What type of cartridge activates a potassium bicarbonate (PKP) portable extinguisher?

The type of cartridge that activates a potassium bicarbonate (PKP) portable extinguisher is a CO2 cartridge. PKP extinguishers use the pressure from the CO2 cartridge to expel the potassium bicarbonate powder, which is effective for extinguishing fires, especially those involving flammable liquids and electrical fires. The CO2 serves to pressurize the extinguisher and propel the agent out, which allows the user to direct the PKP at the source of the fire.

Understanding the mechanics behind the operating systems of fire extinguishers is critical for effective fire response. The other options listed do not align with this activation method since water cartridges, dry powder cartridges, and foam cartridges refer to other types of extinguishing agents or systems that do not utilize CO2 for operation.