Compact Fluorescent Bulb information
Did You Know?
If every American home replaced just one light with a light that's earned the ENERGY STAR, we would
save enough energy to light 3 million homes for a year, save about $600 million in annual energy costs,
and prevent 9 billion pounds of greenhouse gas emissions per year, equivalent to those from about
800,000 cars.
Earning the ENERGY STAR means products meet strict energy efficiency guidelines set by the US
Environmental Protection Agency. Lighting products that have earned the ENERGY STAR deliver
exceptional features, while using less energy. Saving energy helps you save money on utility bills and
protect the environment by reducing greenhouse gas emissions in the fight against climate change.
An ENERGY STAR Qualified Compact Fluorescent Light bulb (CFL):
-can save more than $40 in electricity costs over its lifetime
-uses about 75% less energy than standard incandescent bulbs and lasts up to 10 times longer
-produces about 75% less heat, so it's safer to operate and can cut energy costs associated with home
cooling
Frequently Asked Questions:
What is a CFL?
CFL stands for compact fluorescent lamp, and it is a small fluorescent light bulb that uses 75% less
energy than a traditional incandescent bulb and can be screwed into a regular light socket. Don’t let the
fact that it is fluorescent turn you off! ENERGY STAR qualified CFLs must pass extensive testing to
ensure they produce only the highest quality light.
Qualified bulbs labeled “warm white” or “soft white” produce light like typical incandescent light bulbs.
CFLs that have a cooler color (similar to bright white incandescent bulbs) are usually labeled “bright
white” or “daylight” on the product packaging.
I want to start replacing my "regular" (incandescent) light bulbs with compact
fluorescent light bulbs (CFLs). Should I throw away my incandescent bulbs
now or wait until they burn out?
Replacing incandescent bulbs with ENERGY STAR qualified CFLs right away, rather than waiting until they
burn out is beneficial because you can begin to enjoy the energy savings right away. By replacing your
home’s five most frequently used light fixtures or the bulbs in them with ENERGY STAR qualified CFLs
can save you more than 65 each year. ENERGY STAR qualified CFLs use 75% less energy while providing
the same amount of light.
You can save the incandescent bulbs for your fixtures where CFLs aren’t suitable (like in a closet where
the light would only be on for a few minutes at a time, or for a dimmable fixture if you don't have a
dimmable CFL). CFLs provide the most savings in applications where the light is on for at least two hours
a day.
Can I turn my Compact Fluorescent Light Bulbs (CFLs) on and off frequently?
I've been told I have to turn it on and leave it on all day.
Turning a CFL on and off frequently can shorten its life. However, because of the vast diversity of
products and different usages, it is difficult to determine exactly how much. ENERGY STAR specifications
require bulbs to endure rapid cycling for five minute intervals to ensure that the products can hold up to
frequent switching.
To take full advantage of the energy savings and long life of ENERGY STAR qualified CFLs, it is best to use
them in light fixtures you use the most and are on for at least 15 minutes at a time. Good locations
include outdoor light fixtures, indoor fixtures in the living room, family room, kitchen, bedroom,
recreation room, etc. This is not to say you should leave your lights on all day if you use ENERGY STAR
qualified CFLs. It is still a good habit to turn the lights off when you leave the room for an extended
You may also have heard that CFLs use a lot of energy when turning on and off. While there is a brief
surge in energy use when a CFL is turned on, with today's starting technology, that surge usually lasts
about a tenth of a second and consumes about as much energy as five seconds of normal operation. So,
even when turned on and off frequently, a CFL uses less energy than its incandescent equivalent. But
because turning a CFL on and off more frequently can shorten its life and CFLs are more expensive than
incandescents, we recommend consumers use CFLs in applications where they are on for at least fifteen
minutes.
Do CFLs contain mercury?
CFLs contain a very small amount of mercury sealed within the glass tubing - an average of 4 milligrams about the amount that would cover the tip of a ballpoint pen. By comparison, older thermometers
contain about 500 milligrams of mercury - an amount equal to the mercury in 125 CFLs. Mercury is an
essential part of CFLs; it allows the bulb to be an efficient light source. No mercury is released when the
bulbs are intact (not broken) or in use.
Most makers of light bulbs have reduced mercury in their fluorescent lighting products. Thanks to
technology advances and a commitment from members of the National Electrical Manufacturers
Association, the average mercury content in CFLs has dropped at least 20% in the past year. Some
manufacturers have even made further reductions, dropping mercury content to 1.4 - 2.5 milligrams per
light bulb.
How should Compact Fluorescent Light Bulbs (CFLs) be disposed? Do they
need to be recycled?
Because CFLs contain a small amount of mercury, EPA recommends that consumers take advantage of
available local recycling options for CFLs:
These major retailers offer free CFL recycling for unbroken bulbs:
The Home Depot, IKEA, Ace Hardware
These websites have databases of recycling options:
earth911.org
1800recycling.com
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 two plastic bags and put it into the outside trash, or other protected outside
location, for the next normal trash collection. Never send a fluorescent light bulb or any other mercurycontaining product to an incinerator.
Can Compact Fluorescent Light Bulbs (CFLs) be used in recessed cans, outdoor
lights, or track lighting?
Yes! Always read the packaging of the CFL to be sure of its proper application, but there are a wide
variety of ENERGY STAR qualified CFLs that are designed for use in most fixtures in your home, including
recessed cans, outdoor lights, and track lighting.
Why are incandescent light bulbs being phased out? I hear CFLs will be
required by 2012. Is that true?
The Energy Independence and Security Act of 2007 (the “Energy Bill”), signed by President Bush on
December 18, 2007 requires all light bulbs use 30% less energy than today’s incandescent bulbs by 2012
to 2014. The phase-out will start with 100-watt bulbs sold starting in January 2012 and end with 40-watt
bulbs sold starting in January 2014. By 2020, a Tier 2 would become effective which requires all bulbs to
be at least 70% more efficient (effectively equal to today’s CFLs).
It’s not entirely correct to say "CFLs will be required" or “incandescents will be phased out” because the
standards set by the bill are technology neutral, and by 2012, a next generation of incandescent bulbs
could satisfy the 30% increased efficiency. There are also other lighting technologies, such as halogen
and LEDs that will be able to meet the new requirements and are expected to both increase in
performance and drop in cost over the next few years.
Lighting is approximately 20% of the average household’s energy bill. NRDC estimates this law could cut
our nation’s electric bill by more than 10 billion a year. The law applies to the sale of bulbs, not the use
of existing stock of bulbs.
How should I clean up a broken compact fluorescent light bulb (CFL)?
Visit epa.gov/cflcleanup for EPA's recommendations for clean-up and disposal of CFLs.
How much energy does it takes to turn on a CFL, compared to leaving it on?
Even when turned on and off frequently, a CFL uses less energy than its incandescent equivalent. While
there is a brief surge in energy use when a CFL is turned on, with today's starting technology, that surge
usually lasts about a tenth of a second and consumes about as much energy as five seconds of normal
operation.
However, turning a CFL on and off more frequently will also shorten its life. Because of this, and because
CFLs are more expensive than incandescents, we generally recommend that consumers use CFLs in
applications where they are on for at least fifteen minutes. This is where CFLs have the biggest impact
and make the most sense economically.
What is a watt? What is a lumen?
A watt is the measure of power consumption, and is the common way incandescent light bulbs are
identified -- for example 60-watt, 75-watt and 100-watt. When purchasing a light bulb, however, what
you really should look for is lumens, which is the measure of light output. For example, when you
purchase a 60-watt incandescent bulb, you are getting about 800 lumens. By selecting a 13-watt
ENERGY STAR qualified CFL instead, you can still get 800 lumens, but it requires much less power.
How do CFLs result in less mercury in the environment compared to
traditional light bulbs?
Electricity use is the main source of mercury emissions in the U.S. CFLs use less electricity than
incandescent lights, meaning CFLs reduce the amount of mercury into the environment. A 13-watt,
8,000-rated-hour-life CFL (60-watt equivalent; a common light bulb type) will save 376 kWh over its
lifetime, thus avoiding 4.5 mg of mercury. If the bulb goes to a landfill, overall emissions savings would
drop a little, to 4.2 mg. EPA recommends that CFLs are recycled where possible, to maximize mercury
savings.
Does temperature or humidity affect the life of a CFL? For example, would a
CFL work in extremely cold temperatures, or extremely wet climates?
Extreme temperatures can affect CFLs. Some CFLs can be used outside in temperatures down to –10
degrees Fahrenheit and up to 120 degrees Fahrenheit, though when it is very cold they may take longer
to reach full brightness. There are some ENERGY STAR qualified CFLs that are weatherproof and can be
used outside where exposed to rain, so check for “weatherproof” models before installing it in your
outdoor spot light.