources —Household appliances, computers, electric motors
Actual fuel usually insulation on wiring or lubricants
• When possible, de-energize electrical equipment before extinguishing
• Any extinguishing agent used before de-energizing must not conduct electricity

Front 17

Class D Fires

Back 17

• Involve combustible metals
• Powdered materials most hazardous
• In right concentrations, airborne metal dust can cause powerful explosions
• High temperature of some burning metals makes water reactive and other extinguishing agents ineffective
No single agent effectively controls. Materials may be in a variety of facilities. Caution urged when extinguishing — Can react violently to water and may produce toxic smoke/vapors.

Front 18

Class K Fires

Back 18

Involve oils and greases Require extinguishing agent specifically formulated for materials involved
Agents use saponification to turn fats and oils into soapy foam that extinguishes fire

Front 19

What is Incipient Stage

Back 19

Ignition — Point when the three elements of the fire triangle come together and combustion occurs
Once combustion begins, development is largely dependent on characteristics and configuration of fuel involved.Fire has not yet influenced
environment to a significant
extent
Temperature only slightly above ambient, concentration of products of combustion low.•
Occupants can safely escape from compartment and fire could be safely extinguished with portable extinguisher or small hoseline
• Transition from incipient to growth stage can occur quite quickly

Front 20

What is Growth Stage

Back 20

• Fire begins to influence environment within compartment
• Fire influenced by configuration of compartment and amount of ventilation• Thermal layering — Tendency
of gases to form into layers according to temperature.
Isolated flames — As fire moves through growth stage, pockets of flames may be observed moving through hot gas layer above neutral plane
• Rollover/flameover
• Flashover

Front 21

What is Flashover

Back 21

Super heating of entire evidence scene.
A flashover is the near-simultaneous ignition of most of the directly exposed combustible material in an enclosed area. Flashover occurs when the majority of the exposed surfaces in a space are heated to their autoignition temperature and emit flammable gases (see also flash point).

Front 22

What is Fully Developed Stage

Back 22

• Occurs when all combustible materials in compartment are burning. Burning fuels in compartment release maximum amount of heat possible for available fuel and ventilation, producing large volumes of fire gases. Fire is ventilation controlled.

Front 23

What is Decay Stage?

Back 23

• Fire will decay as fuel is consumed or if oxygen concentration falls to point where flaming combustion can no longer be supported.
• Decay due to reduced oxygen concentration can follow much different path if ventilation profile of compartment changes.• Consumption of fuel
• Limited ventilation
• Backdraft

Front 24

What is PC 451 (a)

Back 24

• 451(a)ARSON - WITH GREAT BODILY INJURY? 30,000

Front 25

What is PC 451 (b)

Back 25

• 451(b)ARSON - INHABITED STRUCTURE OR PROPERTY? 20,000

Front 26

What is PC 451 (c)

Back 26

• 451(c)ARSON - STRUCTURE OR FOREST LAND$

Front 27

What is PC 451 (d)

Back 27

(d)ARSON - PERSONAL PROPERTY'S 10,000

Front 28

What is PC 451.5

Back 28

451.5AGGRAVATED ARSON - WILLFUL, MALICIOUS INTENT TO CAUSE INJURY TO ONE OR MORE PERSONS, DAMAGE TO PROPERTY, ETC.$1 Million

Front 29

What is PC 452 (a)

Back 29

452(a)UNLAWFULLY CAUSING A FIRE - WITH GREAT BODILY INJURY$ 15,000

Front 30

What is PC 452 (b)

Back 30

452(b) UNLAWFULLY CAUSING A FIRE -INHABITED STRUCTURE OR PROPERTY$10,000

Front 31

What is PC 452 (c)

Back 31

• 452(c) UNLAWFULLY CAUSING A FIRE -STRUCTURE OR FOREST LAND$ 5,000

Front 32

What is PC 453 (a)

Back 32

• 453(a) POSSESSION OF EXPLOSIVE OR FLAMMABLE MATTER$10,000

Front 33

What is PC 454

Back 33

454ARSON DURING STATE OF EMER6ENCY$ 15,000

Front 34

What is PC 455

Back 34

Attempt

Front 35

What is Point of Origin

Back 35

• The investigator should work backwards from the least damage to the most damaged.
• The point of origin may not be the area of the most destruction.
• Fuel load and fire suppression techniques must be considered.
• Most accidental fires can be traced back to a small area or point.

Front 36

What are fire indicators

Back 36

Heat and Smoke level. Burn Patterns. Charring and depth. Flashover. Glass debris. Fire travel. Melting points. Spalling and Calcination.
Calcination: The calcination process normally takes place at temperatures below the melting point of the product materials.
Spalling: Spall are flakes of a material that are broken off a larger solid body and can be produced by a variety of mechanisms

Front 37

What is a indication of a wide V pattern?

Back 37

A wide V with a diffused line of demarcation
may indicate a slow build-up of heat.

Definition: Demarcation is the act of creating a boundary around a place or thing

Front 38

What is a indication of a narrow V pattern with a sharp line of demarcation?

Back 38

A narrow V with a sharp line of demarcation
may indicate a rapid build-up of heat.

Front 39

What is a indication of a inverted V pattern with sharp lines of demarcation?

Back 39

An inverted V with sharp lines of demarcation
may indicate a very rapid build-up of heat.

Front 40

What is demarcation?

Back 40

The line that is the border between two different fire effects on a material. One example is a line of demaraction on a wall with smoke staining above and none below. This line shows the height of the smoke layer in the room. Another example is the edge of a "V" pattern with soot deposits inside and undamaged wallboard outside. This "V" radiated upward and the line of demarcation can be traced back to the base of that fire plume. A third example is the line of demarcation between a clean burn area and the surrounding sooty wall. This line may show the limit of where flame was in contact with the non-combustible wall surface.

Front 41

What are glass indicators?

Back 41

Glass Debris
- Is the glass inside (Forced Entry)
- Is the glass outside (Forced Exit or Explosion)

- Is the glass on both (Heated by fire) Staining of Glass
- Smoke is baked on to glass with time Crazing
- Caused by a rapid cooling Cracking
- Usually larger cracks caused by heat build-up

Front 42

What can light bulbs indicate and why?

Back 42

Light Bulbs
As heat is applied to the surface of a light bulb, the inside inert gas will expand and cause pressure. As the side of the bulb that faces the direction of the fire softens, the bulb will usually begin to swell or distort toward the source of the heat Most light bulbs will break when the temperature reaches 900-1000* F.

Front 43

What can annealing of bed springs indicate and why?

Back 43

Annealing of Springs / Metal
• The springs of a mattress or other piece of furniture will collapse when heated.
• Use this as a point of origin finder.
• A mattress that is heated rapidly and puts itself out may not experience this effect.

Front 44

Why are substances melting points significant?

Back 44

Melting Points

Melting points of different metals in the structure can point you in the right direction.
- Solder-361' F
- Tin - 449* F
- Lead-618* F
- Zinc-786* F
- Magnesium -1203* F
- Aluminum- 1220' F
- Glass-1400'F
- Copper- 1981* F
- Steel - 2606* F
- Iron - 2795* F

Front 45

Describe Calcination of Sheet Rock and what can it indicate?

Back 45

Calcination of Sheet Rock
• Caused by dehydration of sheet rock (Gypsum) when it is exposed to fire. - Sheet rock has about 21% water as a bonding
agent -When exposed to 220* F and above, the water starts to evaporate anjl ralrin:3ti"r"
e sheetrock will start to crack and then it will become a conductor and can transfer heat or ignite.

Front 46

What does the investigator need to eliminate as a cause?

Back 46

Elimination
• The defense against every arson fire is that the cause could be accidental or natural.
• You must be able to eliminate all reasonable causes that it could be.
• "The burden of proof lies with the state"
• This means us.

Front 47

What is the role of the investigator?

Back 47

• Find the point of origin
• Determine the material first ignited - fuel
• Then the heat source

- Chemical
- Electrical
- Mechanical
- Solar/Nuclear
• The event that brings the heat source and fuel to
ignition is called the fire cause.

Front 48

What terms are not the cause of a fire?

Back 48

Not the cause of a fire
• The following terms are often used to describe the fire cause but are incorrect. -Suspicious
- Unknown
- Undetermined
- Intentional

Front 49

Fire cause is defined as

Back 49

The combination of ignition source and fuel first ignited.

Front 50

The fire scene investigation of a structure begins_______?

Back 50

Exterior of the residence.

Front 51

The three types of incendiary delayed
devices are ______ , ______ , and _____?

Back 51

1. Chemical 2. Electrical 3. Mechanical

Front 52

All fire bombs are _____________ devices?

Back 52

destructive

Front 53

What are two examples of electrical activated
devices?

Back 53

Light bulbs placed in or on combustibles/Electrical appliance-Heating device, electrical clocks, watches, timer. Devices connected to blasting caps. Radio controlled devices. Light switches, thermostats.

Front 54

What are two examples of mechanical activated
devices?

Back 54

Manual clocks used to pull, trip, strike, break. Trip wires, pendulum.

Front 55

What is necessary to charge for a destructive device section in PC 453 (b)

Back 55

1. Breakable container 2. Wick or other means of ignition. 3. Flammable liquid with a flashpoint of 150 degree F or less.

Front 56

What are the Types or disposition of fire causes?

Back 56

Natural
- Lightning
- Spontaneous
Accidental
- Equipment
- Vehicles
- Electrical
Arson (Incendiary)
- Devices
- Open Flame

Front 57

What is a cause by nature which must be eliminate?

Back 57

Lightning
• Evidence of physical damage is not always present
• May produce unnatural burn patterns
• Confirm weather in area at and prior to fire
• Fire may be hidden and smolder for a long period of time after lightning strike.

Front 58

What items can possibly be the result of a fire by sunlight?

Back 58

Sunlight
Sun's rays can be concentrated to produce ignition temperatures of common combustible materials. Many items have been involved
- Fish Bowl
- Shaving and Make-up Mirrors
- Concave bottom of shiny can
- Magnifying Glass
- Eye Glasses
- Clear bottle with clear liquid

Front 59

What are some examples of spontaneous heating?

Back 59

Spontaneous Heating
Many organic materials and some metals are subject to oxidation and/or fermentation which results in spontaneous heating
- Chemical Actions-Hay or mowed grass that is wet.
- Oxidation
- Fermentation

Front 60

How long can spontaneous heating occur?

Back 60

Ignition Temperature
Spontaneous heating may occur for hours, days or months prior to reaching ignition temperature. Spontaneous heating will be accelerated by outside heat sources or increase temps.
- Moisture
- Sunshine
- Storage near heat source
- Friction

Front 61

In a suspected electrical fire, what should be checked?

Back 61

Check electrical service areas
- Electrical (Edison) Meters-may be discoloration.
- Cartridge Fuses -Circuit Breakers
- Look for blown or missing fuses / breakers
- May be taped in the on position
- May be bridged or bypassed
Pennies Aluminum Foil Sparkplug Jumper Cables
- Screw in fuses

Front 62

What are some examples of electrical Circuit Misuse?

Back 62

Circuit Misuse
Extension Cords
Cube Taps (Multiple Outlets)
Overloading of receptacles
Multiple Major Appliances on circuit

Front 63

What are some questions for a suspected electrical fire?

Back 63

Questions
Was the electricity on before the fire?
Recent problems?
Any blackouts or brownouts recently?
Fuses have been blowing?
Circuit breakers tripping?
Has the utility company or service personnel done
any recent work?
Do the lights dim or flicker?
Renovation or remodeling to structure?

Front 64

What are some investigative leads?

Back 64

Check hospitals for burn victims.
Intermixed light, medium & heavy burn patterns with the overall floor patterns.
Increased burn damage at the bottom of boxes, furniture legs, etc
Ghost marks on tile within the pour area.

Front 65

What are Key Properties of Common Ignitable Liquids?

Back 65

Behave like any liquid before ignition.
Most float on water, are immiscible, rainbow
Form explosive vapors at room temperatures
Vapors are heavier than air
Readily absorbed
Powerful solvents
Don't spontaneously ignite
Explosive Limits/Ignition Temperat
Sampling the accelerant fire patterns

Front 66

What Penal Code section is the definitions?

Back 66

PC 450

Front 67

What is the Penal Code section for punishment?

Back 67

PC 451

Front 68

What is the enhancement section of the Penal Code?

Back 68

PC 451 (1). Three of the five circumstances include in Penal Code section 451 (1) (enhancements) are a)prior 451 or 452. b) injured firefighter or police officer. c) defendant proximately cause great bodily harm to multiple d) close proximately to burning of multiple structures.

Front 69

According to Penal Code Section 451.5,
any person convicted of an offense in
Section 451 and burns five or more
inhabited structures, or causes in excess
of $5,000,000 damage, or has been
previously convicted of arson on one or
more occasions within the past 10 years
is guilty of _________arson?

Back 69

Aggravated

Front 70

Reckless burning of personal property is a _________?

Back 70

PC 452

Front 71

The three components of a firebomb
include a/an _________ , _______________
and ________________?

Back 71

1) breakable receptacles. 2) with a wick 3) flash point of 150 f or less.

Front 72

Define Flammable liquids.

Back 72

Flash point below 100°F

Front 73

Define Exothermic

Back 73

Releases heat

Front 74

What is the Fire Tetrahedron ?

Back 74

Heat, fuel, oxygen, chain reaction

Front 75

Define Ignition temperature

Back 75

Minimum temperature needed in order to ignite, independent of heat source

Front 76

Define Conduction

Back 76

Heat transfer - circulating gases

Front 77

Define Combustible liquids

Back 77

Flash point above 100 degrees F

Front 78

The humidity must be below ________percent for a cigarette to start a fire in common wildland fuel.

Back 78

18-22%

Front 79

A fire burning on level ground and absent any wind will spread _____________________

Back 79

In a circle pattern

Front 80

A "backing fire" will weaken grass stems
at their __________ and they will fall
pointing toward where the fire came from.

Back 80

base

Front 81

4. Fires traveling with the wind will destroy the ____________ of the grass stems first.

Back 81

tops

Front 82

5. That side of the vegetation nearest the approaching fire is referred to as the ____________________

Back 82

exposed side

Front 83

6. Fires moving upslope through trees or brush will develop a burn pattern _________________than the slope.

Back 83

Steeper

Front 84

7. Leaves and branches are heated and dried, and facing in the direction of the wind at the time they were dried. This burn indicator is called____________________

Back 84

frozen