Frequently Asked Questions

Q. How do CFLs work?
A. Unlike incandescent bulbs which use a filament, compact fluorescent light bulbs (CFLs) give off light when a mixture of gases are exposed to ultraviolet light from mercury atoms.

Q. How much can I save if I use CFLs?
A. On average you can expect to save $30 or more in energy costs over the life of the bulb. CFLs do cost more upfront, but this cost is recovered after using the CFL for 500 hours.

Q. Where is the best place to use a CFL?
A. For the biggest energy savings, replace standard incandescent light bulbs that are used for several hours at a time, like a porch light or an area light.

Q. Is it a good idea to turn CFL bulbs off when I leave the room?
A. Yes! Turning off lights always saves energy. Turning a CFL bulb on and off very frequently (i.e. flipping the switch up and down) will shorten its life. A good rule-of-thumb might be to turn off the lights whenever you leave the room for five minutes or more.

Q. Do CFL bulbs work outdoors?
A. CFL bulbs generally work fine outdoors. They should always be protected against rain and snow.

Q. Do CFLs have a longer life than incandescent bulbs?
A. Incandescent bulbs generally last 500 to 2,000 hours. ENERGY STAR®® qualified CFLs are guaranteed for 6,000 hours.

Q. How do I get the special pricing?
A. Visit a participating retailer. Special pricing is valid on ENERGY STAR® qualified CFL purchases of 12 CFLs or less.

Q: How can I tell if something is ENERGY STAR® qualified?
A: The easiest way is to look at the product packaging. If you do not see a label on the packaging, you should ask the sales clerk to help you.

Q. Do CFL bulbs flicker and hum?
A. Today's ENERGY STAR® qualified CFL bulbs turn on almost instantly, are quiet and don't flicker.

Q. I tried CFL bulbs a few years ago and didn't like them. What's changed?
A. Early CFL bulbs were expensive and many people didn't like their performance. Users complained about:

Today's ENERGY STAR® qualified CFLs are a whole new generation of products. They cost much less while offering great performance. You can buy CFLs with as much light output as you want. They turn on almost instantly, are quiet, and don't flicker. Light quality is excellent. CFLs come in a wide variety of shapes, most of which are no larger than the standard bulbs they replace. They also last much longer than standard bulbs.

Q. Do CFL bulbs burn out?

A. A CFL bulb will occasionally burn out. More often, it will continue to operate, gradually producing less light as it ages. However, ENERGY STAR® qualified CFLs must produce at least 80 percent of their rated light output at 40 percent of their rated life.

If your CFL bulb fails out of the package or before the manufacturer's warranty expires, you can usually return it to or contact the manufacturer, who is ultimately responsible for warranty claims. Be sure to save the proof-of-purchase and register receipt to document your claim.

Q. How do I dispose of a burned-out CFL?
A. Since CFLs do contain mercury, it is important that you do not throw them in your garbage can, if at all possible. Instead, follow these steps:

Q. What you should know about CFLs and mercury?
A.You should also know that CFLs do contain a small amount of mercury - it's what makes the bulb so energy efficient. But it's important to know that CFLs are safe to use. No mercury is released when the bulbs are in use and they pose no danger when used properly.

Q. What is mercury?
A. Mercury is a naturally occurring metal which has several forms. The metallic mercury is a shiny, silver-white, odorless liquid. If heated or allowed to evaporate, it is a colorless, odorless gas. When liquid mercury is spilled, it forms droplets that emit vapors into the air. However, when mercury emissions deposit into lakes and oceans, they can transform into a highly toxic form that builds up in fish.

Q. What household items contain mercury?
A. Mercury may be found in the following household items:

Q. How do I dispose of a broken CFL?
A. According to guidelines established by the Environment Protection Agency, you can safely clean up the spill yourself if the mercury spill is less than one to two tablespoons and is limited to a small area. If the mercury spill is larger, isolate the contaminated area and call your local environmental agency. The small amount of mercury in a fluorescent light bulb is not likely to cause a health problem, but it still should be cleaned up immediately. Before beginning clean-up:

On a smooth surface On a rug or carpeting When you are done... Questions? For more information on the proper disposal of CFLs or the safe clean-up of mercury spills, please visit: