Compact Fluorescent Light (CFL) Bulbs

CFL ManWhy are CFLs a better choice?

Switching from traditional light bulbs to CFLs is a simple and effective change every American can make to reduce energy use at home and prevent climate change. Because lighting accounts for close to 20 percent of the average home's electric bill, changing to CFLs provides a quick return on your investment. In fact, a CFL will last approximately 10 times longer and use about 73% less energy! Over the lifetime of a CFL a homeowner can save $57.50 on just one bulb.

If every home in America replaced just one incandescent light with an ENERGY STAR rated CFL, it would save enough energy to light more than 3 million homes and prevent greenhouse gas emissions equivalent to those of more than 800,000 cars annually.

Do CFLs contain mercury?

CFLs contain a very small amount of mercury sealed within the glass tubing - an average of 5 mgs which is roughly equivalent to the tip of a ball-point pen. Mercury is an essential element in CFLs and is what allows them to be an efficient light source. Many manufacturers are taking significant steps to further reduce mercury used in their fluorescent lighting products, thanks to technological advances and a commitment from the members of the National Electrical Manufacturers Association.

Should I be concerned about the mercury in CFLs?

CFLs are safe to use in your home. No mercury is released when they are in use and they pose no danger to you or your family when used properly. However, CFLs are made of glass tubing and can break if dropped or roughly handled. Be careful when removing the lamp from its packaging, installing it, or replacing it. Always screw and unscrew the lamp by its base, and never forcefully twist the CFL into a light socket by its tubes. Used CFLs should be disposed of properly (see below).

What should I do if a CFL breaks?

Because there is such a small amount of mercury in CFLs, your greatest risk is getting cut from glass shards. Research indicates that there is no immediate health risk to you or your family should a CFL break and it's cleaned up properly. You can minimize any risks by following these clean-up and disposal guidelines:

  •     * Sweep up-don't vacuum-using stiff paper to collect all of the glass fragments and fine particles.
  •     * Place broken pieces and the paper in a 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 towel in the plastic bag as well.
  •     * Sticky tape such as masking tape or duct tape can be used to pick up small pieces and powder. Also place the tape in the bag.
  •     * Seal the bag tightly inside a second bag. Label the bag as "BROKEN CFL"
  •     * If weather permits, open windows to allow the room to ventilate.
  •     * Wash your hands.
  •     * Set the bag out of reach of children until you can dispose of it at your local Regional Collection Center.

What should I do with a CFL when it burns out?

When a CFL burns out it may smoke a little or the plastic base may appear singed or burned. This is normal and is NOT a fire hazard. The Department recommends that consumers take CFL's to your local Regional Collection Center. ENERGY STAR rated CFLs have a warranty. If the CFL has failed within the warranty period, you should return it to your retailer for replacement.

What is the white powder I see inside my fluorescent bulb?

The white powder that you see inside a fluorescent lamp is called phosphor, which is a substance that emits white, visible light whenever it absorbs light waves. This invisible light travels to the phosphor coating on the bulb, where it is transformed into light visible to the human eye.

What is mercury?

Mercury is an element that can come from both natural and man-made sources. Coal fired power plants are a primary man-made source, as mercury that naturally exists in coal is released into the air when coal is burned to make electricity. Coal-fired power generation accounts for roughly 40% of the mercury emissions in the U.S. Because using CFLs actually reduces mercury emissions from coal-fired power plants, CFLs are more energy efficient. A coal-fired power plant will emit 13.6 milligrams of mercury to produce the electricity required to use an incandescent light bulb, compared to only 3.3 milligrams for a CFL.

EPA offers additional information and resources on all sources of mercury at


DNR Contact DNR Contact
Kathleen Hennings
Susan Johnson