chapter 7 ffi

Essentials of Fire Fighting6th Edition

Firefighter I

Chapter 7 — Portable Fire Extinguishers

Explain portable fire extinguisher classifications.

Learning Objective 1

7–2

Portable fire extinguishers are chosen based on the type of fuel burning.

7–3

Fuel • Textiles• Paper• Plastics• Rubber• Wood

Extinguished with:

•Water

•Water-based agents (Class A foam)

•Dry Chemicals

Class A fires involve ordinary combustibles.

7–4

Fuel • Alcohol• Gasoline• Lubricating Oils• Liquefied petroleum gas (LPG)

Extinguished with:

•Carbon Dioxide

•Dry Chemicals

•Class B Foam

7–5

Class B fires involve flammable, combustible liquids and gases.

Class C fire involves energized electrical equipment.

7–6

Treat as Class A or B once power

is off

Class D fires involve combustible metals and alloys.

7–7

CAUTION!

The use of water or water-based agents on Class D fires will cause the fire to react violently, emit bits of molten metal, and possibly injure firefighters close by.

7–8

Use dry powder, not dry chemical, extinguishers on Class D fires.

7–9

CAUTION!

Do not use a dry chemical extinguisher on Class D fire. The dry chemical often reacts violently with burning metals.

7–10

Class K fires involve combustible cooking oils.

7–11

• Vegetable or animal fats

• Burn at extreme temperatures

• Found at commercial, institutional, industrial, home

Controlled by wet chemical

systems, portable

extinguishers

REVIEW QUESTION

How are the classifications for portable fire extinguishers divided?

7–12

Describe types of portable fire extinguishers.

Learning Objective 2

7–13

Fire extinguishers are organized by type of extinguishing agent and the method used to expel their contents.

7–14

(Cont.)

Fire extinguishes are organized by type of extinguishing agent and the method used to expel their contents.

7–15

7–16

Use pump-type water extinguishers on small Class A fires, ground cover fires.

Use stored-pressure water extinguishers on small Class A fires.

7–17

Use water-mist stored-pressure extinguishers on Class C fires.

7–18

Deionized water

Normal water

Water-mist stored-pressure

Stored-pressure water

Use wet chemical stored-pressure extinguishers on Class K fires.

7–19

Potassium based, low pH

Saponification

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Use aqueous film forming foam (AFFF) extinguishers on Class B fires, small fuel spills.

7–20

Clean agent extinguishers replaced halogenated agents.

7–21C

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REVIEW QUESTION

What are the differences between wet chemical stored-pressure, aqueous film forming foam (AFFF), and clean agent extinguishers?

7–22

Carbon dioxide (CO2) extinguishers discharge as a gas and are most effective on Class B and C fires.

7–23

CO2 is stored under its own pressure and is discharged through a plastic or rubber horn.

7–24

O2

CO2

Dry ice crystals

• Smothers fire

• Little cooling effect

• Reignition possible

CAUTION!

When carbon dioxide is discharged, a static electrical charge builds up on the discharge horn. Touching the horn before the charge has dissipated can result in a shock.

7–25

Operate wheeled (CO2) extinguishers in the same manner as handhelds.

7–26

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Commonly found in airports and industrial facilities

Dry chemical extinguishers use additives to keep extinguishing agents ready for use, even after long storage periods.

7–27

Dry chemical extinguishers may react chemically with other types of extinguishing agents.

7–28

WARNING!

Never mix or contaminate dry chemicals with any other type of agent.

7–29

Dry chemical agents are considered nontoxic and safe for use.

7–30

Follow these steps when using dry chemical extinguishers on Class A fires.

7–31

Handheld dry chemical extinguishers come in two basic designs.

7–32

CAUTION!

When pressurizing a cartridge-type extinguisher, do not place your head or any other part of your body above the top of the extinguisher. If the fill cap was not properly screwed back on, the cap and/or a cloud of agent can be forcibly discharged.

7–33

Wheeled dry chemical extinguishers operate in a similar manner as handheld cartridge-types.

7–34

Agen

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Pre

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gas

Stretch out hose completely;powder can clog

Allow few seconds to pressurizeafter introducing gas

Prepare for significantnozzle reaction

CAUTION!

The top of the extinguisher should be pointed away from the operator and any other nearby personnel when pressurizing the unit.

7–35

Use dry powder extinguishers on fires for Class D metals.

7–36

Dry powder creates a smothering blanket over burning area.

7–37

CAUTION!

Water applied to a combustible metal fire results in a violent reaction that intensifies the combustion and causes bits of molten material to spatter in every direction.

7–38

Follow these steps if burning metal is on a combustible surface.

7–39

REVIEW QUESTION

How do carbon dioxide (CO2), dry chemical, and dry powder extinguishers differ?

7–40

Define the ratings in a portable fire extinguisher rating system.

Learning Objective 3

7–41

Fire extinguishers are rated according to performance capability.

7–42

(Cont.)

Fire extinguishers are rated according to performance capability.

7–43

Fire extinguishers rated for multiple classes of fire are identified by a combination of letters.

7–44

Fire extinguishers are identified by colored geometric shapes or pictographs.

7–45

REVIEW QUESTION

How are the ratings used for portable fire extinguishers determined?

7–46

Explain the considerations taken when selecting and using

portable fire extinguishers.

Learning Objective 4

7–47

Fire extinguishers are chosen to achieve two main goals.

7–48

Consider several factors when selecting the proper fire extinguisher.

7–49

Use clean agent or CO2 extinguishers in areas with computer equipment.

7–50

Dry chemicals can be

damaging

Operating procedures for all fire extinguishers are similar, but be familiar with label instructions.

7–51

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Note

Wear full structural or wildland fire fighting personal protective equipment including appropriate respiratory protection when operating any portable fire extinguisher. Even small incipient fires will produce toxic gases that can injure you.

7–52

After you select the extinguisher make a quick visual inspection.

7–53

Follow these general steps for using fire extinguishers.

7–54

(Cont.)

Follow these general steps for using fire extinguishers.

7–55

• If not extinguished after full discharge, withdraw and reassess

• If solid fuel, use appropriate tool to overhaul

• If liquid fuel, appropriate foam may be necessary

Remember the following considerations when using extinguishers.

7–56

REVIEW QUESTION

When using a portable fire extinguisher, how can you determine

the best way to use it?

7–57

Identify procedures used for the inspection, care, and

maintenance of portable fire extinguishers.

Learning Objective 5

7–58

Inspection, care, and maintenance of extinguishers are mandated by a number of organizations.

7–59

NFPA® 10 requires at least an annual inspection; local SOPs establish policy.

7–60

Follow these general procedures for every extinguisher inspection.

7–61

(Cont.)

Follow these general procedures for every extinguisher inspection.

7–62

Follow these steps if any extinguishers are found to be deficient.

7–63

Follow these general guidelines when caring for extinguishers.

7–64

(Cont.)

Follow these general guidelines when caring for extinguishers.

7–65

Clean extinguishers periodically and after every use.

7–66

Extinguishers should be removed from service for annual maintenance.

7–67

CAUTION!

Never attempt to repair the shell or cylinder of a defective fire extinguisher. Contact the manufacturer for instructions on where to have it repaired or replaced.

7–68

REVIEW QUESTION

What are the basic procedures for the care and maintenance of portable fire extinguishers?

7–69

• Portable fire extinguishers can control or extinguish small incipient or early growth stage fires quickly in the hands of trained personnel; you must be familiar with their characteristics and be able to select and use them properly.

Summary

7–70

(Cont.)

• Not only should you be familiar with their characteristics and be able to select and use them properly, you must also be able to educate the public.

• Inspecting, caring for, maintaining extinguishers assigned to your apparatus and facility are also important skills for you to have.

Summary

7–71

Operate a stored-pressure water extinguisher.

This objective is measured in Skill Sheet 7-I-1.

Learning Objective 6

7–72

Operate a dry chemical (ABC) extinguisher.

This objective is measured in Skill Sheet 7-I-2.

Learning Objective 7

7–73

Operate a carbon dioxide (CO2) extinguisher.

This objective is measured in Skill Sheet 7-I-3.

Learning Objective 8

7–74