Compact fluorescent bulbs, or CFL bulbs, are popular in homes to reduce energy consumption and save on electric bills. Many consumers are concerned about the mercury content in these bulbs and have questions.
Do CFLs Contain Mercury?
Yes, CFL bulbs contain mercury. However, it is important to note that this mercury stays inside the bulb during normal use— you don’t have to worry about it if the bulb is unbroken. Proper handling, storage, and disposal keep the mercury from being a problem.
How Much Mercury Is in a CFL Bulb?
CFL bulbs contain a very small amount (4-6 mg) of elemental mercury inside the glass tubing. As a comparison, an oral thermometer can contain about 500 mg of elemental mercury. Some older thermostats used in heating systems can contain around 3,000 mg (3 grams) of mercury in a single unit.
That’s not to say the mercury in a CFL bulb is completely insignificant. With the right care and disposal, it doesn’t have to be an issue.
What Does the Mercury in a Fluorescent Bulb Do? Why Use It at All?
The mercury in a CFL bulb becomes excited when an electric current passes through the gas inside the tube. This process causes the mercury atoms to emit ultraviolet (UV) rays, which are invisible to the human eye.
To make it visible, the inside of the bulb is coated with a phosphor material. When the UV rays strike this coating, it fluoresces, converting the invisible energy into white light that can illuminate a room efficiently.
Before CFL bulbs, light would be generated by heating a filament. However, this process consumed more energy and produced more waste than the mercury method. Nowadays, LED lights are on their way to replacing CFL bulbs as they are even more energy efficient, last longer, and don’t use mercury.
Do CFL Bulbs Put Me at Risk for Mercury Poisoning?
When bulbs remain intact, there is no risk of being exposed to mercury. If it breaks, there is a possibility of inhaling the mercury. Please read our much more detailed write-up on inhaling the vapors.
Briefly handling a broken CFL bulb does not put you at risk through contact alone. This is because skin does not absorb elemental mercury well. Touching a broken bulb is considered non-toxic. The biggest concern is hurting yourself on sharp pieces of broken glass.
Why Should I Be Concerned About Mercury?
Mercury poisoning occurs when too much mercury builds up in the body. Once absorbed, it can affect the nervous system, lungs, and kidneys. The symptoms of mercury poisoning are shortness of breath, nausea, vomiting, metallic taste, and headache, especially with prolonged or high-level exposure.
This becomes a concern when broken CFL bulbs are not cleaned up properly, or if there’s long-term exposure. Mercury in CFLs does not need to be an issue if they are handled and cleaned up correctly.
How Do I Prevent Bulbs From Breaking?
- Only handle bulbs after they have been cooled.
- Do not over-tighten bulbs; screw in only until snug.
- Use CFL bulbs with glass or plastic covers over the spiral tube, as they are more durable.
- Consider using a disposable cloth or towel under the bulb when changing it, so if it breaks, it can be easily managed.
How Should I Clean Up a Broken CFL Bulb?
- Open a window or door to ventilate the room, and if practical, turn off the heating/cooling system.
- Do not vacuum or use a broom, as it may spread the powder or vapor.
- For hard surfaces, use stiff cardboard to scoop up broken pieces and use sticky tape, such as duct tape, to pick up any remaining glass or powder. Using a flashlight may help to visualize the tiny beads of mercury.
- Wet wipes or wet paper towels can be used to clean hard surfaces and can then be discarded.
- Place all contaminated items in a plastic trash bag, seal them with duct tape, and place them in the outdoor trash or bring them to a disposal site in your area.
- Wash the skin well with soap and water after cleanup.
- If a spill involves a large volume of mercury or a large surface area, consider using a professional cleaning company that is licensed in environmental mercury cleanup.
- You may also access these cleanup guidelines online at: epa.gov/cfl/cleaning-broken-cfl
Have Questions? Call the Missouri Poison Center
Whether you break a CFL bulb or an old-fashioned thermometer, the Missouri Poison Center is open 24 hours a day, 7 days a week to answer your poison-related questions. As safer, more efficient bulbs arrive on the market, the CFL may one day be phased out of use. Until then, it’s always a good idea to be smart about the risks involved.
Frequently Asked Questions
CFLs were introduced to consumers in the 1980s but became more common in homes during the 1990s and 2000s as energy-saving alternatives to traditional incandescent bulbs.
Instead of heating a metal filament, CFLs create light by exciting gas and mercury vapor. This process uses far less electricity, making it more efficient for everyday use.
Yes. Many hardware stores and recycling centers accept CFLs. Recycling prevents mercury from entering landfills and allows valuable materials like glass and metals to be reused.
Production of CFLs has slowed as LEDs have become the preferred option. Some regions have phased them out, but they remain available in certain stores and markets.
CFLs contain mercury, requiring careful disposal. LEDs contain no mercury and are considered safer, though they can still contain small amounts of metals that should be recycled responsibly.
Referencing content from this page? Please attribute the Missouri Poison Center with either of these links: https://missouripoisoncenter.org/ or https://missouripoisoncenter.org/how-much-mercury-in-a-cfl-bulb/
Suggested APA citation:
Missouri Poison Center Trending Topics Blog. (2016, May 21). How Much Mercury Is in a CFL Bulb?. Missouri Poison Center. https://missouripoisoncenter.org/how-much-mercury-in-a-cfl-bulb/