An aerosol fire extinguisher for dispensing a liquid wet chemical fire extinguishing agent, and a composition for the liquid wet chemical fire extinguishing agent, where the liquid wet chemical fire extinguishing agent is rated for class A, B, C and K fires. The fire extinguisher includes a container and a valve assembly affixed to the container. A hag is positioned within the container, where the bag includes an output tube connected in fluid communication to the valve assembly. An actuator is connected in fluid communication to the valve assembly opposite the output tube, where. the actuator has an elongated output orifice. A liquid wet chemical fire extinguishing agent is disposed within the bag and a propellant is disposed within the container, wherein the bag isolates the liquid wet chemical fire extinguishing agent from the propellant. The: configuration of the elongated output orifice expels the liquid wet chemical fire extinguishing agent in a substantially planar pattern onto the fire.