Portable Fire Extinguishers Flashcards

What is the primary advantage of a CO2 fire extinguisher over a dry chemical extinguisher when used on energized electrical equipment?

Answer: CO2 leaves no residue that could damage sensitive equipment

CO2 discharges as a gas and leaves no residue, making it ideal for energized electrical equipment and sensitive electronics.

A wet chemical (Class K) fire extinguisher is specifically designed for use in:

Answer: Commercial cooking operations with vegetable or animal oils

Wet chemical extinguishers create a soapy foam that cools cooking oils and seals the surface, preventing re-ignition — making them essential for commercial kitchens.

Which type of portable fire extinguisher is most appropriate for a Class D (combustible metal) fire?

Answer: Specialized dry powder agent designed for the specific metal

Class D fires involving combustible metals like magnesium or sodium require specialized dry powder agents; water and CO2 can intensify these fires.

An extinguisher labeled '2-A:10-B:C' — what does the '2-A' rating indicate?

Answer: It is equivalent to approximately 2.5 gallons of water on Class A fires

The numerical prefix in a Class A rating represents water firefighting equivalency — each unit equals approximately 1.25 gallons of water.

Which extinguishing agent should NEVER be used on a fire involving a commercial deep fryer with cooking oil?

Answer: Water

Water causes a violent steam explosion when applied to hot cooking oil, dramatically spreading the fire and creating a dangerous fireball.

A stored-pressure dry chemical extinguisher differs from a cartridge-operated unit in that:

Answer: Stored-pressure units hold the propellant gas pre-mixed with the dry chemical agent in one cylinder

In stored-pressure units, the dry chemical agent and propellant (nitrogen or dry air) are pre-mixed in the same cylinder, while cartridge units keep them separate.

Clean agent extinguishers (such as those using Halon alternatives like FM-200) are preferred in server rooms because they:

Answer: Extinguish fires without leaving residue or depleting oxygen to dangerous levels

Clean agents suppress fires chemically without leaving residue and do not reduce oxygen to levels harmful to people who may remain in the space.