What maintenance task is required annually for fire extinguishers?

The annual maintenance task required for fire extinguishers is a thorough inspection and servicing by a professional. This process is crucial to ensure that the fire extinguisher is in good working condition and ready to function effectively in case of a fire emergency. During this inspection, various checks are performed, including verifying that the extinguisher is easily accessible, checking the pressure gauge to ensure it's in the operable range, looking for any physical damage, and confirming that the inspection tags or labels are up to date.

This professional servicing is mandated by safety regulations and standards, such as those set forth by the National Fire Protection Association (NFPA). The company or technician performing the service will often display a service tag indicating the date of the service and the condition of the extinguisher, ensuring compliance with safety protocols.

In contrast, the other options do not align with the required annual maintenance for fire extinguishers. For instance, replacing the extinguisher every year is not a standard requirement; refilling is only necessary when the extinguisher has been discharged; and simply cleaning the exterior does not address the internal functionality or safety concerns addressed during a professional inspection.