Chapter 24 Adds Layered Explanations
It is now required that the system designer must identify rooms and spaces where audible notification shall be used. The designer must also identify rooms and spaces where notification will not be provided. Photography ©istockphoto.com/yenwen
In Paragraph 24.3.2, Microphone Use, all users of microphones that are to be used for emergency communications shall be provided with posted instructions on how to use the mics. This can be accomplished through a diagram.
The concept of mass notification system (MNS) layers has been added to the standard:
- Layer 1 - In-Building MNS, controlled only by authorized users.
- Layer 2 - Wide-Area MNS, controlled only by authorized users.
- Layer 3 - Distributed Recipient MNS, notification of personnel through individual measures.
- Layer 4 - Public Media Notification, Broadcast Radio, TV and so forth.
The section on Risk Analysis for Mass Notification Systems has been expanded to provide additional information for the practitioner. A risk analysis checklist has been added to the annex. Within Section 24.4, One-Way Emergency Communications Systems, the concept of message templates has been added to the standard. This requires messages be established for each scenario included in the emergency response plan.
For all evacuation messages, a tone in accordance with Chapter 18 must be used for two cycles before and after the message. For all test messages, the message now must clearly state, “This is a test.” In protected premises where occupants may be sleeping, the message shall be preceded and followed by a low-frequency tone for two cycles.
The MNS documentation goes beyond the basic requirements found within Chapter 7. This includes but is not limited to risk analysis documentation. This chapter clarifies that colored strobes are not required by the standard, but may be required by others, such as the Department of Defense (DoD). When colored strobes are used for public mode notification, their spacing must be accomplished by using the effective intensity of the strobe.
Shane Clary, Ph.D., has more than 37 years of security and fire alarm industry experience. He serves on a number of NFPA technical committees, and is Vice President of Codes and Standards Compliance for Pacheco, Calif.-headquartered Bay Alarm Co.
5 Big Changes to NFPA 72
- New requirements for total coverage
- Requirements for remote alarm indication
- Design requirements for audible and visible notification
- Mass notification system (MNS) layers
- Requirements for evacuation messages