iPedia Free Information Center

Information about Smoke

For other uses, see Smoke (disambiguation).
Enlarge picture
Smoke from a wildfire
Smoke is the airborne solid and liquid particulates and gases emitted when a material undergoes pyrolysis or combustion, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires (including stoves and lamps) and fireplaces, but may also be used for pest control (cf. fumigation), communication (smoke signals), defense (smoke-screen) or smoking (tobacco, marijuana, etc) or inhalation of other drugs. Smoke is sometimes used as a flavouring agent and preservative for various foodstuffs. Smoke is also sometimes a component of internal combustion engine exhaust gas, particularly diesel exhaust.

Smoke inhalation is the primary cause of death in victims of indoor fires. The smoke kills by a combination of thermal damage, poisoning and pulmonary irritation caused by carbon monoxide, hydrogen cyanide and other combustion products.

Smoke particles are actually an aerosol (or mist) of solid particles and liquid droplets that are close to the ideal range of sizes for Mie scattering of visible light. This effect has been likened to three-dimensional textured privacy glass—the smoke cloud does not obstruct an image, but thoroughly scrambles it.

Chemical composition

Enlarge picture
"Bling-bling": Skywriters use smoke to spell.
The composition of smoke depends on the nature of the burning fuel and the conditions of combustion.

Fires with high availability of oxygen burn in high temperature and with small amount of smoke produced; the particles are mostly composed of ash, or in large temperature differences, of condensed aerosol of water. High temperature also leads to production of nitrogen oxides. Sulfur content yields sulfur dioxide. Carbon and hydrogen get completely oxidized to carbon dioxide and water. Fires burning with lack of oxygen produce significantly wider palette of compounds, many of them toxic. Partial oxidation of carbon produces carbon monoxide, nitrogen-containing materials can yield hydrogen cyanide, ammonia, and nitrogen oxides. Content of chlorine (eg. in polyvinyl chloride) or other halogens may lead to production of eg. hydrogen chloride, phosgene, dioxin, and chloromethane, bromomethane and other halocarbons.

Pyrolysis of the burning material also results in production of large amount of hydrocarbons, both aliphatic (methane, ethane, ethylene, acetylene) and aromatic (benzene and its derivates, polycyclic aromatic hydrocarbons; eg. benzo[ayrene]], studied as a cancerogen, or retene), terpenes. Heterocyclic compounds may be also present. Heavier hydrocarbons may condense as tar.

Presence of sulfur can lead to formation of eg. hydrogen sulfide, carbonyl sulfide, sulfur dioxide, carbon disulfide, and thiols; especially thiols tend to get adsorbed on surfaces and produce lingering odor even long after the fire. Partial oxidation of the released hydrocarbons yields in a wide palette of other compounds: aldehydes (eg. formaldehyde, acrolein, and furfural), ketones, alcohols (often aromatic, eg. phenol, guaiacol, syringol, catechol, and cresols), carboxylic acids (formic acid, acetic acid, etc.).

The visible particles in such smokes are most commonly composed of carbon (soot). Other particulates may be composed of drops of condensed tar, or solid particles of ash. Content of metals yields particles of metal oxides. Particles of inorganic salts may also be formed, eg. ammonium sulfate, ammonium nitrate. Many organic compounds, typically the aromatic hydrocarbons, may be also adsorbed on the surface of the solid particles.

Smoke emissions may contain characteristic trace elements. Vanadium is present in emissions from oil fired power plants and refineries; oil plants also emit some nickel. Coal combustion produces emissions containing selenium, arsenic, chromium, cobalt, copper, and aluminium.

Some components of smoke are characteristic for the combustion source. Guaiacol and its derivates are products of pyrolysis of lignin and are characteristic for wood smoke; other markers are syringol and derivates, and other methoxy phenols. Retene, a product of pyrolysis of conifer trees, is an indicator of forest fires. Levoglucosan is a pyrolysis product of cellulose. Hardwood vs softwood smokes differ in the ratio of guaiacols/syringols. Markers for vehicle exhaust include polycyclic aromatic hydrocarbons, hopanes, steranes, and specific nitroarenes (eg. 1-nitropyrene). The ratio of hopanes and steranes to elemental carbon can be used to distinguish between emissions of gasoline and diesel engines. [1]

Dangers of smoke

Smoke from oxygen-deprived fires contains a significant amount of compounds that are flammable. A cloud of smoke, in contact with atmospheric oxygen, therefore has the potential of being ignited - either by another open flame in the area, or by its own temperature. This leads to effects like backdraft and flashover.

Many compounds of smoke from fires are highly toxic and/or irritant. The most dangerous is the carbon monoxide, leading to carbon monoxide poisoning, sometimes with supporting effect of hydrogen cyanide and phosgene. Smoke inhalation can therefore quickly lead to incapacitation and loss of consciousness.

Smoke can obscure visibility, impeding occupant exiting from fire areas. In fact, the poor visibility due to the smoke that was in the Worcester Cold Storage Warehouse fire in Worcester, Massachusetts was the exact reason why the trapped rescue firefighters couldn't evacuate the building in time. Due to the striking similarity that each floor shared, the dense smoke caused the firefighters to become disoriented.[1]

Visible and invisible particles of combustion

Depending on particle size, smoke can be visible or invisible to the naked eye. This is best illustrated when toasting bread in a toaster. As the bread heats up, the products of combustion increase in size. These particles begin as invisible but become visible if the toast is burnt.

Smoke from a typical house fire contains hundreds of different chemicals and fumes. As a result, the damage caused by the smoke can often exceed that caused by the actual heat of the fire. In addition to the physical damage caused by the smoke of a fire - which manifests in the form of stains - is the often even harder to eliminate problem of a smokey odor. Just as there are contractors that specialize in rebuilding/repairing homes that have been damaged by fire and smoke, Fabric Restoration companies specialize in restoring fabrics that have been damaged in a fire.

See also

Enlarge picture
Smoke from a bee smoker, used in beekeeping

References

1. ^ [2]

External links

Smoke is a cloud of particles suspended in the air.

Smoke may also refer to:
  • Smoke, the 44th chapter of the Qur'an
  • Smoke (song), a 1998 single by Australian singer Natalie Imbruglia
  • The Smoke, a 1960s band from York, England.

..... Click the link for more information.
Pyrolysis is the chemical decomposition of organic materials by heating in the absence of oxygen or any other reagents, except possibly steam.

It is used in chemical analysis to break down complex matter into simpler molecules for identification, for example by pyrolysis gas
..... Click the link for more information.
Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames.
..... Click the link for more information.
A by-product is a secondary or incidental product deriving from a manufacturing process, a chemical reaction or a biochemical pathway, and is not the primary product or service being produced. A by-product can be useful and marketable, or it can have severe ecological consequences.
..... Click the link for more information.
Sources:

For cooking stoves, see .
“Stove Top” redirects here. For the brand of stuffing, see Stove Top stuffing.

..... Click the link for more information.
Lamp (from Greek λαμπάς: torch) can be:
  • An oil lamp, the original use of the term.
  • A portable light fixture such as a table lamp or reading lamp (common usage)

..... Click the link for more information.
Episode no. Season 1
Episode 1
Written by –
Original airdate –

Episode chronology
← Previous Next ?
"It Came From Next Door." –

This is a disambiguation.
..... Click the link for more information.
A smoke signal is a form of optical communication used over a long distance, developed both in the Americas and in China. By covering a fire with a blanket and quickly removing it, a puff of smoke can be generated.
..... Click the link for more information.
smoke screen is a release of smoke in order to mask the movement or location of military units such as infantry, tanks or ships.

It is most commonly deployed in a canister, usually as a grenade.
..... Click the link for more information.
Editing of this page by unregistered or newly registered users is currently disabled.
If you are prevented from editing this page, and you wish to make a change, please discuss changes on the talk page, request unprotection, log in, or .
..... Click the link for more information.
Tobacco smoking is the act of burning the dried or cured leaves of the tobacco plant and inhaling the smoke for pleasure, for ritualistic or social purposes, self-medication, or simply to satisfy physical dependence.
..... Click the link for more information.
Cannabis, also known as marijuana[1] or ganja,[2] is a psychoactive product of the plant Cannabis sativa L. subsp. indica (= C. indica Lam.).
..... Click the link for more information.
Inhalation (also known as inspiration) is the movement of air from the external environment, through the airways, into the alveoli during breathing.

Inhalation begins with the onset of contraction of the diaphragm, which results in expansion of the intrapleural space
..... Click the link for more information.
A psychoactive drug or psychotropic substance is a chemical substance that acts primarily upon the central nervous system where it alters brain function, resulting in temporary changes in perception, mood, consciousness and behavior.
..... Click the link for more information.
The internal combustion engine is an engine in which the combustion of fuel and an oxidizer (typically air) occurs in a confined space called a combustion chamber. This exothermic reaction creates gases at high temperature and pressure, which are permitted to expand.
..... Click the link for more information.
Exhaust gas is flue gas which occurs as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel, fuel oil or coal. It is discharged into the atmosphere through an exhaust pipe or flue gas stack.
..... Click the link for more information.
Exhaust gas is flue gas which occurs as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel, fuel oil or coal. It is discharged into the atmosphere through an exhaust pipe or flue gas stack.
..... Click the link for more information.
Smoke inhalation is the primary cause of death in victims of indoor fires.

It is estimated that "50-80% of fire deaths are the result of smoke inhalation injuries rather than burns.
..... Click the link for more information.
Death is the permanent end of the life of a biological organism. Death may refer to the end of life as either an event or condition.[1] Many factors can cause or contribute to an organism's death, including predation, disease, habitat destruction, senescence,
..... Click the link for more information.
Fire is an oxidation process that releases energy in varying intensities in the form of light (with wavelengths also outside the visual spectrum) and heat and often creates smoke. It is commonly used to describe either a fuel in a state of combustion (e.g.
..... Click the link for more information.
poisons are substances that can cause damage, illness, or death to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism.
..... Click the link for more information.
lungs flank the heart and great vessels in the chest cavity.[1]]]

The lung is the essential respiration organ in air-breathing vertebrates, the most primitive being the lungfish.
..... Click the link for more information.
Carbon monoxide, with the chemical formula CO, is a colorless, odorless, and tasteless gas. It is the product of the incomplete combustion of carbon-containing compounds, notably in internal-combustion engines.
..... Click the link for more information.
Hydrogen cyanide is a chemical compound with chemical formula HCN. A solution of hydrogen cyanide in water is called hydrocyanic acid. Hydrogen cyanide is a colorless, very poisonous, and highly volatile liquid that boils slightly above room temperature at 26 °C (78.8 °F).
..... Click the link for more information.
Particulates, alternatively referred to as particulate matter (PM), aerosols or fine particles, are tiny particles of solid or liquid suspended in a gas. They range in size from less than 10 nanometres to more than 100 micrometres in diameter.
..... Click the link for more information.
Mist is a phenomenon of small droplets suspended in air. It can occur as part of natural weather or volcanic activity, and is common in cold air above warmer water, in exhaled air in the cold, and in a steam room of a sauna.
..... Click the link for more information.
Mie theory, also called Lorenz-Mie theory or Lorenz-Mie-Debye theory, is a complete analytical solution of Maxwell's equations for the scattering of electromagnetic radiation by spherical particles (also called Mie scattering).
..... Click the link for more information.
visible spectrum (or sometimes optical spectrum) is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light.
..... Click the link for more information.

..... Click the link for more information.
Sulfur dioxide (also sulphur dioxide) is the chemical compound with the formula SO2. This important gas is the main product from the combustion of sulfur compounds and is of significant environmental concern.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter