Those energy-efficient compact fluorescent lamps hold a dirty little secret: mercury, a toxic substance that makes disposal of used CFLs problematic.
Mercury, whether inhaled or ingested, can cause serious damage to the human central nervous system.
While the small amount of mercury found in CFLs -- 2 to 6 milligrams -- doesn't make them unsafe, it does create disposal problems, especially at landfills.
That's because mercury released from CFLs, as well as from watch batteries, thermometers and other products, can leach into water supplies, producing a highly toxic form of organic mercury known as methylmercury.
It's methylmercury that contaminates fish and other types of seafood.
Recently, the Modesto Irrigation District launched a campaign to make its customers aware of the potential danger in CFLs.
"Yes, these things are potentially hazardous," said Bob Hondeville, MID energy services supervisor. "(But) we don't want to scare people away from using them."
Still, Hondeville said, the MID is urging its customers to take care when handling and disposing of CFLs.
A state law passed in February 2006 requires that CFLs be recycled, not tossed into the garbage can.
Care also must be used when handling a broken CFL.
Under no circumstances, Hondeville said, should anyone use a vacuum cleaner to pick up the debris from a broken CFL.
"A vacuum (cleaner)," he said, "will stir up the (mercury) vapors and spread them."
The U.S. Department of Energy and the Environmental Protection Agency advise consumers to open the windows and leave the room for at least 15 minutes if a CFL breaks when dropped.
When cleaning up the debris, the agencies recommend putting on disposable rubber gloves.
They also recommend using a piece of stiff paper or cardboard to scoop up the pieces, rather than a broom and dustpan.
Once the pieces have been collected, the area should be wiped with damp paper towels or disposable wipes.
Experts say the fragments should be placed in a plastic bag that can be sealed. Paper towels and other materials used in the cleanup also should be sealed in plastic bags.
Once bagged, the CFL is ready to be taken to a disposal center.
Hondeville said Stanislaus County residents have four disposal center options:
County Center IV, 1716 Morgan Road
Fink Road landfill, Crows Landing
ProClean Supply, 701 Kearney Avenue
Orchard Supply Hardware stores
"We prefer they take them to County Center IV," said Sonya Harrigfeld, the county's Environmental Resources director. "We will sort them at the landfill, but they (eventually) get sent to County Center IV."
From there, Harrigfeld said, the used or broken CFLs are repackaged for shipment by a private contractor to an out-of- county recycling center.
Some companies, Hondeville said, give consumers the option of returning used or broken CFLs in postage-paid boxes or other types of containers.
Harrigfeld said the county is not certain how many CFLs are being tossed with the household trash and ending up in the landfill.
"They're increasing in popularity as people realize there are some advantages to using them," Harrigfeld said, "and we don't want them going into the waste-to-energy plant or landfill."
CFLs use about 25 percent of the energy to produce the same light as a standard incandescent bulb. The fluorescent lamps also last up to nine times longer than incandescents.
Rick Saunders, regional director of marketing for Orchard Supply Hardware in Northern California, said OSH will dispose of CFLs for its customers.
"Our service is not designed for big commercial accounts," said Saunders. "It's something we offer to our customers."
OSH customers will not find a drop-off bin or barrel for used CFLs. Saunders said customers must seek help from a sales clerk.
Saunders said clerks will take CFLs to an area of the store not open to customers. There, he said, CFLs are repackaged for shipment to a recycling center.
For more information on the handling and disposal of compact fluorescent lamps, call the Stanislaus County Environmental Resources Department at 525-6700, or visit the Energy Star Web site at www.energystar.gov. A list of CFL disposal sites is available at http://earth911.org.
Bee staff writer Michael G. Mooney can be reached at email@example.com or 578-2384.