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

The correct answer is that a CO2 cartridge activates a potassium bicarbonate (PKP) portable extinguisher. In fire suppression systems, PKP extinguishers utilize potassium bicarbonate as the extinguishing agent, which is effective against flammable liquids and has a high rate of smothering capability.

The CO2 cartridge provides the necessary pressure to propel the potassium bicarbonate from the extinguisher. This is a critical operational feature because the CO2 acts as a propellant allowing the user to effectively release the dry chemical agent onto the fire.

Focusing on the other types of extinguisher agents listed: dry chemical extinguishers are often activated by their own built-in mechanisms rather than an external cartridge like that used with CO2, water mist utilizes water as the primary agent, and AFFF (Aqueous Film Forming Foam) requires different methods of delivery that do not rely on a CO2 cartridge. Understanding this distinction is vital for effective use and operation of portable extinguishers in firefighting scenarios.