Portable Fire Extinguishers

Question 1

How do the 4 agents in extinguishers, extinguish fire?

Answer 1

• Smothering (oxygen exclusion)
• Cooling (reducing burning material below it’s ignition temperature)
• Chain breaking (interrupting the chemical chain reaction)
• Saponification (forming an oxygen-excluded soapy foam)

Question 2

In what 3 ways can a fire extinguisher expel its agents?

Answer 2

Manual pump
Stored pressure
Pressure cartridge

Question 3

What are the 5 classifications of Fire?

Answer 3

1. Class A (ordinary combustibles, paper, wood, plastic)
2. Class B (combustible liquids and gases, oil, gas, alcohol)
3. Class C (electrical energy)
4. Class D (combustible metals, magnesium, alloy, potassium)
5. Class K (combustible cooking oils)

Question 4

What are pump-type extinguishers used for?

Answer 4

Small class A fires (ordinary materials).

Question 5

What are stored-pressure water extinguishers used for?

Answer 5

Small class A fires (ordinary materials).

Question 6

What are water mist stored pressure extinguishers used for?

Answer 6

Class A (ordinary materials), Class C (energized electrical equipment)

Question 7

When are wet chemical stored-pressure extinguishers used?

Answer 7

Class K (specifically deep fryers)

Question 8

What are aqueous film forming foam extinguishers used for?

Answer 8

Class A (ordinary materials) and Class B (combustible liquids and gases).

Question 9

What are clean agent extinguishers used for?

Answer 9

Class A, B, and C

Question 10

What are carbon dioxide extinguishers used for?

Answer 10

Most effective on Class B and C fires.

Question 11

What are dry chemical extinguishers used for?

Answer 11

Class A-B-C fires

Question 12

What are dry powder agent extinguishers used for?

Answer 12

Class D

Question 13

How do carbon dioxide CO2 portable fire extinguishers work?

Answer 13

CO2 mixed with dry ice displaces available oxygen and smothers fire.

Question 14

What are the three most common combinations for fire extinguishers with multiple markings?

Answer 14

Class A-B-C

Class A-B

Class B-C

Question 15

List 3 factors that affect the selection of the proper portable fire extinguisher. (8 listed)

Answer 15

• Classification of the burning fuel
• Rating of the extinguisher
• Hazard to be protected
• Size and intensity of the fire
• Atmospheric conditions
• Any life hazard or operational concerns
• Ease of handling the extinguisher
• Availability of trained personnel

Question 16

What should be checked immediately before using a fire extinguisher?

Answer 16

• External condition(no damage)
• Hose/nozzle (in place)
• Weight(feels like it contains agent)
• Pressure gauge(in operable range)

Question 17

What is the PASS method of using a fire extinguisher?

Answer 17

Pull pin
Aim
Squeeze
Sweep

Question 18

What procedures should be part of every fire extinguishers inspection? (8)

Answer 18

1. Proper location and accessible.
2. Inspect discharge nozzle.
3. Inspect external shell.
4. Operating instructions are legible.
5. Check lock pin and tamper seal.
6. Check to make sure agent is full (pressure gauge, weighing, or visually).
7. Check inspection tag for previous maintenance date.
8. Hose condition and it’s fittings.