Compact fluorescent light bulbs (CFLs) use 75% less energy than traditional incandescent bulbs and last about six times longer, but it’s no secret that CFLs contain a small amount of mercury (about 4 milligrams per bulb on average).

Like any glass product, CFLs tend to break occasionally, causing many homeowners to worry about potential mercury exposure and adverse health effects. So, just how dangerous is a broken CFL? Should you dig out the gas mask and Hazmat suit, or have well-intentioned greenies overblown potential peril?

Earth911 sat down with John Rogers, a senior energy analyst for the Union of Concerned Scientists who specializes in clean energy, to get to the bottom of these pressing questions about CFL safety, cleanup and disposal. You may be surprised by what we found!

Oops … I Broke a CFL!

With headlines circulating about mercury in CFLs, the initial freak-out moment after breaking a bulb is understandable. But clean energy expert John Rogers is here to ease your mind.

Don’t panic,” he assured us. “This is a manageable problem. Most of the time they don’t break. If they do break, there are procedures we follow.”

Any level of mercury exposure carries potential health concerns, but due to the small amount of mercury and short duration of exposure, a broken CFL is not likely to present any significant risk to you or your family, Rogers told Earth911.

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CFLs save loads of energy when compared to incandescent light bulbs, but they contain small amounts of mercury. Photo Courtesy of Emilian Robert Vicol

“You’re talking under 5 milligrams of mercury,” he said. “That figure won’t mean much to people, so to put it in perspective: if you think about the mercury thermometers that I grew up with, it’s less than 1% of the amount of mercury that was in one of those thermometers.”

Make note of the following cleanup instructions in case you ever break a bulb again, but don’t stress about exposure from a prior cleanup.

1. Before Cleanup

  • Have people and pets leave the room.
  • Air out the room for five to 10 minutes by opening a window or door.
  • Shut off the forced-air heating and cooling system, if you have one.
  • Collect the following materials to clean up the broken bulb: Stiff paper or cardboard, sticky tape, damp paper towels or disposable wet wipes (for hard surfaces), and an airtight container, such as a glass jar with a metal lid or a resealable plastic bag.

2. During Cleanup

  • Do not vacuum. Vacuuming is not recommended unless broken glass remains after all other cleanup steps have been taken, as doing so may spread mercury-containing powder or mercury vapor.
  • Thoroughly scoop up glass fragments and powder using stiff paper or cardboard. Use sticky tape, such as duct tape, to pick up any remaining small glass fragments and powder.
  • Place the used tape in the glass jar or plastic bag. See detailed cleanup instructions from the EPA for more information, and for differences in cleaning up hard surfaces versus carpeting or rugs.
  • Place cleanup materials in a sealable container.

3. After Cleanup

  • Promptly place all bulb debris and cleanup materials, including any vacuum cleaner bags used, outdoors in a trash container or protected area until materials can be disposed of. Avoid leaving any bulb fragments or cleanup materials indoors.
  • Use Earth911 to track down a recycling solution near you. Avoid throwing CFLs (broken or unbroken) into your regular waste bin.
  • If weather and other conditions allow, continue to air out the room where the bulb was broken and leave the heating and air conditioning system shut off for several hours (a study conducted by the journal Science of The Total Environment found that the critical exposure period passes after four hours).

Discovering Our Overall Mercury Footprint

Despite the small amount of mercury that may be released into the atmosphere if a CFL breaks or is disposed of improperly, the use of CFLs actually helps reduce total mercury emissions in the U.S., according to the EPA, the Union of Concerned Scientists, and other sources.

Part of the discussion is pulling the lens back a little bit and helping people understand why if you care about mercury, which you should, you should use more CFLs, not fewer,” Rogers explained, pointing to the role of coal-fired power plants as the leading source of atmospheric mercury contamination.

According to the Union of Concerned Scientists, the electricity required to power a 13-watt CFL over its 8,000-hour lifetime releases about 1 milligram of mercury emissions into the atmosphere, assuming coal supplies 40% of that electricity (close to the national average). Most of the mercury in a CFL is bound to the bulb and is therefore harmless. Even if a CFL breaks, total emissions are only about 1.4 milligrams.

Under the same assumptions, the electricity required to power a 60-watt incandescent bulb for its lifetime would release about 4.4 milligrams of mercury into the atmosphere – dwarfing the impact of CFLs with respect to the nation’s overall mercury footprint.

It’s important to understand that the mercury emissions from coal aren’t just about the environment, they’re about us,” Rogers said. “Where does that mercury end up? It ends up in our lakes and streams and in the fish we eat.”

Mercury contamination in American waterways is no myth. The EPA National Listing of Fish Advisories reports 4,836 active fish advisories due to chemical contamination of waterways, with 3,834 of these advisories instated due to mercury pollution. In a 2010 EPA survey, a whopping 55 of 56 respondents, including U.S, states, territories and Native American tribes, identified mercury as a contaminant of primary human health concern in their jurisdictions.

So, how can we shrink our overall mercury footprint? The answer is simple, Rogers said: use less energy. For tips on reducing energy consumption in your home, check out these ideas for cutting use in the kitchen and laundry room, or these 10 ways to save energy all over the house. For more information on electricity and atmospheric mercury pollution, head to this fact-sheet from the EPA.

The Importance of CFL Recycling

Due to mercury content, it’s very important to dispose of CFLs properly and avoid tossing them in your regular waste bin. Some states actually ban the disposal of CFLs in landfills. Luckily, CFL recycling is readily available in almost all communities through retailer take-back programs and local household hazardous waste (HHW) collection.

Use Earth911 to track down a recycling solution in your area, and be sure to use caution when removing and recycling a burnt-out CFL.

The best solution is that we use [CFLs] until the end of their life and then dispose of them in ways to capture that mercury,” John Rogers said. “Part of what we need to do is educate people better about the importance of recycling. That’s an easy thing we can do to keep the mercury down to, essentially, zero.”

Pin this for later!

I had no idea CFLs contained mercury. So glad I looked up how to recycle CFLs before just tossing one into the trash. This article gives great step by step directions on how to clean up a broken CFL.

This article was originally published on Jan 11, 2013. It was updated on May 12, 2016.

By Mary Mazzoni

Mary is a lifelong vegetarian and enjoys outdoor activities like hiking, biking and relaxing in the park. When she’s not outside, she’s probably watching baseball. She is a former assistant editor for Earth911.