What is the recommended maintenance practice for a fire extinguisher after it has been used?

After a fire extinguisher has been used, it is essential to assess its condition thoroughly, which includes checking if it requires annual maintenance. This practice ensures that any necessary repairs or inspections are performed to maintain the extinguisher's functionality and compliance with safety standards.

Fire extinguishers contain pressurized agents that can be depleted after being discharged, even if they appear to be partially full. Annual maintenance typically involves a professional inspection, recharging if necessary, and ensuring that all operational components are functioning correctly. This proactive approach helps to ensure that the extinguisher will be reliable for future use.

The other options do not adequately address the appropriate steps required post-use. Keeping a used extinguisher without servicing it compromises safety, replacing it immediately may not be necessary if it can be recharged, and merely storing it in a cool place does nothing to ensure it is ready for effective operation when needed. Proper maintenance after use is crucial for ensuring fire safety readiness.