Definition Of Terms In Fire Technology And Arson Investigation
DEFINITION OF TERMS IN FIRE TECHNOLOGY AND ARSON INVESTIGATION – Here are the following definition of terms in fire technology and arson investigation.
Definition of terms, to put it simply, is a collection of terms used by people in a certain field; or in the field of research, an annex in a book that contains key terms in the study that are clearly defined.
Here are the following terms used in the field of investigating arson and fire technology, according to FireTechnology:
- Accelerant
- refers to any material used to initiate or promote the spread of a fire.They are usually in the form of flammable or combustible fluids. It can be a solid, liquid or in some instances, a gas.
- Adiabatic flame temperature
- theoretically, the highest temperature at which a fuel can burn.
- Area of origin
- the area where a fire started.This term is used when a fire originates in a large area or when the exact point of origin can not be determined.
- Arson
- a criminal act of setting fire to a building or other property on purpose.
- Arson trail
- the use of various types of materials such as cloth rags, newspapers, or wood that have some type pf flammable liquid poured on the material by which the fire can travel along.This trail can leave a distinct mark on the floor of a fire scene.
- Asbestos
- a white or light-gray mineral, obtained primarily from actinolite and amphibole, occurring in long slender needles or fibrous masses that may be woven or shaped into acid-resisting,non-conducting,and fire proof articles.
- Atomize
- to break into discrete atoms,usually by the application of extreme heat,as in atomic absorption.
- Auto-ignition temperature
- the lowest temperature at which a gas or vapor air mixture will ignite from its own heat source or a contacted heated surface without a spark or flame.
- Azeotrope
- a mixture of two or more compounds that have a constant boiling point. These mixtures cannot be separated by fractional distillation.
- Boiling point
- refers to the temperature at which the vapor pressure of a liquid equals the atmospheric pressure and the liquid becomes vapor.
- Burn pattern
- the visible path of fire on a surface or surfaces.
- Burning
- normal combustion in which the oxidant is molecular oxygen.
- Burning rate
- the rate at which combustion proceeds across a fuel.
- Butane
- a fuel gas having the formula C4 H10.One of the constituents found in LP gas.
- Catalyst
- a substance that increases the rate of chemical reaction without undergoing a permanent change in its structure.
- Chain reaction
- a self-propagating chemical reaction in which activation on one molecule leads successfully to the activation of may others.One type of chain reaction is called combustion reaction.
- Combustion
- an exothermic chain reaction between oxidation and reducing agents or between oxygen and fuel.
- Compound
- a chemical combination of two or more elements or two or more different atoms arranged in the same proportions and in the same structure throughout the substance.A compound is different from a mixture in that the components of a mixture are not chemically bonded together.
- Conductivity
- the ability of a material to transfer energy from one place to another.Conductivity is the opposite of resistivity.
- Conductivity (thermal)
- describes a substance’s ability to transmit heat.
- Conductivity (electrical)
- describes a substance’s ability to transmit electrical current.
- Control zones
- areas at a hazardous materials incident whose boundaries are based on safety and the degree of hazard generally includes the hot zone,decontamination zone,and support zone.
- Convection
- transfer of heat by the movement of molecules in a gas or liquid with the less dense fluid rising.The majority of heat transfer in a fire is by convection.
- Deflagrate
- to burn with intense heat and light.
- Ethyl-benzene
- a component of gasoline but also a major breakdown product of pyrolysis released when certain polymers are heated.
- Evaporation
- conversion of a liquid to the vapor state by the addition of latent heat.
- Evaporation rate
- a measure of the quantity of a liquid converted to vapor in a unit of time.Among single component liquids,the rate varies directly with the surface area,the temperature and vapor pressure are inversely with the latent heat of vaporization of the liquid.
- Exothermic reaction
- a chemical reaction that involves heat;combustion reaction is a type of exothermic reaction.
- Explosion
- the sudden conversion of chemical energy into kinetic energy with the release of heat,light,and mechanical shock.
- Explosion limit
- Also known as flammability limit, it refers to the highest or lowest concentration of a flammable gas or vapor in air that will explode or burn readily when ignited.This limit is usually expressed as a volume percent of gas or vapor in air.
- Explosives
- compounds that are unstable and breakdown with the sudden release of large amount of energy.
- Explosivity
- the characteristics of undergoing very rapid decomposition or combustion to release large amounts of energy.
- Fire
- the light and heat manifested by the rapid oxidation of combustible materials.A flame may be manifested but is not required.
- Fire load
- amount of material that can burn.
- Fire pattern
- marks left by fire,smoke, and soot on structures and devices.
- Fire point
- the temperature generally a few degrees above the flash point at which burning is self-sustaining after removal of an ignition source.
- Fire Tetrahedron
- fuel,heat,oxygen and a chemical chain reaction.
- Fire Triangle
- refers to fuel, heat and oxygen.
- Flame
- a rapid gas phase combustion process characterized by self-propagation.
- Flammable
- able to ignite and burn
- Flammable liquid
- a combustible liquid that has a flash point below 100 degrees Fahrenheit.Liquids having a vapor pressure of over 40 psi at 100 degrees Fahrenheit are classified as flammable gases.
- Flammable explosive range
- the range of gas or vapor concentration (percentage of volume in air) that will burn or explode if an ignition source is present.
- Flammable vapor
- a vapor air mixture of any concentration within the flammable range of that vapor.
- Flash
- a general term for any auxiliary,sudden,brilliant light.
- Flash fire
- a fire that spreads with usual speed as one that races over flammable liquids or through combustible gases.
- Flash point
- the temperature at which a pool of liquid will generate sufficient vapor to form an ignitable vapor/air mixture.
- Fraction
- one of the portions of a volatile liquid within certain boiling point ranges such as petroleum naphtha fraction or gas-oil fractions.
- Freezing point
- temperature at which crystals start to form as a liquid is slowly cooled,alternatively,the temperature at which a solid substance begins to melt as it is slowly heated.
- Flashback
- the movement of a flame to a fuel source;typically occurs via the vapor of a highly volatile liquid or by a flammable gas escaping from the cylinder.
- Fuel oil
- heavy petroleum distillate ranging from 1 (kerosine or range oil), up to 6 (heavy bunker fuel). In order for it to be identified as fuel oil, a sample must exhibit a homologous series of normal alkaline ranging from C9 and upward.
- Fume
- gas,smoke,or vapor that smells strongly or is dangerous to smell.
- Fume hood
- an enclosed laboratory cabinet with a movable sash or fixed access port on the front,connected to a ventilating system that may incorporate air scrubbing or filtering facilities.In operation it draws in and then exhaust air from the lab to prevent or minimize the escape of air contaminants.It enables employees to manipulate materials in the hood using only their hands and arms.
- Gas
- a physical state of matter that has low density and viscosity,can expand and contract greatly in response to changes in temperature and pressure and readily and uniformly distributes itself throughout any container.
- Gas chromatograph
- are used to identify unknown compounds such as debris collected from arson’s,on the basis of the retention time or relative retention time of a peak under certain operating conditions.
- Gas chromatography
- a separation technique involving passage of a gas as the mobile phase,moving through a column containing a fixed adsorbent material.It is used principally as a quantitative analytical technique for volatile compounds or simple gases.
- Gasoline
- refine petroleum used as fuel for internal combustion engine.A mixture of more than 2 volatile hydrocarbons in the range of C4 to C12,suitable for use in a spark ignited internal combustion engine.Regular automotive gasoline has a flash point of -40 degrees Fahrenheit.
- Headspace concentration
- a technique for concentration of all or most of the flammable or combustible liquid vapors in a sample on to a tube of charcoal,a wire coated with charcoal,a charcoal-coated polymer,or some other adsorbing material that will later be desorbed in order to analyze the concentrated vapor.This is primary form of sample preparation in arson debris analysis.This is also known as adsorption/elution,vapor concentration,or total headspace.
- Heat
- a mode of energy associated with and proportional to molecular motion that may be transferred from one body to another by conduction,convection or radiation.
- is energy transferred from one system to another by thermal interaction.
- High explosives
- explosives that produce an extremely intense explosive effect and a supersonic pressure wave when they detonate.
- Hot zone
- the area immediately surrounding a chemical hazard incident.
- Ignition
- the means by which burning is started.
- Ignition temperature
- the minimum temperature to which a fuel must be heated in order to initiate or cause self-sustained combustion independent of another heat source.
- Ignition source
- location of a flame,arc,spark or chemical reaction that provides sufficient heat energy in the presence of a fuel and an oxidizer to initiate combustion.
- Incendiaries
- substances or mixtures of substances consisting of a fuel and an oxidizer used to initiate a fire.
- Incendiary fire
- fire intentionally set by human hands often involving the use of an accelerant to increase and spread the rate and intensity of burning.
- Incidental accelerants
- flammable or combustible liquids that are usual and incidental to an area where they are detected.
- Intumescent char
- in plastics,the swelling and charring that results in a higher ignition point used in the preparation of flame retardant materials.
- Ion
- an atom,molecule or radical that has lost or gained one or more electrons thus,acquiring an electric charge.positively charge ions are cations.Negatively charge ions are anions.
- Kelvin
- unit of temperature (K) measurement used to measure the color temperature of light.
- Kerosine
- a flammable hydrocarbon oil used as fuel in lamps and heaters.
- Liquid accelerant
- combustible or flammable liquid used to accelerate ignition and spread of fire.
- Low explosive
- explosives having a detonation less violent than high explosives and that produce a subsonic pressure wave.
- Magnesium (Mg)
- a silvery metal used in some metal incendiaries,the dust is highly explosive with an ignition point of 650 degrees Fahrenheit.
- Molecule
- the smallest particle into which a substance can be divided without changing its chemical properties.A molecule of an element consists of one atom or two or more atoms that are similar.A molecule of a compound consists of two or more different atoms.
- Origin determination
- observing a fire scene,collecting and analyzing evidence and conducting interviews with witnesses to determine where the fire began.
- Oxidation
- a chemical reaction in which oxygen combines with another substance.
- Pentane
- is usually used to extract flammable or combustible liquid residues from fire debris samples.
- Plant
- an ignition device that ignites the first fuel or assists the initial flame to build in intensity,it may include a timing mechanism.
- Polarity
- the measure of an electrical charge on a molecule.Most flammable or combustible liquids are non polar.
- Potassium nitrate (KNO3)
- transparent,colorless,or white crystalline powder or crystals used in pyrotechnics,explosives,matches,metallurgy and glass manufacture.
- Propane
- an alkaline having the formula C3H8. It is the major constituents of LP gas with an explosive limit of 2.4 to 9% One cubic foot of propane has a heating value of 2500 BTU.
- Pyrolysis
- decomposition by the application of or as a result of heat.
- Pyromania
- an irresistible impulse or compulsion to start a fire or set something on fire.
- Pyrophoric distillation
- the slow drying and passive pyrolysis of wood materials.
- Serial arson
- three or more separate arson events with an emotional cooling off period between fires.
- Spontaneous heating
- also known as spontaneous combustion,initially a slow exothermic reaction at ambient temperatures.Liberated heat,if undissipated (insulated),accumulates at an increasing rate and may lead to spontaneous ignition of any combustible present.
- Trailer
- fast burning materials used by arsonist as fuses to rapidly spread fire throughout a structure or area.ex, s linear pour of a liquid accelerant or distribution of a twisted sheet of paper that will lead a fire from one location to another.
- Turpentine
- Gum-form – the pitch obtained from living pine trees,a sticky viscous liquid.
- Oil-form – a volatile liquid obtained y steam distillation of gum turpentine consisting mainly of pine and deterpene.Turpentine is frequently identified in debris samples containing burned wood from arson cases.
- V-shape pattern
- fire pattern seen when a flame impinges on a vertical surface.
- Vapor
- the gaseous form of a substance that is normally a solid or a liquid at room temperature and pressure.
- Vapor density
- the weight of a given volume of a vapor or a gas compare to the weight of an equal volume of dry air,both measured at the same temperature and pressure.
- Vapor pressure
- a measure of the tendency of a liquid to become a gas at a given temperature.
- Vaporization
- the physical change of going from a solid or a liquid into a gaseous status.
- Vermiculite
- a micaceous hydrated silicate mineral used as a planting medium and as insulation.
- Vestibule
- is a lobby,entrance hall,or passage between the entrance and the interior of a building.
- Volatile
- prone to rapid oxidation.Both combustible and non combustible materials may be volatile.