If you missed Part 1 of this article, which covered design and operating features, regulations, and assessment recommendations, check it out here.

In Part 2, let’s take a deeper dive into eight key features of life safety for business and industrial occupancies that we commonly see in buildings: 

1. Number of Exits
2. Travel Distances to Exits
3. Dead End Corridor Limits
4. Minimum Width of Corridors
5. Exit Signs
6. Sprinkler Protection
7. Fire Extinguishers
8. Fire Alarm System

As the Life Safety Code is the most prominent standard for life safety, these features are based on provisions from the most recent edition of the Life Safety Code (2021 edition).

But first, let’s get a clear definition of business versus industrial occupancies. Business occupancies are defined in the Life Safety Code simply as “occupancies used for the transaction of business, other than mercantile.”  Examples of business occupancies include office buildings and laboratories.  Industrial occupancies are defined as an occupancy in which products are manufactured or in which processing, assembling, mixing, packaging, finishing, decorating, or repair operations are conducted.  Examples of industrial occupancies include factories, power plants, and maintenance buildings/shops.

1.    Number of Exits

The minimum number of “means of egress” is two for most applications.  The means of egress is a continuous path from any point in a building to an exit that ultimately leads to the outdoors.  This minimum number of means of egress (or exits) increases as the occupant load of a story increases (e.g., occupant load greater than 1,000 requires at least 4 means of egress).  There are exceptions regarding the minimum number of means of egress for business occupancies, based on the occupant load, travel distance to an exit, and/or number of stories.  For industrial occupancies, there are exceptions regarding the minimum number of means of egress based on hazard of contents.

2.    Travel Distances to Exits

The Life Safety Code specifies the maximum distance an occupant may travel from any point in the building to the nearest exit.  For business occupancies not protected with an approved automatic sprinkler system, the maximum travel distance to an exit is 200 feet.  For business occupancies protected with an approved automatic sprinkler system, the maximum travel distance to an exit is 300 feet.  For general purpose industrial occupancies without a sprinkler system, the maximum travel distance to an exit is 200 feet. For sprinklered general purpose industrial occupancies, the maximum travel distance to an exit is 250 feet.  There are exceptions for industrial occupancies that meet the criteria for “special purpose” industrial occupancies or have high hazard contents.

3.    Dead End Corridor Limits

Dead end corridors are limited to 50 feet in length in general purpose industrial occupancies.  Dead end corridors are also limited to 50 feet in length in business occupancies, except for new business occupancies not protected with an approved automatic sprinkler system, which are limited to 20 feet in length.

4.    Minimum Width of Corridors

The general minimum width of corridors is 36 inches for new construction and 28 inches for existing construction.  For business occupancy corridors serving 50 or more people, the minimum corridor width is 44 inches.  Industrial equipment access doors, walkways, platforms and stairs serving no more than 20 persons are permitted to have a clear width of 22 inches.

5.    Exit Signs

Exits shall be marked by an approved exit sign that is readily visible from any direction of exit access (except main exterior exit doors that obviously serve as an exit).  Exit signs with directional indicators are generally required in occupancies where the direction of travel to the nearest exit is not apparent.   There are a few exceptions to these general requirements, including the requirement that an exit sign must be within 100 feet of any location within an exit access corridor in a new occupancy.

6.    Sprinkler Protection

The Life Safety Code generally does not require business or industrial occupancies to be protected with an approved automatic sprinkler system.  (Note:  there may be local jurisdictional codes requiring sprinkler protection in such occupancies.)  However, “high-rise” business occupancies are required to be protected with an approved automatic sprinkler system.  New high-rise general purpose industrial occupancies (with ordinary hazard contents) are also required to be protected with an approved automatic sprinkler system.

7.    Fire extinguishers

Fire extinguishers are required in business occupancies, but not required in industrial occupancies.  Fire extinguishers should meet the installation provisions of NFPA 10: Standard for Portable Fire Extinguishers.

8.    Fire alarm system

Fire alarm systems are required in business occupancies meeting any of the following provisions:

• Building is 3 or more stories in height
• Occupant load of 50 or more above or below level of exit discharge in new business occupancies (or occupant load of 100 or more above or below level of exit discharge in existing business occupancies).
• Occupant load of 300 or more in new business occupancies (or 1,000 or more in existing business occupancies)

Fire alarm systems are required in industrial occupancies, unless the building occupant load is less than 100 persons and fewer than 25 persons are above or below the level of exit discharge.  The Life Safety Code also has separate provisions addressing initiation of the fire alarm system and how occupants are notified of a fire alarm.

These eight life safety provisions represents a small portion of all requirements.  If you have questions about a life safety issue, please reach out to Leo Old, PE, CIH, CSP, CHFM, FASHE, EnSafe Fire Protection Engineer.