NFPA 731 Section 4.6.3.1 requires the installation of all wiring, cable, and equipment to be performed in accordance with NFPA 70 (NEC), Article 725 or Article 800, where applicable. Many circuits in a security system are “signal circuits” and NEC^® Article 725 must be followed.

One requirement in NEC^® 725.3(C) is to ensure any Class 1, 2 or 3 remote-control, signaling, and power-limited circuits are installed in accordance with NEC^® 300.22. This section has specific rules when circuit wiring or equipment is installed in a plenum.

NEC 300.22(C)(1) provides additional requirements for the proper listing of nonmetallic plenum rated cable ties. Part of the testing of a plastic plenum rated cable tie includes ensuring that the cable tie exhibits a maximum peak optical density of .50 or less, an average optical density of .15 or less, and a peak heat release rate of 100 kW or less when tested in accordance with ANSI/UL 2043 which is the Standard for Fire Test for Heat and Visible Smoke Release for Discrete Products and Their Accessories Installed in Air-Handling Spaces.

Testing and listing of plenum rated wiring methods, equipment and devices has nothing to do with the toxicity of the fumes released when something melts but has everything to do with visible smoke release and optical density levels. The idea is to make sure that if a cable or plastic cable tie melts in a plenum, the smoke released back into the return air, and recirculated back into the building supply air system isn't so dense that it blocks emergency lights and exit signs from being seen by building occupants during egress.

Below is a sample of NFPA 731. For the complete section, see the actual NFPA 731 text at NFPA.ORG. Once there, click on the free access link to the latest edition of  NFPA 731.

4.6.3 Wiring.

4.6.3.1 The installation of all wiring, cable, and equipment shall be performed in accordance with NFPA 70, Article 725 or Article 800, where applicable.

Below is a sample of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the latest NEC^® edition of NFPA 70.

300.22(C)(1) Nonmetallic cable ties and other nonmetallic cable accessories used to secure and support cables shall be listed as having low smoke and heat release properties.

Informational Note: One method to determine low smoke and heat release properties is that the nonmetallic cable ties and other nonmetallic cable accessories exhibit a maximum peak optical density of 0.50 or less, an average optical density of 0.15 or less, and a peak heat release rate of 100 kW or less when tested in accordance with ANSI/UL 2043-2008, Fire Test for Heat and Visible Smoke Release for Discrete Products and Their Accessories Installed in Air-Handling Spaces.