Either type of device may be applied to doors that are used to exit a building during an emergency, which swing in the direction in which occupants are exiting (normally outward). An exit sign is typically visible at most of these doors. These two types of exit devices look the same, but are used differently depending on the door application.
The International Building Code (IBC 2006) requires panic exit hardware to be installed on certain types of buildings, such as educational and assembly facilities, as well as buildings with occupancies of 50 or more persons. In addition, high-hazard occupancies, as well as certain electrical and battery rooms, must include panic exit hardware. Code officials may require panic exit hardware on other types of buildings depending on local jurisdiction.
In some instances, doors along the path toward an emergency exit are designed to slow the spread of fire and smoke. Fire-rated door assemblies are incorporated into fire-rated walls, which help to compartmentalize and contain a fire; this provides time for a building to be evacuated and for emergency personnel to rescue occupants and extinguish the fire.
Fire-rated walls and doors are typically located inside a building and are not part of an external wall or door that leads directly outside. Examples of fire-rated doors include:
- Doors that lead to an enclosed stairwell
- Doors that lead to a common hallway
- Doors within a separation wall, inside a building
A panic exit device is defined as a locking mechanism that can be released quickly by pushing on a horizontal bar, applying pressure in the direction of egress. Pushing on the push pad or bar should release a latch and unlock the door, allowing quick exit during a panic situation. To be classified as panic exit hardware, the mechanism should:
- Release a latch quickly and easily when pressure is applied to the push pad or push bar in the direction of exit travel
- The pressure on the push pad or push bar should not exceed 15 pounds
- The push pad or push bar should cover at least half the width of the door
Panic exit devices are also commonly referred to as "panic devices," "exit devices," "crash bars" and "push bars." Panic exit devices may utilize a latch or a bolt to secure the door; but it is not required that panic devices re-lock or re-latch when the door closes. Many panic exit devices do re-latch, however. (See UL 305, Standard for Panic Hardware.)
All fire-rated exit devices are also panic exit devices and must meet the criteria above. In addition, a fire-rated exit device:
- Must be used on fire-rated doors that are self-closing, and must re-latch or re-lock when the door closes
- Must pass industry testing that proves that the panic device can keep a fire-rated door locked and secure during a fire emergency
- Must have a listing or approval label from a third-party listing agency for a specific time rating, typically 20 minutes, 45 minutes, 60 minutes, 90 minutes or 3 hours
- Must not have the ability to be mechanically dogged, which prevents re-latching upon door closure (Note: electric dogging is allowed on fire-rated exit devices)
The rating of a fire-door assembly is determined by the lowest rated component or product used in the assembly.