Emergency communication systems indicate the existence of an emergency and communicate the information necessary to protect life. NFPA 72, National Fire Alarm and Signaling Code , describes six different types of systems: one-way emergency communication system, distributed recipient mass notification system (DRMNS), in-building fire emergency voice/alarm communications system, in-building mass notification system, wide-area mass notification system, and two-way emergency communications system. Each of these types of systems are suitable for various structures, locations, and situations. Determining the right system for the right structure and application is a performance-based task that must rely on a risk analysis.
A thorough risk analysis will determine if a system is needed and what type should be installed. There are nine elements that a risk analysis for mass notification systems must include.
Emergency response plan. Is there a written emergency response plan in place? If a current plan exists then the mass notification system can be designed to address the hazards presented in the plan. If no plan exists, the a full risk analysis must be conducted. Integrating and installing mass notification systems will require the development of an emergency response plan. These plans are to be developed in accordance with NFPA 1600 and NFPA 1620.
Occupant load. The risk analysis should consider the amount of people that occupy a given structure or space. This analysis must be based on the maximum occupant load of the entire structure, using the occupant load factor shown in Table 126.96.36.199 of NFPA 101, Life Safety Code.
Occupancy type. What is the occupancy classification of the structure? What activities take place within the building?
Perceived peril. What factors would contribute to the harm of a building’s occupants? What dangers or hazards exist? What are some obstacles to protection of life?
Building characteristics. What is the buildings function or purpose? What is the structures layout? What are normal operation conditions within the property? What systems and safety precautions are in place, or built into the structure? Using a tool like the, S.C.O.P.E. worksheet can aid in this process.
Occupant behavior. How will certain design elements affect occupant behavior? Based on the building characteristics how will occupants behave in an emergency situation? Are there systems and structures in place that would be detrimental to occupants based on their planned behavior?
Hazard development. At what rate will an event occur? Will storage, systems, or processes contribute to an increased rate of development? What could escalate an emergency incident? Are there any systems in place to mitigate or decrease the rate of hazard development?
All-hazards approach. All practical potential events should be considered in the risk analysis. General categories of potential events include, natural hazards, human caused, and technological events.
Extent of notification. How many people and in what locations will need to be notified? What will they need to be notified of? How extensive will the notification need to be? This will be different for each event and the risk analysis should outline the notification extent for each potential event identified.
Fire and emergency events require quick and decisive decision-making. Any emergency communication system should be designed to activate quickly and provide the most appropriate, clear, and concise information to the occupants.