Chapter 8

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Chapter 8 Portable Fire

Extinguishers

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IntroductionPortable fire extinguishers designed

to fight:Small firesUnusual firesFires that cannot be reached quickly with

hoselinesFire extinguishers are valuable

tools.Four basic PASS stepsFire extinguishers come in a variety

of types and sizes.

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Fire Classification and RiskType of material burning defines

class of fire.Classes of fire used to identify

type of extinguishers and agentsPre-incident plan for fuel types

and locations

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Class AInvolves ordinary combustiblesCan be extinguished with:

WaterWater-based agentsFoamMultipurpose dry chemicals

Water usually the agent used

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Class BFlammable and combustible

liquids, gases, and greasesSpecial hazardsCommon extinguishing agents:

Carbon dioxideRegular and multipurpose dry

chemicalFoam

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Class CInvolves energized electrical

equipmentWater-based agents cannot be used.Turn off electrical power.Categorized with another class of

extinguisher: BC or ABCAgents include:

Carbon dioxideRegular and multipurpose dry

chemicals

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Class DCombustible metals and alloysErratic behaviourWater and other agents can react

violentlyNo universal Class D extinguisher

for all metalsClass D agents called dry powders 

Not to be confused with dry chemicals

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Class K

New classification as of 1998 Fires in combustible cooking fuelsAgents usually wet chemicalsAgents used in fixed systems

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Class K equipment.

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Types of Fire ExtinguishersFactors for selecting an

extinguisher:Type and amount of fuelPerson using extinguisherType of building construction and

occupancyType of equipment protected

Main objective extinguishing the fire

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Various types of fire extinguishers.

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Types of Extinguishing AgentsWater is the basic agent for Class A

materials.Loaded stream extinguisher Water-based foam extinguishers

Aqueous film-forming foam (AFFF) Film-forming fluoroprotein foam (FFFP) Better penetration for Class A materials Reduces surface tension of the water

Carbon dioxide Inert gas stored under pressure as a liquid

capable of being self-expelledDry chemical agents

Particles propelled by gaseous medium

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Kinds of ExtinguishersMany types:

Small and handheldLarge and require a wheeled cart

Pump-type extinguishersStored pressure extinguishersCartridge-operated

extinguishers

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(A) Older versions of fire extinguishers are labeled with colored geometrical shapes with letter

designations. (B) Newer fire extinguishers are labeled with a picture label system. (C) Many fire extinguishers can be used to fight more than one

type of fire.

(A) (B) (C)

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Inner workings of a stored pressure water extinguisher.

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Inner workings of a stored pressure dry chemical extinguisher.

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Inner workings of a carbon dioxide extinguisher with a fixed nozzle.

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Rating Systems forPortable Extinguishers

Each class of fuel subjected to a separate type of extinguisher test for its class

Conducted by independent testing agency

Appropriate ratings and symbolsClass A Class BClass C

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Class C test for electrical conductivity of agent.

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Limitations of PortableExtinguishers

Exceeding capabilitiesDesigned for specific purposesFirst-aid method for fire

extinguishmentPick the larger sizeWrong class extinguisher may not

do the job.

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Portable ExtinguisherOperation

PASS outlines four simple steps for extinguisher useP: Pull the pinA: Aim the nozzleS: Squeeze the handleS: Sweep the base of the fire

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Care and Maintenance ofPortable Extinguishers

Simple inspections and careful storage prevent most problemsMove unit from its bracket. Do hand test weight. Do visual check.

Recharging water extinguisher a simple process performed by any firefighter

238.23

(A) Unscrew and remove the top. (B) Add the manufacturer’s recommendation of water. (C)

Add foam, if required.

(A)

(B) (C)

Re-servicing an Extinguisher

248.24

(D) Replace the top. (E) Charge the extinguisher with the manufacturer’s recommendation of air.

(D) (E)

Re-servicing an Extinguisher

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Inspection RequirementsMany fire extinguishers are

obsolete.Inspection is usually a visual

inspection.If something does not look right, it

should be removed and replaced.Extinguishers returned to service

should be examined prior to their placement on apparatus.

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Lessons LearnedFire extinguishers can be used as:

Initial response toolsTo fight fires in special situations

Firefighters classify fires by their fuels.

Four-step process for using an extinguisher: PASS