How long will a 20 pound ABC fire extinguisher in use last?

A 20-pound ABC fire extinguisher typically discharges its contents for about 10 to 30 seconds, depending on the specific model and the pressure applied by the user. The duration can also vary based on the type and intensity of the fire being fought. It's important to remember that while the extinguisher may last this long, effective use and proper technique are crucial for extinguishing the fire efficiently. Always follow safety guidelines and manufacturer instructions when using a fire extinguisher.