A fire alarm system is not useful in isolation. Its purpose is to provide timely warning so that occupants can evacuate and the fire department can respond before the fire grows to a life-threatening size. The key word is timely: in The Station nightclub fire of 2003, fatal conditions in the worst-affected areas of the building developed within approximately two minutes of ignition (Grosshandler et al., 2005). In the Beverly Hills Supper Club fire of 1977, delayed notification to the fire department and to occupants in other parts of the building directly contributed to the 165 deaths (National Fire Protection Association [NFPA], 2023a).

A fire warning system for a live event must be designed around the specific characteristics of the venue and the event — its size, layout, occupancy, and the types of hazards present. Understanding what the governing standard requires and how to apply it to an event setting is essential for every event safety planner.

The Governing Standard: NFPA 72

NFPA 72, National Fire Alarm and Signaling Code, is the primary standard governing fire alarm system design, installation, testing, and maintenance in the United States. It is referenced in both the IFC and NFPA 1 and adopted in most U.S. jurisdictions. NFPA 72 establishes requirements for initiating devices (smoke detectors, heat detectors, manual pull stations), notification appliances (horns, strobes, voice announcement systems), power supplies, and system monitoring (NFPA, 2022a).

A key requirement of NFPA 72 is that any fire alarm system component that requires a power supply to operate must also have a backup power supply capable of maintaining required performance for a specified duration. In most assembly occupancy applications, the backup power must maintain the system in standby mode for 24 hours and then provide full alarm output for 5 minutes (for systems with voice evacuation capability) or 4 minutes (for systems with notification appliances only) (NFPA, 2022a).

What a Warning System Must Accomplish

The purpose of a fire warning system is specific and practical: to provide information to everyone present in the venue so that all can evacuate safely before escape routes become impassable through fire, heat, or smoke (NFPA, 2022a; International Code Council [ICC], 2021a).

This purpose drives the design requirements. The system must:

• Be audible throughout the entire occupied area, including restrooms, back-of-house areas, and any space where staff or performers may be present
• Produce a signal that is distinctly recognizable as a fire alarm — not easily confused with music, background noise, or production effects
• Activate automatically upon detection of a fire — not require a human decision to sound the alarm before notification begins
• Provide manual activation capability at strategic locations throughout the venue so that any person who discovers a fire can immediately sound the alarm
• Be audible above the ambient noise level in each area — a requirement that presents specific challenges in venues with high-volume sound systems (NFPA, 2022a)

Indoor Venues: Designed for Assembly

An indoor venue that has been designed for public assembly and has previously been approved for entertainment events will typically have an approved fire alarm system in place. Before the event, organizers should confirm that the system has been tested within required timeframes and that any recent modifications to the building or production setup have not compromised system coverage or audibility (FEMA, 2010).

Production sound systems at significant volume levels can make fire alarm signals inaudible to occupants. This is a recognized challenge at concerts and theatrical events. The AHJ may require that fire alarm signals be integrated with the production sound system so that the alarm overrides the event audio at sufficient volume to be heard throughout the venue. NFPA 72 permits emergency voice/alarm communication systems to use the venue’s distributed sound system for this purpose, subject to specific technical requirements (NFPA, 2022a).

Event lighting and pyrotechnic effects, including theatrical fog and haze, can cause nuisance activations of smoke detectors. Organizers should communicate planned production effects to the venue management and AHJ well in advance. The AHJ may approve temporary adjustment of detection sensitivity or detector type for the event, but this adjustment must be documented and must not leave the building without detection capability (NFPA, 2022a; ICC, 2021a).

Buildings Not Designed for Assembly

Buildings designed for industrial, warehousing, or other non-assembly use may have fire alarm systems designed around the hazards and occupancy densities of those uses — which are fundamentally different from a public entertainment event. A warehouse fire alarm may be calibrated for a small number of trained workers in a familiar environment; it may be inadequate in both audibility and coverage for hundreds of members of the public who are unfamiliar with the building layout.

Where an existing alarm system is unsuitable or absent, the options are to modify the existing system or to install a temporary system for the event. NFPA 72 permits the use of radio-transmission-based temporary alarm systems, which have the advantage of not requiring electrical wiring or permanent building modifications. The local fire and building authorities having jurisdiction must review and approve any temporary system before the event opens (NFPA, 2022a; FEMA, 2010).

Temporary and Outdoor Events

At events in tents, temporary structures, or outdoors, the fire warning system must be designed from scratch for the specific event configuration. The system must cover all occupied structures and areas, with particular attention to locations where fire could develop without being quickly visible — sleeping accommodations at multi-day events, backstage areas with high fuel loads, generator enclosures, and catering structures (FEMA, 2010; ICC, 2021a).

For outdoor events, NFPA 72 requires that manual alarm stations be available throughout the site. Static alarm stations can be supplemented or replaced by mobile alarm points — radio-equipped staff who can raise the alarm from wherever they are on the site, without requiring the person who discovers the fire to leave the area and find a fixed station. The use of radio communications for fire alarm purposes is an effective approach for large outdoor events and is consistent with NFPA 72 requirements (NFPA, 2022a).

Campsites at multi-day events require particular fire warning attention. Conditions in sleeping accommodations can allow a fire to grow significantly before it is noticed, and the sleeping state of occupants means they will not self-evacuate immediately upon fire detection. Battery-operated smoke alarm units or a permanent fire watch by designated crew members — or both — should be in place at any event with overnight camping (FEMA, 2010).

Manual Call Points and Alarm Stations

Manual fire alarm stations — pull stations or break-glass call points — must be positioned so that any person who discovers a fire can activate the alarm quickly without having to travel more than a specified distance. NFPA 72 and the IFC require manual alarm stations on each floor of a building near each exit and in sufficient quantity that the maximum travel distance to any station does not exceed 200 feet (61 m) in most occupancy types (NFPA, 2022a; ICC, 2021a).

At events, manually activated alarm stations are particularly important because automatic detection systems may not cover all areas — and because a person who can raise the alarm immediately upon fire discovery may provide the time needed for evacuation before automatic detection would have activated. Stewards and event staff should know the location of all alarm stations and be trained to activate them without hesitation if they observe or smell fire (FEMA, 2010).

Smoke and Heat Detection

Automatic fire detection — through smoke detectors, heat detectors, or flame detectors — initiates the fire alarm before a person must discover the fire and manually activate it. In assembly occupancies, early automatic detection is particularly valuable because fires can grow rapidly and because occupants may not notice a fire beginning in a remote area of the building until conditions are already dangerous.

Photoelectric smoke detectors are generally more sensitive to the slow, smoldering fires that characterize ordinary combustibles (Class A fires — the most common type in assembly occupancies). Ionization detectors respond more quickly to fast-flaming fires. Combination or multi-sensor detectors are increasingly common and address both fire types. The selection of detector type should be matched to the anticipated fire hazard in each area of the venue (NFPA, 2022a).

Testing Before the Event

Every fire alarm system used for an event must be tested before the event opens. NFPA 72 establishes a regular testing schedule for permanently installed systems, but event organizers should not rely on a certification from a previous inspection without confirming the test date. For temporary systems, full functional testing must be completed before the venue is opened to the public. Test results should be documented in writing (NFPA, 2022a; FEMA, 2010).

References

Federal Emergency Management Agency. (2010). Special events contingency planning job aids manual. U.S. Department of Homeland Security.

Grosshandler, W. L., Bryner, N., Madrzykowski, D., & Kuntz, K. (2005). Report of the technical investigation of The Station nightclub fire (NIST NCSTAR 2). National Institute of Standards and Technology.

International Code Council. (2021a). International fire code. ICC.

National Fire Protection Association. (2022a). NFPA 72: National fire alarm and signaling code. NFPA.

National Fire Protection Association. (2023a). Learn about fire: Historical fires. NFPA. https://www.nfpa.org