How is carbon dioxide stored in a fire extinguisher?

Carbon dioxide (CO2) in a fire extinguisher is stored under its own pressure as a compressed gas. This means that the CO2 is maintained in a pressurized environment, which allows it to remain in a gaseous state until it is released through the nozzle when the extinguisher is activated. The high pressure causes the gas to be forced out rapidly, displacing oxygen in the vicinity of the fire, which effectively helps to suffocate the flames and stop the combustion process.

When CO2 is released from the pressurized container, it expands rapidly and turns into a gas, making it effective for putting out fires involving flammable liquids and electrical fires, as it does not leave any residue. The other choices misrepresent how CO2 is stored; it is not in a liquid state at room temperature and does not exist in solid form within an extinguisher. Additionally, it is not absorbed onto sponge material but is contained within the cylinder under pressure until discharged.