Q Can compact fluorescent light bulbs (CFLs) create a fire hazard? We had one that smoked recently. The base was red hot. What is the potential danger?

A Although not common, there have been cases of CFLs smoking, emitting a pungent odor, sometimes even flashing. That raises the worry, and rightly so, that the bulbs might be fire hazards. But experts say they are not. Indeed, they say those worrisome events indicate that fire is being avoided.

Basically, what is happening is that the circuitry in the bulb is failing. This can happen at the end of its useful life. At that time, the arc contained in a fluorescent light sometimes elevates the temperature of the plastic near one end of the tube, according to the U.S. Environmental Protection Agency's Energy Star. It can produce limited smoke and odor. In some cases, a flashing arc internal to the fluorescent tube or ballast may occur. In extreme cases, a deformation, significant distortion or small breach of the plastic material may happen.

All this means that safety measures built into the bulb are managing heat and preventing subsequent hazards.

However, end of life isn't the only cause of smoking and odor. It also can happen when CFLs are defective or used inappropriately.

Air needs to circulate around the bulbs. Generally, CFLs can be used in enclosed fixtures when they are not recessed, according to GE Lighting. Such fixtures (for example, a can light in the ceiling that has a cover over the bulb) create temperatures that are too high, leading to early failure.

Another cause for failure could be improperly screwing the bulb into the socket. Don't hold the bulb by the glass, as you would with an incandescent light. That can cause the vacuum seal or tubing to break, exposing components to oxygen and making them more liable to become defective or overheat. Instead, hold a CFL bulb by its plastic base.

If a fluorescent light begins to smoke or smolder, immediately shut off the power to the light. Once it has cooled, remove it from the light socket. Then e-mail cfl@energystar.gov to report the incident. Include the manufacturer's name and model number on the CFL base and how and where the bulb was used. Also, be sure to contact the manufacturer and ask for replacement or refund. (It's always a good idea to keep the receipts for these purchases.)

When buying a CFL, look for UL on the base, which means it meets UL standards. Or just buy Energy Star-qualified bulbs. They incorporate end-of-life requirements and higher safety standards. Although the base or glass tubing may darken, an Energy Star CFL should never catch on fire.

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