Author(s): Wayne Moore. Published on July 1, 2014.

In many large assembly occupancies, including performing arts centers, concert halls, sports venues, and other entertainment venues with an occupancy of more than 300, NFPA 101®, Life Safety Code®, requires fire alarm notification to occur at a constantly attended location within the building. When the building is occupied, the individuals who receive the alarm signals initiate emergency action for the protection of the rest of the occupants in the building. In the past, the public address system seemed the obvious system to provide voice instructions to occupants. While this approach made sense for economic reasons, neither NFPA 101 nor NFPA 72®, National Fire Alarm and Signaling Code, contained any clearly stated requirements that would ensure that the public address system could meet the reliability and intelligibility expected of a code-required fire emergency voice/alarm communications system (EVACS).

The Life Safety Code does permit an EVACS or public address system that complies with certain minimum requirements to provide automatically transmitted or live voice announcements. The first requirement states that a receiving station, constantly attended by personnel trained to respond to an emergency, will initiate occupant notification, either live or recorded. Additionally, all new systems must have an approved secondary power supply. Finally, the system must provide sounds that will remain clearly audible above the expected ambient noise level. Furthermore, NFPA 72 requires that the system must also meet intelligibility requirements. Chapter 9 of the Life Safety Code, which focuses on fire protection systems, includes additional requirements that apply to voice systems, provisions that reinforce the above requirements and add that emergency announcements must take precedence over any other use.

NFPA 101 also states that “audible and visible fire alarm notification appliances shall be used only for fire alarm system or other emergency purposes.” This requirement goes on to permit the use of these systems for other purposes subject to the approval of the authority having jurisdiction, provided that fire alarm and mass notification messages take precedence. In addition, where the authority having jurisdiction determines that a constantly attended receiving station is impractical, the building owner must provide an EVACS system operating in compliance with NFPA 72. A supervising station must also monitor this system in accordance with NFPA 72.

NFPA 72 now permits the use of fire alarm speakers for non-fire purposes, including other emergency announcements for mass notification and normal non-emergency paging. However, for such non-emergency use, the system must retain the monitoring integrity requirements of NFPA 72. Further, the contractor installing the system used for non-emergency purposes must locate the loudspeakers and associated audio equipment in such a way that they are protected against tampering or misadjustment of those components essential for the intended emergency notification.

NFPA 72 now also provides the authority having jurisdiction with guidance on determining the acceptability of a public address system that will provide emergency communication. Chapter 24 requires that an emergency communications system designer evaluate the voice communications or public address system used for mass notification to determine applicability and compliance. The code also requires the documentation of this evaluation by the emergency communications system designer in accordance with Chapter 7, attesting that the evaluation of the public address system has determined that it meets the performance requirements of Chapter 24 and the emergency response plan for the building.

In these ways, NFPA 101 and NFPA 72 complement each other in order to ensure the reliable delivery of emergency messages to the occupants of large assembly buildings.

Wayne D. Moore, P.E., FSFPE, is vice president at Hughes Associates.