FE Extinguishing Agent Properties & Chemistry

Question 1

What is the primary extinguishing mechanism of ABC dry chemical agents such as monoammonium phosphate?

Accepted Answer

Interrupting the chemical chain reaction of combustion

Answer

ABC dry chemical agents interrupt the free-radical chain reaction in the flame, which is the primary mechanism by which they extinguish fires.

Question 2

Which extinguishing agent is electrically non-conductive and leaves virtually no residue after discharge?

Accepted Answer

Carbon dioxide (CO2)

Answer

Carbon dioxide (CO2) is electrically non-conductive and dissipates completely as a gas, leaving no residue on equipment or surfaces.

Question 3

Purple-K dry chemical extinguishing agent contains which primary chemical compound?

Accepted Answer

Potassium bicarbonate

Answer

Purple-K is a potassium bicarbonate-based dry chemical agent, which is approximately twice as effective as sodium bicarbonate on Class B fires.

Question 4

Carbon dioxide (CO2) extinguishes fires primarily by which two mechanisms?

Accepted Answer

Oxygen displacement and cooling

Answer

CO2 extinguishes fire by displacing oxygen (smothering) and by absorbing heat energy, providing a cooling effect on the burning material.

Question 5

Halon 1211 (bromochlorodifluoromethane) is classified as what type of extinguishing agent?

Accepted Answer

Halogenated agent

Answer

Halon 1211 is a halogenated (halocarbon) agent that extinguishes fire by chemically interrupting the combustion chain reaction.

(FE) Certified Portable Fire Extinguisher Technician Practice Test