Call to Fire-Rate Cables Tabled but Still Smoldering


NFPA's recent World Safety Conference in Las Vegas provided a plethora of action and scuttlebutt on various code and standard developments. One key standard revision voted on was the proposed revision to NFPA 90A, Standard for the Installation of Air-Conditioning and Ventilating Systems . In a nutshell, the proposed revision would have required all electrical cabling in ceiling air plenums be fire-rated. The NFPA membership, however, returned the report. According to Bob Vondrasak, NFPA's vice president, Codes and Standards Operation, that means the document will not be released as is, but instead has been returned to the committee for further processing for another revision cycle. It also means the current edition of 90A is unaffected and will continue to be published.

"The Standards Council will determine whether the 90A committee can go back to the ROC [Report on Comments] stage, let the ROP [Report on Proposals] stand and just call for new comments, or will have to go all the way back to the ROP stage and call for proposal again," said Vondrasak. "The Council will also determine what revision cycle the document will enter."

One person who would like to see the change succeed is John Michlovic, National Marketing and Technical Manager of H.H. Robertson Floor Systems. Michlovic has repeatedly written and lectured on this matter and has some very firm opinions. According to Michlovic, of the 700,000-plus office buildings in the United States, at least 500,000 have combustible, plastic-coated cabling in the ceiling or plenum spaces. If telecom cable in ceiling plenums burns, he said, it can create toxic, highly acidic smoke that can recirculate and incapacitate building occupants. As it stands now, he said, NFPA 90A allows an exception for combustible or "CMP" cable. The problem, in his eyes, is that the exception, made in 1975, was intended for limited use. However, limited use was never written into 90A as a restriction. "As a result, the use of CMP cable in plenums remains unrestricted and there are now massive quantities of CMP cable in plenums," said Michlovic.

"We estimate that there's some 60 billion ft. of cable out there," added Pat Lindner, communications cabling solutions global business manager with DuPont, who is hopeful NFPA will eventually approve the 90A revision. "It's good that the code bodies are recognizing that not only is there a lot of cable, but a lot of combustible cable," he said.

For the record, NFPA, in its 2002 edition of NFPA 70, did mandate that abandoned cable be removed, but Michlovic points out that's only if it's accessible and not tagged for future use. Furthermore, the code change does not address new or active cable, which he said is equally dangerous in a fire.

Michlovic believes existing plenum spaces should be cleared of all abandoned cable not in conduit or an enclosed steel raceway or cells. DuPont is alsohammering home the message to clean out cabling, and in fact, has started a service to evaluate and remove abandoned cable for building owners. The company also recently launched a new limited combustible cable that it claims reduces cable smoke production up to 20 times that of standard cable.

While that's a start, Michlovic said the industry must also look elsewhere when it comes to smoke penetration and cabling. For example, he said poke-through outlets must be redesigned to prevent smoke penetration before they can be safely used as a wire-distribution method. "Also, existing poke-throughs must be caulked with fire-safing materials to prevent smoke penetration through floor slabs," he said.

Lindner, however, is not as cynical as his industry counterpart, and thinks the NFPA 70 provision will make a greater impact as more jurisdictions adopt it. Based on the 3,000 RFIs DuPont received from owners interested in its cable-removal program, the company is also optimistic that owners, given some options, will remove the cable, particularly since it should improve HVAC system performance.

The Council is scheduled to meet in July to determine these issues.

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