As fire is considered one with a light phenomenon (fire, flame, glow, glow, sparks ) associated combustion or Seng process that has emerged without a proper stove or him - has left to spread unchecked under its own power - unchecked. He usually leads to property, injury or damage to the environment and is therefore also known as hostile fire. The main task of the fire department is to fight such fires or damage fire.
The causes that lead to the occurrence of a fire, may be of different nature. Basically, however, the conditions of combustion must be met for the occurrence of fire.
Fire causes may be technical causes of fire, natural causes of fire and other causes of ignition sources to combustible materials, and with the latter the man plays the main role.
In the presence of a technical or natural cause of fire as in an electrical fire, it is quite possible that a criminal relevance is given on the basis of breach of duty. If the technical or natural cause of the fire set by the disregard of generally recognized technical rules, including the offense of arson (usually negligent) can be met.
A fire can arise from carelessness when handling burning objects, such as cigarettes, fireworks and candles or for technical reasons, for example due to overheating of electrical cables or camps. Also, the loss of control of friendly fire, for example, when burning of leaves or during welding may lead to fire. Through the spread of flames adjacent fire places, for example to neighboring buildings, or after an explosion (gas) fires occur as a result of impact.
Willfully or intentionally set fires are usually caused by the use of simple ignition, such as matches, lighters or candles, but often with the aid of accelerants or incendiary devices. Some substances may ignite due to ingress of oxygen by itself. Also occurring in nature ignition sources such as lightning strikes can cause a fire.
With the identification of causes of fire deals fire cause determination.
Course of fire
Starting point for a fire is the inflammation of combustible material by a source of ignition. In this first phase ( up to about 4 minutes ) results in a so-called " initial or smoldering ", whose duration depends on the oxygen concentration of the room.
In the second phase ( approximately 4 to 9 Brand minute), a local fire which heats the air in the room more and more developed. The gas concentration reaches about 3 minutes from the values that limit the capacity of people - and from the 5th minute values that are life-threatening to humans.
The room temperature exceeds the ignition temperature of the objects in the room, there is a sudden fire spread, the so -called " flash-over " (about 9 to 10 minutes ).
The now emerging temperatures can quickly reach 1000 ° C and more. According to the existing fire load and the supply of fresh air, the fire gets to this temperature level ( fully developed fire phase ) until it decays slowly.
Other possible phases or fire events are:
- The Backdraft
- The chimney effect
- The flue gas ignition
The main danger in case of fire, the toxic smoke represents the respiratory poisons contained in it (eg, carbon monoxide, Cyangase ( cyanogen, hydrocyanic acid ), and more. ) Lead after just a few breaths to unconsciousness and may cause toxic pulmonary edema. Death usually occurs by suffocation.
The high temperature is a further danger; they can quickly bring an organism to drying out or charring. Also skin burns are the result when you come into contact with the flames.
Primary is the fire damage from the destroyed by the fire belongings. But the consequential damage (secondary damage) are not to be overlooked. This includes smoke damage, water damage, environmental damage and consequential loss.
From Smoke Damage is used when, still unusable by the toxic smoke constituents objects that were not directly affected by the heat or fire.
Environmental damage is one of the first disposal of the fire debris that needs to be mitkalkuliert. Also, can cause great damage toxic firefighting water drains in public waters, such as the extinguishing water in fire Sandoz in Basel great damage in the Rhine in 1986 caused (see Swiss hall). These consequences, albeit on a smaller scale can also occur in small house fires. For this reason, there are rules for Löschwasserrückhaltung.
A loss of profits arises when a living opportunity must search for example in a house fire the injured to repair itself. With production facilities can be a total failure pull large contract losses by themselves, which can lead to final plant closure. So say American studies that never produce up to 75 percent of the companies whose production facilities are burned again. Historical Cultural goods are after a fire often irretrievably lost or damaged as the fire in the Duchess Anna Amalia Library.
Fire protection and construction
Almost every city has been plagued throughout its history of major fires. These negative experiences led over time to the preparation of the local fire protection code.
In today's time, the fire involved in the prevention of fires ( fire prevention ) and a limitation of any existing fires ( active fire protection). Meaningful structural measures include the installation of fire detectors and the installation of fire walls.
Logically are fire regulations still essential components of the building codes. The building regulations account for the structural fire protection ( by fire-resistant components) in the foreground, while technical fire protection measures (eg fire alarm systems, sprinkler systems ) play a role only in special constructions.
Are supplemented the more general building regulations (suitable for residential and office buildings) by special regulations for special installations and structures ( special buildings ). In many countries there are for restaurants, places of public assembly, retail outlets, hospitals, schools, skyscrapers, etc. own rules, in which the specific hazards and operational needs are taken into account.
For construction projects and changes of use of buildings of buildings classes 4,5 and special constructions according to model building code of the builder / architect must submit a fire protection system (fire proof ). The compatibility of the project with public building regulations must be proven so.
Classification by size
Fires can be classified according to their size. In Germany this is done according to DIN 14010 in four categories ( small fire a, b small fire, center fire, big fire ). This classification helps to take corresponding countermeasures such as alerting of emergency services of the fire department in the area of fire and disaster protection.
Every fire, if it is not arson, begins with a developing fire. This is not uncommon for a smoldering fire, caused by defects in electrical equipment, forgotten hobs, unattended candles or similar. Fires can be extinguished with a bucket of water, usually without specific extinguishing device, but they are sufficient to produce enough smoke that people be seriously jeopardized. So you should already be taken into account in a developing fire breathing protection.
Small fires are the most common fires, to which, however, need not always turn out the fire department. To delete especially a fire extinguisher or a stirrup pump is suitable. The fire department distinguishes between:
- A small fire using a small extinguisher.
- Small fire b using no more than a C- tube.
Examples of fires smaller extent, smaller car fires, grass fires or burning trash cans.
Most fires, which disengages the fire department, are means fires and can be effectively combated usually of one or more rarely two fire trucks of the fire department. According to official German definition is not more than 3 carbon pipes and no special tubes are used.
Examples of fires medium expansion are house fires, larger car fires, building fires, rail vehicle fires, smaller forest fires (without tops fire).
Large fires are rare exceptions dar. By definition, more than 3 carbon tubes or / and special pipes such as B- pipes, monitors or foam lance can be used.
To combat several trains or even associations of the fire department may be needed over a longer period. This can be supported under certain circumstances of civil protection units. The successful extinguishing the burning object can remain extremely low. In part, the assistants must confine itself to limit the spread of fire and to protect neighboring property values ( neighboring buildings, etc.). For this purpose also monitors, B- pipes, turning pipes, hydraulic shields and other large water dispensing faucets to be used. Examples of fires large extent are Tankzugbrände, tank farm fires, fires in large buildings, industrial plants and agricultural properties, but especially larger forest fires and fires in garbage dumps. In history, there were also fires that developed into full-blown " fire storms " in which entire cities or large parts burned this.
See section fire disasters;
Classification according to flammability rating and type
For a successful fire fighting a fire must be correctly detected and classified in order to make a correct choice of extinguishing agents.
In Europe, the classification is standardized and performed according to the European Standard EN 2, after the fires are divided into fire classes. The individual fire classes are designated by the letters A, B, C, D, and F.
( This includes substances that are liquid by increasing the temperature )
Background for the spin-off of the substances of Class F from the fire class B is the fact that the standard extinguishing agents for Class A, B and C are only very limited use of these substances. The use of unsuitable extinguishing agents can be connected under certain circumstances ineffective or even dangerous.
In the European standard EN2, a fire class E was provided initially. This should be used for fires in electrical low voltage equipment are ( up to 1,000 volts). However, it was rejected again, as all fire extinguishers can be used in low-voltage systems, provided the printed price on the fire extinguisher safety distance is maintained.
Causes of fire
The most common fires in Germany house fires after a power cut, where the residents have tried to make do with candles. In most cases, just fell only a candle from the table and set the carpet on fire, the second most of the fire occurs during the handling of a gas cooker. Firefighters discover after fires but often adventurous fireplace designs, in the middle of the apartment, as if the inhabitants lived in caves.
In the year 2011 312.000 power connections have been blocked in Germany according to the Federal Network Agency. As the apartments are conceptually not designed for open fire, it comes here also quick to carbon monoxide poisoning, with adverse health effects.
- Metal fire
- Tank farm fire
- Treetop fire
- Forest fires
- Ship fire
- Mine fire in a mine
In history there have been a variety of devastating fire and explosion disasters, a selection is included in the list of largest fire disasters.
Burnt offering in international comparison
Deaths by fire per 1 million population per year (as of 2003)
From the CIS, Asia and Africa are no reliable figures.