Mass notification primer

Greg Kessinger looks at NFPA guidelines for installing mass notification systems

"Consider that the mass notification system will be used by authorities such as police and fire departments, emergency medical squads, government and even state militias."

A new day has dawned in mass notification which equals an enhanced and heightened level of security. Mass Notification Systems (MNS) facilitate fast and safe evacuation, or re-location of occupants in emergency situations; not just from fire, but cowardly terrorist attacks, a crazed gunman’s murder spree, biological/chemical/hazardous chemical incidents, accidents, weather-related emergencies or any combination of these.

You may not be aware that this better type of system for the notification of large groups was developed at request of the U.S. Air Force. The previous (2007) edition of NFPA 72 National Fire Alarm Code placed information on what was known as MNS into the Annex. Since the Annex material of any NFPA standard is not adopted as part of the code’s requirements, it served as a basic guideline for these new systems and their installation.

The ‘ink’s still wet’ 2010 edition of the Code moved the Mass Notification guidelines out of the Annex and into the body as Chapter 24. This now means that any jurisdiction that has adopted NFPA 72 can now refer to Chapter 24 in their building and/or fire code as the chapter in the standard that contains installation rules for any required MNS. Even NFPA 72 has been fundamentally changed to allow for a fire alarm’s voice evacuation system to serve as the backbone of a building or campus-wide MNS. For example, the rule requiring an AHJ to give permission before the use of the voice alarm system could include anything other than fire alarm messages has been removed. Now, the rule in section specifically allows the fire alarm, emergency voice/alarm communication (EVAC) system and the MNS to be used for background music, general paging and other non-emergency purposes. Eventually, this will lead to the installation of more voice alarm systems (as opposed to horns and bells), since this new option will mean cost savings for building owners. The 2007 edition began this integration when it specifically allowed other live emergency voice messages to override the fire alarm system message. Which begs the question, ‘who will do this overriding?’

Consider that the mass notification system will be used by various authorities such as police and fire departments, emergency medical squads, government and even state militias. Even local security/emergency forces employed by property owners will have input. Because of the potential for several groups to respond to the question, ‘who’s in charge here?’ a careful threat assessment must be made, detailing what the chain of command will be for each specific scenario. This must be done with input from all stakeholders, by someone with experience and training in risk assessment.

Basic fire alarm installation requirements for voice alarm systems did not change in the 2010 edition of NFPA 72. However, the additional features and interconnections with other systems could become significant. Mass notification may require the voice alarm system to accept live voice messages from a location outside the protected premises. This will require the communication method be secured from tampering or interference. The menu of pre-recorded voice messages must be greatly expanded to cover multiple occurrences. Since this list of possible announcements cannot be comprehensive, live announcement capability will have to be expanded. Data or network communications will be built into most proprietary voice systems but a simple relay with dry contacts will play an equal part in this interconnection since several technologies will be needed to communicate with the masses. Voice announcements will penetrate into all areas of a building. Voice intelligibility will be necessary in most areas. Some areas will be exempt from this requirement due to a building’s unique structural acoustics. Since voice messages cannot always be understood due to language or hearing difficulties, text messages will begin to be used extensively.

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