BIG CHANGES ON THE HORIZON FOR COMMUNICATIONS & DATA CABLING
A proposed change in the National Electric Code for the NEC 2005 may force far-reaching changes in communications cabling. A move to replace CMP (plenum rated cable listing) with a variation on "limited combustible" cable listing could force cable manufacturers to rework their entire plenum cable product lines.
Throughout the 3 year development cycle for the NEC (National Electric Code) 2002, there was a significant jousting match between two groups over the NFPA's (National Fire Protection Assoc.) acceptance of a "limited combustible" cable listing as an OPTION to NFPA 262 - CMP plenum rated cable. The only cables that have passed the test for limited combustible are insulated and jacketed with FEP (fluorinated ethylene propylene). In the end, the group representing the interests of several chemical and testing companies won the match and the NFPA approved the option.
Since then, the optional "limited combustible" CMP cable has had almost no market acceptance. A poll of more than 50 distributor locations found the limited combustible product in stock at only ONE location. Most of the distributors that were contacted were unfamiliar with this product.
The group that pushed the limited combustible cable as "just an option" has changed their tune. Now, they want the code (law) to REQUIRE the consumer to purchase the limited combustible type cable for use in air systems. Under this new strategy, the NEC 2005 would no longer recognize the current CMP listing for new installations. Unfortunately, the strategy of manipulating the code process may run afoul of the legal system that regulates the code (law) making process.
On August 19-21, 2003, the NFPA Air Conditioning Technical Committee met in Santa Ana, CA. The NFPA 90A committee (NFPA 90A - Standard for the Installation of Air-Conditioning and Ventilating Systems) voted to take the first step towards revamping the code (NEC 2005) that covers all plenum cables. Essentially, the proposal included revising the testing and listing for limited combustible cable (for use in Air-Conditioning and Ventilating Systems), AND dropping the current listing for CMP (NFPA 262/UL910) return-air plenum approved cables. Almost half of the attendees and guests were connected with the group (chemical & testing companies) pushing for this proposed change.
The NFPA 90A committee member that we spoke with said, " What concerns us is the committee's failure to address the incapacitation factor." The debate continues to rage over the question "Is limited combustible cable really safer?"
The FEP jacketing and FEP insulating materials used in limited combustible cable are subject to heat decomposition and the emission of sublethal toxic fumes. Some of the fumes can incapacitate (by blinding and choking) building occupants. Current and proposed testing makes no provision to recognize toxicity or emissions that are essentially colorless (i.e., hydrogen fluoride, which converts to hydrofluoric acid upon contact with any moisture).
FEP materials are normally very stable. But, when they burn or are heated, the halogens separate and become highly reactive - forming toxic and highly corrosive gases that can significantly damage organic, inorganic and metallic materials. Hydrogen fluoride is one of the gases produced from heat decomposition of FEP.
Hydrogen fluoride vapor causes severe irritation and deep-seated burns of the eye and eyelids if it comes in contact with the eyes. If the chemical is not removed immediately, permanent visual defects or blindness may result. Hydrofluoric acid is a severe irritant to the nose, throat, and lungs. Severe exposure causes rapid inflammation and congestion of the lungs. Death may occur from breathing this chemical.
The cabling industry is inundated by a media blizzard reminding the users about the high performance (electrical) properties and the low fire hazard associated with FEP. Face it, FEP is hard to burn.
There are two major areas of concern that remain un-addressed in the NEC 2002 (National Electric Code). As the building industry is besieged with litigation revolving around the mold toxicity issue, we asked the question: "Does the testing process for fire safety measure the TOXICITY of the cables when overheated or burned?" The answer is shockingly "NO".
Most of the cabling industry participants understand the meaning of terms like: fire, smoke and fuel load. The testing for the current code measures only flame spread, and smoke index. The testing does not measure heat decomposition, thermal toxicity, toxic gases or the incapacitation factor.
Many safety experts feel that the NFPA revision of the scope that defines the safety issues should include sublethal toxicity and the incapacitation factor. If the testing does not recognize these other areas, then the full safety factor is not included. As a simple example: imagine chaining your legs to a large anchor and dropping to the bottom of the pool. The chain and anchor won't kill you, drowning will.
Communications infrastructure (cabling & connectors) is focused on two major areas - performance and safety. Typically, performance is placed in the arena of standards (EIA/TIA) and safety is related to codes (NFPA/NEC). Most of the information provided by the manufacturers deals with performance and interoperability. The information about safety is usually described in relationship to meeting certain codes.
Remarkably, fire safety performance SUSTAINABILITY is not measured. Who wants a product that is safe today and useless tomorrow? You should know how long these products maintain their fire safety performance. This important aspect of safety is also completely absent from the criteria of the current of the NEC (2002) and the proposed criteria of the upcoming NEC (2005).
Cables that are listed and approved for use in air spaces (CMP & LC) should be tested and monitored to determine if the safety performance falls below the minimum code threshold. Fire safety equipment such as sprinkler systems and extinguishers are periodically monitored to assure performance that meets a code requirement. Fire safety performance is required over time. Currently the cable fire safety performance is only tested once.
During the past several decades, you may have seen the effect of product “toxicity” on various industries and the victims. No one can ignore the echoing repercussions from tobacco, asbestos, and lead. The finger pointing and lawsuits continue to be prominent in the news. One common area of the litigation over these products seems to be the failure to warn the buyers/users about the dangers.
In the last cycle of the National Electric Code (NEC 2002) another important safety development for the cabling industry took place. The need to reduce the fuel load in the return air plenums was identified and the code added a provision for the removal of "abandoned" cable.
In the commercial real estate world, cable removal is a hot topic. Most building owners can work with existing tenants to comply with the NEC 2002 mandate for the removal of abandoned cable. The tenants may minimize the downstream costs associated with cable removal by maintaining proper labeling and keeping good cable management records. By working with the building owners the new tenant might accept your cabling infrastructure. The old tenant and the new tenant will both save money.
Further Info: Web Resources:
NFPA's Research Foundation examines how quickly smoke incapacitates
Study aims to assure escape from burning buildings
NFPA smoke toxicity
International Study of the Sublethal Effects of Fire Smoke on Survivability and Health
Phase I final Report
Combustion atmosphere toxicity of materials intended for internal cables - white paper by Borealis
Link to Mike Holt's - National Electric Code Internet Connection: Toxicity and Safety in Communication Cabling
Hydrofluoric Acid MSDS (Material Safety Data Sheet) by DuPont
Occupational Health Guideline for Fluorine
Occupational Health Guideline for Hydrogen Fluoride
UL limited combustible cable testing program revised:
Link to article on critical cabling safety issues:
"Cabling what you don´t know can kill you" article by Stephen Saunders
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