Classes Of Fires And Types Of Extinguishers
Classes of Fires andTypes of ExtinguishersEACH CLASS of fire—A, B, C, or D—has a different source. Someprinciples apply to putting out all fires. However, certain procedures and products are used only in extinguishing specificclasses of fires. Knowing the basic skills and the materialsneeded can keep a minor fire from growing into a major one.Objectives:þ1. Identify general principles for extinguishing allfires.2. Identify the classes of fires and choose the properextinguisher for each.Key Terms:ÑClass A firesClass B firesClass C firesClass D firesGeneral Principles forExtinguishing All FiresAny one or a combination of these general principles can be used to extinguish a fire:tttCool the fire.Cut off the oxygen supply.Remove the fuel.E-unit: Classes of Fires and Types of ExtinguishersPage 1 u AgEdLibrary.comCopyright by CAERT, Inc. — Reproduction by subscription only.020037
An example of cooling a fire is spraying water on burning wood. This lowers the temperature of the wood below that at which it will burn. An example of cutting off the oxygen supplyis covering a container of burning material until all the oxygen is consumed. An example ofremoving the fuel is turning off the fuel valve on an oxy-acetylene torch. In any of the threeinstances, the fire will go out.Classes of Fires andExtinguishersNot all fires are the same. Fires are classified by the typesof materials that are burning. Extinguishers are labeled tocorrespond to the classes of fires they are designed to fight.If you use the wrong type of fire extinguisher on a fire, youcan, in fact, make matters worse. Understanding the fourdifferent fire classifications is therefore very important.Class A fires involve ordinary combustibles, likewood, paper, cloth, trash, and plastics. They do not containmetals, combustible liquids, or electricity. (Class A firesgenerally leave Ashes.)Class A fires can be extinguished with water. A Class Aextinguisher is typically either a pressurized can of waterthat can be sprayed on a fire or a container of water with apump mechanism. Class A extinguishers are for use only onClass A fires. A Class A fire extinguisher is marked with agreen triangle containing the letter A.An alternative method of extinguishing a Class A fire isto smother it with a blanket, a gloved hand, or other material.Class B fires involve flammable liquids. Typical flammable liquids are gasoline, oil, grease, paint, and acetone.Class B fires can be very difficult to control because theyinvolve burning nonmetals in a liquid state. This classification also includes flammable gases. (Class B fires generallyinvolve materials that Boil or Bubble.)Electricity is not present in Class B fires. A Class B fire isextinguished with carbon dioxide (CO2) contained in aheavy cylinder and under pressure. CO2 is very cold whenunder pressure and displaces the oxygen around the fire,causing the fire to be extinguished. It should not be sprayedon people or animals. The use of a Class B extinguisherusually results in very little mess and no damage to prop-ORDINARYCOMBUSTIBLESFIGURE 1. Class A fires.FLAMMABLELIQUIDSFIGURE 2. Class B fires.E-unit: Classes of Fires and Types of ExtinguishersPage 2 u AgEdLibrary.comCopyright by CAERT, Inc. — Reproduction by subscription only.020037
erty. However, avoid breathing CO2. Class B extinguishersmay be used to extinguish both Class A and Class B fires. AClass B fire extinguisher is marked with a red square containing the letter B.Class C fires involve electrical equipment. Thus, electricity is always present. It is often combined with combustible materials. An additional hazard of a Class C fire is thepotential for electric shock while fighting the fire. If possible, always turn off the source of electricity before fightingan electrical fire. The fire may be extinguished, but if theelectricity is not turned off, the fire may rekindle. (Class Cfires deal with electrical Current.)A Class C fire is extinguished with a dry chemical, whichdoes not conduct electricity. The chemical is a very finepowder that smothers the fire when applied. A disadvantageis the mess the chemical makes when ejected from theextinguisher. Avoid breathing dry chemical extinguisherpowder. Class C extinguishers may be used to extinguishClass A, Class B, and Class C fires. A Class C fire extinguisher is marked with a blue circle containing the letter C.Class D fires involve combustible metals. Potassium,sodium, aluminum, and magnesium burn at extremely hightemperatures. Unless you work in a laboratory or in anindustry that uses these materials, it is unlikely you’ll haveto deal with Class D fires. They are uncommon in agriculture.Burning metal is very difficult to extinguish, and onlyClass D extinguishers are recommended on burning metal.Class D fire extinguishers are not used on any other class offire. The material in a Class D extinguisher is a foam product that puts out the fire by replacing the oxygen near it.Class D fire extinguishers are the most expensive. Class Dextinguishing equipment is marked with a yellow star containing the letter D.As extinguishers progress from A to D, they becomemore expensive to use. Water is generally the cheapestmaterial for extinguishing a fire. However, water works wellon Class A fires only. Water should not be used on Class Bfires. Doing so may actually cause them to spread, as manyflammable liquid fires involve petroleum products that floaton water. Water must never be used on a Class C electricalfire, as the firefighter could be electrocuted. Water is not ofELECTRICALEQUIPMENTFIGURE 3. Class C fires.COMBUSTIBLEMETALSFIGURE 4. Class D fires.E-unit: Classes of Fires and Types of ExtinguishersPage 3 u AgEdLibrary.comCopyright by CAERT, Inc. — Reproduction by subscription only.020037
value in fighting the burning metal of Class D fires.The temperatures are generally too high for water to beeffective.Fire extinguishers are clearly marked with theclasses of fires they will extinguish safely. Some aresuitable for more than one type of fire. A common typeis the A-B-C extinguisher, which is for use in fightingClass A, B, and C fires.Put fire extinguishers close to where they might beneeded. Class A extinguishers should be located inareas where paper, wood, and other ordinary combustibles are used. Class B extinguishers should be locatedwhere flammable liquids are present. Class Cextinguishers should be placed where they would beeasily accessible for electrical fires. Extinguisherslabeled A-B-C are good for general use because theycontain a dry chemical and are effective in fightingClass A, B, or C fires.Fire extinguishers should be located in clean, dryareas that are easy to access. They should be hung sothe top is between 31/2 and 5 feet above the floor andmust be quick and easy to remove. Their locationsshould be clearly marked, and everyone familiarizedwith their locations and use.FIGURE 5. Fire extinguishers should be readilyavailable.Summary:2To extinguish any fire, lower the temperature, cut off the oxygen supply, or removethe fuel source. Fires are categorized by the type of material that is burning. Class Afires involve ordinary combustibles. Class B fires involve flammable liquids. ClassC fires involve electrical equipment. Class D fires involve combustible metals.Choose the correct type of extinguisher for the type of fire. Be sure fireextinguishers are easy to access. Know the location of fire extinguishers and how touse them.Checking Your Knowledge: 1. What kinds of burning materials can be extinguished with a Class A fire extinguisher?2. What kinds of burning materials can be extinguished with a Class B fire extinguisher?E-unit: Classes of Fires and Types of ExtinguishersPage 4 u AgEdLibrary.comCopyright by CAERT, Inc. — Reproduction by subscription only.020037
3. What type of fire can be extinguished with a Class C extinguisher?4. What are the symbols that represent the different types of fire extinguishers?5. Where should fire extinguishers be located?Expanding Your Knowledge:LVisit the local fire department to observe the types of equipment used and the typesof hand-held fire extinguishers recommended for different locations in agriculturalbusinesses. Collect a variety of fire extinguishers, both old and new, and observehow fire extinguishers have been improved.Web Links::Classes of lHow Fire Extinguishers .htmE-unit: Classes of Fires and Types of ExtinguishersPage 5 u AgEdLibrary.comCopyright by CAERT, Inc. — Reproduction by subscription only.020037
Class D fire extinguishers are not used on any other class of fire. The material in a Class D extinguisher is a foam prod-uct that puts out the fire by replacing the oxygen near it. Class D fire extinguishers are the most expensive. Class D extinguishing equipment is marked with a yellow star con-taining the letter D.
TFRS Volume 12, Issue 9/University Housing Fires (2007-2009) Page 2. Type of Fires. Building fires consist of two major categories of incidents: fires that are confined to specific types of equipment or objects (confined fires) and those that are not (noncon-fined fires). Confined building fires are small fire incidents
These include confined cooking fires, confined chimney or flue fires, confined trash fires, confined fuel burner or boiler fires, confined commercial compactor fires, and confined incinerator fires (incident type 113-118). Losses are generally minimal in these fires, which are assumed to have been limited to the object of origin.
large loss building fires were defined as fires that resulted in a total dollar loss of 1 million or more. 4. Even though large loss fires made up less than 1 percent of all building fires from 2007 to 2009, they accounted for 26 percent of all building fire dollar loss during the 3-year period. These fires, though small in number, caused a large
present in 45 percent of reported nonconfined fires in occupied hotels and motels. In 1980, the National Fire Protection Association (NFPA) estimated that 12,200 fires occurred in hotels and motels. The estimated numbers of fires in hotels and motels has sharply declined since then. Deaths and injuries resulting from these fires has also declined.
The estimated number of fires in structures under construction has increased since 2014 after declining between 2008 and 2010. Three of every four fires in structures under construction involved residential properties. Cooking equipment is the leading cause of fires on construction sites. These fires tend to be minor.
ii) Welding, cutting, soldering operations with arc or gas in u/g may result the mine fires. iii) Static or Frictional electricity, may result fires. iv) Friction of belts against pulleys produces sparks. v) Goaf fires may originate due to ignition of coal dust. 8.2.2.2 (ii) Preventive Measures of Fires:
motel fires reported to the National Fire Incident Reporting . System (NFIRS) between 2005 and 2007. continued on next page. TFRS Volume 10, Issue 4/Hotel and Motel Fires Page 2. . predominant fire incident between 7 a.m. and 10 a.m. and . again between 4 p.m. and 10 p.m. Of the hotel and motel fires that occur during these two time periods .
From 2013 to 2015, fire departments responded to an estimated 243,700 fires in one- and two-family residences each year across the nation. 1,2. These fires resulted in an annual average of 2,175 deaths; 7,575 injuries; and 5.3 billion in property loss. One- and two-family residential building fires accounted for 64 percent of all residential
