A fire extinguisher is a portable small extinguisher with a total weight of a maximum of 20 kilograms. It is used to extinguish small and incipient fires and contains extinguishing agents that are ejected through stored pressure or pressure generated during commissioning.
Development history of fire extinguishers
The Philipps Fire-Annihilator, patented by WH Philipps around 1850, and the Bauer'sche Fire-Annihilator at the end of the 19th century are among the historical forerunners . The latter weighed 7 kg when empty, 35 kg filled with a fire extinguishing compound dissolved in water.
Another early predecessor of the fire extinguisher was invented by the Englishman George William Manby . The Minimax company founder Wilhelm Graaff (1872–1931) patented the first mass-produced fire extinguisher with the " pointed cone " and brought it onto the market in December 1902. The centrifugal dry fire extinguisher had no pressure vessels; the powder was applied to the fire by spinning the container.
The "Internationale Feuerlösch-Gesellschaft mbH" (later TOTAL Feuerschutz GmbH ) presented the first "quick dry fire extinguisher" in Berlin in 1912. This extinguishing device was patented in 1912 by the imperial patent office under the patent number "277836 vz B. 1912 compressed gas fire extinguisher with an extinguishing gas used as a pressure medium". It can be seen as the forerunner of all modern, mobile fire extinguishers and thus revolutionized fire fighting.
The Komet process for the production of extinguishing foam , patented by Clemens Wagner in 1932 , was further developed by Total.
Carbon tetrachloride in the fire extinguisher
The liquid, low-reaction carbon tetrachloride (CCl 4 , also known as tetrachloromethane) was filled into pressureless hand pumps made of brass or chrome at the beginning of the 20th century . When the fireplace was sprayed, the carbon tetrachloride evaporated and produced an oxygen-displacing gas cloud. Until the 1950s, the fire extinguisher with carbon tetrachloride was used for liquid and electrical fires, until harmful effects on the nervous system and internal organs were found.
Standard EN 3
|European Standard||EN 3-1… 10|
|National standards||DIN EN 3 (replaces: DIN 14406: 1–3), ÖNORM EN 3 (from 2006–07: part 7, 8, 10), SN EN 3|
|Regulates||Portable fire extinguishers|
|Brief description||Part 1: Designation, functional duration, test objects
Part 2, 3, 5: Testing, execution
Part 4: Fill quantities, minimum requirements
Part 6: Confirmation of conformity
Parts 7, 8, 9: Properties & requirements
Part 10: Confirmation of conformity
- The main difference to the previous approval is the assignment and testing of the extinguishing capacity of each fire extinguisher on the basis of test objects (extinguishing objects, standard fires ) instead of the fill quantity.
- In January 2005 (DIN) and December 2004 (ÖNORM) the newly created fire class F made a revision necessary. In addition, there is no longer a pictogram for electronic fires (fire class E).
- Chemical pressure generation is no longer provided for in the current standard, see this section .
- The use of code letters is also no longer provided, see this section . However, it is still partly used internally to categorize the fire extinguisher types.
Fire extinguishers according to the previous standard DIN 14406-1… 3 will continue to be approved in Germany.
Fire classes and extinguishing capacity
The extinguishing agents used in a fire extinguisher are suitable due to their extinguishing effect for certain types of fires, which are divided into fire classes.
The fire classes for which a fire extinguisher is suitable are indicated on each fire extinguisher and depicted with pictograms and abbreviated with the letters A, B, C, D and F. The colloquial name is often derived from the suitability of a fire extinguisher for certain fire classes, for example an ABC extinguisher is suitable for fire classes A, B and C.
The assignment and testing of the extinguishing capacity of each fire extinguisher is regulated on the basis of test objects of different sizes (extinguishing objects). The largest test object that can still be extinguished with the fire extinguisher defines its maximum extinguishing capacity (rating). Since this can differ depending on the type of fire of the test object, it is determined separately for each fire class by means of a standardized test fire .
The test objects are graded as follows: In the event of a fire, the
- Fire class A : 5A, 8A, 13A, 21A, 27A, 34A, 43A, 55A
- Fire class B : 21B, 34B, 55B, 70B, 89B, 113B, 144B, 183B, 233B
- Fire class C : It is only checked whether the fire extinguisher extinguishes burning gas that escapes at the end of a pipe.
- Fire class D : An aluminum / magnesium fire and a sodium fire are tested
- Fire class F : 5F, 25F, 40F and 75F. Example: An extinguisher has a rating of 40F, ie: extinguishing capacity for 40 liters of burning cooking oil
- Fire class E : Fire class E , which was intended for fires in electrical low-voltage systems (up to 1000 volts), has been abolished . All current fire extinguishers can be used in low-voltage systems, provided that the safety distance printed on the fire extinguisher is observed.
Fire extinguishers according to DIN EN3 are mandatory in the commercial sector. Since the extinguishing services cannot be added, there is an auxiliary quantity extinguishing agent units. This makes it easy to determine the need for fire extinguishers for commercial purposes. For example, 9 extinguishing agent units correspond to a rating of 27A in fire class A and 144B in fire class B.
Marking on fire extinguishers
According to EN 3-7, fire extinguishers have five writing fields:
- The word fire extinguisher, the capacity, type of extinguishing agent and its extinguishing capacity.
- The operating instructions in writing and as a pictogram , as well as the fire classes for which the fire extinguisher is suitable.
- A warning for use in electrical systems.
- The description of the extinguishing agent, the propellant, the functional area, number of approval and type designation.
- Information about the manufacturer.
According to the architecture of the pressure generation, one differentiates between the following types of fire extinguishers:
Charging extinguishers consist of two containers (extinguishing agent container and propellant gas container), so the extinguishing agent and propellant gas are separate. Principle: If a connection is established between the two containers, for example by opening the valve on the propellant gas container, the propellant (propellant gas, e.g. carbon dioxide ) flows into the extinguishing agent container and pressurizes it. It is said that the charging extinguisher is “charged” - it is now ready to expel the extinguishing agent. A distinction is made between charging extinguishers with a propellant gas bottle attached outside or inside (in the extinguishing agent container). Charging extinguishers with extinguishing foam exist both as a premixed solution or as a cartridge with foam concentrate. Charging extinguishers have a service life of up to 25 years (regular maintenance required). In addition, they are said to be more reliable than permanent pressure extinguishers. The acquisition costs are a little higher, but the fire extinguisher is easier to maintain, which in turn reduces maintenance costs.
Permanent pressure extinguisher
In the case of permanent pressure extinguishers, the extinguishing agent and propellant gas are together in an extinguishing agent container. Principle: the propellant gas ( nitrogen or carbon dioxide ) contained in the extinguishing agent container exerts constant (permanent) pressure on the extinguishing agent. After actuating the release device, e.g. B. a switch lever valve, the extinguishing agent rises under pressure via the riser pipe and exits the fire extinguisher via the extinguishing hose through the extinguishing nozzle. The operating pressure for permanent pressure extinguishers is 15 bar.
The advantage of this design is the low technical effort, which is why these extinguishers belong to the inexpensive standard class. The disadvantage is that the extinguishing agent container is constantly under pressure (thus subject to pressure container legislation). This means that there is a risk that the propellant gas will escape unnoticed due to minor leaks in the extinguisher (so-called creeping gases) and the extinguisher will become inoperable. Likewise, the life expectancy is around 20 years (assuming regular maintenance) and, due to the technology used, maintenance costs are slightly higher than for rechargeable extinguishers.
Another possibility of pressure storage are so-called "gas extinguishers", in which the extinguishing agent ( carbon dioxide , CO 2 ) is also the propellant.
Chemical pressure generation (obsolete)
Extinguishers with chemical pressure generation are no longer provided for in the current EN 3 standard and should now be taken out of service everywhere. In the past, chemical pressure generation was mainly used for water and foam extinguishers: alkaline salts were dissolved in the extinguishing agent; To start up, an acid ampoule was smashed with a push button - the subsequent chemical acid-base reaction led to the formation of carbon dioxide , which acted as a propellant.
The following abbreviations for pressure generation are no longer prescribed in EN 3. They can therefore no longer be found on newer fire extinguishers and therefore only have historical significance:
- Code letter C : Chemical pressure generation during commissioning
- Code letter H : Charging extinguisher, a separate propellant container puts the extinguishing agent container under pressure during commissioning. The propellant container can either be attached outside of the extinguishing agent container and thus more easily recognizable as such, or inside, where it is usually only recognized by the name.
- Code letter L : permanent pressure extinguisher, the extinguishing agent container is constantly under pressure. Due to their design, they are cheaper.
Suitability of fire extinguishers
|Extinguishing agent||Code letter 4||Solids||liquids||Gases 5||Metals||Edible fat|
|Metal fire powder||PM|
|Carbon dioxide CO 2||K||2|
|Grease fire extinguishing agent||F.||/ 6||2|
Duration of function
The duration of the extinguishing agent discharge is often estimated to be unrealistically high. Due to the limited amount of extinguishing agent and at the same time a high emission rate, only very short times can be expected.
According to DIN EN 3, it is not the amount of extinguishing agent but the so-called extinguishing capacity that is decisive for the classification of a fire extinguisher. However, the amount of extinguishing agent has an impact on the service life of a fire extinguisher.
The duration of the function is the time in which the extinguishing agent continuously exits with the interruption device fully open.
|Capacity||Carbon dioxide extinguisher||Powder extinguisher||Water and foam extinguishers||Water mist extinguisher|
Fire extinguishers in traffic
Fire extinguishers are required for the transport of dangerous goods and buses , and in some countries such as Belgium or Greece also for cars. These are not mandatory for trucks , but it is advisable to have at least a 6 kg extinguisher. In France, however, fire extinguishers are mandatory for trucks: tractor 2 kg 8A 34 B, semi-trailer 6 kg 21A 113B.
At least a 2 kg extinguisher should be carried in cars , as an inexperienced person can hardly achieve an extinguishing success with a smaller filling quantity. The fire extinguisher should be stored within reach (e.g. under the passenger seat), as restricted access (e.g. in the trunk) delays the start of use and the fire can spread further.
Fire extinguishers in rail transport
In Germany, fire extinguishers must be provided in locomotives and passenger coaches that meet the requirements for electrical systems and are operational at least from −20 ° C. In most cases, 6 liter foam or water extinguishers are used.
In Denmark a carbon dioxide extinguisher must be carried in the locomotive, in Austria a foam extinguisher and in Italy a powder extinguisher.
Fire extinguishers in aviation
Despite the ecological concern, halon extinguishers are still carried in airplanes because of their good extinguishing effect , whereby the extinguishing agent halon is increasingly being replaced by alternative fire extinguishers, which, however, primarily relates to the aircraft cabin. However, Halon is still often used as an extinguishing agent for engines, auxiliary generators ( APU , mostly in the rear of the aircraft) and the cargo holds and waste containers in the on-board toilets.
In the event of an aircraft fire (e.g. in the cabin ), one must always remember to extinguish the fire very specifically, as the extinguishing time of a 6 kg extinguisher is only about 20 seconds until it is completely emptied. Even smaller extinguishing agent containers are often carried in small aircraft.
In aircraft, sources of fire are ideally extinguished from an extinguishing distance of around 70-100 cm. In the case of airplanes, it should be noted that after the use of CO 2 extinguishers, dizziness can occur after exposure times of 30 seconds (assumed concentration: 10%), which can impair safe further flight.
Fire extinguishers in workplaces
The basis of calculation for the equipment with fire extinguishers depending on the fire hazard are the extinguishing agent units (LE). They were introduced in order to be able to compare the different extinguishing effects ( classification number ) of different extinguishers (water, foam, powder, carbon dioxide). A fire extinguisher can have up to 15 LE. A wall hydrant corresponds to 27 LE, however, according to the workplace directive ASR A2.2, a maximum of one third of the required extinguishing agent units may be provided by wall hydrants.
In Germany , the basis for the calculation method is the workplace directive ASR A2.2 and the German version of the European standard DIN EN 3. According to the workplace directive, it is mandatory to provide fire extinguishers and to mark them with the fire protection symbol for fire extinguishers in accordance with DIN EN ISO 7010 . Based on the professional association rule BGR 133 , the output result is optimized with regard to the extinguishing agent units without affecting the regulations made by the workplace directive ASR A2.2 and DIN EN 3.
In Austria - in addition to the above standards - the TRVB F 124 is decisive.
Maintenance / testing
For the maintenance of a fire extinguisher there is the DIN 14406-4 in Germany , in Austria the ÖNORM F-1053 inspection and maintenance (11/2004) and (primarily) the maintenance instructions issued by the manufacturer. In Austria, people or companies who maintain fire extinguishers must be certified by TÜV Austria every four years .
Since January 2008, it has been mandatory for fire extinguisher operators in Germany to also have them checked by a person who has been trained in accordance with TRBS 1203/2 and who is qualified to inspect them in accordance with the Industrial Safety Ordinance .
According to these standards, a fire extinguisher must be checked for function no later than two years (special regulations must be observed).
The main purpose of maintenance is:
- the proper functioning of the fire extinguisher
- the safety of the user of a fire extinguisher (high pressures are used)
After proper maintenance, the fire extinguisher receives a maintenance certificate.
Triggered fire extinguishers must be handed over to appropriate specialist companies to restore operational readiness.
Other extinguishing agents and systems
- Lower Austrian Civil Protection Association: First Extinguishing Aid - Clear overview
- Fire extinguisher calculator for workplaces in Germany
- Fire extinguishers from an (Austrian) legal point of view in the blue light 01/2015
- Keepers of the Flame: The Role of Fire in American Culture, 1775-1925 . Princeton University Press, 2014, ISBN 978-1-4008-6299-3 , pp. 110 ( books.google.de ).
- Donau-Zeitung Passau: 1852.1 / 6 . Donau-Zeitung, 1852 ( books.google.de ).
- Universal lexicon of the present and past or the latest encyclopedic dictionary of the sciences, arts and crafts: Phenylamine - Sieboldia . Pierer, 1853, p. 4 ( books.google.de ).
- Siegfried Bauer's Feuer-Annihilator, in: Zeitschrift für Instrumentenbau 1883-84, p. 203 (digitized version of the Bavarian State Library)
- 'Extinguishing foam then and now' Feuerwehr-Magazin special issue 2006 "Fire fighting with foam", page 9
- Nuremberg Fire Brigade Museum . In: https://www.nuernberg.de .
- Ordinance on the prohibition of certain halogenated hydrocarbons that deplete the ozone layer ( Memento of March 5, 2016 in the Internet Archive )
- Telesto Deutschland GmbH: Telesto fog in the mobile fire extinguisher ( Memento from February 8, 2015 in the Internet Archive )
- Federal Railway Office: Fire Extinguishers ( Memento from July 7, 2016 in the Internet Archive )
- Institute for land and sea traffic: Operating systems of electric railways - barriers for international rail traffic
- Technical rules for workplaces Measures against fires .
- Tests according to BetrSichV on portable fire extinguishers accessed on February 7, 2013