CFL Safety
Proper care and feeding of the compact fluorescent light bulb.
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CFL Safety
Hi there Green Guys and Gals! Welcome to Make-it-Green Girl’s Quick and Dirty Tips for an Earth Friendly Life. If you tuned in to Fiat Lux, part 1, you’ll remember I kicked off a topic we all want to know more about–the compact florescent lightbulb.
Natural questions that arise after you’ve bought all of them are how to handle them and what to do once they’ve burned out. This week, I’m going to address both safe handling and disposal, with particular emphasis on the key element in CFLs: mercury. Element number 80 has a lot of drama surrounding it, so this is going to be a hands-on, politics-off guide to mercury and how it relates to CFLs.
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CFLs Need Mercury
If you’ve already joined the many American households who’ve tossed out those old incandescent light bulbs, you’re on the right track. The EPA estimates that between 12% to 20% of the electricity used in the average American home goes towards lighting, so it’s a great place to start saving money and power. epa.gov
However, many of us are concerned about the safety of these devices, mostly because they contain mercury. Mercury is a key element of CFL operations; the small amount of mercury vapor allows the gas trapped in the glass tube (or ballast) to emit light of the correct color, allowing the white phosphor coating on the inside of the ballast to glow. All fluorescent light bulbs contain some amount of mercury, including the overhead lights you probably see in your office building or your kitchen at home. The bulbs simply would not function without that little bit of mercury. The swirly CFLs you buy to replace regular light bulbs usually contain around five milligrams of mercury vapor. By comparison, those mercury thermometers you used to have to cart down to the landfill or the pharmacy for recycling contained around 500 milligrams–100 times as much!
Mercury is Toxic
Exposure to mercury can happen in a few different ways. Mercury exists in our habitat as elemental, or metallic mercury; inorganic mercury compounds; and organic mercury compounds. The latter two are topics for another discussion–elemental mercury is what’s inside your CFLs.
Metallic mercury is a liquid at room temperature (you’ve probably seen it referred to as quicksilver), but like most liquids, small amounts escape into the gas phase and get into the air. Touching the liquid, or even swallowing it causes surprisingly little damage compared to inhaling mercury vapor. Toxicology studies indicate that absorption via the skin is about 100 times less than the absorption that occurs via the lungs. (pubmed.gov)
So the real danger from elemental mercury in your CFLs is when the ballast breaks open, allowing the mercury vapor inside to escape into the room. Elemental mercury is a neurotoxin, interfering with the growth and function of nerve cells. It is especially dangerous to young developing children, and can cause birth defects if women are exposed during their pregnancy.
When the Bulb Breaks
In order to ensure your own safety, the EPA and Energy Star have come up with some guidelines for how to treat CFLs with care, and how to deal with a busted bulb.
In the event of a break in the ballasts, you need to start ventilating the room, and then leave the spill alone. After about fifteen minutes, you can come back into the room and sweep up the spill. Sweep, not vacuum. The logic here is that any vapor that is going to escape will do so while you’re out of the room, so you certainly don’t want to stir up more with a vacuum.
If this still seems a bit scary to you, here’s some perspective. The safe level of mercury in the air of our workplaces is regulated by the Occupational Safety and Health Administration (or OSHA); they set the maximum concentration at a tenth of a milligram of mercury in every cubic meter of air. Remembering that your CFLs contain no more than six milligrams of mercury per bulb, you would need to have sixty cubic meters of air to dilute the vapor to 40-hour work week levels. A typical bedroom in your house probably only has about twenty-five cubic meters of air in it. This is assuming, however, that all the mercury contained in the bulb will vaporize–at ambient temperatures and pressures, however, not even half will evaporate.
Still, it’s a good idea to let the windows open, or turn on a fan before you come back to sweep up. Take your dustpan, stuff the whole mess into a plastic bag, and take it to your outside trash can. This ensures that any remaining mercury won’t escape before it gets to the landfill. Energy Star has more information about the proper use of CFLs, or you can visit the EPAs website at epa mercury.
Tipping the Scales
I started to wonder–and you probably are, too–with all this kerfuffle, is the CFL just another green pipe-dream? A good idea gone horribly wrong? Why should I replace my safe-but-wasteful bulbs with a bulb that saves me money, but might endanger me and my family? Well, it’s a simple matter of perspective.
Much of our electricity in the United States comes from coal-fired power plants, which are the main source of mercury air toxic emissions. That electricity goes to power your lights at home. So the more energy you use at home, the more mercury floats into the air to settle in the environment–specifically, in the food chain, where you don’t want it to settle.
That mercury is turned into organic mercury compounds by clever little bacteria living in the waters and soils around these power plants, which makes it more easily adsorbed into your body when you eat the organisms that come out of these ecosystems, especially fish. Since you have to eat to live, you can choose foods lower in mercury, but unless you turn out your lights too, our food chain is still contaminated. So instead, by using CFL light bulbs, you can save electricity and confine the mercury to a few bulbs around the house.
Also remember, that if a bulb does break, this is a single exposure for you and your family. Your food, by comparison, will continue to poison you as long as we’re still burning fossil fuels.
Lastly, by disposing of the bulb in a bag in a landfill, you can control the path the mercury travels. Mercury emitted from power plants cannot be directed or controlled once it’s out of the stacks.
California Dreamin’
As a footnote for those of you living in California, since the expiration of the California Universal Waste Rule on February 8, 2006, mercury-containing fluorescent bulbs are banned from your trash. You’ll need to find a recycling collection center in your area by visiting your city or county’s website, or contacting Earth 911 at www.earth911.org or calling Earth 911 at 1-800-CLEAN-UP. If you do find a drop-off center, keep in mind that most landfills and recycle centers can only accept certain wastes at certain times.
Thanks for tuning in, folks. I know this stuff can be hard to swallow, but if we use our heads, we can make the right choices. You can find a transcript of this show at QuickAndDirtyTips.com. While you’re there, be sure to check out all the Quick and Dirty Tips podcasts, especially our two newest shows, Sales Guy, and Small Biz Tech Girl. You can send your questions and comments to greengirl@quickanddirtytips.comcreate new email or leave me a voicemail at 206-600-3051.