A darker side of compact fluorescents?

Claims that compact fluorescent light bulbs (CFLs) use about two-thirds less energy and last up to 10 times longer than their incandescent cousins have earned them center stage of energy-saving efforts like the EPA's Change a Light, Change the World initiative and Wal-Mart's declared mission to sell 100 million CFLs this year and the giant retailer's participation in the 18seconds.org campaign.

If CFLs deliver on those claims, it'll be a while before you'll have to decide what to do with a spent bulb since CFLs last so long. But when a CFL does burn out or accidentally break, it's important for you to know what to do with the bulb, for environmental as well as health reasons.

CFLs contain a small amount of mercury, a neurotoxin that can cause brain and kidney damage at high exposure levels. While an intact bulb doesn't pose a danger to you, disposing of spent CFLs improperly can add mercury to landfills, where the toxin can potentially contaminate soil and groundwater. That's why recycling a bulb at the end of its life in accordance with the hazardous-waste laws in your town is so essential.

If a bulb does break, don't handle it and take these precautions when cleaning it up.

It might seem as if the use of CFLs is simply swapping one problem with another. But according to the EPA, replacing incandescents with CFLs actually results in less mercury in the environment. That's because most of the electricity in the U.S. comes from coal, which emits mercury when burned. Since CFLs require less electricity than incandescents, mercury emissions would actually decline.

In the long run, producing efficient lighting without toxins like mercury should be a goal for the lighting industry.—Kristi Wiedemann, Science and Policy Analyst, GreenerChoices.org

Essential information: Visit GreenerChoices.org for the latest news on environmental issues and expert advice on ways to save energy and money everyday. And look for our compact fluorescent light bulb report in the October 2007 issue of Consumer Reports, on sale in September.