How do CFLs Work?
CFLs produce light differently than incandescent bulbs. In an incandescent, electric current runs through a wire filament and heats the filament until it starts to glow. In a CFL, an electric current is driven through a tube containing argon and a small amount of mercury vapor. This generates invisible ultraviolet light that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light.
CFLs need a little more energy when they are first turned on, but once the electricity starts moving, use about 75 percent less energy than incandescent bulbs. A CFL’s ballast helps "kickstart" the CFL and then regulates the current once the electricity starts flowing.
Older CFLs used large and heavy magnetic ballasts that caused a buzzing noise in some bulbs. Most CFLs today — and all ENERGY STAR qualified CFLs — use electronic ballasts, which do not buzz or hum.
For more information on CFLs and to learn how to get the most from them, visit www.energystar.gov
Connections Between Mercury and CFLs
Using CFLs reduces the amount of mercury released into the environment
- Mercury is found in many rocks including coal. When coal is burned at a utility power plant to produce electricity, mercury is released into the environment.
- Coal-burning power plants are the largest man-made source of mercury emissions to the air in the United States, accounting for about half of all domestic human-caused mercury emissions (source: 2005 National Emissions Inventory).
- Using energy-efficient CFLs reduces demand for power, which in turn reduces the amount of mercury released into the environment by coal-burning power plants.
CFLs contain very small amounts of mercury
- Mercury is an essential part of CFLs; it allows the bulb to be an efficient light source.
- On average, CFLs contain abut four milligrams of mercury sealed within the glass tubing. By comparison, older thermometers contain about 500 milligrams of mercury – an amount equal to the mercury in over 100 CFLs.
- Manufacturers of fluorescent lighting products are working to reduce the amount of mercury content in CFLs.
- No mercury is released when the bulbs are intact (i.e., not broken) or in use, but CFLs release mercury vapor when broken.
Why use CFLs if they contain mercury?
Small amounts of mercury can be released into the environment when CFLs break, or if they are improperly disposed of at the end of their useful lives. The total amount of mercury that could be released into the environment through breakage and improper disposal, however, is small compared to the amount of mercury that doesn't get released into the environment because Americans are choosing energy-efficient CFLs, reducing demand for electricity.
Information provided by http://www.epa.gov/mercury/consumerinfo.htm#cfl.
Cleaning up a Broken CFL
Fluorescent light bulbs contain a small amount of mercury sealed within the glass tubing. When a fluorescent bulb breaks in your home, some of this mercury is released as mercury vapor. The broken bulb can continue to release mercury vapor until it is cleaned up and removed from the residence. To minimize exposure to mercury vapor, EPA recommends that residents follow the cleanup and disposal steps described below.
Before Cleanup
- Have people and pets leave the room
- Air out the room for 5 - 10 minutes by opening a window or door to the outdoor environment
- Shut off the central forced air heating/air-conditioning system, if you have one
- Collect materials needed to clean up the broken bulb
During Cleanup
- Be thorough in collecting broken glass and visible powder
- Place cleanup materials in a sealable container
After Cleanup
- Promptly place all bulb debris and cleanup materials outdoors in a trash container or protected area until materials can be disposed of properly. Avoid leaving any bulb fragments or cleanup materials indoors
- If practical, continue to air out the room where the bulb was broken and leave the heating/air conditioning system shut off for several hours
View the detailed recommendations at http://www.epa.gov/cfl/cflcleanup-detailed.html.
Download and print a three-page PDF version of this overview and the detailed recommendations here.
What Happens When a CFL Burns Out?
CFLs have a very different death than their incandescent cousins. Incandescent bulbs tend to burn out with a pop and a flash, and when shaken, the familiar rattle confirms the bulb needs to be changed. With CFLs, light dims over time and the lamp may produce a more dramatic pop, emit a distinct odor and even release some smoke. Sometimes the plastic at the base of the CFL will turn black, which is normal.
Recycling and Disposal After a CFL Burns Out
Why is Recycling CFLs Important?
- Recycling prevents the release of mercury into the environment
- Other materials in the bulbs get reused
- Your area may require recycling
How and Where Can I Recycle CFLs?
- Contact your local waste collection agency
- Visit your local retailers; many hardware supply stores and other retailers offer in-store recycling
- Find out about mail-back services; some bulb manufacturers and other organizations sell pre-labeled recycling kits that allow you to mail used bulbs to recycling centers
For more information about any of the above-mentioned options, visit www.Earth911.com