Compact Fluorescent Light Bulbs 
How does a compact fluorescent light bulb work?

Fluorescent light bulbs (including compact fluorescents) are more energy-efficient than regular bulbs because of the different way they produce light. Regular bulbs (known as incandescents) create light by heating a filament inside the bulb. The heat makes the filament white-hot, producing the light you see. A lot of energy used to create the heat that lights an incandescent bulb is wasted.

A fluorescent bulb contains a gas that produces invisible ultraviolet light (UV) when the gas is excited by electricity. The UV light hits the white coating inside the fluorescent bulb and the coating changes it into the light you see. Because fluorescent bulbs don't use heat to create light, they're far more energy-efficient than regular incandescent bulbs.

What should I do if a CFL breaks?

The amount of mercury in a CFL is so small you're only at risk from the broken glass when a CFL breaks. There is no immediate health risk to you or your family from a broken CFL that's cleaned up properly. Follow these clean-up and disposal guidelines:

• Sweep up -- don't vacuum -- the glass fragments and fine particles.
• Place broken pieces in a sealed plastic bag and wipe the area with a damp paper towel to pick up any stray shards of glass or fine particles. Put the used paper towel in the plastic bag as well.
• If weather permits, open windows to ventilate the room.

For more information on CFLs and mercury, visit Energy Star's Frequently Asked Questions page.