Fire Classification & Extinguishers Flashcards

Which class of fire involves flammable liquids such as gasoline, oil, or paint thinner?

Answer: Class B

Class B fires involve flammable and combustible liquids, including gasoline, oil, grease, tar, oil-based paint, lacquer, and flammable gases.

A CO2 (carbon dioxide) fire extinguisher is most effective on which types of fires?

Answer: Class B and C fires (liquids and electrical)

CO2 extinguishers work by displacing oxygen and are rated for Class B (flammable liquids) and Class C (electrical) fires without leaving residue.

What does the letter 'A' rating on a fire extinguisher indicate?

Answer: The extinguisher is effective on ordinary combustibles

The 'A' classification on a fire extinguisher means it is rated for Class A fires involving ordinary combustibles such as wood, paper, cloth, and plastics.

Which extinguisher type should NEVER be used on electrical fires?

Answer: Water (stored pressure)

Water is electrically conductive and must never be used on live electrical equipment. It can cause electrocution and spread the fire.

How should a fireguard hold a portable fire extinguisher when using the PASS technique?

Answer: Aim at the base of the fire and use a side-to-side sweeping motion

PASS stands for Pull, Aim, Squeeze, Sweep. The nozzle should be aimed at the BASE of the fire and swept side to side to knock down and extinguish flames at their fuel source.

What minimum fire extinguisher rating is typically required at a hot work site under FDNY regulations?

Answer: 2-A:20-B:C

FDNY and NFPA 51B require at least a 2-A:20-B:C rated extinguisher within 30 feet of hot work operations to handle typical fire scenarios.