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Canadian fire brigade fighting the fire
Burning house in Japan

A fire is a combustion process associated with a light phenomenon ( fire , flame , embers , glow , sparks ) that has arisen unintentionally or has left its intended location in order to spread uncontrollably on its own. It usually leads to property damage, personal or environmental damage and therefore also as a destructive fire or malicious fire called. Fighting and preventing fires and providing fire protection is primarily the task of the fire brigade .


The old Germanic word mhd. , Ahd. Brant is an education for the im Nhd. lost strong verb mhd. brinnen , ahd. brinnan "burn, shine". The verb mhd. Burn , ahd. Brennan is the causative for this and has in the Nhd. the meaning of the strong verb with taken over.

Causes of fire

Consequences of arson : Fire in the north tower of the Göttingen St. Johannis Church
The high oxygen content of some organic molecules, here the wood component lignin , promotes both the rotting and the spontaneous combustion of stored wood chips and the fire of old and green wood and a rapid spread of fire.

A fire starts as soon as the prerequisites for combustion are met at the location of the fire and goes out as soon as they are no longer met. These requirements can be met in a number of ways. The cause of the fire is the process and the circumstances that lead to the fulfillment of the fire requirements.

The causes of fire can be technical causes of fire , natural causes of fire and other effects of ignition sources on flammable substances , with humans playing the main role in the latter. The cause of fire investigation deals with the determination of the causes of fire .

Not only fires that are directly caused by humans can be criminally relevant. Technically or naturally caused fires such as a cable fire or a fire after a lightning strike can be criminally relevant due to breaches of duty. If the technical or natural cause of the fire is set by disregarding generally recognized technical rules , the criminal offense of arson (mostly negligent) can also be fulfilled.

There is usually enough oxygen in the area. The fire arises, for example, from carelessness when handling burning objects such as cigarettes , fireworks and candles by bringing an ignition source together with combustible material, or the ignition source arises for technical reasons, for example due to overheating of bearings or electrical cables . Loss of control over useful fires, for example when burning leaves or welding , can also lead to a fire. When flames spread from neighboring areas of fire, for example to neighboring buildings, or after an explosion (gas), fires occur as a consequence. Ash can act as an ignition source as long as it still contains embers or has not cooled down sufficiently, which takes a long time with peat ash .

If an oxidizing agent (such as oxygen) is initially missing (as before a flue gas explosion ) , but there is already an ignition source (such as embers) on the combustible material (such as unburned smoke gases), it ignites as soon as oxygen is added. Some substances can ignite spontaneously when oxygen is exposed to them even at normal room temperature .

Willful or deliberate fires are usually caused by the use of simple ignition devices such as matches, lighters or candles, but often (especially in the case of arson attacks ) also with the aid of fire accelerators or incendiary devices .

Course of a fire

Roof apartment fire in Munich
Combustion triangle

The starting point for a fire is the ignition of flammable substances by an ignition source. In this first phase (up to approx. 4th minute) a so-called "initial or smoldering fire " occurs, the duration of which depends on the oxygen concentration in the room.

In the second phase (approx. 4th to 9th minute of fire) a local fire develops, which heats the air in the room more and more. From the 3rd minute onwards, the gas concentration reaches values ​​that limit people's ability to act - and from the 5th minute onwards, values ​​that are life-threatening for people.

If the room temperature exceeds the ignition temperature of the objects in the room, the fire spreads suddenly, the so-called " flashover " (approx. 9th to 10th minute).

The temperatures that now arise can quickly reach 1000 ° C and more. Depending on the existing fire load and the fresh air supply, the fire is maintained at this temperature level (full fire phase) until it slowly subsides.

Other possible phases or fire incidents are:

Health hazards

Major fire on a landfill

The main danger in a fire is the poisonous smoke . The breath poisons contained in it (eg carbon monoxide , cyano gases ( dicyan , hydrogen cyanide ) and much more ) lead to unconsciousness after just a few breaths and can cause toxic pulmonary edema . Most death occurs from suffocation.

Skin burns occur not only through direct contact with flames, but also through hot gases (e.g. the exhaust gas from fire) or vapors. They are very painful and can also lead to circulatory shock .

Fire damage

Consequences of a major fire: View of the destroyed roof structure

Personal injury

People can suffer various injuries as a result of heat, pressure surge or flying particles from an explosion, lack of oxygen, fumes, collapsing components, attempting to escape by jumping out of a house. Rapid and complete recovery, permanent physical or psychological damage, rapid or long-term death as a result of a fire are possible.

Property damage

Fire damage primarily consists of the belongings destroyed by the fire. But the consequential damage (secondary damage) cannot be overlooked either. This includes smoke damage, fire extinguishing water damage, environmental damage and failure damage.

We speak of smoke damage when the toxic smoke constituents make objects that were not directly affected by the heat or fire, nonetheless unusable.

First of all, environmental damage includes the disposal of the fire debris, which must be taken into account. In addition, toxic fire-fighting water runoff can cause great damage in public waters, such as the extinguishing water caused great damage in the Rhine during the Sandoz fire in Basel in 1986 (see major fire in Schweizerhalle ). These consequences, albeit on a smaller scale, can also occur in small house fires. For this reason there are rules for retention of extinguishing water .

Failure damage occurs if, for example, in the event of a house fire, the victim has to look for a place to live until it is repaired. In the case of production companies, a total failure can result in large order losses, which can lead to the final closure of the company. American studies say that up to 75 percent of companies whose production facilities have burned down never produce again. Historical cultural assets are often irretrievably lost or badly damaged after a fire, as was the case with the fire in the Duchess Anna Amalia Library .

Fire sites are often closed by the authorities after a fire, because fire substances and damaged buildings pose a risk of breathing and entry and undisturbed traces are necessary to determine the cause and damage of the fire.

Preventive fire protection and building law

Almost every city has suffered major fires throughout its history. Over time, these negative experiences led to the establishment of local and regional fire protection regulations .

Nowadays, fire protection deals with the prevention of fires ( preventive fire protection ) and the limitation of fires that have already started ( defensive fire protection ). Useful structural measures are, for example, the installation of fire alarms and the erection of fire walls .

Consequently, fire protection regulations are still an essential part of the building regulations . The building regulations focus on structural fire protection (through fire-resistant components), while technical fire protection measures (e.g. fire alarm systems , sprinkler systems ) only play a role in special structures .

The more general building regulations (suitable for residential and office buildings) are supplemented by special regulations for special systems and structures ( special structures ). Many countries have their own sets of rules for restaurants, places of assembly, sales outlets, hospitals, schools, high-rise buildings, etc., in which the special dangers and operational needs are taken into account.

In the case of construction projects and changes in use of buildings in building classes 4.5 and special structures in accordance with the model building regulations , the client / architect must submit a fire protection concept / proof of fire protection. The compatibility of the construction project with the public building regulations must be proven.


Classification according to size

Fires can be classified according to their size. In Germany, this happens in four categories according to DIN 14010 (small fire a, small fire b, medium fire, large fire). This classification helps to take appropriate countermeasures such as alerting fire brigade emergency services in the area of fire and disaster control . In Austria, this classification is only used retrospectively in order to be able to reassess future risks.

Incipient fire

Every fire, provided it is not arson , begins with an incipient fire . It is not uncommon for this to be a smoldering fire , triggered by defects in electrical devices, forgotten hotplates, unattended candles or the like. Incipient fires can usually be extinguished with a bucket of water without special extinguishing equipment , but they are sufficient to produce enough smoke that people are seriously endangered. That is why breathing protection should be worn even if a fire breaks out.

Small fire

Small fire B or medium fire
Small fire B or medium fire

Small fires are the most common fires, but the fire brigade does not always have to go out. To delete in particular a suitable fire extinguisher or a stirrup pump . The fire brigade differentiates between:

Examples of smaller-scale fires are small car fires , lawn fires or burning garbage cans .

Medium fire

Most fires on which the firefighters forth, are means fires and can usually one or rarely two fire trucks of firefighters to be tackled effectively. According to the official German definition, no more than 3 C-pipes and no special pipes (such as B-pipes , monitors or foam jet pipes ) are used.

Examples of fires medium expansion are house fires, larger vehicle fires , building fires, rail vehicle fires, small fires (without tops fire).

Major fire

Burning warehouses in Helsinki

Large fires are the exception. In Germany, a fire is considered a major fire if more than three C-pipes and / or the special pipes mentioned above are used.

Several trains or even associations of the fire brigade may be needed over a longer period of time to combat them . Under certain circumstances, these can also be supported by disaster control units. The extinguishing success on the burning object can remain extremely low. In some cases, the auxiliary workers have to limit the spread of the fire and protect neighboring property (neighboring buildings, etc.). For this purpose also be monitors , B-pipes , turning pipes , hydraulic shields and other large water discharge valves used. Examples of large-scale fires are tank truck fires, tank farm fires, fires on large objects, industrial plants and agricultural properties, but especially larger field and forest fires and fires in landfills . If such fires are particularly large, one speaks of area fires. In history there have also been fires that developed into veritable “ firestorms ” in which entire cities or large parts of them burned down.

Classification according to fire class and type

To successfully fight a fire , a fire must be correctly identified and classified in order to make the right choice of extinguishing agent .

In Europe, the classification is standardized and takes place according to the European standard EN2 , according to which the fires are divided into fire classes. The individual fire classes are designated with the letters A, B, C, D and F.

Fire class definition Examples Extinguishing agent
Fire Class A.svg Fires involving solid substances, mainly of an organic nature, which normally burn with embers Wood , coal , paper , textiles , car tires , some plastics , straw , etc. Water , aqueous solutions , foam , carbon dioxide , ABC powder
Fire Class B.svg Fires involving liquid and liquefying substances

(This also includes substances that become liquid when the temperature increases)

Gasoline , ethanol , tar , wax , many plastics , ethers , lacquers , resin , etc. Foam , ABC powder , BC powder , carbon dioxide
Fire Class C.svg Gas fires Ethyne (acetylene), hydrogen , natural gas , propane , town gas , etc. ABC powder , BC powder , ( carbon dioxide only in exceptional cases: there are seldom specially designed fire extinguishers with gas jet nozzles), cut off the gas supply by pushing off the line
Fire Class D.svg Metal fires Aluminum , magnesium , sodium , potassium , lithium , etc. and their alloys Metal fire powder (D powder), dry sand, dry gritting or cattle salt, dry cement, cast iron chips
Fire Class F.svg Burns of edible fats and oils in deep-frying and fat frying devices and other kitchen equipment and appliances (fat fire ) Edible oils and fats Special extinguishing agent (liquid extinguishing agent from fire class F hand-held fire extinguishers)

The background for the separation of the substances of class F from fire class B is the fact that the standard extinguishing agents for fire classes A, B and C can only be used to a very limited extent on these substances. The use of unsuitable extinguishing agents can under certain circumstances be ineffective or even be dangerous.

Fire class E was initially provided in the European standard EN2 . This should apply to fires in electrical low-voltage systems (up to 1,000 volts). However, it was discarded again because all fire extinguishers can be used in low-voltage systems, provided the safety distance printed on the fire extinguisher is observed.

Place of fire

In nature, earth fires , for example coal fire or peat fire , as well as vegetation fires such as field fire and forest fire occur. A mine fire develops in a mine. City fires , chimney fires and tank farm fires can occur in settlements and in trade, craft and industry facilities . Vehicles burn, for example, in a vehicle fire and a ship fire . Depending on the local area, the different fires can act as a mutual ignition source: For example, a coal fire can trigger a ground fire and vice versa.

Fire disasters

Hamburg fire in 1842

There have been a multitude of devastating fire and explosion disasters throughout history , a selection is included in the list of the largest fire disasters .

International comparison of burnt victims

Fire deaths per 1 million inhabitants per year (as of 2003)

country Dead ( ppm )
Denmark 16
United States 14th
Norway 13
Canada 12
Ireland 11
Sweden 11
France 10
Great Britain 9
Australia 7th
Germany 7th
Netherlands 7th
Austria 6th
Switzerland 5

No reliable figures are available from the Eastern European countries, Asia or Africa.

See also

Web links

Wiktionary: Brand  - explanations of meanings, word origins, synonyms, translations
Commons : fire  - collection of pictures, videos and audio files
Wikiquote: Fire  - Quotes

Individual evidence

  1. ^ The dictionary of origin (=  Der Duden in twelve volumes . Volume 7 ). 5th edition. Dudenverlag, Berlin 2014 ( pp. 184 , 186 ). See also DWDS ( "Brand" ) and Friedrich Kluge : Etymological Dictionary of the German Language . 7th edition. Trübner, Strasbourg 1910 ( pp. 67 , 70 ).
  2. Two injured people in a fire at the shooting range, February 1, 2018, accessed on February 1, 2018. - Fire in a shooting channel, Desselbrunn, Upper Austria. Blocked by the mayor. Picture 24/24.
  3. ^ Franz-Josef Sehr : The fire extinguishing system in Obertiefenbach from earlier times . In: Yearbook for the Limburg-Weilburg district 1994 . The district committee of the Limburg-Weilburg district, Limburg-Weilburg 1993, p. 151-153 .
  4. DIN 14010-2005-10 (D): Information on the statistical recording of fires
  5. Classification of fire operations in the incident report on the website of the Gänserndorfer district fire brigade, accessed on April 5, 2017
  6. ^ Statistics from the World Fire Statistics Center (WFSC); Table 4 (PDF file; 0.1 MB) ( Memento from November 22, 2008 in the Internet Archive )