Are Compact Fluorescent Bulbs A Fire Hazard?

Updated February 21, 2007

A Reader Writes The Green Guide:

As The Green Guide recommended, I installed compact fluorescent bulbs to save energy. But rather than be long-lasting, two of the Energy Wiser bulbs I put in burned out in less than a year. But what really worries me is that there are burn marks where the coil meets the base, and some of the plastic has melted. I've also heard from a friend that a fluorescent light caused a fire in a neighbor's apartment. Are compact fluorescent bulbs a fire hazard?

Paul
New York

The Green Guide Responds:

Although a melted plastic base might lead you to believe otherwise, the Energy Wiser compact fluorescent bulbs (CFLs) you purchased are not a fire hazard. In fact, the melted plastic and burn marks are a sign that the bulb was working just as it should.

If you look at the plastic base, or ballast, of the light bulb, you should see a symbol indicating that the ballast is UL certified, which means that the plastic on the exterior can safely function during bulb operation and at the end of the bulb's life. The fact that the plastic on your bulb's ballast melted and turned black is totally normal, says John Drengenberg, consumer affairs manager at Underwriters Laboratory (UL), the company that evaluates plastics for, among other things, flammability characteristics. A CFL generates light from an electric current that runs through glass tubing filled with gases. The electrified gases emit ultraviolet radiation, which then comes in contact with a phosphorous lining on the glass, thus creating light. Bulbs burn out when the ballast overheats and an electronic component, the Voltage Dependent Resister (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. The melted plastic you're seeing where the glass coil connects to the ballast is simply a sign that the heat is escaping as intended in the design of the bulb.

There's no mistaking the cost- and energy-saving benefits of CFLs over incandescent bulbs. When used properly, Energy Star-certified compact fluorescent bulbs average 10,000 hours of use versus 1,000 hours for an incandescent—and save 147 pounds of CO2 per year, if you swap out a 75-watt incandescent that you use four hours per day with a 19-watt CFL. In fact, switching to CFLs has such a drastic effect on reducing greenhouse gases that Australia aims to eliminate incandescents by 2010, and two California legislators have introduced the "How Many Legislators Does It Take to Change a Light Bulb?" act, which would ultimately ban the sale of energy-hogging incandescents in 2012 (although it has yet to grapple with the problem of mercury entering landfills as a result of improper disposal; see "What to Look For" below).

Why CFLs Die

Regarding the shortened life span of your bulb, there are a number of reasons why it may have burned out prematurely, most of which have to do with usage. Bulbrite, the company that manufactures Engergy Wiser bulbs, gave us the following possible explanations.

CFLs generate quite a bit of infrared heat, that is, heat that escapes the bulb into the surrounding room rather than heat that stays within the bulb itself, as in an incandescent bulb. While this design adds energy efficiency, it can shorten its lifespan or reduce its light output when used in an enclosed area, like a recessed-lighting or tightly enclosed ceiling fixture, where the infrared heat doesn't have room to dissipate. In order to maximize the lifespan of your bulb, use it underneath a lampshade or other open fixture that allows air to circulate around the bulb and infrared heat to escape. But not all enclosed fixtures will cause premature burn-out, says Russell Leslie, associate director of the Lighting Research Center at the Rensselaer Polytechnic Institute. "New Energy Star specifications require that ballasts specify maximum temperature requirements and that the fixture will not exceed those temperatures," he adds. So if you're looking to replace a light fixture, seek out those bearing the Energy Star label.

Also, "Repeatedly turning on a CFL shortens its burning life," says Leslie. You'll get the longest use from your compact fluorescents if you install them in rooms where the bulbs are on for long periods of time as opposed to rooms such as bathrooms that are only used for short periods, since turning light bulbs on and off adds wear and tear to the electrical components in the ballast. But turning lights of any variety off when you leave a room reduces energy consumption, says Leslie. "You might reduce its lifespan by a few days, but it's still usually worth replacing a frequently used incandescent with a CFL," he says.

Finally, while Bulbrite's Energy Wiser bulbs aren't prone to this particular problem, some compact fluorescent bulbs can be damaged when roughly handled or when screwed into the base by holding on to the glass coils. Energy Wiser's glass coils are directly connected to the ballast, or side-mounted, but other bulbs have glass coils that connect to the ballast via two straight, thin glass tubes. When handled roughly, the seal between the ballast and the thin glass tubes can crack, shortening the bulb's lifestpan. This is another situation in which you might see smoke or melting plastic where the glass connects to the ballast. But again, if the ballast is UL certified, its electrical current is interrupted by internal controls to prevent excessive heat and fire.

What To Look For

According to its web site, the U.S. Consumer Product Safety Commission has only recalled two brands of compact fluorescent bulbs (Durabright's 32 watt 3-way bulb and Teng Fei Energy Saving Light Bulbs) because of overheating and potential burn hazards, but to be safe and to ensure you get the best bang for your buck, always look for the UL symbol on a compact fluorescent's ballast. UL has researched plastics extensively to ensure that they can withstand high temperatures. Nevertheless, if something about your UL-certified product is particularly worrisome or if you think it poses an unusual hazard, Drengenberg says UL is always interested in looking at malfunctioning products in order to improve its standards. To report a problem, visit www.ul.com/consumers/ and click on the "Report a problem with a UL-certified product" link in the right-hand menu column.

Lastly, due to the very small amount of mercury in CFL bulbs (about 4.0 milligrams), though they pose no health threat if broken, they should still be disposed of at household hazardous waste sites to avoid mercury buildup in landfills. Better still, encourage retailers who sell CFLs to recycle them, as Ikea does, and encourage takeback programs similar to those being instituted for other electronics (see "Responsible Electronics Recycling"). Also, seek out lower-mercury bulbs. Philips just recently introduced its ALTO line of CFLs and fluorescent tubes, have 70 percent less mercury than fluorescent bulbs manufactured in 2001.

What To Look For...A Few Years From Now

Even though CFLs are getting away from their flickering, cold blue roots, early adopters are already shirking them in favor of light-emitting-diode (LED) bulbs and fiber optic lighting. Still expensive and more commonly available for use in residential accent lamps and chandeliers, LEDs are preferred over CFLs due to their focused light and their color variety. They also have a longer life and increased efficiency; current LED bulbs last up to 60,000 hours and can use as little as two watts of energy. Fiber optic lighting, already in use in grocers like Whole Foods and Albertsons, uses 80 percent less energy than halogen lights or incandescents and generates no heat (making them ideal for grocery-store freezers). One major manufacturer, Fiberstars (www.fiberstars.com), has plans to introduce residential fiber optic products within the next year or so.

Shopping Suggestions and Resources

CFL Recycling:
See www.ikea.com for stores in your area
See www.earth911.org for your local hazardous waste site

For help selecting an appropriate CFL for your home, see "Find an Energy-Saving Light Bulb".

The Green Guide's Light Bulb Product Report

Philips ALTO CFLs

LED bulbs:
www.theledlight.com
www.ccrane.com
store.sundancesolar.com