Compact Fluorescent Light Bulb (CFL) FAQs

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Compact Fluorescent (CFL) Bulbs Find bulbs that use up to 75% less energy and last up to 10 times longer than standard bulbs.

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How does a compact fluorescent light bulb work?
Fluorescent light bulbs (including compact fluorescents) are more energy-efficient than regular bulbs because of the different method they use to produce light. Regular bulbs (also known as incandescent bulbs) create light by heating a filament inside the bulb; the heat makes the filament white-hot, producing the light that you see. A lot of the energy used to create the heat that lights an incandescent bulb is wasted. A fluorescent bulb, on the other hand, contains a gas that produces invisible ultraviolet light (UV) when the gas is excited by electricity. The UV light hits the white coating inside the fluorescent bulb and the coating changes it into light you can see. Because fluorescent bulbs don’t use heat to create light, they are far more energy-efficient than regular incandescent bulbs.

What’s the difference between a compact fluorescent light bulb and a fluorescent bulb?
The primary difference is in size; compact fluorescent bulbs are made in special shapes (which require special technologies) to fit in standard household light sockets, like table lamps and ceiling fixtures. In addition, most compact fluorescent lamps have an “integral” ballast that is built into the light bulb, whereas most fluorescent tubes require a separate ballast independent of the bulb. Both types offer energy-efficient light.

What compact fluorescent light bulb do I buy to replace an incandescent (regular) bulb?
While a regular (incandescent) light bulb uses heat to produce light, a fluorescent bulb creates light using an entirely different method that is far more energy-efficient — in fact, 4-6 times more efficient. This means that you can buy a 15-watt compact fluorescent bulb that produces the same amount of light as a 60-watt regular incandescent bulb.

Don’t worry about the math, though — we make it easy for you to figure out which compact fluorescent bulb to buy by displaying the equivalent regular watts you’re used to prominently on the package. Just look for the wattage you would normally buy in a regular bulb.

In case you’re curious, here are the watts needed by regular incandescent bulbs and compact fluorescent bulbs to produce the same amount of light.

	Standard Bulb		CFL Bulb
	40w	=	10w
	60w	=	13w-15w
	75w	=	20w
	100w	=	26w-29w
	150w	=	38w-42w
	250w-300w	=	55w

Because the wattage of a CFL bulb is much lower than that of an incandescent, you can use higher wattage CFL giving you the equivalent light of a higher wattage incandescent. For example: If your fixture says not to exceed 60 watts, you can use a 15 watt CFL to get the same amount of light as an incandescent bulb or use up to a 42 watt CFL and increase the amount of light.

Related information: How does a compact fluorescent light bulb work?

Can I use a compact fluorescent light bulb with a dimmer switch?
To use a compact fluorescent bulb on a dimmer switch, you must buy a bulb that’s specifically made to work with dimmers (check the package). GE makes a dimming compact fluorescent light bulb (called the Energy Smart Dimming Spirals®) that is specially designed for use with dimming switches. We don’t recommend using regular compact fluorescent bulbs with dimming switches, since this can shorten bulb life. (Using a regular compact fluorescent bulb with a dimmer will also nullify the bulb’s warranty.)

Can I use a compact fluorescent light bulb on my 3-way lamp?
GE does make CFL bulbs for use in 3-way lamps. Check the package for this application. If a regular CFL is use in a 3-way switch, it will work on the middle (medium) setting and it should not damage the bulb. The 3-way switch does not alter the performance of the bulb.

Why does my compact fluorescent light bulb flicker or appear dim when I first turn it on?
The first compact fluorescent bulbs flickered when they were turned on because it took a few seconds for the ballast to produce enough electricity to excite the gas inside the bulb. Thanks to the refined technology in our new GE compact fluorescent bulbs, there is now no significant flicker (less than 1 second). However, these bulbs do require a short warm-up period before they reach full brightness, which is why they may appear dim when first turned on. Compact fluorescent bulbs are best used in fixtures that are left on for longer periods of time, rather than in fixtures that are turned off and on frequently.

Related information: How does a compact fluorescent light bulb work?

Can I use a CFL in applications where I will be turning the lights on/off frequently?
Compact fluorescent light bulbs work best if they are left on for over 15 minutes each time they are turned on. These types of lamps can take up to 3 minutes to warm-up. Warm-up will probably not be noticeable from a user stand point, but the lamp needs to warm-up in order to reach the point of most efficient operation. Frequently switching them on and off will shorten the life of the product. If the life of the lamp is shortened significantly, you will not reap the financial benefits (includes energy & life of lamp), that are common to CFL lamps.

Can I use a compact fluorescent light bulb in an enclosed light fixture?
Compact fluorescent light bulbs may generally be used in enclosed fixtures as long as the enclosed fixture is not recessed. Totally enclosed recessed fixtures (for example, a ceiling can light with a cover over the bulb) create temperatures that are too high to allow the use of a compact fluorescent bulb.

Can I use a CFL bulb outside?
Many CFL bulbs can be used outdoors if used in an enclosed fixture. To be certain, look for the package or bulb to say that it can be used outdoors and verify the lowest operating temperature for the area where the product is being used.

Related information: My outdoor light has a timer. Can I use a CFL bulb?

Can I use a CFL in any position?
Yes, GE screwbase CFL bulbs can be used in any operating position unless there is text printed on the lamp or packaging that indicates a required operating position.

Can I use a CFL in applications involving vibration such as a ceiling fan or garage door opener?
Generally it is not recommended to use CFLs in vibrating environments. Vibration can cause the electronics in the CFL to fail. There is one CFL bulb (FLE11) that is available for use in a ceiling fan. Check the package for this application.

Can compact fluorescent bulbs create interference with electronic equipment, such as radios?
Many electronic devices, such as radios, televisions, wireless telephones, and remote controls, use infrared light to transmit signals. Infrequently, these types of electronic devices accidentally interpret the infrared light coming from a compact fluorescent bulb as a signal, causing the electronic device to temporarily malfunction or stop working. (For example, your television might suddenly change channels.) Fortunately, this only happens when light is produced at the same wavelength as the electronic device signals, which is rare.

To reduce the chance of interference, avoid placing compact fluorescent bulbs near these kinds of electronic devices. If interference occurs, move the bulb away from the electronic device, or plug either the light fixture or the electronic device into a different outlet.

Can I use a compact fluorescent light bulb with an electronic timer or photocell (AKA electric eye)?
Some electronic timers and photocells contain parts that are incompatible with compact fluorescent light bulbs; using these bulbs in incompatible products will result in a shorter light bulb life. To find out if an electronic timer or photocell is compatible with compact fluorescent bulbs, check with the manufacturer of the timer or photocell.

Does the EPA recommend the use of CFL bulbs?
Yes. CFLs, when compared with standard incandescent bulbs, offer many benefits. First, they help save energy and money. They use 2/3 less energy than standard incandescent light bulbs, and last up to 10 times longer. Replacing a 60-watt incandescent with a 13-watt CFL can save you at least $30 in energy costs over the life of the bulb. Second, CFLs offer convenience, because they last longer, and come in different sizes and shapes to fit almost any fixture. In addition, CFLs produce about 70% less heat than standard incandescent bulbs, so they’re safer to operate and can help cut energy costs associated with home cooling. When shopping, always look for ENERGY STAR qualified CFLs.

Download the Environmental Protection Agency (EPA) faq sheet on CFLs. (PDF, 70 KB)
Learn More

Is it true that CFLs contain mercury? Why and how much?
CFLs contain a very small amount of mercury sealed within the glass tubing – an average of 5 milligrams (roughly equivalent to the tip of a ball-point pen). Mercury is an essential, irreplaceable element in CFLs and is what allows the bulb to be an efficient light source. By comparison, older home thermometers contain 500 milligrams of mercury and many manual thermostats contain up to 3000 milligrams. It would take between 100 and 600 CFLs to equal those amounts.

There is currently no substitute for mercury in CFLs; however, manufacturers have taken significant steps to reduce mercury used in their fluorescent lighting products over the past decade.

Download the Environmental Protection Agency (EPA) fact sheet on Mercury in CFLs. (PDF, 17 KB)
Learn More

Should I be concerned about using CFLs in my home or should I take any special precautions?
CFLs are safe to use in your home. No mercury is released when the bulbs are in use and they pose no danger to you or your family when used properly. However, CFLs are made of glass tubing and can break if dropped or roughly handled. Be careful when removing the lamp from its packaging, installing it, or replacing it. Always screw and unscrew the lamp by its base, and never forcefully twist the CFL into a light socket by its tubes. Used CFLs should be disposed of properly, learn how to properly dispose.

I have heard CFLs can overheat and smoke – should I be worried? Why does it happen?
The vast majority of CFLs reach the end of useful life and fail passively. In some cases, electronic components in the ballast power supply (such as capacitors and resistors) may fail in a manner that will result in some smoke, odor, or discoloration (browning) of the plastic housing. The failure of some electrical components can result in an audible “popping” or “sizzling” sound. It is the function of the ballast housing to contain such failures and prevent the plastic or failed components from igniting. GE CFLs are ENERGY STAR qualified and meet UL standards, which require the materials to be self–extinguishing. It is the nature of fire retardant materials to exhibit some deformation or discoloration in a protective mode. At the first sign of any odor, smoke or erratic behavior, disconnect power to the lamp. Allow it to cool and unscrew it from the socket by the handling the base, not by the glass.

For more information please visit…
http://www.ul.com/newsroom/cfl/index.html
http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=3147

I have a CFL that has produced a very unpleasant odor and some smoke when it failed. Is this common? Hazardous? What should I do if this happens in the future?
The vast majority of CFLs do not produce either an odor or smoke when the CFL either fails or reaches its normal end of life. However, CFLs, like many electrical or electronic products, can sometimes fail in a way where one of the electrical components or plastic materials will briefly produce a very irritating odor and possibly some smoke. Any smoke or odor produced is in a low concentration, which will not result in a hazard. However, in the relatively small number of cases where this might occur, it can produce a very pungent smell that is certainly not pleasant.

If this situation occurs, the easiest way to eliminate any odor is to follow the same approach that one would use to eliminate any other unpleasant odor or smell. Briefly leave the immediate area if it is very irritating. Next, after waiting 10 or 15 minutes, air out the room by opening any doors or a window if there is one. This will quickly dissipate the remaining fumes or smell. If available, a normal portable household fan or ceiling fan will accelerate the process. Properly dispose of the lamp.