Because Compact Fluorescent Light Bulbs (CFLs) contain a small amount of mercury, EPA recommends that consumers take advantage of available local recycling options for CFLs:
1) These major retailers offer free CFL recycling for unbroken bulbs:
2) These websites have databases of recycling options:
3) Or contact your local municipal solid waste agency
If your state or local environmental regulatory agency permits you to put used or broken CFLs in the garbage, seal the bulb in a plastic bag and put it into the outside trash, or other protected outside location, for the next scheduled trash collection. Never send a fluorescent light bulb or any other mercury-containing product to an incinerator.
ENERGY STAR qualified CFLs have a 2 year warranty. Here's what to do if your bulb has failed within the warranty period.