Compact fluorescent lamps (CFLs) contain a small amount of mercury, about 3-4 milligrams each,sealed within the glass tubing.
CFLs produce light differently than incandescent bulbs. In an incandescent, electric current runs through a wire filament and heats the filament until it starts to glow. In a CFL, an electric current is driven through a tube containing argon and a small amount of mercury vapor. This generates invisible ultravioletlight that excites a fluorescent coating (called phosphor) on the inside of the tube, which then emits visible light.
CFLs need a little more energy when they are first turned on, but once the electricity starts moving, use about 75 percent less energy than incandescent bulbs. A CFL’s ballast helps “kick start” the CFL and then regulates the current once the electricity starts flowing.
This entire process typically takes 30 seconds to 3 minutes to complete, which is why CFLs take longer than other lights to become fully lit. CFLs with decorative covers like globe or reflector shapes have a unique design challenge that results in the tradeoff of a slower warm up time, which is why these CFLs take longer than bare spirals to reach full brightness.
Older CFLs used large and heavy magnetic ballasts that caused a buzzing noise in some bulbs. Most CFLs today — and all ENERGY STAR qualified CFLs — use electronic ballasts, which do not buzz or hum. Read more →
The Consumer Product Safety Commission estimates that 50 people die every year from accidental electrocutions involving residential wiring, panel boards, circuit breakers, and outlets. Another 40 electrocutions each year involve household appliances that are connected to the wiring of homes.
By making sure you have a thorough electrical inspection completed by a qualified electrician before buying, selling, or remodeling a home, you can help ensure your home’s electrical system operates at the highest level of safety possible.