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Compact fluorescent light bulb.Questions and Answers on CFLs


Health concerns

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What does the proposed phase-out of inefficient lighting mean for home automation systems that are not compatible with CFLs?

It’s true that CFLs may not work with some home automation systems. That is because CFLs contain a ballast, which may block the signal from a controller. However, other high-efficiency light bulbs are available for home automation systems which are not compatible with CFLs, and still more are on the way. By 2012, we expect that a new generation of energy-efficient incandescent light bulbs will be available.

CFLs end-of-life, is it safe?

Millions of compact fluorescent light bulbs (CFLs) have been in use in Canada and around the world for years. As with any electrical product sold in Canada, CFLs must meet specific requirements for electrical safety, fire and shock hazard. For example, CFLs are tested to simulate failure of any part of the bulb to determine whether such a failure would cause any safety concern. Any CFL that carries the Canadian Standards Association (CSA) and Underwriters Laboratory (UL) certification marks on the package and on the bulb itself has passed these tests.

We also recommend paying attention to the manufacturers' recommendations regarding installation location. For more details

Can CFLs be used outside in cold temperatures?

Yes, there are CFLs that can be used outdoors in temperatures as low as -30 oC. However, check the low temperature rating on the package to make sure it suits your local climate. It is also preferable to have your CFL enclosed in an outdoor fixture to protect it from the cold, wind and humidity. If your CFL is used outdoors with a motion detector, the life of your CFL may be shortened.

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Should I turn off fluorescent lighting when leaving a room?

Short Answer: Turn them off if you will be gone for more than about 15-20 minutes (for details).

Where can I install CFLs?

They can be installed indoors or outdoors. The package will tell you where the CFL can be used. You'll find CFLs to fit almost all fixtures, from ceiling units to standing lamps. A good idea is to start installing CFLs in areas where lights are on longest, such as the kitchen, family room and outdoors. Many people install CFLs in hard-to-reach areas because they don't have to be changed as often.

Do CFLs work with dimmer and three-way switches?

Some CFLs are specially designed to work with dimmers and three-way switches. Check the package to make sure.

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Are there spiral CFLs that can be used for plants as a source of light?

Not at this time. Some fluorescent tubes are specifically designed to provide natural light to indoor plants; their light output contains blue, green, red and orange spectrums to promote plant growth

Aren't fluorescent lights just for offices?

Not any more! Thanks to a number of technological advances in recent years, ENERGY STAR® qualified CFLs are a great choice for your home and office. They come in a range of designs and shapes to fit almost any fixture, indoors and out. CFLs can provide warm light for a living room, or brighten up a workspace. And they don't flicker or hum like fluorescent lights of the past.

Are LEDs a viable replacement for inefficient lighting?

Light emitting diodes (LEDs) can reduce energy consumption and costs by 90 percent compared to an incandescent bulb and are expected to become an effective replacement technology for inefficient lamps in the years ahead. Before that can happen on a large scale, however, manufacturers must address outstanding issues related to LED efficacy and cost. Although some LED lamps are now available for desktop or direct lighting applications, the use of this technology in the residential sector is currently quite limited. LEDs have found a niche in the decorative light string market, where they are functional, attractive and cost-competitive with incandescent lights. In fact, LED is the only technology that currently meets the ENERGY STAR specification for decorative light strings. Despite the current limitations, great strides are being made and this technology will continue to evolve over time.

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Heath Concerns

Is the proposed phase-out of inefficient lighting bad news for people who suffer from migraine headaches?

Although fluorescent lights have long been blamed for causing or intensifying migraine headaches, technology improvements have largely addressed this problem, especially for CFLs. Magnetic ballasts run fluorescent lamps at about 60 cycles per second (the lamp will turn on and off 120 times per second, or twice per cycle), which causes the lamps to flicker noticeably and may cause headaches and other irritants. The new generation of energy-efficient fluorescent lamps – including ENERGY STAR qualified CFLs – use electronic ballasts, which operate at a minimum of 40,000 cycles per second. This rapid cycling eliminates the perceptible flicker associated with health complaints.

Another possible source of headaches is glare from poorly designed lighting – but that applies regardless of the light source.

If CFLs contain mercury, how can they be better for the environment than incandescent lights?

Despite the presence of small amounts of mercury, CFLs provide significant environmental benefits compared to incandescent products. Here's why:

  • CFLs use far less energy than incandescent bulbs, so they reduce greenhouse gas emissions from electrical generating stations powered by fossil fuels
  • CFLs last up to 10 times longer than incandescent bulbs, so fewer bulbs and less packaging ends up in landfills
  • the amount of mercury in a CFL is so small – less than one-fifth of the mercury found in a wristwatch battery – that it does not pose a significant threat to human health or the environment (nevertheless, CFLs should be handled with care and disposed of properly)
  • by decreasing the demand for electricity from coal-fired generation plants – one of the largest sources of mercury emissions in Canada – CFLs can actually reduce mercury levels in the environment

The environmental benefits of energy-efficient lighting are impressive. The lighting efficiency standards proposed by the Government of Canada could help Canadians reduce greenhouse gas emissions in the residential and commercial sectors by more than six million tonnes a year, equivalent to taking 1.4 million vehicles off the road.

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How much mercury is in compact fluorescent bulbs?

The average mercury content in a CFL is about 3 milligrams – roughly the amount it would take to cover the tip of a ball-point pen. By comparison, older thermometers contain 500 milligrams of mercury – the equivalent of more than 100 CFLs. A common wristwatch battery contains five times more mercury than a CFL.

Although there is currently no substance that can replace the efficiency properties of mercury to produce light in fluorescent lamps, manufacturers have reduced the amount of mercury used in lamps. Some manufacturers have voluntarily reduced the mercury content in CFLs by about 80% in the past decade, to as little as 2 mg per bulb. Research is ongoing to achieve further reductions and, ultimately, to develop a mercury-free fluorescent lamp.

The chart below compares the mercury content in a CFL to other household items.

Product Amount of Mercury Number of Equivalent CFLs
fluorescent lamp
5 milligrams 1
Watch battery 25 milligrams 5
Dental amalgams 500 milligrams 100
Home thermometer 500 milligrams – 2 grams 100 – 400
Float switches in sump pumps 2 grams 400
Tilt thermostat 3 grams 600
Electrical tilt switches and relays 3.5 grams 700

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How should I dispose of a broken CFL?

A spill of the amount of mercury found in household products, such as CFLs does not usually pose an immediate health risk to you or your family. However, proper clean up and disposal is required. You can minimize any risk of mercury contamination by following these basic guidelines:

When a CFL breaks on a hard surface:

  • Open windows (if possible) to ventilate the room for a few minutes.
  • Wear rubber gloves and scoop or sweep up the debris with a stiff paper or cardboard, and then place the debris in a sealed plastic bag.
  • Wipe the area with a damp paper towel and put it all in that same sealed plastic bag.
  • Dispose of the bag in accordance with local disposal options as mentioned above.

When a CFL breaks on a carpet:

  • Open windows (if possible) to ventilate the room for a few minutes.
  • Wear rubber gloves to remove as much debris as possible with a stiff paper or cardboard.
  • Use sticky tape (such as duct tape) to pick up any small pieces of glass or fine particles, and then if necessary, vacuum the area and then immediately dispose of the vacuum bag along with the debris and sticky tape in a sealed plastic bag.
  • Dispose of in accordance with local disposal options as mentioned above.

All of this can be done by oneself – no need to call in a hazardous waste team.

What is the correct way to dispose of compact fluorescent bulbs?

Just like paint, batteries, thermostats and other household chemicals, compact fluorescent bulbs should be disposed of safely. Homeowners are encouraged to take advantage of local disposal programs for CFLs, where available. Governments are working with CFL manufacturers and major Canadian retailers to expand recycling options.

Many municipalities have programs that accept household products that contain mercury. Some have implemented collection programs specifically for mercury-containing switches such as those found in your car, while others collect mercury-containing products as part of their household hazardous waste programs. Contact your municipality to find out about local disposal options.

ENERGY STAR qualified CFLs have a warranty. If the bulb fails within the warranty period, return it to your retailer.

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Does the mercury contained in compact fluorescents make incandescent bulbs better for the environment?

No. Although compact fluorescents (CFLs) contain small amounts of mercury, they are far more energy-efficient compared to incandescent bulbs. This means CFLs reduce greenhouse gas emissions from electrical generating stations powered by fossil fuels, as well as the need to build new power generating stations. And because CFLs last about 8 times longer, fewer bulbs and far less packaging ends up in landfills.

Should I be concerned about using CFLs in my home?

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 handled properly. An extremely small amount of mercury, an average of five milligrams, is sealed within the glass tubing. For a basis of comparison, there are about 500 milligrams to two grams of mercury in your average home thermometer. It would take between 100 to 400 CFLs to equal that same amount of mercury!

What is my health risk should a CFL break in my home?

Research indicates that there is no health risk to you or your family should the bulb break as there is such a small amount of mercury in CFLs. The greatest risk is getting cut from the glass shards. Please follow the proper procedure to handle the broken bulb.

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What does the mercury in a CFL look like?

It may be difficult to see the mercury for several reasons. Simply put, there's just not much there to begin with. Five milligrams – the average amount in a CFL – is about the size of the very tip a ballpoint pen. Additionally, the mercury will be in vapor form or absorbed on the lamp walls, the metal lamp ends or other bulb components. At the end of a bulb's rated life, very little of the mercury is available for release into the environment.

Is a CFL harder on the eyes than an incandescent light?

No it's not. Some of the older models of fluorescent tubes would sometimes flicker and cause some people to have headaches. However, the light emitted by a CFL is a little different than that of an incandescent; this does not change the fact that the “lumen” output is the same when comparing equivalent products.

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Ambience or task lighting? What colour of light should I look for when purchasing CFLs?

ENERGY STAR qualified CFLs are available in many of the same colour temperatures as regular bulbs. Choose the colour that works best for the room and for the specific application you have in mind. Whether you are trying to create a warm, cosy ambience, simulate natural daylight or provide effective task lighting, choosing the right light colour can make all the difference.

  • For a warm, inviting light, choose an ENERGY STAR qualified CFL that states “warm white” or “soft white#8221; on the package, with a colour temperature of 2700 to 3000 K.*
  • For a cool, white light suitable for task lighting, choose an ENERGY STAR qualified light bulb that states “cool white” or “daylight” on the package, with a colour temperature of 3500 to 6500 K.

* Colour temperature is measured in units kelvin (K). Lower kelvin numbers mean the light has a warmer colour, while higher kelvin numbers mean the light has a cooler colour.

Different fixtures need different types of bulbs. Using the chart, find your fixture and then see which bulbs will work best.

Table with information on different types of LCDs

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When I replace my incandescent lamp with a CFL, and the fixture indicates a maximum wattage of 60 W or 40 W, should I worry about using a CFL with a lower wattage then what is cautioned?

No. There is no minimum value for the wattage used in these fixtures, only a maximum. Depending on your needs, consult the CFL equivalency chart (link) to either keep the same light output (measured in lumens) or to increase it.

Is there a CFL equivalent to an incandescent tri-light of 50-100-150?

Yes, however, the wattage equivalency for a specific CFL may vary slightly between manufacturers. Also, there are different ranges of wattage for CFL tri-lights.

How does a CFL do in areas where power surges occur, such as rural areas?

CFLs may not hold up to the stress of power surges. So using them in areas such as workshops may not be advisable.

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Does the wattage indicated on the package of a CFL include the wattage necessary to run the ballast?

Yes it does.

Why do CFLs use less energy than incandescent bulbs?

Fluorescent technology is much more efficient at converting energy to light. Standard incandescent bulbs, which have been produced the same way using the same materials for more than 100 years, waste 90% of their energy by producing heat, not light.

Will my home energy costs increase if I switch to CFLs?

The answer to this question may vary from one part of Canada to another, depending on the type of fuel used for home heating, the efficiency of your heating system, local climate and other factors. As a general rule, however, the following applies.

Incandescent lamps are only 5 to 10 percent efficient, which means that most of the energy they consume is converted into heat energy rather than light. Depending on where the bulb is located and the time of year, your home heating system may have to replace this heat when you switch from an incandescent bulb to a CFL. The cost of replacing the heat will depend on the efficiency of your heating system, the fuel source and the price of the fuel.

Having said that, most homeowners in Canada will save money and reduce greenhouse gas emissions by switching to energy-efficient lighting. This is because the impact of incandescent lights on the heating load is negligible in most homes, and any additional cost is usually more than offset by the energy savings from using CFLs. Installing CFLs will also reduce the load on cooling systems for homes that have air conditioning. Switching from incandescent bulbs to CFLs can also make homes that do not have air conditioning more comfortable during hot weather, as less heat will be generated inside the home.

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Given their higher purchase price, do CFLs really save money over their lifecycle?

Absolutely! ENERGY STAR qualified CFLs use only about one-third as much electricity as a conventional bulb to produce the same amount of light. Although they cost a bit more, ENERGY STAR qualified CFLs are rated to last up to 10 times longer than incandescent bulbs. The combination of energy savings and long life means CFLs will pay for themselves many times over, especially since their purchase price has declined significantly in recent years. CFLs are now often available for as little as $2 per lamp.

How much can consumers expect to save by switching to high-efficiency lighting?

The proposed phase-out of inefficient lighting, when fully implemented, could save consumers up to $60 a year on their electricity bills. In residential lighting alone, replacing conventional incandescent bulbs with ENERGY STAR qualified CFLs could save Canadian consumers almost $600 million a year on their electricity bills.

What accounts for the price difference in CFLs?

CFLs come in a wide range of designs and shapes, and some are specifically made for tri-lights and dimmers. Prices may vary according to these characteristics and according to the manufacturer.

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Why should I buy a compact fluorescent light bulb?

To save energy. Compact fluorescent light bulbs, or CFLs, use only one quarter of the energy of standard incandescent bulbs. A 15-watt CFL produces the same high-quality light as a typical 60-watt incandescent bulb.

Why are CFLs more expensive?

Because they are a better product. Production costs for CFLs have dropped a great deal in the last 10 years, and manufacturers and retailers are passing these reductions on to consumers. But CFLs still cost more because they are more expensive to make than standard incandescent bulbs. The CFL manufacturing process is more complex, requiring more electronic materials and higher product-inspection and quality-control costs.

How much will I save by using CFLs?

An average Canadian home has 30 light fixtures, indoors and out, that consume close to $200 of electricity every year. Replacing just five bulbs with ENERGY STAR qualified CFLs in high-use areas can save up to $30 a year, depending on location and amount of time used. That means you'll pay off the added cost of the bulbs in less than two years, and they last for at least five. Better still, you won't have to change them as often!

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Why choose an ENERGY STAR qualified CFL?

On CFLs, the ENERGY STAR symbol means that the product meets strict specifications for quality, including long life, colour and brightness as well as energy savings.

Compact fluorescent light bulb.How do I compare incandescent light bulbs with CFLs?

The packaging for ENERGY STAR qualified compact fluorescent lights will give you all the information you need to make a true comparison with other bulbs. On each package, look for:

  • the amount of light produced by each bulb, measured in lumens
  • the average expected life of the bulb in hours
  • the wattage of the bulb
  • the wattage of an equivalent incandescent bulb

Remember, the wattage rating listed on light-bulb packaging is a measure of the power used, not the light output. CFLs use much less energy to deliver the same light output as incandescent bulbs.

Replacing even one 60-watt incandescent bulb with a 15-watt CFL in each of Canada's 12 million households could save up to $73 million a year in energy costs.

It would also reduce GHG emissions by approximately 397 000 tonnes – the equivalent of taking more than 66 000 cars off the road each year.


ENERGY STAR is an international symbol that will help you quickly identify products that reduce energy use in your home. When you see the ENERGY STAR symbol, you can be sure you're looking at the most energy-efficient products on the market.

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 The ENERGY STAR name and the ENERGY STAR symbol are registered trademarks of the United States Environmental Protection Agency and are used with permission.