Archive for the ‘light bulbs’ tag
Mercury and Compact Fluorescents #
I’m probably not the only one who’s heard some bad things about newer compact fluorescent light bulbs. The most daunting fact had been the mercury (see quote), though there’s also the aesthetic case.
But what about the mercury? The toxic heavy metal is integral to the design of current CFL bulbs: Electricity agitates the mercury molecules, causing them to emit ultraviolet light. That light then spurs a bulb’s phosphor coating to give off visible light. But the amount contained in each bulb is barely enough to cover the tip of a ballpoint pen, and won’t cause any bodily harm as long as simple precautions are taken. The National Electrical Manufacturers Association has voluntarily imposed a limit of 5 milligrams per bulb on all CFLs sold in the United States—about 1 percent of the mercury contained in an old home thermometer. Since manufacturers are well aware that health fears are preventing the widespread adoption of CFLs, most have committed to making bulbs with even less mercury than NEMA’s standard. The average CFL bulb now contains around 4 milligrams of mercury, and that figure should drop closer to 2 milligrams in the very near future. Much of the credit for these reductions goes to Wal-Mart, which has pressured GE, Royal Phillips, and Osram Sylvania to cut down on the quicksilver.