Fire accelerant
Encyclopedia
In fire protection
, an accelerant is any substance or mixture that "accelerates" the development of fire
. Accelerants are often used to commit arson
, and some accelerants may cause an explosion
. Some fire investigators use the term "accelerant" to mean any substance that initiates and promotes a fire without implying intent or malice.
A fire is a self sustaining, exothermic
oxidation reaction that emits heat and light. When a fire is accelerated, it can produce more heat, consume the reactants more quickly, burn at a higher temperature, and increase the spread of the fire. An accelerated fire is said to have a higher "heat release rate," meaning it burns more quickly.
known as accelerant detection canines trained to smell ignitable liquids. The dog can pinpoint areas for the investigator to collect samples. Fire debris submitted to forensic laboratories employ sensitive analytical instruments with GC-MS
capabilities for forensic chemical analysis
.
-based fuel
s, sometimes referred to as petroleum
distilates
: gasoline
, diesel fuel, kerosene
, turpentine
, butane
, and various other flammable solvent
s. These acclerants are also known as ignitable liquids. Ignitable liquids can leave behind tell-tale marks in the fire debris. These irregular burn patterns can indicate the presence of an ignitable liquid in a fire.
The properties of some ignitable liquids make them dangerous accelerants. Many ignitable liquids have high vapor pressure
s, low flash point
s and a relatively wide range between their upper and lower explosive limit. This allows ignitable liquids to ignite
easily, and when mixed in a proper air-fuel ratio
, readily explode. Many arsonists who use generous amounts of gasoline have been seriously burned or killed igniting their fire.
. Whether available combustible materials constitute an accelerant depends on the intent of the person responsible for their use.
Sales of certain accelerants are limited to the particular group allowed to purchase them for trainings and fire demolitions (to train new firefighters).
Fire protection
Fire protection is the study and practice of mitigating the unwanted effects of fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of...
, an accelerant is any substance or mixture that "accelerates" the development of fire
Fire
Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....
. Accelerants are often used to commit arson
Arson
Arson is the crime of intentionally or maliciously setting fire to structures or wildland areas. It may be distinguished from other causes such as spontaneous combustion and natural wildfires...
, and some accelerants may cause an explosion
Explosion
An explosion is a rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. An explosion creates a shock wave. If the shock wave is a supersonic detonation, then the source of the blast is called a "high explosive"...
. Some fire investigators use the term "accelerant" to mean any substance that initiates and promotes a fire without implying intent or malice.
A fire is a self sustaining, exothermic
Exothermic reaction
An exothermic reaction is a chemical reaction that releases energy in the form of light or heat. It is the opposite of an endothermic reaction. Expressed in a chemical equation:-Overview:...
oxidation reaction that emits heat and light. When a fire is accelerated, it can produce more heat, consume the reactants more quickly, burn at a higher temperature, and increase the spread of the fire. An accelerated fire is said to have a higher "heat release rate," meaning it burns more quickly.
Fire investigation
Indicators of an incendiary fire or arson can lead fire investigators to look for the presence of accelerants in fire debris. Accelerants can leave behind evidence of their presence and use. Accelerants present in areas they should not be can indicate an incendiary fire or arson. Investigators often use special dogsPolice dog
A police dog, often referred to as a "K-9 dog" in some areas , is a dog that is trained specifically to assist police and other law-enforcement personnel in their work...
known as accelerant detection canines trained to smell ignitable liquids. The dog can pinpoint areas for the investigator to collect samples. Fire debris submitted to forensic laboratories employ sensitive analytical instruments with GC-MS
Gas chromatography-mass spectrometry
Gas chromatography–mass spectrometry is a method that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC-MS include drug detection, fire investigation, environmental analysis, explosives investigation,...
capabilities for forensic chemical analysis
Forensic chemistry
Forensic chemistry is the application of chemistry to law enforcement or the failure of products or processes. Many different analytical methods may be used to reveal what chemical changes occurred during an incident, and so help reconstruct the sequence of events...
.
Types of accelerants
Many accelerants are hydrocarbonHydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
-based fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...
s, sometimes referred to as petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
distilates
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
: gasoline
Gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
, diesel fuel, kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
, turpentine
Turpentine
Turpentine is a fluid obtained by the distillation of resin obtained from trees, mainly pine trees. It is composed of terpenes, mainly the monoterpenes alpha-pinene and beta-pinene...
, butane
Butane
Butane is a gas with the formula C4H10 that is an alkane with four carbon atoms. The term may refer to any of two structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, butane refers only to the unbranched n-butane isomer; the other one being called "methylpropane" or...
, and various other flammable solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
s. These acclerants are also known as ignitable liquids. Ignitable liquids can leave behind tell-tale marks in the fire debris. These irregular burn patterns can indicate the presence of an ignitable liquid in a fire.
The properties of some ignitable liquids make them dangerous accelerants. Many ignitable liquids have high vapor pressure
Vapor pressure
Vapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system. All liquids have a tendency to evaporate, and some solids can sublimate into a gaseous form...
s, low flash point
Flash point
The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source...
s and a relatively wide range between their upper and lower explosive limit. This allows ignitable liquids to ignite
Ignite
Ignite is a program for gifted and talented young people in South Australia, created in 1998 and formerly known as SHIP . It is administered by the South Australian Department of Education and Children's Services....
easily, and when mixed in a proper air-fuel ratio
Air-fuel ratio
Air–fuel ratio is the mass ratio of air to fuel present in an internal combustion engine. If exactly enough air is provided to completely burn all of the fuel, the ratio is known as the stoichiometric mixture, often abbreviated to stoich...
, readily explode. Many arsonists who use generous amounts of gasoline have been seriously burned or killed igniting their fire.
Available combustibles
Common household items and objects can accelerate a fire. Wicker and foam have high surface to mass ratios and favorable chemical compositions and thus burn easily and readily. Arsonists who use large amounts of available combustible material rather than ignitable liquids try to avoid detection. Using large fuel loads can increase the rate of fire growth as well as spread the fire over a larger area, thus increasing the amount of fire damage. Inappropriate amounts and types of fuel in a particular area can indicate arsonArson
Arson is the crime of intentionally or maliciously setting fire to structures or wildland areas. It may be distinguished from other causes such as spontaneous combustion and natural wildfires...
. Whether available combustible materials constitute an accelerant depends on the intent of the person responsible for their use.
Sales of certain accelerants are limited to the particular group allowed to purchase them for trainings and fire demolitions (to train new firefighters).