A: CFLs are a fluorescent bulb designed to emit as much light as traditional light bulbs while using less energy. CFLs use about 75 percent less energy than standard incandescent bulbs and can last up to 10 times longer. CFLs also produce about 75 percent less heat, so they're safer to operate and can cut home cooling costs.
A: From the Underwriters Laboratory, which is responsible for testing and certifying certain electric products:
For as long as anyone can remember, light bulbs burn out the same way - a pop, a flash and, when shaken, the familiar rattle confirming that the bulb needs to be changed. With CFLs, everything consumers know about a bulb burning out changes.
"People expect to see the bright flash and to hear the popping like a traditional incandescent bulb, but the burn out of a CFL is different. The light dims over time and might produce a more dramatic pop, emit a distinct odor, and maybe even release some smoke," said Drengenberg.
In some cases, Drengenberg said that the plastic at the base of a CFL can turn black, but comments that this is also normal in most cases, as safety standards require the use of special flame retardant plastics in the base that do not burn or drop particles.