“We gotta get out of this place, if it’s the last thing we ever do.”  — Cynthia Weil/Barry Mann

How many exits do we need from our control room? And what direction do the doors need to swing?

Seem like easy questions. But as any good consultant will tell you: “It depends.”

The Standards for Exits

The go-to standard on exits is NFPA 101, The Life Safety Code. OSHA weighs in on exits in 1910 Subpart E, Exit Routes and Emergency Planning, but it refers back to NFPA 101, 2009 Edition, or the exit-route provisions of the International Fire Code, 2009 Edition. Unlike federal regulations, which OSHA only seems able to change at a glacial pace, the consensus standards are routinely updated. The NFPA, for instance, typically revises the Life Safety Code every three years; the current edition of NFPA 101 is 2018. The current edition for the IFC is also from 2018.

So what do the standards say about exits from control rooms?  Let’s consider NFPA 101.

Doors vs. Exit Routes vs. Egress

The first thing to keep in mind is that the standards are not just interested in doors, but in exit routes. An exit route is the path from any point within a workplace to a place of safety. The exit route consists of three parts: access to the exit, the exit itself, and the discharge from the exit.

The access to exit is the part of the exit route that leads to the exit and includes every part of the path inside a building. Unless the doors in a control room open to the outdoors, then the doors in a control room are components in the access to the exit.

The discharge from the exit leads directly outside to a street, walkway, refuge area, public way, or open space away from the building.

Traditionally, the Life Safety Code referred to “means of egress”, but OSHA refers to “exit routes”. The two terms mean the same thing, but I think OSHA was concerned that the regulated community would confuse “egress” with “egrets”, large birds whose plumage was so valued by western milliners that the birds were almost hunted to extinction.


Photo credit:  Santa3, on Pixabay

So, How Many Exits from a Control Room?

Any evaluation of a space should start with the assumption that two exit routes are required from any space.  From there, exceptions may allow that number to be reduced to one or may require that the number be increased to three or more. In the absence of any other information, the requirement is two exit routes, which means two doors.

What would require more than two exits? According to NFPA 101 §7.4.1.2, if the occupancy is greater than 500, then there must be at least three exits; if the occupancy is greater than 1,000, then there must be at least four exits. Since no control room anywhere is intended for an occupancy of more than 500, two exit routes will be enough.  But is one enough?

Whether a single exit route is enough depends on the type of occupancy, which NFPA 101 addresses in Chapters 11 through 43.  Types of occupancy include High-Rise Buildings (Chapter 11), One- and Two-Family Dwellings (Chapter 24), and New Business Occupancies (Chapter 38).  It doesn’t include control rooms, but it does include Industrial Occupancies (Chapter 40).  Chapter 40 is the part of the Life Safety Code that covers control rooms.

Chapter 40 requires at least two exit routes from each control room (§40.2.4.1.1) but allows just one exit route when two conditions are met:

  1. The control room and the path from the control room are through low hazard (contents make a self-propagating fire impossible) or ordinary hazard (contents likely to burn with moderate rapidity, such as ordinary combustibles like paper or wood) industrial occupancies. If any part of access to an exit is through a high hazard (contents burn extremely rapidly or with a potential for explosion, such as solvents) occupancy, a single exit route is not enough,
  2. The access to the exit—the path to the exterior door—is no further than the permitted distance. The permitted distance, when protected throughout by an approved automatic sprinkler system, is 100 ft. Without a sprinkler system, the permitted distance is 50 feet.

This distance—either 50 feet or 100 feet, depending on sprinklers—is from the control room to out of the structure, not just from a point in the control room to the control room door.

For more details see §40.2.4.1.1 and Table 40.2.5.1

What Way Does the Door Swing?

Start with the assumption that the door should swing out, in the direction of travel during egress. This is true without exception when the occupancy is 50 or more or when the door serves a high-hazard contents area. If the occupancy is less than 50 (which is undoubtedly true for a control room) and doesn’t serve a high-hazard contents area (which is considerably less likely to be true for a control room), then doors may swing in.

So, doors to offices or conference rooms in the admin building can swing in.  Doors in the control room may be allowed to swing in as well, as long as the exit route does not pass through any high-hazard areas.

Doors to the Control Room

In all cases, the easy answer to the questions, “How many doors does my control room need and what way should they swing,” is two doors, swinging outward. There will never be a need to justify these choices.

There are some exceptions that allow for just one door as part of one exit route and that allow for the doors to swing inward. However, the burden will be on the employer to prove that the exceptions are satisfied.

Check Your Control Rooms

The Process Safety Management Standard (29 CFR 1910.119) requires that facility siting be addressed as part of a process hazard analysis. An obvious part of facility siting is assuring that exit routes are adequate. So, take a look at your control rooms and satisfy yourself that when an emergency comes and it’s time to “get out of this place,” that it’s NOT the last thing you ever do.