Two families of hardware let people out of a locked door in an emergency and they are not interchangeable. Panic hardware is for places where the public gathers and people may be in a crowd pushing. Emergency exit hardware is for places where everybody is familiar with the building. Choosing the wrong one is a real defect even though both open the door.
Panic hardware
Horizontal bars, either push bars or touch bars, designed to release the door when pushed anywhere along their length by somebody who does not know the building and may be pressed against it by a crowd. They are specified for premises used by the public: assembly buildings, entertainment venues, shops and anywhere a crowd could form at the door. The defining feature is that the door opens under pressure from a body, not from a hand seeking a device.
Emergency exit hardware
Push pads and lever handles designed to release the door with a single simple action by somebody familiar with the building. They suit workplaces where everyone using the exit knows where it is and what it does. They are not suitable where a crowd might form, because a person pressed against the door cannot reach a pad with a hand.
Green emergency door release units
The green break glass units beside electrically locked doors cut the power to the lock and release the door, and they are deliberately green so nobody confuses them with a red fire alarm call point. Some use a resettable element and a key, which is what the emergency door release key is for. They need testing on the same cycle as the lock they release, and the key needs to be somewhere findable.
Fitting them to a fire door
Exit hardware on a fire door is part of the certified assembly, so it must be fire tested as well as tested for its exit function, and the door manufacturer's permitted hardware list governs. A panic bar bolted through a fire door with no evidence for that combination is a common finding, and it cannot be resolved with paperwork after the event.
Questions people ask about fire door push bar
What is the difference between panic and emergency exit hardware?
Panic hardware is for places where the public gathers and a crowd could press against the door. Emergency exit hardware is for buildings where everybody using the exit is familiar with it.
What is the green break glass by an exit door?
An emergency door release that cuts power to an electric lock and releases the door. Green distinguishes it from the red fire alarm call point, which does a completely different job.
Can I fit any push bar to a fire door?
No. Exit hardware on a fire door must be covered by the door's certification and the manufacturer's permitted hardware list, as well as being suitable for the exit function.