“Absolutely, categorically untrue. An urban myth.” That’s how National Lighting Bureau Chair Howard P. Lewis (Visioneering Corporation) describes claims that compact-fluorescent lamps (CFLs) pose a fire hazard when they reach the end of their lives. Mr. Lewis, who represents the Illuminating Engineering Society of North America (IES) on the Bureau’s board of directors, dismissed the claim as “a vampire rumor: It feeds on fear and refuses to die.”
Ironically, the basis of the rumor might very well be the normal performance of well-designed CFLs’ fire-safety systems. In most CFL end-of-life situations, these safety systems remain dormant, Mr. Lewis said. “Most commonly, CFLs get somewhat dimmer as they enter failure mode, and then expire or, in some cases, expire with a popping sound similar to the sound made by an incandescent bulb when it ‘gives up the ghost.’” In some cases, however, capacitors, resistors, or other electronic components located in the CFL's ballast may fail in such a way that they make a slight sizzling sound and/or cause odor or smoke. It’s even possible for the ballast housing to discolor or deform, principally because of the fire-inhibiting chemicals incorporated into the plastic that the housing is fabricated from. Such reactions pose no danger, Mr. Lewis said. “What it really is,” he noted, “is a demonstration of the CFL’s remarkable fire-safety design working exactly as it’s supposed to, to protect consumers and keep them safe.”
According to Snopes.com (http://www.snopes.com/inboxer/household/cflbulb.asp), the well-respected fact-checking Website, “[H]ealthy CFL bulbs may emit a bit of smoke and have burnt-looking bases when they die, but that’s as it should be – there’s no fire danger to any of that and, indeed, the bulbs are functioning properly when they act that way.” The Snopes Website also quotes the National Geographic Green Guide as stating CFL bulbs “burn out when the ballast overheats and an electronic component, the Voltage Dependent Resistor (VDR), opens up like a fuse in your home’s fuse box, shutting off the circuit and generating heat and possibly a small amount of smoke. This might sound dangerous, but the VDR is a cut-off switch that prevents any hazards.” In some cases, the ballast’s plastic housing can melt slightly where the glass coil connects to the ballast, the Green Guide states, noting that this “is simply a sign that the heat is escaping as intended in the design of the bulb.”
Those who want a complete technical description of the process can download a free white paper published by the National Electrical Manufacturers Association (http://alturl.com/z9jht).
Established in 1976, the National Lighting Bureau is an independent, IRS-recognized not-for-profit, educational foundation that has served as a trusted lighting-information source since 1976. The Bureau’s services are made possible by the generous funding of its sponsors; professional societies, trade associations, manufacturers, and agencies of the U.S. government, including, among others:
Illuminating Engineering Society of North America (IES);
Imperial Lighting Maintenance Company;
interNational Association of Lighting Management Companies (NALMCO);
Lighting Alternatives (a division of Visioneering);
Lighting Controls Association;
Lutron Electronics Company, Inc.;
National Electrical Contractors Association (NECA);
National Electrical Manufacturers Association (NEMA) and its enLIGHTen America campaign;
OSRAM SYLVANIA; and
U.S. General Services Administration.
Obtain more information about the Bureau by visiting its website (www.nlb.org) or contacting its staff at [email protected] or 301/587-9572.