Fire class

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Fire class is the term used to indicate the type of fire, in relation to the fuel that has been (or may) be turned on. This has an impact on the type of suppression or suppression that can be used. Class letters are often assigned to different types of fire, but these differ across regions. There are separate standards in the United States, Europe, and Australia.

Video Fire class

Fire type

Maps Fire class

Flammable

Class A Fire consists of regular fuels such as wood, paper, cloth, and most of the waste.

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Flammable liquid and gas

It is a fire whose fuel is flammable or flammable liquid or gas. The US system sets all such fires "Class B". In the European/Australian system, flammable liquids are designated "Class B" which has a flash point of less than 100 ° C, while the combustible gas is separately defined "Class C". This fire follows the same basic fire tetrahedron (heat, fuel, oxygen, chemical reactions) as common combustible fires, except that the fuel in question is flammable liquids such as gasoline, or gases like natural gas. Solid water flow should not be used to extinguish this type because it can cause fuel to spread, spreading fire. The most effective way to extinguish liquid or gas fires is to inhibit the chemical chain reaction of the fire, carried out by dry chemicals and Halon extinguishers, even if smeared with CO ₂ or, for liquids, foams as well effective. Halon is no longer favored lately because it is an ozone depleting substance; The Montreal Protocol states that Halon should no longer be used. Chemicals such as FM-200 are now the recommended halogenation suppliers.

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Electricity

An electrical fire is a fire involving potentially energy-intensive electrical equipment. The US system sets this "Class C"; the Australian system designates them "Class E". This type of fire may be caused by short-circuit machines or overloaded power cables. These fires can be a great danger to firefighters by using water or other conductive materials, because electricity can be done from fire, through water, to the fire department, and then to the earth. Electrical shock has caused many deaths of firefighters.

Electrical fire can be fought in the same way as ordinary fires, but water, foam, and other conductive substances are not used. While the fire may or may be electrically energized, it can be fought with a fire extinguisher that is rated for an electric fire. Carbon dioxide CO ₂ , NOVEC 1230, FM-200 and dry chemical fire extinguishers such as PKP and even baking soda are perfect for extinguishing this kind of fire. PFM should be the last solution to extinguish the fire due to its corrosive tendency. Once the electricity is turned off to the equipment involved, it will usually be a common flammable fire.

In Europe, "electric fires" are no longer recognized as separate classes of fire because the electricity itself can not burn. The items around the power source can burn. By turning off the power source, the fire can be fought by one of the other firefighting classes.

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Metal

Class D Fire involves flammable metals - especially alkali metals such as lithium and potassium, alkaline earth metals such as magnesium, and group 4 elements such as titanium and zirconium.

Metal fires are a unique danger because people are often unaware of the characteristics of this fire and are not really ready to fight it. Therefore, even a small metal fire can spread and become a larger flame around the combustible material around it. Certain metals burn when in contact with air or water (eg, sodium), which exaggerates this risk. In general, the combustible metal mass does not represent the risk of large fires because the heat is carried away from the hot spots so efficiently that burning heat can not be maintained. Therefore, significant heat energy is required to ignite adjacent masses of combustible metals. In general, metal fires are a hazard when the metal is in the form of sawdust, engine shavings or "fines" of other metals, which burn faster than larger blocks. Metal fires can be ignited by the same fire source that will start another common fire.

Care should be taken when extinguishing a metal fire. Water and other common fire extinguishers can trigger a metal fire and make it worse. The National Fire Protection Association recommends that a metal fire should be carried out with a dry powder extinguishing agent that works by retaining heat and heat absorption. The most common agents are sodium chloride granules and graphite powders. In recent years, copper powder has also begun to be used. This dry powder should not be confused with those containing the dry chemical agent. Both are not the same, and only dry powder should be used to extinguish the metal fire. Using the wrong dry chemical extinguishers, in place of dry powder, may become ineffective or actually increase the intensity of the metal fire.

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Cooking oil and grease (kitchen fireplace)

Class K Fire involves unsaturated cooking oil in well-insulated cooking utensils located in commercial kitchens.

Fires involving cooking oil or fat are named "Class K" under the American system, and "Class F" under the European/Australian system. Although such fires are technically a subclass of combustible liquids/gases, the specific characteristics of these types of fires, ie higher flame points, are considered important enough to be recognized separately. The water mist can be used to extinguish such fire. The proper fire extinguishers may also have a hood on it that helps put out the fire. Sometimes fire blankets are used to stop the fire in the kitchen or on the stove.

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See also

• Fire extinguisher

References

External links

• Classification of Portable Fire Extinguishers, Occupational Safety and Health Administration
• eTool Evacuation Plans and Procedures, Occupational Health and Safety Administration
• Information on Fire Extinguishers, Fire Safety Advice Center
• For Firefighter, Wollongong Extinguisher Service-Australia

Source of the article : Wikipedia