Unused cable in ceilings and walls raises questions over health hazards
National Fire Code requires removal of cable with combustible jackets
9/6/2006 2:20:00 PM By: Grant Buckler
Your network keeps evolving, carrying more types of information - and requiring regular upgrades of everything from network interface cards to the cabling itself. But as it evolved, your network has probably left an undesirable legacy behind it in walls and ceilings.
Abandoned communications cable has been quietly accumulating above ceiling tiles, inside plenums and behind drywall for several decades. It’s a serious problem not only because of the space limitations but because of the fire hazard and possible other health hazards it presents.
“I think there should be a concern,” says Roberta Fox, president of Fox Group Consulting Inc., a telecommunications consultancy in Mount Albert, Ont. “I don’t think there’s an awareness of it in Canada.”
There may be more awareness soon. While the National Electrical Code in the U.S. has for several years required abandoned cable to be removed unless it was earmarked for future use, Canada had no comparable requirement. But the 2005 edition of the National Fire Code requires removal of any disused optical fibre, cable with combustible jackets or installation, or electrical cable, as well as non-metallic cable raceways.
inspectors can order removal
The clause contains significant loopholes, allowing cable to remain if its is enclosed within the structure or finish of the building (for instance, behind drywall or concrete), if removing it would disturb the building’s structure or if it cannot be removed without disturbing live cable. The net effect, says Philip Rizcallah, senior technology advisor at the National Research Council’s Canadian Code Centre, is to give inspectors the authority to require removal during renovations.
The new code is not yet law in most of the country. Rizcallah explains that it is a model code, which provincial and territorial authorities can adopt as is, adapt to their needs or ignore. But the abandoned cable provision will probably be adopted unchanged across the country, he says - it is already part of the federal code that applies to Crown buildings.
Not that regulations are the only reason for removing abandoned cable. Craig Gilian, associate principal and senior designer at DataCom Design Group, Inc., in Austin, Tex., says older cable in particular presents a serious fire hazard. Pound for pound, the polyvinyl chloride (PVC) jackets on much of this cable provide a fuel load “roughly equivalent to gasoline,” he says. And because of the way they run throughout buildings, PVC-coated cables will spread a fire throughout a building - “dripping molten plastic along the way to start new fires,” Gilian says.
Frank Bisbee, who runs the Wireville.com cabling news Web site and is president of Communication Planning Corp. in Jacksonville, Fla., says even so-called limited-combustible cables are not fireproof. And when they do burn, many types of cable jackets give off toxic gases.
Bisbee adds another concern: lead. Many PVC cable jackets contain lead, and Bisbee says the lead in the dust coming off these cables is enough to exceed safe levels.
Given that these cables sometimes run through cold-air return plenums that are part of the building’s air-circulation system, “we’ve got a problem that will rival asbestos,” Bisbee says.
Whatever the codes say, Gilian observes, the reality is that nobody is likely to be forced to remove abandoned cable until the premises are inspected during renovations. Does that mean you should forget about the issue until you renovate? “From a life safety point of view, of course not,” Gilian says. But he allows that in reality, many building owners and tenants will do exactly that.
When the time does come to confront the issue, it can be tricky. One concern is who is responsible for abandoned cable in leased office space - the landlord or the tenant. Gilian says the rule of thumb is that it’s the landlord’s responsibility unless the lease specifically addresses it. The question is likely to arise more and more in landlord-tenant negotiations.
When an organization does have abandoned cable to remove, Gilian says, the first step is a survey to determine the extent of the problem. Cables - both those still in use and those to be removed - need to be tagged. Care must be taken not to cut live cables. The project probably requires the services of a cabling contractor to do the actual removal work and a consultant to oversee and administer the contract, he suggests.
Removing abandoned cable can be time-consuming and expensive, and it’s tempting to ignore the problem - but that may not be an option for much longer.](“http://ad.ca.doubleclick.net/click;h=v8/3ae7/0/0/*/g;231020508;0-0;1;25970414;2321-160/600;38836942/38854699/1;;~okv=;tile=4;pos=skyscraperros;sz=160x600;~sscs=?http://www.itworldcanada.com/”)