6DISCUSSION QUESTIONHas anyone in the class ever used a portable fire extinguisher to extinguish a fire?
7Portable Extinguisher Discharge Mechanisms All use some form of pressure:Manual pumpStored pressurePressure cartridgeCylinder (wheeled units)
8Fire ClassificationsFire extinguishers classified & rated according to their intended useClass A fires — Involve ordinary combustiblesEasily extinguished with water, water-based agents (foam), dry chemicalsWater most common agent used by fire service(Continued)
9Fire ClassificationsClass B fires — Involve flammable/ combustible liquids, gases, greasesSpecial fire hazards; should not be extinguished until fuel gas shut offSpecial-hazard fires get larger as fuel volume increasesExtinguishing agents include carbon dioxide, dry chemical, Class B foam(Continued)
10Fire ClassificationsClass C fires — Involve Class A or B fires created by electrical energyDo not use water or water-based agents until electricity is shut offRecommended method is to turn off or disconnect electrical power before using appropriate extinguisher(Continued)
11Fire ClassificationsClass D fires — Involve combustible metals, alloysCan be identified by bright white sparks & emissions from fire processClass D, dry powder extinguishers work best(Continued)
12DISCUSSION QUESTIONWhy should water-based agents not be used on Class D fires?
13Fire Classifications Class K fires — Involve combustible cooking oils Examples are vegetable fats that burn at extremely high temperaturesMost fuels found in commercial kitchens; can also be found in private homesWet chemicals used in extinguishing systems
14Stored-Pressure Water Extinguishers Air-pressurized water extinguishers or pressurized water extinguishersUseful for all types of small Class A fires(Continued)
15Stored-Pressure Water Extinguishers Often used for extinguishing hot spotsOperationWater stored in tank w/air or nitrogenGauge shows pressurizationPressure forces water up tube, out hoseClass A foam concentrate sometimes added
16Stored-Pressure Water Extinguishers Affected by freezing weatherLoaded stream extinguishers have an anti-freeze addedNot suitable for Class C & D firesMaximum size is 2A
17Wet Chemical Stored-Pressure Extinguishers Specifically designed to control/extinguish Class K fires in deep fryersContain special potassium-based alkaline agent to cool/suppress fires in unsaturated cooking oilsCourtesy of Ansul Corp.
18Aqueous Film Forming Foam (AFFF) Extinguishers Suitable for Class A, Class B firesFires/vapors from small liquid fuel spillsDifferent from stored-pressure water extinguishersTank contains specified amount of AFFF concentrate mixed with waterAir-aspirating nozzle aerates solution(Continued)
19Aqueous Film Forming Foam (AFFF) Extinguishers Water/AFFF solution expelled by compressed air or nitrogenTo prevent disturbance of foam blanket, do not apply directly onto fuel; allow to rain onto surface/deflect off object(Continued)
20Aqueous Film Forming Foam (AFFF) Extinguishers When AFFF/water mixed, finished foam floats on fuels lighter than waterVapor seal created by film of water extinguishes flame, prevents reignition(Continued)
21Aqueous Film Forming Foam (AFFF) Extinguishers Foam has good wetting, penetrating properties on Class A fuels; ineffective on polar solventsNot suitable for fires in Class C, D fuelsNot suitable for flowing fuelsMost effective on static pools of flammable liquids
22Clean Agent Extinguishers Designed to replace halons, & use “clean agents” that discharge as rapidly evaporating liquids that leaves no residueNonconductive so can be used on Class CApproved by U.S. EPAHalon replacements work by inhibiting the chemical chain reaction
23Carbon Dioxide (CO2) Extinguishers Found as both handheld/wheeled unitsMost effective in Class B, C firesLeaves no residueHave limited reach; gas can be dispersed by wind(Continued)Courtesy of Ansul Corp.
24Carbon Dioxide (CO2) Extinguishers Carbon dioxide stored under its own pressure as liquefied gas ready for release at any timeWheeled units similar to handheld except they are biggerCourtesy of Badger Fire Protection.
25Carbon Dioxide (CO2) Extinguishers Hazards Do not touch horn during dischargeStatic electricity shockCold injuriesIn confined spaces it displaces oxygen
26Dry Chemical Extinguishers For Class A-B-C fires and/or Class B-C fires; dry powder used on Class D onlyTwo types:Cartridge operatedStored pressure(Continued)Courtesy of Ansul Corp.
27Dry Chemical Extinguishers Puts out fire by breaking chemical chain reactionTwo basic chemicals:Regular B:C-ratedMultipurpose and A:B:C-ratedCourtesy of Ansul Corp.
28Dry Chemical Extinguishers AgentCommon NamesClass of FireSodium bicarbonateRegularB&CPotassium bicarbonatePurple KPotassium chlorideSuper KMonoammonium phosphateMulti-purposeABC
29Wheeled Fire Extinguishers 3/25/2017Wheeled Fire ExtinguishersLarge units mounted on wheeled carriagesTypically contain 150 to 350 lbs of extinguishing agentIndoor use requires wide doorways & aisles6–29
30Wheeled Fire Extinguishers 3/25/2017Wheeled Fire ExtinguishersLong delivery hoses allow operators to attack fire from multiple sidesUsually pressurized by separate cylindersInstalled in special hazard areas6–30
31Controlling/Extinguishing Metal Fires Special extinguishing agents, application techniques developed to control/extinguish metal firesNo single agent controls/extinguishes fires in all combustible metalsAgent is usually a powderNote: Dry powder & dry chemical not the same thing(Continued)
32Controlling/Extinguishing Metal Fires Some powdered agents applied with portable extinguishers, others with shovel or scoopAppropriate application technique described in manufacturer’s technical sales literature(Continued)
33Controlling/Extinguishing Metal Fires Portable extinguishers for Class D come in both handheld & wheeled unitsCourtesy of Amerex Corp.(Continued)
34Controlling/Extinguishing Metal Fires Powder must be applied in sufficient depth to completely cover burning area to create smothering blanket(Continued)
35Controlling/Extinguishing Metal Fires If small amount of burning metal on combustible surface, fire should be covered with powder1 to 2 inch (25 to 50 mm) layer spread nearby, burning metal shoveled onto layerAfter extinguishment, material left undisturbed until cooled
36Portable Extinguisher Rating System Portable extinguishers classified according to types of fire they extinguishClass A, B also rated according to performance capabilitySystem based on tests by UL, ULC
37Classifications Class A — From 1-A through 40-A Class B — From 1-B through 640-BClass C — No testsClass D — Test fires varyClass K — Recognized by UL, ULC since 1996
38Classifications A Rating: Based on 1.25 gallons (5 L) of water 2A = 2.5 gallon (10 L)B Rating: Based on square foot or square meter20B = 20 sq ft (1.8 sq m)C Rating: Bases on electrical shock hazard (no shock, it’s a Class C)
39Classifications D Rating: Used for metals only, no rating Must be specific to types of metalK Rating: Used for hot cooking oil application (deep fryers)
40Multiple MarkingsExtinguishers for more than one class of fire identified by combinations of A, B, and/or C or symbols for each classMost common are A-B-C, A-B, B-CAll must be labeled appropriatelyUnlisted units should not be usedRatings for each class are independent
41Identification — Two Ways Geometric shapes of specific colors with class letter shown within shapeNFPA 10 recommended — Uses pictographs to make selection easier; shows types of fires on which extinguishers should not be used
42Classification of Fire Extinguishers 3/25/2017Classification of Fire ExtinguishersCOOKING OILSK6–42COOKING FATS
43Classification of Fire Extinguishers 3/25/2017Classification of Fire ExtinguishersRed slash across pictograph means Do Not UseUse of the fire extinguisher on this type of fire could be dangerous6–43
44Extinguisher Selection Factors Classification of burning fuelRating of extinguisherHazards to be protectedSize/intensity of fire(Continued)
45Extinguisher Selection Factors Outside conditionsAvailability of trained personnelEase of handling extinguisherLife hazard/operational concerns
46Extinguisher Selection Considerations Select those that minimize risk to life/ property & are effective in extinguishing the fire typeDry chemical extinguishers should not be selected for use in areas where highly sensitive computer equipment is located
47Extinguisher Check Immediately before use External conditionHose/nozzleWeightPressure gaugeAfter selecting size/type for situation, approach fire from upwind side
48DISCUSSION QUESTIONWhy should you always have an escape route?
49Fire Extinguisher Operation Most extinguishers operate in a similar mannerPick up extinguisher by handles, carry to point of application(Continued)
50Fire Extinguisher Operation Once in position, use PASS methodP — Pull the pinA — Aim the nozzle at the base of the fireS — Squeeze handles togetherS — Sweep nozzle back & forth(Continued)
51Fire Extinguisher Operation Be sure agent reaches fireApply agent from point where stream reaches but does not disturb fuelAfter fire knocked down, move closer for final extinguishment(Continued)
52Fire Extinguisher Operation If extinguishment not achieved after entire extinguisher discharged, withdraw/reassessIf fire is in solid fuel reduced to smoldering phase, may be overhauled using appropriate tool(Continued)
53Fire Extinguisher Operation If fire in liquid fuel, it may be necessary to apply foam through hoseline or attack with more than one extinguisherIf more than one extinguisher used, work together & maintain constant awareness
54Fire Extinguisher Inspections NFPA 10 & most fire codes require portable extinguishers inspected at least once/yearVerify that extinguishersAre in designated locationsNot tampered with or activatedNo obvious damage/other condition(Continued)
55Fire Extinguisher Inspections Servicing responsibility of property owner/building occupantFFs should include inspections in building inspection program(Continued)
56Fire Extinguisher Inspections Three factors determine usefulness of fire extinguishersServiceabilityAccessibilitySimplicity of operationNFPA 10 describes procedures for hydrostatic testing of cylinders
57Parts of Fire Extinguisher Inspections Ensure extinguisher in proper location/accessibleInspect discharge nozzleInspect extinguisher shellCheck for legible operating instructions on nameplateINACCESSIBLE(Continued)
58Parts of Fire Extinguisher Inspections Check locking pin, tamper sealDetermine whether full of agent, fully pressurizedCheck for date of previous inspectionExamine condition of hose/fittingsIf any items deficient, remove from service
59Damaged Fire Extinguishers Can fail at any time; could result in serious injuryLeaking, corroded, otherwise damaged shells/cylinders should be discarded or returned to manufacturer for repair(Continued)
60DISCUSSION QUESTIONHow should a defective fire extinguisher be repaired?
61Damaged Fire Extinguishers Only slight damage/corrosion & uncertain whether safe — Should be hydrostatically testedIf allowed by SOP, leaking hoses, gaskets, nozzles, & loose labels can be replaced by FFs
62Obsolete Portable Fire Extinguishers Since 1969Manufacturers stopped making inverting-type extinguishersAll extinguishers are carried uprightManufacturing of extinguishers made of copper or brass with cylinders soft soldered or riveted together discontinued(Continued)
63Halon Fire Extinguishers Included in Montreal ProtocolDamages the ozoneWorld stopped producing halogens at end of 1993By 2010 all halons, fixed or otherwise, are to be removed
64SummaryIn many cases, fire extinguishers can control or extinguish small fires in less time than it takes to deploy a hoseline(Continued)
65SummaryEven though portable fire extinguishers may be found in many of the homes, apartments, & businesses that must be entered to extinguish fire, FFs should only rely on those carried on the fire apparatus.(Continued)
66SummaryTo use fire extinguishers safely & effectively, FFs must know capabilities & limitations of the extinguisher — & their own capabilities & limitations — as well as the proper techniques for their application
67Skills Operate a stored pressure water extinguisher Operate a dry chemical (ABC) extinguisherOperate a carbon dioxide (CO2) extinguisherClean, service & place a portable fire extinguisher back in service. (Skill Sheet FF-I-101)Operate a dry chemical wheeled unit (Exercise 2)