fast facts 

Fire Barriers Limit the Movement of Fire and Smoke August 2010 

Office of Compliance 

advancing safety, health, and workplace rights in the legislative branch 

www.compliance.gov 

Fire Barrier Penetrations 

Fire barrier penetrations are items 

that pass through fire walls, floors 

or ceilings to accommodate utility 

systems like electrical, mechanical, plumbing or other systems. 

See Figures 1 and 2. Where fire 

walls or other fire barriers are 

penetrated, the openings must be 

filled with approved materials 

equally fire resistant as the surrounding walls or barriers, such as 

fire caulking materials. 

If left unsealed, fire, smoke 

and toxic gases driven by the 

heat and pressure of the fire 

will move through the holes 

and travel rapidly to other 

parts of the building. 

Even small holes can pose a serious 

fire, smoke and toxic gas exposure 

risk to building occupants, especially 

those in adjoining spaces or on the 

floors above the fire location. See 

Figure 3. 

Figure 2: Floor Penetration Through 

Pipe Sleeves 

Figure 3: Hole Through Fire 

Door 

Unenclosed Stairwells 

Stairwells are the primary way to escape a 

multi-story building from the upper floors 

in a fire or other emergency. An open 

stairwell such as those shown in Figures 4 

and 5 allows the rapid spread of fire and 

products of combustion to upper floors, 

exposing occupants to intense heat, 

smoke, and toxic gases as they attempt to 

evacuate the building. People have 

perished from smoke inhalation while 

attempting to use exit stairways that were 

not properly enclosed, such as the MGM 

Grand Hotel fire in 1980 (9 deaths) and 

the Cook County Administration Building fire in 2003 (6 

deaths). 

Open exit stairwells in multi-story 

buildings must be enclosed by 

fire-rated barrier walls and side 

swinging 

fire doors. 

Fire doors 

are part of 

an exit 

component 

that must be fire 

rated, equipped with proper hardware 

and labeled by an OSHA recognized 

test laboratory. 

See Figure 6. 

 Figure 4: Unenclosed 

 Exit Stairway 

Figure 5: Open Stairwell 

Figure 6: Exit Stairway Door with 

Panic Bar Hardware 

Figure 1: Pipe Poking Through a 

Fire Wall 

Efficient fire barriers are the main passive fire protection technology that limits the spread of fire and restricts smoke and toxic gas 

movement to other parts of a building. They divide a building into fire compartments that are enclosed on all sides to confine the 

fire and smoke to the compartment in which the fire started. Fire barriers are extremely important, especially in multi-story buildings, because they provide extra time for employees and visitors to safely evacuate the building in a fire emergency. High hazard 

areas are enclosed in fire barriers to protect people and buildings. The Occupational Safety and Health Administration (OSHA) 

regulations require that exit stairwells be enclosed with properly rated and approved fire walls and doors. Open vertical shafts and 

stairways are the main pathways that will permit the smoke and toxic gases to rapidly spread upward from a fire on a lower floor 

level. 
fast stats 

In 2009, fires and smoke caused 3,010 civilian fatalities in the United States of America. 

In 2009, fires and smoke caused 17,050 nonfatal civilian injuries in the United States of America. 

Source: National Fire Protection Association (NFPA) Journal, September/October 2010 

The National Center for Injury Prevention and Control, a part of the Centers for Disease Control and Prevention of 

the U.S. Dept. of Health and Human Services, states in its Fire Deaths and Injuries: Fact Sheet that most victims of 

fires die from smoke and toxic gases and not from burns. A National Fire Protection Association (NFPA) 2008 

report of Home Fire Victims found that smoke inhalation was the leading cause of fire deaths and that smoke 

inhalation was twice as likely to kill a victim as burns from a fire. 

 

 

This information does not constitute advice or an official ruling of the Office of Comp liance or the Board of Directors and is 

intended for educational purposes only. For further information, please refer to the Congressional Accountability Act (2 U.S.C.

1301 et seq.) and the regulations issued by the Board, or you may contact the Office of Compliance.

The Office of Compliance advances safety, health, and workplace 

rights in the U.S. Congress and the Legislative Branch. Established as an independent agency by the Congressional Accountability Act of 1995, the Office educates employees and employing 

offices about their rights and responsibilities under the Act, provides an impartial dispute resolution process, and investigates and 

remedies violations of the Act. 

If you have any questions, please contact the Office of Compliance: 

Room LA 200, John Adams Building 

110 Second Street, SE 

Washington, D.C. 20540 

t/ 202-724-9250 

tdd/ 202-426-1912 

f/ 202-426-1913 Peter Ames Eveleth 

General Counsel 

Mary-Margaret Smith 

Editor Download the entire Fast Facts suite at http://www.compliance.gov 

Applicable Regulations 

 • An exit door must be unlocked and employees must be able to open an exit route door from the inside at all times 

without keys, tools, or special knowledge. (29 CFR §1910.36 (d)(1)) 

 • NFPA Life Safety Code 2000 edition [adopted by OSHA in 29 CFR§1910.35] permits delayed opening for exit 

discharge doors where the delay can be set for 15 or 30 seconds of delay to permit security concerns to be addressed 

before the exit discharge door can be opened. Once the panic bar is pushed, an alarm sounds. After the elapsed 

time, the door lock releases. If the building fire alarm is activated, it will immediately release the door lock so that it 

can be opened without delay. (NFPA 101 Section 7.2.1.6.1) 

 • An exit stair must be separated from other building compartments by fire resistant materials: a one-hour fire resistance-rating if the exit connects three or fewer stories, and a two-hour fire resistance-rating if the exit connects four 

or more stories. (29 CFR §1910.36 (a)(2) and NFPA 101 section 7.1.3.2.1) 

 • Every large building needs to be divided into fire compartments to limit the spread of fire and restrict the 

movement of smoke. (NFPA 101 Section 8.2.2.1) 

 • Fire compartments are formed by fire barriers that are continuous from outside wall to outside wall or from one 

fire barrier to another, or a combination thereof, including continuity through all concealed spaces, such as those 

found above a ceiling, including interstitial spaces. (NFPA 101 Section 8.2.2.2) 

• Penetrations constructed as a fire barrier shall be protected by an approved firestop system or device. (NFPA 101 

Section 8.2.3.24). Some examples of these penetrations are cables, cable trays, conduits, pipes, tubes, combustion 

vents and exhaust vents, wires and similar items to accommodate electrical, mechanical, plumbing, communications 

and other systems that pass through a wall, floor, or floor/ceiling assembly.