Fire review for board examination for Criminology PDF

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CRIMINOLOGY REVIEWFIRE TECHNOLOGY AND ARSON INVESTIGATIONPrepared by: FILIBERT PATRICK F. TAD-AWAN, MS CRIMFIRE BEHAVIOR It is the manner in which fuel ignites, flame develops, and fire spreads. ARSON INVESTIGATION Deals with the knowledge and study, cause and the point of origin of the fire. The Te...

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1 CRIMINOLOGY REVIEW FIRE TECHNOLOGY AND ARSON INVESTIGATION Prepared by: FILIBERT PATRICK F. TAD-AWAN, MS CRIM

FIRE BEHAVIOR – It is the manner in which fuel ignites, flame develops, and fire spreads. ARSON INVESTIGATION – Deals with the knowledge and study, cause and the point of origin of the fire. The Technology of Fire Fire had been produced by two principal methods: FRICTION AND PERCUSSION. In the friction method, friction raises the temperature of a combustible material (kindling) to ignition temperature. The percussion method produces a spark to set a kindling fire. -

In Friction methods, two pieces of wood surrounded by combustible materials are rubbed together until the ignition temperature is reached. In the stick and groove method, a stick is rubbed in a groove in another piece of wood. The most basic percussion method of producing fire is by striking together two pieces of flint, or by striking flint against pyrite. Later steel was substituted for the pyrite. The flint and steel method prevailed throughout the civilized world until about 1827, when matches came into use. With matches, friction is used to heat the tip of the match to point at which chemicals in the match head ignite.

Important Personalities and their Inventions: 1. John Walker – He was the English Pharmacist who invented the first match in 1827. The tip of this match was coated a mixture of antimony sulfide and potassium chlorate that was held on the wooden matchstick by gum Arabic and Starch. 2. Antoine Lavoisier – a French Chemist who proved in 1777 that burning is the result of the rapid union of oxygen with other substances. As substances burn, heat and light are produced. 3. Thomas Alva Edison –an American inventor who was able to send an electric current through a carbon filament(wire) until the filament became so hot that it gave off light. The Chemistry of Fire FIRE defined: FIRE is the heat and light that comes from burning substances produced by the combustion of substances. It is the manifestation of rapid chemical reaction occurring between a combustible matter and an oxidizer. Such rapid chemical reaction releases energy in the form of heat and light. When a substance burns, heat and light are produced. Burning is also called combustion. Oxidation - a chemical change in which combustible material and an oxidizing agent react Combustion (rapid oxidation of Materials)– the burning of any substance, is a process that evolves heat and light. It is a self-sustaining chemical reaction producing energy or products that cause more reactions of the same kind. The 3 elements of fire - Three elements necessary to create/produced fire in equal proportion; ways to extinguish the fire. 1. Heat- ignition temperature 2. Fuel- combustible material (organic material, hydrocarbons) 3. Oxidizing agent- the common oxidizing agent is oxygen

OXYGEN - A colorless and odorless gas and one of the compositions of air that supports fire which is approximately 21% by volume. Common Types of Gases 1. Natural gas 2. Propane 3. Butane 4. Hydrogen 5. Acetylene 6. Carbon monoxide

7. Others

2 HEAT -

A form of energy measured in degree of temperature, the product of combustion that caused the spread of fire. Types of Energy (Common Sources of Heat)

1. 2. 3. 4. 5. 6. FUEL –

Chemical Energy Electrical Energy Nuclear Energy Mechanical Energy Heat Lights

Any substance/combustibles which reacts chemically with oxygen and produces flames. Sources of Fuel

1. Solid - molecules are closely packed together. 2. Liquid - molecules are loosely packed. 3. Gas - molecules are free to move. Common Types of Solid A. 1. 2. 3. 4.

Bulky Coal Wood Wax Grease

B. 1. 2. 3. 4.

Finely Divided Plastic Paper Cork Leather

C. Dust 1. Saw dust 2. Sugar 3. Grain 4. others

Air is composed of:  Oxygen -21%  Nitrogen – 78%  Inert gases – 1% 21% - normal Oxygen 12% Oxygen – insufficient to produce fire 14% - 15% Oxygen – Can support flash point 16% - 21% - can support fire point To burn a fuel, its temperature must be raised (increased) until ignition point is reached. Thus, before a combustible matter starts to burn or before it can be ignited, it has to be exposed to a certain degree of temperature. When the temperature of a substance is very high, it releases highly combustible vapors known as FREE RADICALS. The lowest temperature at which a substance gives off vapor that burns momentarily (when a flame or spark is applied) is called the FLASH POINT. If a fuel’s temperature has reached its flash point, then it can be instantly ignited thus producing a momentary fire. If its temperature still increases, such that it continuously releases combustible vapors, the condition results to sustained burning (combustion). Hence, the fuel is deemed to have reached its fire point. FIRE POINT is the temperature at which the fuel continues to burn after it has been ignited – that even if the source of ignition has been removed, the fuel continues to burn. Flash point of a substance is usually a few degrees lower than the fire point.

If a substance automatically burns without any human or mechanical intervention, the temperature of the substance has been spontaneously increased until it reaches the AUTO-IGNITION POINT. Auto-ignition point or SELFIGNITIONPOINT is the lowest temperature at which a substance can be heated to release vapors that will ignite without the application of a flame or spark. It refers to the temperature at which spontaneous combustion take place. Auto-ignition point is usually much higher (in temperature) than the fire point. 

FLAMMABLE means easily ignited and capable of burning with great rapidity. A flammable substance is therefore a highly combustible substance. The terms FLAMMABLE and INFLAMMABLE are synonymous; meaning that they have the same meaning thus they can be interchangeably used.

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Combustion may be in the form of: 1. GLOWING COMBUSTION (Condense-phased combustion) -manifested by embers 2. GAS PHASED COMBUSTION – manifested by flame Three Elements of Fire A.FUELS ( Combustible Materials) SOLID FUELS BIOMASS  Biomass is the name given to such replaceable organic matter as wood, garbage, and animal manure that can be used to produce energy. Biomass materials other than wood are used as fuel. For example, heat produced by burning nutshells, rice and oat hulls, and other by-products of food processing are often used to operate plant equipment.

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Factors affecting the combustibility of wood and wood-based products: 1. 2. 3. 4. 5. 6.

Physical Form Moisture content- water content Heat Conductivity Rate and Period of Heating Rate of Combustion Ignition Temperature

PLASTICS 

Plastics are included as ordinary fuels under class A except those materials composed of or containing cellulose nitrate. Cellulose nitrate is a chemical (powder) used in bombs. Materials that use cellulose nitrate are also called PYROXYLIN.

COAL  Coal is used to heat buildings and to provide energy for industrial machinery. The forms of coal are: 1. lignite, or brown coal 2. sub- bituminous coal 3. bituminous coal; and 4. anthracite Bituminous coal is the most plentiful and important coal used by industry. It contains more carbon and produces more heat than either lignite or sub-bituminous coal. It is also the coal best suited for making coke. Anthracite is the least plentiful and the hardest coal. It contains more carbon and produces more than other coals. However, anthracite is difficult to ignite and burns slowly. PEAT It is partially decayed plant matter found in swamps called bogs and used as a fuel chiefly in areas where coal and oil are scarce. In Ireland and Scotland, for example, peat is cut, formed into blocks and dried. The dried blocks are then burned to heat homes. LIQUID FUELS 

Liquid fuels are made mainly from petroleum, but some synthetic liquid fuels are also produced. Petroleum also called crude oil, ranges from clear yellow- brown oils to thick, black tars. Most petroleum is refined to produce such fuels as gasoline, diesel oil, and kerosene. Gasoline is used to provide energy for most motor vehicles and pistonengine airplanes. Diesel oil powers most trains, ships, and large trucks. Kerosene provides energy for jet airplanes.

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In the Canadian province of Alberta, plentiful bituminous sands are processed to yield oil. In Brazil, such biomass as sugar cane, pulp and cassava plants are used to produce fuel for automobiles.

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Some motorists in the United States use a similar fuel, called gasohol, in their cars. Gasohol consists of a mixture of gasoline and alcohol. The alcohol in gasohol is often produced from such grains as corn and wheat.

Two (2) general groups of Liquid Fuels: 1. FLAMMABLE LIQUIDS- liquids have a flash point below 37.8o C (100 o F) 2. COMBUSTIBLE LIQUIDS- liquids have a flash point at or above 37.8o C (100 o F) GAS FUELS CLASSIFICATION OF GASES: A. Based on source: 1. Natural Gas 2. Manufactured Gas B. Based on or according to Physical Properties: 1. Compressed gases 2. Liquefied gases3. Cryogenic gases C. Based on usage: 1. Fuel gases 2. Industrial gases 3. Medical gases CHEMICAL FUELS Chemical fuels, which are produced in solid and liquid form, create great amounts of heat and power. They are used chiefly in rocket engines. Chemical rocket propellants consist of both fuel and an oxidizer. A common rocket fuel is the chemical hydrazine. The oxidizer is a substance, such as nitrogen tetroxide, that contains oxygen. When the propellant is ignited, the oxidizer provides the oxygen the fuel needs to burn. Chemical fuels are also used in some racing cars. NUCLEAR FUELS Nuclear fuels provide energy through the fission or fusion of their atoms. Uranium is the most commonly used nuclear fuel, though plutonium also provides nuclear energy. When the atoms of these elements undergo fission, they release tremendous amounts of heat. Nuclear fuels are used mainly o generate electricity. They also power some submarines and ships. Nuclear energy can also be produced through the fusion of hydrogen atoms. *Nuclear Fission- split of the nucleus of the atoms *Nuclear Fusion- combination two light nuclei of atom B. HEAT (Temperature) HEAT defined: In physics, transfer of energy from one part of a substance to another or from one body to another by virtue of a difference in temperature. Heat is energy in transit; it always flow from a substance at a higher temperature to the substance at a lower temperature, raising the temperature of the latter and lowering that of the former substance, provided the volume of the bodies remains constant. Heat does not flow from a lower to a higher temperature unless another form of energy transfer, work, is also present.

LATENT HEAT  The process of changing from solid to gas is referred to as SUBLIMATION, from solid to liquid as melting, and from liquid to vapor as VAPORIZATION. If the pressure is constant, these processes occur at constant temperature.  The amount of heat required to produce a change of phase is called LATENT HEAT, and hence, latent heats of sublimation, melting, and vaporization exist. SPECIFIC HEAT The heat capacity or the measure of the amount of heat required to raise the temperature of a unit mass of a substance one-degree is known as specific heat.

5 TRANSFER OF HEAT  The physical methods by which energy in the form of heat can be transferred between bodies are conduction and radiation. A third method, which also involves the motion of the matter, is called convection. 1. BACKDRAFT is the sudden and rapid (violent) burning of heated gases in a confined area that occurs in the form of explosion. This may occur because of improper ventilation. If room is not properly ventilated, highly flammable vapors maybe accumulated such that when a door or a window is suddenly opened, the room violently sucks the oxygen and simultaneously, a sudden combustion may occur which may happen as an explosion (combustion explosion). 2. FLASHOVER is the sudden ignition of accumulated radical gases produced when there is incomplete combustion of fuels. It is the sudden burning of accumulated free radicals, which is initiated by a spark/flash produced when temperature rises until flash point is reached. When accumulated volume of radical gases suddenly burn, there will be a very intense fire that is capable of causing flames to jump at a certain distance in the form of FIREBALLS. Fireballs can travel to a hundred yards with in a few seconds. 3. BITEBACK is a fatal condition that takes place when the fire resists the extinguishment operation and becomes stronger and bigger instead. 4. FLASHFIRE is better known as dust explosion. This may happen when a metal post that is completely covered with dust is going to be hit by lightning. The dust particles covering the metal burn simultaneously thus creating a violent chemical reaction that produces a very bright flash followed by an explosion. 3. Oxidizing agent

The fourth element of fire known as the “Chemical chain reaction.” •

material/substance that yield oxygen or oxidizing gases during the process of a chemical reaction.

- material or substance being burned in the combustion process.

- the energy component of he fire tetrahedron. When heat comes in contact with a fuel, the energy supports the combustion process.

– a series of eve ts t at occu in seque ce with the esu ts of each individual reaction being added to the rest. Once flaming starts, it can only continue when enough heat or energy is produced to cause the continued chain reaction.

FIRE TETRAHEDRON

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Stages/steps wherein fire is created.

Input Heat Fuel Oxygen Proportioning Mixing Ignition continuity

Physical Properties of Matter Related to Fire 1. Specific gravity 2. Vapor density 3. Vapor pressure 4. Temperature- the measure of thermal degree of the agitation of molecules of a given substance; the measure of the molecule activity within a substance 5. Boiling point 6. Fire point 7. Flash point 8. Auto-ignition point- Kindling temperature

1. Endothermic reaction - changes whereby energy is absorbed or is added before the reaction takes place. 2. Exothermic reaction - reactions or changes that release or give off energy thus they produce substances with less energy than the reactants. 3. Oxidation - a chemical change in which combustible material and an oxidizing agent react.

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4. Combustion/Flame - A matter that is produced by fire.

7 5. Flame Vapor Density of the more common Flammable Materials Materials Acetylene Butane Gasoline Hydrogen JP-4 Kerosene Propane

Vapor Density 0.9 2.0 3–4 0.1 3.0 3.0 1.6 Combustion Products and Their Effects

1. Heat – the product of combustion responsible for the spread of fire. - a form of energy generated by the transmission of some other form of energy. Injuries caused by heat are: a. dehydration b. heat exhaustion c. injury to the respiratory tract d. burn 2. Flame – it is the luminous body of a burning gas. When burning, gas is mixed with proper amount of oxygen; the flame becomes hotter and less luminous. This loss of luminosity is because of a more complete combustion of the carbon. - It is the manifestation of fire when the fire is in its gas phased combustion. 3. Fire gases – in most fires, it consist of mixture of oxygen, carbon dioxide, carbon monoxide, nitrogen and finely divided particles (soot). - chemical composition of the fuel, percent of oxygen present, and the temperature of the fire.

4. Smoke – some materials give off more smoke than others do. - a visible product of incomplete combustion, a mixture of oxygen, nitrogen, CO, CO2 and finely divided particles released from the burning material. PROTECTION FROM FLAME, HEAT, AND SMOKE  In order to avoid injury or loss of life, protective outfit must be worn. Before entering a space where a fire exists, pant legs should be tucked into socks, collar should be buttoned. One should wear asbestos gloves, a helmet, a headlamp, an Oxygen Breathing Apparatus (OBA).  The flame and the heat from a fire are intense but proper dress will help to prevent burns. The smoke will make it hard to see and hard to breathe, but the OBA and the headlamp will help the person to cope up with these problems.

1. Causes pyrolysis or vaporization of solid and liquid fuels and the production of ignitable vapors or gases; 2. Provides the energy necessary for ignition; 3. Causes the continuous production and ignition of fuel vapors or gases to continue the combustion reaction or burning process. Types of Poisonous Gases 1. Hydrogen Sulfide (H2S) 2. Hydrogen Cyanide (HCN) 3. Hydrogen Chloride (HCL) Types of Flames A. According to Color and Completeness of Combustion B. According to Burning Fuel & Air Mixture C. Based on Smoothness

the initial or beginning stage of fire.

8 the second phase of burning whereby materials or structures are burnin in the presence of adequate oxygen supply.

the final phase of burning wherein flame ceases but dense smoke and heat completely fill the confined room

A. Based on Causes: 1. Natural fire 2. Accidental fire 3. Intentional fire

B. Based on Burning Fuel Four (4) Classes of Fire: 1. Class A 2. Class B 3. Class C 4. Class D 5. Class K This classification was added to the NFPA portable extinguishers Standard (for kitchen fire) Fire classifications

In order to facilitate consistent extinguishment approaches, and maximize occupant and fire fighter safety, fires are classified using code letters in many countries. Below is a table showing the standard operated in Europe and Australasia against the system used in the United States.

European/Australian Classification

Type of Fire

Fires that involve flammable solids such as wood, cloth, rubber, paper, and Class A some types of plastics.

Fires that involve flammable liquids or liquifiable solids such as petrol/gasoline, oil, paint, some waxes & plastics, but not cooking fats or oils

United States Classification

Class A

Class B Class B

Fires that involve flammable gases, such as natural gas, hydrogen, propane, butane

Class C

Fires that involve combustible metals, such as sodium, magnesium, and potassium

Class D

Class D

Fires that involve any of the materials found in Class A and B fires, but with the introduction of an electrical appliances, wiring, or other electrically energized objects in the vicinity of the fire, with a resultant electrical shock risk if a conductive agent is used to control the fire

Class E

Class C

Fires involving cooking fats and oils. The high temperature of the oils when on fire far exceeds that of other flammable liquids making normal extinguishing agents ineffective.

Class F

Class K

Heat Measurement

HEAT defined:

9 In physics, transfer of energy from one part of a substance to another or from one body to another by virtue of a difference in temperature. Heat is energy in transit; it always flow from a substance at a higher temperature to the substance at a lower temperature, raising the temperature of the latter and lowering that of the former substance, provided the volume of the bodies remains constant. Heat does not flow from a lower to a higher temperature unless another form of energy transfer, work, is also present. TEMPERATURE defined: TEMPERATURE is the measure of the degree of thermal agitation of molecules; the hotness or coldness of something; measure of the thermal agitation of molecules of matter. Thermometer is the instrument used to measure. Temperature, which can be commonly, expressed in Degrees Celsius (C...