CFL's - Compact Fluorescent Lights - Advantages and Problems, from Energy Savings to Toxic Mercury
Compact fluorescent lamps (CFL's), are small household
lamp-sized fluorescent lamps. They are generally intended to replace
incandescent light bulbs. They have become very popular mainly due to their
lower energy consumption (about one-fourth - 25%) for the same amount
of light output compared to incandescent light bulbs. As a result,
they are perceived as being "green". But, like all man-made devises,
there are advantages and disadvantages, pro's and con's to using them.
We will present these below, along with references to credible authoritative
sources and some conclusions to help you decide when CFL's are right for
How do CFL's work / How are they different from
CFL's are a type of fluorescent lamps. This means that
the pass electricity through a gas, which becomes charged and emits light.
Incandescent lights heat a wire (called a filament) in a vacuum until the
wire glows and gives off light... and heat. The heat is wasted energy.
In a CFL, an electric current is driven through a tube containing
argon gas and a small amount of
mercury vapor. This generates invisible
ultraviolet light. But that UV light excites (energizes) a
fluorescent coating (called a
phosphor) on the inside of the tube, which then emits the
visible light that you see.
CFL design details
CFLs have two main components: a gas-filled tube (also called bulb or
burner) and a magnetic or electronic ballast. Electronic ballasts contain a
small circuit board with
rectifiers, a filter
and usually two switching
transistors connected as a high-frequency resonant series DC to AC
inverter. The resulting high frequency, around 40 kHz or higher, is
applied to the lamp tube. Since the resonant converter tends to stabilize
lamp current (and light produced) over a range of input voltages, standard
CFLs do not respond well in dimming applications and special lamps are
required for dimming service.
Standard shapes of CFL tube are single-turn double helix, double-turn,
triple-turn, quad-turn, circular, and butterfly.
CFLs need a little more energy when they are first turned on, but once
the electricity starts moving, but 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.
The most important technical advance has been the replacement of
ballasts with electronic ballasts; this has removed most of the
flickering and slow starting traditionally associated with typical
fluorescent lighting. Older CFLs used large and heavy magnetic ballasts that
caused a buzzing noise in some bulbs. Most CFLs today (including all ENERGY
STAR qualified CFLs) use new electronic ballasts, which do not buzz or hum.
Lumens, efficiency and longevity
Light is measured by lumens. A traditional 75 watt
incandescent light bulb produces 1170 lumens of light and lasts on average
750 hours. But a CFL that produces the 1170 lumens uses only 20-21
watts of electricity. The CFL uses only 1/4 to 1/3 the amount of energy to
produce the same light as an incandescent light bulb. The long term savings
are improved further because CFLS are expected to last anywhere from six to
eleven times longer than their incandescent bulbs. burnout rate. An article
in the Wall Street Journal on Janry 20, 2011 stated that PG&E assumed
the useful life of each bulb would be 9.4 years, but with experience,
it has cut the estimate to 6.3 years, Field tests also showed higher burnout
rates in certain locations, such as bathrooms (humid) and in recessed
lighting (trapped heat). Frequently turning them on and off also appears to
Research just published in July 2012 shows that most CFL
bulb emit harmful amounts of UV (ultraviolet) radiation.
See this page for more information.
Although some companies like
Sylvania managed to make small CFLs containing only 1.5 milligrams of
mercury, the, the Environmental Protection Agency states that the
CFL contains 4 milligrams of mercury Here are some of the
EPA's other statements about mercury in CFL's
- Mercury is an essential part of CFLs; it allows the bulb to be an
efficient light source.
- On average, CFLs contain abut four milligrams of mercury sealed
within the glass tubing. By comparison, older thermometers contain about
500 milligrams of mercury an amount equal to the mercury in over 100
- Manufacturers of fluorescent lighting products are working to reduce
the amount of mercury content in CFLs.
- No meNo mercury is released when the bulbs are intact (i.e., not broken)
or in use, but CFLs release mercury vapor when broken.
Mercury is widely known to be a health risk if inhaled or ingested,
especially in small children, and has always been one of the downsides to
CFLs. Mercury is a potent neurotoxin, and it's especially dangerous for
children and fetuses. Most exposure to mercury comes from eating fish
contaminated with mercury, The use of mercury in CFLs has been the concern
of several consumer-advocacy groups, and the EPA has
guidelines on how to handle broken CFLs
, which can release a small amount of mercury if its tubes
are broken. Some manufacturers have even made a
CFL light bulb that can contain its mercury even in the event of a tube
Cleaning up after a broken CFL bulb
Here are some useful guides which you can download and print:
- Before cleanup
- Have people and pets leave the room.
- Air out the room for 5-10 minutes by opening a window or door to
the outdoor environment.
- Shut off the central forced air heating/air-conditioning (H&AC)
system, if you have one.
- Collect materials needed to clean up broken bulb.
- During cleanup
- Be thorough in collecting broken glass and visible powder.
- Place cleanup materials in a sealable container.
- After cleanup
- Promptly place all bulb debris and cleanup materials outdoors in
a trash container or protected area until materials can be disposed
of properly. Avoid leaving any bulb fragments or cleanup materials
- For several hours, continue to air out the room where the bulb
was broken and leave the H&AC system shut off.
The EPA offers a checklist at epa.gov/mercury that suggests you do not use a vacuum cleaner, as that will only spread the problem.
They suggest that the next time you vacuum the area, you should then immediately dispose of the vacuum bag.
Some states and local jurisdictions have more stringent regulations
than U.S. EPA does, and may require that you recycle CFLs and other
mercury-containing light bulbs.
and , for , for example, all prohibit mercury-containing lamps from being
discarded into landfills. Visit
to contact your local
waste collection agency, which can tell you if such requirement exists in
your state or locality. Some retailers
such as IKEA, take used CFLs for recycling. See the following paragraph for
How and Where Can I Recycle
collection agencies |
| Mail-back services
- Contact your local
waste collection agency by visiting Earth911.com. Many
counties and cities have household hazardous waste drop-off locations
and/or curbside and other special collection programs. To find locations
where you can drop off bulbs, and when and where a collection may be
held in your area, contact your local waste collection agency directly
by visiting Earth911.com
. Note that waste collection agencies:
- provide services that are usually free, though some may charge a
- sometimes collect household hazardous wastes only once or twice
a year, so residents will have to hold on to their light bulbs until
the collection takes place. Other collection agencies provide
collection services throughout the year.
- may also collect paints, pesticides, cleaning supplies or
- usually accept waste only from residents, although some
collection programs include small businesses as well.
- Visit your local
retailers. Ace Hardware, Home Depot, IKEA, Lowe's, Orchard
Supply and other retailers offer in-store recycling. Visit
to find stores in your area. Check directly with the
store before you go; not all stores in regional or nationwide chains may
be equipped to recycle. EPA is working with retailers to
expand recycling and disposal options.
- Find out about mail-back
services. Some bulb manufacturers and other organizations sell
pre-labeled recycling kits that allow you to mail used bulbs to
recycling centers. The cost of each kit includes shipping charges to the
recycling center. You fill up a kit with old bulbs, seal it, and bring
it to the post office or leave for your postal carrier. Websites that
provide more information about mail-back services
- EHSO does not endorse, recommend, certify, authorize or
approve of any of these services;
- there may be other similar services of which we are not aware;
- we only provide these links as a convenience to our web
Some states, cities and counties have outlawed putting CFL bulbs in the
trash, but in most states the practice is legal. As of January 2011,
California, Minnesota, Ohio, Illinois, Indiana, Michigan and Wisconsin
are the only states that ban disposing of fluorescent bulbs as general
A federal law takes effect in January 2012 requires a 28%
improvement in lighting efficiency for conventional bulbs in standard
wattages. Effectively this means that compact fluorescent lamps will replace
traditional incandescent light bulbs, since by law, the incandescent light
bulbs will not be allowed to be sold after 2014. California began phasing
out sales of incandescent bulbs in January 2011, one year ahead of the rest
of the nation.
Advantages / Pro's
- Energy Star qualified CFLs use at least two-thirds less energy than
standard incandescent bulbs
- CFLS can last about 6 times longer (average lifespan
of a CFL is five to six years).
- CFLs save $30 or more in energy costs over each bulb's lifetime.
- CFLs produce 70 percent less heat, making them safer to operate.
- Skin cancer risk, due to leaking UV radiation, is a
concern, which only came to light (so to speak) in July 2012.
See the research report here
- Like all fluorescent lamps, CFLs contain mercury, which complicates
their disposal and if the bulbs are broken indoors, does present a
health risk, especially to small children.
- LED bulbs, although typically more expensive to buy than CFL's, may
be preferable, as they last longer, contain no mercury, do not emit UV
radiation and consume less energy per lumen produced.
- To get the most energy savings, replace bulbs where lights are on the
most, such as the family and living rooms, kitchen, dining room and porch.
- To minimize breakage risk, especially where children are present,
install them in hard to reach fixtures, like ceiling fans, ceiling
- Make sure the CFL matches the right fixture by reading any restrictions
on the package. Some CFLs work with dimmers, others are specially made for
recessed or enclosed fixtures.
- To lengthen their life, avoid turning the light son and off
frequently (leave them on for at least 2 minutes at a time) and avoid
- To get the most energy savings, replace incandescent bulbs with
CFL's where lights are on the most, such as the family and living rooms,
kitchen, dining room and porch.