Compact Fluorescent Lights: The Mercury Matter

But not all CFL bulbs are the same. Some have lower mercury content than others, and some last much longer. Unfortunately, you can't tell the best of the best by their labels – or by the U.S. government Energy Star logo they now carry. Some Energy Star labeled bulbs could not be legally sold in Europe due to excessive mercury content.

Putting mercury in CFLs in perspective

Mercury is a dangerous chemical; exposure, even at low levels, can cause neurological damage, memory and learning problems, and delays in speech and reading ability in children. Now found in the blood of one in three women, according to Dan Laks, a neuroscience researcher at the David Geffen School of Medicine at the University of California, Los Angeles. Mercury exposure in people comes from eating contaminated fish, inhaling polluted air, and from dental amalgams. How does it get in our fish, you wonder? The same way it gets in our air. It’s spewed (some 140 million tons a year) along with other pollutants from the smoke stacks of coal-fired power plants, cement kilns, refineries, smelters and mining operations, where it settles in water, and then bio-accumulates in the bodies of fish. Large fish high up on the food chain, such as big-eye and ahi tuna, tend to have higher amounts of mercury in their bodies – enough to be a health concern for young children and pregnant women in particular.

The average CFL contains just four milligrams of mercury. That tiny quantity of mercury—essential for the energy efficiency of CFLs—is about the size of the tip of a ballpoint pen and is far less than the mercury inside other common household objects. For example, watch batteries have five times the mercury and older thermometers have 500 milligrams, equal to 125 CFLs. But more importantly, because the CFL is so much more efficient than the standard incandescent bulb, the amount of mercury contained in a CFL ends up being less than half the amount of mercury that would be released into the atmosphere from coal-fired power plants to keep an incandescent bulb lit over the lifespan of a standard CFL.

So there is less mercury added to the CFL to make it more efficient than is produced as a pollutant in generating the energy to light the incandescent. That said, the latter is an ambient pollutant, if the CFL in your home breaks, mercury exposure is a matter of immediate concern. Simple Steps heeds the warnings of the American Academy of Pediatrics, which makes very clear that mercury in all its forms is very toxic and that exposure must be minimized, and strongly urges you take the advice provided here when shopping for, installing and disposing of CFLs.

Shopping for CFLs with the lowest mercury content

When shopping for CFLs, buy those with the lowest mercury content. The Environmental Working Group maintains a list of low-mercury bulbs

Disposing CFLs properly

Never throw broken or burnt-out CFLs in the trash? Contact your municipal collection program to learn about proper disposal options or check the EPA’s bulb recycling website or www.earth911.org for nearby recycling and disposal sites. Many major retailers, including Ikea and Home Depot, accept CFLs for recycling. 

If a CFL bulb breaks, open windows to allow volatile mercury vapors to escape, keep people and pets away for at least 15 minutes. Wear gloves, a dust mask and old clothes when scooping up the bulb fragments. Seal the waste in a glass jar with a tight lid. Pat the area with sticky tape to collect tiny splinters and dust, then wipe with dampened paper towels or baby wipes. Place wipes and towels in the jar with the bulb. Properly dispose of the jar and its contents, and also dispose of any materials (bedding, etc.) that came in contact with the bulb or its dust. Towels, bedding, and clothing that come in contact with the broken bulb should be discarded--not laundered. Mercury particles could contaminate the washing machine or the water flowing into the sewage system.

If a bulb breaks on a carpet, the EPA recommends vacuuming it and then cleaning the vacuum. However, the Maine Department of Environmental Protection (DEP) conducted several tests and concluded that vacuuming stirs up room air and can result in elevated mercury levels in the air. Using the vacuum elsewhere in the house could spread the mercury to other rooms. The Maine DEP suggests removing the carpet altogether, especially if pregnant women or children spend time in that area. If the carpet is not removed, be sure to ventilate the area frequently since mercury vapors can release from the carpet over long periods of time.