Panic Hardware: Exit Devices, Fire Exit Hardware, and the Codes Behind Them

Origins and the Von Duprin Story

After the 1903 Iroquois Theatre fire in Chicago, Carl Prinzler worked with architectural engineer Henry H. DuPont on an exit latch that released when a person pushed against a crossbar. Prinzler managed the builders hardware department of the Vonnegut Hardware Company, and the Encyclopedia of Indianapolis gives the fire's death toll as 596.

Von Duprin dates its first exit device to 1908, and patent applications followed that autumn. One example is U.S. Patent 983,355, "Emergency exit-lock," filed by Henry H. DuPont on November 9, 1908. It was assigned to Von Duprin Fire Exit Latch Co. and granted February 7, 1911. The name Von Duprin combines Vonnegut, DuPont, and Prinzler.

How an Exit Device Works

Pushing the actuating bar retracts one or more latch bolts. What differs between device types is where the latches are. Von Duprin's general information lists the device type (rim, mortise, surface vertical rod, or concealed vertical rod) as one of the basic choices when ordering.

• Rim devices mount on the face of the door and latch into a strike on the frame.
• Mortise devices operate a lock body set into a pocket in the door edge. See mortise locks.
• Surface vertical rod (SVR) devices run rods up and down the face of the door to latches at the head and floor. ANSI/BHMA A156.3 numbers this as Type 2.
• Concealed vertical rod (CVR) devices hide the rods inside the door.

On pairs of doors, vertical rod devices let each leaf latch at the head and floor instead of into the other leaf (see the less-bottom-rod option below). A removable mullion is another option for pairs.

The outside of the door is controlled by trim. A156.3 numbers trim functions. For example, it describes Function 10 as "entrance by knob or lever," with a key that locks or unlocks the trim and an outside key that releases the latch. A rim cylinder is the usual keyed part.

Panic Hardware vs. Fire Exit Hardware

These are two different listings:

• Panic hardware is listed to UL 305.
• Fire exit hardware is listed to both UL 10C (fire) and UL 305. The 2021 International Building Code, as adopted in Illinois, states both listings in section 1010.2.9.3.

Von Duprin's older general information describes what the listings involved at the time. For UL panic listing, a device went through 100,000 controlled open-and-close cycles, and its activating mechanism had to work with 50 pounds of pressure or less while 250 pounds pushed against the door in the swing direction. For the fire exit hardware label, a device also had to pass a burn test, holding fire doors closed for up to three hours at temperatures over 1,900°F, and then a hose-stream test. The document is dated. Treat these figures as historical description, not the current UL text.

Fire exit hardware has rules of its own. Door-hardware consultant Lori Greene explains on iDigHardware:

• It cannot include mechanical dogging, which would hold the latch retracted and could leave a fire door unlatched during a fire.
• Fire doors that use it must carry a label saying the door is to be equipped with fire exit hardware.
• On pairs, it can be supplied less bottom rod (no bottom rods, latches, or floor strikes). Most listings then require an auxiliary fire pin that projects only at high temperature to keep the doors aligned.
• Electric latch retraction is allowed on fire doors, as long as the door relatches when the fire alarm activates.

See fire-rated door hardware and electric latch retraction.

What the BHMA Standard Tests

ANSI/BHMA A156.3-2025 covers exit devices and trim, automatic flush bolts, removable mullions, coordinators, and carry-open bars. BHMA's summary highlights:

• Durability: Grade 1 exit devices go through 500,000 loaded cycles with no loss of operation.
• Strength: the latch must withstand a 400-pound load in the direction of egress without the door swinging open, and outside trim must resist heavy forces.
• Operating force: opening and closing forces are defined and measured. BHMA notes exit devices meet accessibility criteria for operable parts, with an operating force limit of 15 pounds.
• UL 305: BHMA certification includes compliance with UL 305 for panic devices.

For comparison with locks, ANSI/BHMA A156.2-2022 sets the Grade 1 bored lock figure at 1,000,000 cycles, and A156.36 sets the Grade 1 deadbolt figure at 250,000. Each product standard sets its own test, so cycle figures are not directly comparable across product types. See ANSI/BHMA lock grades.

Where Codes Require It

This section is a high-level summary of one model code as adopted in one state. The code adopted where a building sits, and the authority having jurisdiction (AHJ), decide what applies.

Under section 1010.2.9 of the 2021 International Building Code as adopted in Illinois (via UpCodes):

• Where it is required: swinging doors serving a Group H occupancy, and swinging doors serving rooms or spaces with an occupant load of 50 or more in a Group A or E occupancy, may not have any latch or lock other than panic hardware or fire exit hardware. The section lists exceptions.
• Special rooms: it also requires panic or fire exit hardware on certain refrigeration machinery rooms and rooms with certain electrical equipment.
• Installation: the actuating portion must extend at least half the width of the door leaf, and unlatching force may not exceed 15 pounds.

NFPA 101, the Life Safety Code, has its own provisions where it is adopted. See door closers for the closing side of the opening.

Alarms, Electrified Locking, and Delayed Egress

Security needs often push against free egress. The standards and codes address this with specific products rather than ad-hoc locks.

ANSI/BHMA A156.29-2022 covers exit locks, exit alarms, and alarms for exit devices. It sets operational and finish tests for exit locks and exit alarms, and operational tests only for alarms that attach to exit devices.

The same IBC section allows panic-hardware doors serving Group A or E occupancies to be electrically locked, but only under the conditions of sections 1010.2.11 and 1010.2.12. Delayed egress is one such arrangement, where code permits it. See:

• delayed-egress locks
• electromagnetic locks
• request-to-exit

Installation and Service

Exit devices are life-safety hardware, and how they are installed matters as much as what they are. Fire exit hardware depends on the door being reinforced for it and on its labels staying intact. Von Duprin's ordering guidance asks for the device type, handing, and door material (wood or hollow metal), which shows how much the door decides what fits. Changes to a fire-rated opening should follow the hardware and door listings, and the AHJ may require inspection.

Related Topics

• Fire-rated door hardware: listings and labels
• Electric latch retraction: remote dogging and relatching
• Delayed-egress locks
• Removable mullion
• Rim and mortise cylinders: outside trim cylinders
• Mortise locks
• Door closers
• Electromagnetic locks and request-to-exit
• Access control

Sources