A crash bar is a mechanism for unlatching a door, consisting of a spring-loaded metal bar fixed horizontally to the front of the door (the side of the door that opens outward) and hinged. It is operated by pushing on it, which unlatches and opens the door.

Many countries' building code

Building code

A building code, or building control, is a set of rules that specify the minimum acceptable level of safety for constructed objects such as buildings and nonbuilding structures. The main purpose of building codes are to protect public health, safety and general welfare as they relate to the...

s require them on all fire and emergency exit

Emergency exit

An emergency exit in a structure is a special exit for emergencies such as a fire: the combined use of regular and special exits allows for faster evacuation, while it also provides an alternative if the route to the regular exit is blocked by fire, etc....

s. They are so named because they can be operated by someone "crashing" into them; the alternate term "panic bar" implies a similar meaning. In the UK, British Standards EN179 and EN1125 apply to panic hardware for workplace access and public access buildings respectively.

Many of these doors are one-way, and cannot be opened from the outside. To use this device on a two-way door, another type of door handle

Door handle

A door handle is an attached mechanism used to open or close a door. In the United States, door handle can refer to any fixed or lever-operated door latch device, including on car doors. The term door knob tends to refer to round operating mechanisms.-History:The first documented invention of the...

 must be mounted on the opposite side.

The idea was first put into practice after the events of the Victoria Hall disaster

Victoria Hall disaster

The Victoria Hall disaster, in which 183 children died, occurred in Sunderland, Great Britain on 16 June 1883 at the Victoria Hall, which was a large concert hall on Toward Road facing onto Mowbray Park.-Background:...

 in Sunderland, England in 1883. It saw widespread use after the Iroquois Theater Fire

Iroquois Theater Fire

The Iroquois Theatre fire occurred on December 30, 1903, in Chicago, Illinois. It is the deadliest theater fire and the deadliest single-building fire in United States history...

 in Chicago, USA, which killed 602 people on December 30, 1903, and the Italian Hall Disaster

Italian Hall disaster

The Italian Hall Disaster is a tragedy that occurred on December 24, 1913 in Calumet, Michigan...

 on Christmas Eve 1913 (popularized by Woody Guthrie

Woody Guthrie

Woodrow Wilson "Woody" Guthrie is best known as an American singer-songwriter and folk musician, whose musical legacy includes hundreds of political, traditional and children's songs, ballads and improvised works. He frequently performed with the slogan This Machine Kills Fascists displayed on his...

's song, "1913 Massacre

1913 Massacre

"1913 Massacre" is a topical ballad written by Woody Guthrie, and recorded and released in 1941 for Moses Asch's Folkways label. The song originally appeared on Struggle: Documentary No. 1, an album of labor songs, it was eventually re-released in 1999 on Buffalo Skinners: The Asch Recordings, Vol. 4...

").