Food for Thought: What are those new light bulbs on the shelf?

By Nancy Schuster
Frontier District Extension Agent

Since the new Department of Energy standards of 2012, the light bulb world has become very confusing! I discovered this very fact recently trying to buy a replacement light bulb. So with guidance from government sources and several consumer information sites, meet the new light bulbs on the shelf.

LEDs or light-emitting diodes are one of the light bulbs on the shelf. When an LED is switched on, electrons and electron holes come together with the end result of a release of energy in the form of photons, or light. LEDs are rated to last for tens of thousands of hours of light. LED lights don’t “burn out,” the way that incandescent bulbs do. Instead, they undergo “lumen depreciation,” gradually growing dimmer and dimmer over time.

foodforthoughtAnother new light bulb is the CFL, or compact fluorescent lights. CFLs use between one-fifth and one-third the energy of incandescent bulbs and save one to five times their purchase price over the course of their lifetime. CFL bulbs that are regularly turned on and off for short periods of time have a much shorter life expectancy so save them for lighting that you’re going to keep on for longer periods of time.

Like all fluorescents, CFLs contain trace amounts of mercury – typically 3 to 5 milligrams (mg), although some contain less. The amount of mercury vapor in a standard CFL bulb is about one-hundredth of that you’d find in an old-fashioned thermometer. Even in such a small amount, mercury merits a degree of caution, as direct exposure can cause damage to the brain, lungs and kidneys. If a CFL shatters on your kitchen floor, be sure to open a window and let the room air out for 10 to 15 minutes, then carefully transfer the glass and dust into a sealable container – don’t use a vacuum cleaner that will stir the chemicals up into the air. Take the broken bulb to a recycling center for proper disposal.

The other new light bulb on the shelf is halogen, incandescent bulbs with a bit of halogen gas trapped inside with the filament. This gas helps “recycle” the burned-up tungsten gas back onto the filament, making for a slightly more efficient light. Unlike the mercury in CFLs, this gas isn’t anything that could be classified as hazardous waste.

Read the halogen bulb package. This bulb should not be touched by human hands. A small bit of grease from our hands can cause this bulb to shatter when turned on. Always use a cloth or tissue when handling halogen bulbs.

Tips to consider when buying light bulbs:

  • Bring your old bulb with you so you know the LED or CFL fits your fixture; some energy-saving bulbs are bigger or heavier than the incandescent bulb they are replacing.
  • Not every CFL or LED should be used in every type of light fixture so check the information on the package before buying one for a specific application. For example, not all CFLs and LEDs are intended for use in ceiling fans in which the bulb hangs down.
  • Some CFLs and LEDs can be used in fully enclosed fixtures.
  • Many of the CFLs and LEDs work outdoors but cannot get wet.
  • CFLs and LEDs can be used in vintage light fixtures; read “Light Facts”.

Explosive bulbs?

What about the stories of light bulbs exploding? Poorly made light bulbs occasionally have thin glass, which can crack easily, while high quality or specialty bulbs often have thicker glass. Once the glass cracks or develops any sort of irregularity, the outside air’s pressure will cause a light bulb explosion. These irregularities or cracks can be caused by water, overheating, or oils.

As a light bulb is used, the filament gradually burns, becoming weaker and weaker. In rare cases, the filament can break and fly towards the glass light bulb, rather than simply snapping and remaining in the center of the bulb, which how light bulbs normally burn out.

The most common type of light bulb to explode is the halogen bulb. Halogen bulbs get hotter and any oils on the glass bulb itself can cause the bulb to heat irregularly and explode. When installing and changing halogen bulbs, never touch the bulb itself with your bare hands; use a paper towel or thin cloth gloves to prevent an explosion.


schustersmNancy Schuster is a Frontier Extension District family and consumer science agent whose responsibilities include providing information about food safety, nutrition, food science and food preparation. She is based in the Garnett office of the Frontier Extension District and can be reached at 785-448-6826 or email [email protected].

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