Application of Portable Fire Extinguishers

Given a selection of portable extinguishers, full personal protective equipment, and a controlled instructional environment, the student will be able to demonstrate the proper techniques of inspecting, selecting, and using portable extinguishers...

• Chlorine and Freon will form phosgene gas when heated by fire

• Banned from use because of health hazard

IV. Ratings of Extinguishers (1-4)

Class designations or markings

Notes: IFSTA Unit 5 S #9

• Letter indicates class of fire for which extinguisher is suited

• By color and shape

• Class A: green triangle - ordinary combustibles

• Class B: red square - flammable liquids

• Class C: blue circle - electrical equipment

• Class D: yellow star - combustible metals

• NAFED picture symbols (National Association of Fire Equipment Distributors, Inc.)

Notes: IFSTA Unit 5 S #10

• Replaced colors and shapes as the standard as of July 1, 1978

Notes: IFSTA Unit 5 S #10

• Geometric shapes of specific colors with class letters shown within the shape

• Pictographs show the types of fires you can't use it on

• NFPA 10 - Standard for Portable Fire Extinguishers

Notes: S-1-7

• Number(s) rating indicates relative effectiveness of the extinguisher and performance capability

• Rated to non-expert use

• Recognized classification rating and approval agencies

• Underwriters Laboratories, Inc. (UL)

• Underwriters Laboratories, Inc. of Canada (ULC)

• Factory Mutual (FM)

• United States Coast Guard

• Ratings

• Class A

Notes: 2A = 2 1/2 gal. of water

• Based on 13 gallons of water

• 1A - 40A (range)


• Class B

Notes: 20B = 20 sq. ft. of surface area

• Based on square foot area of flammable liquid surface

• 1B - 640B (range)


• Class C: no numerical rating - only letter rated


• Class D: no numerical rating - cannot be given a multipurpose rating for use on other classes of fire

V. Types of Extinguishers (1-5)

Notes: Prearrange with AHJ, company, or a station to have one of each of the following extinguishers on hand to go over this material with the students. Demonstrate types and simulate operation.

Pump tank extinguisher (Class A)

• Backpack type

• Operation

Notes: Have students don PPE and a pump tank to experience the weight factor. Ask if students can bring a specialized extinguisher to class for demonstration purposes.

• Carried on back with shoulder straps

• Pump is held in hands. One hand on nozzle end; the other on the handle. Handle moves back and forth with short, quick strokes

• Extinguishes by cooling and penetrating


• Advantages

• Can be immediately refilled with water by user

• Water saturates material and prevents rekindling

• The effective range is thirty to forty feet

• Non-corrosive wetting agents may be added to the water

• Intermittent use is possible


• Disadvantages

• Must be protected from freezing

• For Class A fires only

• Hazards

• Water will conduct electricity

• Water will spread fires from Class B origin


• Stirrup pump type (Class A)

• Operation

• Place tank on ground with one foot on the stirrup

• Direct nozzle with one hand and operate the pump handle up and down with the other using short, quick strokes

• Direct stream at the base of the fire and move it around to cool combustibles

• Extinguishes by cooling


• Advantages: same as for backpack type


• Disadvantages: same as for backpack type


• Hazards: same as for backpack type


• Stored pressurized water extinguisher/air-pressurized water (APW) extinguisher (Class A)

• Operation

• Check gauge

• Break the wire seal

• Indicates full charge

• Indicates correct agent

• Remove safety pin or release the latch which locks the control valve

• Hold the extinguisher by the carrying handle, with the thumb or palm resting on the valve lever

• Direct the nozzle with the other hand

• Squeeze the valve lever to operate

• Direct the stream at the base of the fire and move it around to cool the combustibles