What indicates a charged, ready-to-use extinguisher on the gauge?

• A. The red zone.
• B. A ticking sound.
• C. The pressure gauge needle in the green operating zone.
• D. A green label on the tank.

Answer: (C)

Knowing whether a fire extinguisher is charged and ready depends on the pressure gauge reading. When the needle sits in the green operating zone, the extinguisher has the correct internal pressure for proper discharge and is ready to use. If the needle shows in the red zone, the pressure is outside the safe, effective range—either too low to expel the agent properly or too high, which can be unsafe. A ticking sound isn’t a reliable indicator of readiness, and a green label on the tank doesn’t reflect current pressure status. So the green operating zone on the gauge is the best sign that the extinguisher is charged and ready.