Abandoned cabling is a Pandora's Box.

The National Electric Code (NEC 2002) requires the removal of abandoned cable. In most structures, there is a substantial volume of communications cable.

Often, a large portion of this cabling is abandoned (not in use and no longer connected). This new code has been widely adopted by State governments and local authorities having jurisdiction.

The enforcement of these new code provisions is being reported throughout the country. The mandate for abandoned cable removal will be enforced.

The electrical inspectors, fire marshals, and building inspectors have a long reputation for strict enforcement when it comes to fire safety.

A building inspector or fire marshal starts looking at your installed cabling--first they find one problem ... then another ... and another ... and another ...

Removal of abandoned cable is focused primarily on Plenum cable (CMP). Prior to the code approval of the use of low smoke and low flame spread cable in the return-air-plenum spaces, all cables had to be placed in metal conduit.

The architects of the NEC (National Electric Code) did not include any provision dealing with the allowable volume of cable in the return-air plenum. Theoretically, you could fill the entire return-air plenum space with cable and still be code compliant. Clearly, the latest version of the National Electric Code (NEC 2002) is not perfect.

Initially, you may find that much of the abandoned cable was not installed by the current tenant.

Now, you may discover that there are significant quantities of cable in the return-air-plenum space that is NOT CMP (Code Approved and UL tested for use in return-air-plenum space).

Non-plenum cable installed in return-air plenum space must be removed even if it is in use. You might also find out that the cabling penetrations of the various firewalls have not been properly fire stopped.

This practice may have left the approved firewall condition looking more like Swiss cheese than code compliant.

For more than two decades, the cabling manufacturers have used PVC jackets on cables for both plenum and non-plenum rated applications. In making the cable, they add compounds with plasticizers and stabilizers. The plasticizers help make the PVC flexible.

The stabilizers helped maintain the compounds so the material stays pliable for a longer period of time. PVC in its normal state is rigid (like a PVC pipe). Here is the clincher: the stabilizer almost always contained LEAD, usually 5-10% by weight. In 2001, the PVC compound manufacturers developed a non-leaded stabilizer, which was made available at no increase in cost.

PVC breaks down over time and the decomposition is accelerated by increased temperature or humidity, even with stabilizers. The chalking on the surface of the cable jacket contains high levels of LEAD. This poses an exposure danger to the cabling technicians and the building occupants.

Some experts predict the LEAD-DUST from cabling decomposition could create another type of "sick building syndrome". The clean up associated with LEAD-DUST may be an entirely new chapter in maintaining Indoor Air Quality (IAQ)) and Indoor Environmental Quality (IEQ).

Several experts have analyzed the cabling scenario and determined that the majority of the costs for this clean up will be placed upon the building owners. Leases are being rewritten and the cabling in the building is being evaluated by many commercial real estate organizations. But that's just my opinion...

Frank Bisbee is a communications consultant with more than 31 years of experience, specializing in datacom cabling and related issues. His focus has expanded to public awareness and safety related issues surrounding datacom cabling and the workplace. He is very familiar with the code-making process and with the efforts of commercial real estate owners and managers to