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Very tight shot of a fire alarm.

Impairment Prep

 

Why it's important to plan carefully around fire alarm system testing impairments.

BY WAYNE D. MOORE

THE FIRE PROTECTION INDUSTRY commonly accepts that the testing of a fire alarm system places the protected premises at risk during the test because the testing impairs a key component of the fire protection system. When this kind of fire alarm system testing occurs, the owner must have impairment plans in place to react to any real fire condition and provide proper notification to the occupants.

The individuals performing the fire alarm system tests must use common sense to ensure they complete the tests without misinterpreting the requirements of NFPA 72®, National Fire Alarm and Signaling Code. For example, large fire alarm systems may take more than eight hours to properly test. In such cases, each floor of the building should be tested and serviced before testing begins on the next floor. This would limit the length of an impairment on any particular floor and keep the majority of the system in service.

NFPA 72 defines an impairment as an “abnormal condition, during either a planned or emergency event, where a system, component, or function is inoperable.” A fire alarm system may experience either a planned impairment or an emergency impairment.

An example of an emergency impairment, as stated in the annex of the code, is physical damage to a control unit or wiring. By contrast, planned impairments may include the addition of new devices or appliances, the reprogramming of system software, or the testing of the fire alarm system. When testing a system, the code requires those who conduct the test to notify the owner or the owner’s designated representative whenever they impair a system or part of a system. Impairments to systems must include any out-of-service event.

The term “out of service” refers to any time the entire fire alarm system or a substantial portion of the system cannot operate as intended. This includes the disruption of an entire initiating device circuit, signaling line circuit, or notification appliance circuit.

The code requires the building owner to notify the authority having jurisdiction, typically the local fire official, whenever a system impairment exceeds a duration of more than eight hours. No matter how long an impairment may last, the building owner must always take appropriate measures to minimize the impact of the impairment.

The owner will need to determine the nature of the mitigating measures on a case-by-case basis. The owner must consider a number of factors: the building construction and occupancy type; the nature and duration of the impairment; the building occupancy level during the impairment period; the active work conducted on the fire alarm system during the impairment; the condition of other fire protection systems and features, such as automatic sprinklers and structural compartmentation; and the hazards and the assets at risk. Appropriate mitigating measures range from simple occupant notification that an impairment exists to a full-time fire watch making patrols throughout the impaired area.

Chapter 7 of NFPA 72 requires the preparation of a documented test plan describing the expected impairments, their anticipated duration and mitigation, and a plan to notify the occupants in the event a real fire occurs during the time the impairment to the fire alarm system exists. All parties—the owner or the owner’s designated representative, as well as the authorities having jurisdiction, including the fire department—must receive notification when the impairment resolves.

WAYNE D. MOORE, P.E., FSFPE, is vice president at JENSEN HUGHES.

Action shot of people going up and down an escalator.

Mixed Approach

 

The AHJ has final say in mixed-occupancy protection.BY RON COTÉ

 

Food trucks are a current rage. An education session at the NFPA Conference & Expo last June, as well asa related story in NFPA Journal, focused on food trucks via a review of applicable provisions of NFPA 96, Ventilation Control and Fire Protection of Commercial Cooking Operations, along with Chicago’s innovative permitting process.

A question on a related topic recently landed within the NFPA life safety group. The inquiry asked for guidance on occupancy classification—for purposes of applying NFPA 101®, Life Safety Code®—of a storage container that had been repurposed as a kitchen, food preparation, and sales area. Service windows are provided for order taking and passing food to customers outside the container. The structure, unlike a mobile food truck, is permanently fixed in place.

An industrial occupancy classification should provide adequate protection for the workers inside the container, but I was uncomfortable with the gaps that classification might leave for customer protection. For example, customers should be protected from the hazards associated with fuel cylinders, such as the propane tank that exploded on a food truck in Philadelphia in 2014, killing a mother and daughter who were working in the truck and injuring a dozen people, some of whom were set afire. I offered that an occupancy classification of mercantile or one of mixed occupancies—part mercantile and part industrial—would be better than that of an industrial occupancy alone.

My opinion was based on the code provisions, applicable to occupancies other than industrial, requiring occupants to be protected from any contents that are relatively more hazardous than those typically associated with the occupancy. The industrial occupancy chapter provisions, in contrast to those of the other occupancies, require occupant protection from high-hazard operations or processes. Other code provisions require all occupancies to be protected from the hazard of commercial cooking equipment in accordance with NFPA 96.

A code provision applicable to multiple-occupancy buildings allows mercantile, business, industrial, and storage occupancies to be considered incidental to the predominant occupancy. In applying this provision, the code user needs to be careful not to defer to an industrial occupancy classification just because it comprises the greater floor area. For example, in a building where 20 percent of the floor area is used as business and 80 percent as industrial, the business occupants might not be adequately protected if the entire building is classified as an industrial occupancy.

I’ve had discussions with authorities having jurisdiction (AHJs) that led them to classify the business and industrial building addressed above as a multiple-occupancy building—part business occupancy and part industrial occupancy. Then, where the mixed occupancies form of protection is utilized, the shared exit access paths must be protected against relative hazards that do not necessarily rise to the category of high hazard—something the industrial occupancy requirements alone would not do.

The mixed-occupancies form of protection requires that the structure comply with the most restrictive requirements of the occupancies involved, unless separate safeguards are approved. Contrast that with the separated occupancies form of protection, where each occupancy meets only the requirements to which it is subject; in this method, the distinct occupancies are required to be completely separated from each other by fire barriers.

The life safety technical committee wisely included code text making occupancy classification subject to the AHJ’s ruling in cases where there is a question of proper classification.

RON COTÉ, P.E. is principal life safety engineer at NFPA.