A plumber is replacing a section of gas piping in a building's mechanical room. The room has adequate ventilation, but the task involves disconnecting live gas lines. Which type of fire extinguisher should be readily available?

Question: A plumber is replacing a section of gas piping in a building's mechanical room. The room has adequate ventilation, but the task involves disconnecting live gas lines. Which type of fire extinguisher should be readily available?

Answer options:

• Class A
• Class B ✅ Class C
• Class D

Correct answer: Class C

Explanation: Class C fire extinguishers are specifically designed for electrical fires and fires involving energized equipment. While disconnect of live lines is involved, the primary hazard here is gas, which is a Class B fire, but due to potential ignition sources (electrical), a Class C is also appropriate or even more suited for the common hazards in mechanical rooms where gas is present.