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Category: Agriculture and Industry > Fire
Date & country: 11/12/2007, UK
Words: 160

Substances or mixtures of substances consisting of a fuel and an oxidiser used to initiate a fire

Incendiary Fires
Fire set by human hands

Incidental Accelerants
Flammable or combustible liquids which are usual and incidental to an area where they are detected. Gasoline is incidental to an area where gasoline powered appliances are kept. Kerosene is incidental to an area where a kerosene heater is kept. Flammable liquids may also comprise a part of a product such as insecticide, furniture polish, or paint. …

Infrared Spectrophotometry (IR)
An analytical technique which utilises an instrument which passes infrared radiation through a sample or which bounces infrared radiation off the surface of a sample. A very sensitive heat detecting device measures the amount of infrared radiation absorbed as the wavelength of the radiation reaching the detector is changed. IR can give useful infor…

Intumescent Char
In plastics, the swelling and charring which results in a higher ignition point. Used in the preparation of flame retardant materials

An atom, molecule or radical that has lost or gained one or more electrons, thus acquiring an electric charge. Positively charged ions are cations; negatively charged ions are anions

One of two or more forms a chemical compound which have the same number and type of each atom but a different arrangement of atoms

A mixture of branched alkanes usually available as a narrow 'cut' of a distillation. Exxon manufactures a group of products known as 'Isopars' ranging from Isopar A through Isopar J. These solvent mixtures have a variety of uses. Gulf Oil manufactures a similar series of solvents, the most commonly available of which is Gulf Life Charcoal Starter F…

A type of gas chromatographic analysis wherein the column is maintained at a uniform temperature throughout the analysis. (See Programming)

(#1 Fuel Oil): Flash point generally between 100 and 150 degrees F. Explosive limits of 0.7% to 5.0%. Kerosene consists mostly of C9 through C17 hydrocarbons. In order to be identified as kerosene, a sample extract must exhibit a homologous series five consecutive normal alkanes between C9 and C17. Kerosene is the most common 'incidental' acceleran…

A type of organic compound having a carbonyl functional group (C=O) attached to two alkyl groups. Acetone is the simplest example of a ketone

A silvery metal used in some metal incendiaries. The dust is highly explosive. Ignition point of 650°F

Mass Spectrometry
A method of chemical analysis which vaporises, then ionises the substance to be analysed and then accelerates the ions through a magnetic field to separate the ions by molecular weight. Mass spectrometry can result in the exact identification of an unknown compound, and is a very powerful analytical technique, especially when combined with chromato…

Substrate. the material from which a substance of interest is removed for analysis

Meta-ethylitoluene (m-ethyltoluene)
A component of gasoline

The simplest hydrocarbon and the first member of the paraffin (alkane) series, having a formula CH4. Methane is the major constituent of natural gas. Methane has a heating value of 1009 BTU/cubic foot. Its explosive limits are 5% to 15%

Methyl alcohol. Wood alcohol. The simplest alcohol. Methanol is water soluble and has a flash point of 54°F and explosive limits of 6% to 36.5%

Methyl Silicone
A nonvolatile oily liquid used in gas chromatography to separate nonpolar compounds. Methyl silicone columns typically separate compounds according to their boiling point

A common polymer pyrolysis product

Mineral Spirits
A medium petroleum distillate ranging from C8 to C12. The flash point of mineral spirits is generally around 100°F. Mineral spirits, sometimes known as mineral turps, is commonly known as a solvent in insecticides and certain other household products. Many charcoal lighter fluids are composed almost entirely of mineral spirits

Molecular Weight
The sum of the atomic weight of all of the atoms within a molecule. Generally, molecules of the same type have higher boiling points if the molecular weight is higher

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 alike. A molecule of a compound consists of two of more different atoms

The simplest unit of a polymer. Ethylene is the smallest unit of polyethylene. Styrene is the smallest unit of polystyrene

Am ambiguous term which may mean high flash naphtha (mineral spirits), or low flash naphtha (petroleum, ether, low boiling ligroin) or something altogether different. Flash point and explosive limits vary. The term naphtha is so ambiguous that it should not be used

Natural Gas
A mixture of low-molecular weight hydrocarbons obtained in petroleum bearing regions throughout the world. Natural gas consists of approximately 85% methane, 10% ethane and the balance propanes, butanes and nitrogen. since it is nearly odourless, an odorising agent is added to most natural gas prior to final sale

To form a mist of fine droplets from a liquid. To atomise

A gaseous element which makes up approximately 80% of the earths atmosphere. Nitrogen is relatively inert and does not support either combustion or life. Nitrogen is usually found in the molecular N2 form

(1) An alkane having the formula C8H18. Flash point 56°F. Explosive limits of 1% to 3.2%. (2) A measure of the resistance of a sample of gasoline to premature ignition (knocking). 100 octane fuel has the knocking resistance of 100% iso-octane (2, 2, 4-trimethyl pentane). Zero octane fuel has the knocking resistance of a mixture of 89% iso-octane a…

An alkene. An organic compound similar to an alkane, but containing at least one double bond. Olefins have the formula CnH2n. The simplest olefin is ethylene, C2H4

Organic Chemistry
the study of the carbon atom and the compounds it forms, mainly with the 20 lightest elements, especially hydrogen, oxygen and nitrogen. Some 3 million organic compounds have been identified and named

Originally, oxidation meant a chemical reaction in which oxygen combines with another substance. The usage of the word has been broadened to include any reaction in which electrons are transferred. The substance which gains electrons is the oxidising agent

A gaseous element which makes up approximately 20% of the earths atmosphere. It is usually found in the molecular ... form. Oxygen is the most abundant element on earth

An alkane having the formula C5H12, flash point of -40°F, and explosive limits of 1.4% to 8%. Pentane is frequently used to extract flammable or combustible liquid residues from debris samples

Petroleum Distillates
By-products of the refining of crude oil. Low boiling or light petroleum distillates (LPD) are highly volatile mixtures of hydrocarbons. These mixtures are sometimes called ligroin, petroleum ether, or naphtha. LPDs are used as cigarette lighter fluid, as copier fluid, and as solvents. Medium boiling petroleum distillates (MPD) are sometimes known …

Photoionisation Detector (PID)
A type of detector used in chromatography which employs ultraviolet radiation rather than a flame to ionise compounds as they pass through a detector. Photoionisation detectors are particularly sensitive to aromatic compounds

The measure of an electrical charge on a molecule. Most flammable or combustible liquids are nonpolar. Many water soluble compounds, including alcohols and acetone, are polar

A large molecule consisting of repeating units of a monomer. Polymers may be natural, such as cellulose or synthetic such as most plastics

A method of gas chromatographic analysis which reproducibly raises the temperature of the column so as to allow better resolution of the components over a wide range of boiling points

An alkane having the formula C3H8. Propane is the major constituent of LP gas. Explosive limits of 2.4% to 9%. One cubic foot of propane has a heating value of 2500 BTUs

(1, 2, 4 - trimethyl benzene) A component of gasoline

The transformation of a substance into one or more other substances by heat alone without oxidation

Pyrophoric Distillation
The slow drying and passive pyrolysis of wood materials

(1) Transfer of heat through electromagnetic waves from hot to cold. (2) Electromagnetic waves of energy having frequency and wavelength. The shorter wavelengths (higher frequencies) are more energetic. The electromagnetic spectrum is comprised of a) cosmic rays, b) gamma rays, c) x-rays, d) ultraviolet rays, e) visible light rays, f) infrared, g) …

1) In chromatography, a measure of the separation of components, 2) in spectroscopy, a measure of the ability of the instrument to detect individual absorbance peaks

Retention Time
The length of time required for a compound of component of a mixture to pass through a chromatographic column

The state in which all available bonds of an atom are attached to other atoms. Alkanes are saturated. Olefins are unsaturated

Destruction of a surface by frost, heat, corrosion, or mechanical causes. Concrete exposed to intense heat may spall explosively. Expansion and contraction of the concrete as well as vaporising moisture contained in the concrete contribute to this effect. It does not necessarily mean an accelerant was used

A light measuring device which incorporates a monchrometer to isolate and project particular wavelengths of electromagnetic radiation through a sample, and a detector to measure the amount of radiation which has passed through the sample

An analytical technique devoted to the identification of the elements and the elucidation of atomic and molecular structure by measurement of the radiant energy absorbed or emitted by a substance in any of the wavelengths of the electromagnetic spectrum in response to excitation by an external energy source

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 combustibles present. Spontaneous ignition occurs sometimes in haystacks, coal piles, warm moist cotton waste, and in stacks …

Vinylbenzene. An aromatic compound having the formula C6H5C2H3. The monomer of polystyrene plastic. A common product of polymer pyrolysis

Matrix. The material from which a substance to be analysed is removed

A nonmetallic yellow element. A constituent of black powder, sulfur burns readily when in powdered form

Volatile hydrocarbons which are normal constituents of wood

Thermal Conductivity Detector
A type of gas chromatographic detector which is sensitive to the change in the ability of the gases emerging from the column to conduct heat. A thermal conductivity (TC) detector is not as sensitive as a flame ionisation detector, but it is capable of detecting some molecules, such as water, which give no signal in FID

Thin Layer Chromatography (TLC)
A procedure for separating compounds by spotting them on a glass plate coated with a thin (about 0.01 inch) layer of silica or alumina, and 'developing' the plate by allowing a solvent to move upward by capillary action. TLC is especially used for identifying and comparing materials which are highly coloured or which fluoresce under ultraviolet lig…

Methylbenzene. An aromatic compound having the formula C6H5CH3. A major component of gasoline. Toluene has a flash point of 40°F and explosive limits of 1.2% to 7%

1) Gum. The pitch obtained from living pine trees. A sticky viscous liquid. 2) Oil. A volatile liquid obtained by steam distillation of gum turpentine, consisting mainly of pinene and diterpene. Turpentine is frequently identified in debris samples containing burned wood

The physical change of going from a solid or a liquid into a gaseous state

Prone to rapid evaporation. Both combustible and noncombustible materials may be volatile