Incandescent lamps: The most common type of household light bulb. An electric current passes through a thin filament, heating it and causing it to emit light.
Halogen lamps: A modified form of incandescent lamp. They are more expensive to buy but last twice as long.
Light Emitting Diodes (LEDs): Potentially the lighting type of the future. LEDs have an extremely long lifespan. It is expected that technological advances will reduce costs such that this lighting type can be introduced into homes in the near future.
Fluorescent lamps: A lamp filled with neon or argon gas, a little bit of mercury and coated with a fluorescent or phosphorescent powder. Fluorescent lamps come in many shapes and sizes. Increasingly popular is the compact fluorescent light bulb (CFL) which is a type of lamp that fits into a regular light bulb socket.
What are the benefits of using CFLs?
A lot of families are switching to CFLs in their homes due to their longer life and to reduce their energy usage, which in turn reduces greenhouse gas emissions.
How does a CFL work?
CFLs are electrical discharge lamps that contain low-pressure mercury vapor and an inert gas, usually argon, making invisible ultraviolet (UV) light. The inside of the glass is coated with a fluorescent made with phosphor powder. The UV light causes the phosphor coating to fluoresce and emit visible light.
What is the concern from using CFLs?
CFLs contain mercury, a metallic element, and when broken, this mercury escapes. Mercury makes CFLs operate more efficiently than an incandescent and halogen lamp. Mercury exists in one of three forms: elemental mercury (metallic), inorganic mercury and organic mercury (e.g. methyl mercury). Elemental mercury is the main type of mercury used in CFLs. Elemental mercury is a silvery liquid that can vaporize at room temperature due to its low vapor pressure and is the kind of mercury found in the old thermometers.2,3 Exposure to mercury can be associated with health effects, but it depends on the form of mercury, the route of exposure and the duration of the exposure.
What is the amount of mercury contained in a CFL?
A CFL contains around 5 milligrams (mg) of mercury which is a lot less than in a mercury thermometer (5 mg vs 500 mg). 1000 mg is about the amount of sugar in a typical sugar packet.
How can I be exposed to mercury?
However, people may be exposed to the mercury contained in a CFL only if it is broken; mercury is not released from normal CFL use. Breaking the CFL results in mercury vapor being released into the air and possibly inorganic mercury adsorbed to phosphor powder separating from the glass. The primary form of mercury will be elemental mercury in air. Over time, the inorganic mercury adsorbed to the phosphor powder will vaporize also.
The primary human exposure pathway will be inhalation of the elemental mercury. There is an initial spike in air-borne mercury concentration following breakage of a CFL or linear fluorescent tube as mercury is released3,4,5 followed by slower release of elemental or inorganic mercury present in solid and liquid forms.
There is some limited potential for dermal exposure to the powder if a person were to touch the powder directly. It is possible that children could crawl on the floor where a CFL has broken and remaining powder might be absorbed by the skin. Given the broken CFL involves glass, it is not likely that children would be allowed in the area of the broken CFL until after clean up.
How Do I Safely Clean-up a Broken CFL?
Here are the 5 simple steps to safely clean-up a broken CFL.
Patricia Nance, M. Ed, M.A., Toxicology Excellence for Risk Assessment (TERA),firstname.lastname@example.org
Natalia Foronda, PhD, New Zealand Ministry of Health,Natalia_Foronda@moh.govt.nz