Question 28 of 30
Dry chemical extinguishers extinguish Class B fires to the greatest extent by:
A
Cooling fuel temperatures down below flashpoint margins
B
Displacing essential atmospheric nitrogen compounds
C
Breaking the chain reaction
D
Freezing burning vapor pools immediately
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Answer & Explanation
The correct answer is Option C: Breaking the chain reaction.
Dry chemical powders interrupt the chemical chain reaction of a fire, effectively stopping the combustion process. While they have some cooling effect, their primary extinguishing mechanism for Class B and C fires is the breaking of the chain reaction.