A CFL bulb will occasionally burn out. More often, it will continue to operate, gradually producing less light as it ages. At some point you'll want to replace it for brighter light. Note that an ENERGY STAR qualified CFL bulb must produce at least 80 percent of its rated light output at 40 percent of its rated life.
Contact the manufacturer, who is ultimately responsible for warranty claims. Be sure to save the proof-of-purchase and register receipt to document your claim.
All fluorescent bulbs, including CFL bulbs, contain small amounts of mercury, an environmental concern. Mercury is a toxic metal associated with contamination of water, fish, and food supplies.
It is legal for residential users of small quantities of CFL bulbs to dispose of them in the trash. However, Fort Collins Utilities would like to minimize mercury in the environment and encourages residents to take them to the Larimer County Household Hazardous Waste Facility, located at the Larimer County Landfill on South Taft Hill Road (498-5773), open Tuesdays, Thursdays, Fridays and Saturdays, 9 a.m. to 4 p.m.