Light bulbs of any type are largely harmless but there are some safety points worth knowing, whether it's tips on safely disposing of broken bulbs or the fire risk of standard incandescent light bulbs.

Light bulb fire safety

Because light bulbs are electrical appliances and all bulbs produce heat as they convert electricity into light, care must be taken to minimise the risk of overheating. Traditional incandescent and halogen light bulbs operate at high temperatures and will cause burns if touched when hot. Never exceed the maximum wattage stated on a light fitting and if there is no maximum wattage label, we recommend you seek expert advice before use or replace the fitting.

Traditional incandescent light bulbs
Because traditional incandescent light bulbs convert nearly 95% of electricity into heat rather than light, they get very hot. You have to be careful not to position lamps where young children could touch the bulb. Light fittings are required to have a clearly marked maximum bulb wattage rating that the fitting can safely withstand. If this rating is not clearly visible you should replace the light fitting. This is especially important where traditional incandescent light bulbs are used in enclosed wall fittings, ceiling domes and down lights. Remember: inserting a higher-wattage lamp could overheat the fitting and its surroundings – creating a fire risk.

New generation halogen bulbs and halogen spot lights
Halogen bulbs operate at high temperatures so fittings should be located where they can't be touched. Never exceed the maximum bulb-wattage fitting rating due to the risk of overheating and fire. You should also check the building regulations in relation to installing recessed lights in ceiling and walls.

CFLs
CFL light bulbs use 805 less energy than standard incandescent light bulbs at converting electricity into light and as a result they produce far less heat than either incandescent or halogen light bulbs. The base material of all CFLs sold in New Zealand must be made from fire-retardant plastic and, while lamps occasionally have been known to overheat and even smoke at the end of life, this is rare. As with all light bulbs, never exceed the maximum wattage on the fitting and if a CFL is obviously overheating, or smoking, switch it off and replace it (once it has cooled).

Light bulb disposal

Dead light bulbs can be wrapped in newspaper to avoid the risk of getting cut by broken glass and disposed of either at your local authority recycling centre or, for places where there are no disposal facilities, put out with the household rubbish.

A CFL that stops working at the end of its life does not release any mercury – so long as the glass tube is not broken. That means you can wrap it in newspaper and dispose of it the same way as any other light bulb i.e. Wrap it in newspaper and dispose with your household rubbish. While you can dispose of CFLs in the household rubbish, it’s obviously best to recycle them if this service is available in your area.

• Ask your lighting supplier if they provide a drop-off service for CFLs.
• Ask your local council if they operate a hazardous waste service. Some offer a drop-off service at the transfer station, such as Wellington City Council and Christchurch City Council. Others offer an annual hazardous waste collection, like Auckland, Bay of Plenty, Hawkes Bay and Palmerston North. Check out www.hazmobile.govt.nz for more information.

• Alternatively, visit the Interwaste website (Interwaste is recycling provider for mercury-containing lamps) and buy a prepay box to fill and send then in to be recycled.

Broken bulb clean-up

If any light bulb is broken in your home, care is required with the clean up of the broken glass and other sharp pieces.

If a CFL is broken, the very small amount of mercury contained in a single bulb is most unlikely to pose any risk if the guidelines for a safe clean-up are followed.

As a precaution, the steps below outline how to clean-up safely:

1. When disposing of any sharp objects like broken glass, always use rubber or latex gloves.
2. Mercury vaporises readily at room temperature, ventilate the room for 15 minutes before you start the clean-up.
3. Sweep the big pieces up using stiff paper or cardboard, wrap in newspaper and place in a plastic bag. It’s a good idea to use the sticky side of duct tape to clean up the smaller pieces.
4. It’s wise not to use a vacuum or a broom to clean up after a broken light bulb as this could potentially vaporise and spread mercury through the air and contaminate the vacuum cleaner or broom.
5. Wipe the area down with a damp paper towel and place used paper towels along with the gloves in a plastic bag.
6. Store the sealed bag outside until the next rubbish collection.

To avoid having to use this process, we suggest you:

• Don't use CFLs where they are likely to get swiped by enthusiastic children and their sports gear. Only use an exposed CFL in a place where you know it is unlikely to get accidentally broken.
• Don't use excessive force when installing any light bulb. For a CFL, hold it by the base and not the glass when installing it if possible. If the bulb won't fit, don't force it.

For more clean-up information see the Ministry for the Environment website.