Which component assists in maintaining safety in door assemblies that must remain closed during a fire?

A self-closing device is crucial for maintaining safety in door assemblies that need to remain closed during a fire. These devices automatically close a door after it has been opened, preventing the spread of smoke and fire from one area to another. Keeping fire-rated doors closed helps to contain flames and smoke within specific compartments, thereby protecting occupants and allowing more time for evacuation and response by emergency services.

While an alarm system can alert occupants to a fire, it does not physically contribute to maintaining the integrity of the door assembly. Access control is focused on regulating who can enter or exit certain areas but does not ensure that doors remain closed during a fire event. Door stops, while useful for holding doors open, directly counteract the purpose of fire doors by not allowing them to automatically close when needed. Thus, the self-closing device stands out as the most effective component for fire safety in this context.