Compact Fluorescent Lamps (CFLs)
Frequently asked questions
Q: How much do they cost to buy?
A: A good quality CFL costs on average $6 at normal retail price and lasts 8-10 times as long as an ordinary bulb. However the Electricity Commission is currently subsidising the cost of CFLs through supermakets and service stations. These CFLs can cost as little as $2 each. >> More information about the subsidies.
Q: How long do CFLs last?
A: A good quality CFL lasts from 6000 to 15,000 hours. We recommend you choose a bulb that lasts over 8000 hours (approximately 8 years). Check the box to find out the lifetime of the bulb.
Q: How much do they cost to run?
A: Good CFLs typically use up to 80% less energy than an ordinary lightbulb (this is based on replacing a 100 Watt incandescent bulb with a 20 Watt CFL). Used 3 hours a day throughout the year will cost $4.40 compared with $21.90 for a standard bulb, saving you $17.50 per year per bulb. Note: this is based on an electricity cost of $0.20/kWh
Q: I hear CFLs contain mercury – is this dangerous?
A: The current average mercury content for a household CFL is 4mg per lamp, enough to cover the head of a pin. The CFLs subsidised by the Electricity Commission have 2.3 – 2.8 mg of mercury. Mercury is a toxin, however the small doses found in a single CFL lightbulb will not put you at risk. Mercury is also found in old style household thermometers.
Q: How do I dispose of them correctly?
The Ministry for the Environment has developed guidelines for safe disposal of CFLs. This work is ongoing and is a focus of the energy efficient lighting and product stewardship work programmes. More information on the product stewardship work programme can be found on the Ministry for the Environment website.
The following councils operate a HazMobile collection service that accepts fluorescent lamps for recycling:
- Auckland
- Bay of Plenty
- Hawke’s Bay
- Upper Hutt
- Hutt City
- Waimakariri District
No material from this process goes to landfill.
Wellington has a hazardous waste facility at the Southern Landfill where residents can drop off domestic quantities of CFL's or fluroescent tubes. The bulbs are eventually sent to Interwaste for recycling. For more information visit the Wellington City Council website.
If you live outside these areas, try your local electrical contractor or lighting supplier to see if they have a recycling programme. If you need to throw them away, wrap them in newspaper, put into a plastic bag and place in the rubbish.
Q: What do I do if I break a CFL at home?
A: The National Poison Centre in Dunedin states that there is very little risk from the mercury if a lamp should break in the home. Inhalation of mercury is usually only a concern if it occurs over a long time, such as days, weeks or months (chronic exposure), or if a large amount is inhaled at once. The mercury in a lamp will be in liquid form, therefore easier and safer to handle and clean-up if the suggested guidance contained in our information sheet is followed. The advice is:
- wear gloves when cleaning up a broken lamp
- open windows and doors to ventilate the area
- DO NOT vacuum the area as this could further disperse the particles
- carefully pick up the glass pieces, wrap them in newspaper and put in a plastic bag
- use a damp cloth or paper towels to clean up any liquid and smaller shards of glass
- an eye dropper or syringe could be used to collect up any liquid
- put all the cloths/paper towels, wrapped glass and gloves in a plastic bag with the normal household rubbish
For more information, please see the “Mercury spills” information sheet on the National Poisons Centre website.
Q: Where can they be used?
A: They are good for general household lighting. Some of the newer ones can be used with dimmers.
Q: Does it require a special fitting?
A: CFLs come in screw and standard bayonet type so can be fitted in place of standard incandescent bulbs.
Q: Is the light quality the same as standard bulbs?
A: CFLs come in a range of light outputs – warm white to cool white. Warm white is closer to the colour from a standard incandescent bulb, whereas cool white has a sharper light effect. Some people prefer cool white lights where contrast is preferred e.g. for reading or bathrooms. Check the packaging of the bulb before you buy to ensure you choose the desired light output.
Q: Can I only buy the spiral CFL bulbs?
A: No. There is a range of styles and types. For example there are candle bulbs, fancy round, reflector lamps, spherical and even replacements for halogen lamps. However, check with your lighting specialist as not all CFLs provide the same light output as the standard bulb they are replacing.
Q: Can they be used with dimmer switches?
A: Most CFLs will not dim when used with dimmer light switches. However, some CFLs do, though they are not widely available. Check with a lighting specialist to find out which bulbs can be dimmed.
