As of Jan. 1, 2014, 40- and 60-watt incandescent light bulbs are no longer manufactured in the U.S. as part of efficiency standards signed into law by President George W. Bush in 2007. Previously, the government regulations phased out 70- and 100-watt bulbs over the last few years, but this ban will be much more widely felt since 40- and 60-watt bulbs are more frequently used in homes. So far, the ban has gone fairly unnoticed, since stores still have incandescent bulbs in stock. Once current incandescent stock sells out in stores, consumers will have to choose between more energy-efficient options, including halogen, LED and CFL bulbs. There has been a lot of debate over CFL bulbs, and many consumers are wary of the higher price tag, efficiency benefits, and presence of mercury. There’s also the issue that the quality of the light with CFLs tends to be brighter, and many consumers experience an increase in headaches with fluorescent lighting (myself included). Fortunately, the technology has come a long way in a short period of time, and CFLs are now sold in a warm tone version, not just the standard bright light.
CFLs also turn on a lot faster than they used to, so you don’t necessarily have to stand in a dark room for 20 seconds while the bulb turns on. While the price tag for CFLs may be slightly higher than incandescents, the lifespan of a 15 watt CFL bulb is between 8,500 hours, versus a 60 watt incandescent that averages around 1,000 lifetime hours. You’ll be putting more money into the initial purchase of CFL bulbs, but replacing incandescent bulbs more frequently ends up being more expensive over time. The average lifespan energy consumption of a CFL is around one-fourth the consumption of incandescent. Unlike CFLs, incandescents produce light by heating the metal filament inside the bulb. When electricity passes through the filament, its temperature rises to 2,300 degrees Celcius, with the heat causing the filament to glow white-hot and emit light. But only 5 to 10 percent of that electricity is transformed into visible light. In other words, incandescents don’t convert heat to light very efficiently, and much of the energy is wasted. CFLs are made of glass tubes filled with gas and a small amount of mercury. They produce light when the mercury molecules are excited by electricity running between two electrodes in the base of the bulb. Mercury emits ultraviolet light, which in turn excites the tubes phosphor coating, leading it to emit visible light. A study in 2012 published in the journal Photochemistry and Photobiology shows that CFLs are best used behind protective glass covers, or behind lamp shades. Long-term exposure to naked CFL bulbs may cause skin damage similar to damage from ultraviolet radiation. There has been concern over the environmental impact of mercury in CFL production. Around 50% of energy produced in the U.S. is generated by coal-fired power plants. When coal is burned, the mercury naturally contained in the coal releases into the air.
Using energy-efficient CFLs reduces demand for power, which in turn reduces the amount of coal burned by power plants and the amount of mercury emitted when coal is burned. So while mercury may be present inside a CFL bulb, incandescent bulbs result in more emissions at the power plant, which is a more harmful consequence to overall air quality. Each CFL bulb contains about 5 milligrams of mercury. If a CFL bulb breaks, it’s important to take safety precautions when handling a broken bulb, but keep in mind that not all the mercury in the bulb dissipates when a bulb breaks. As long as a child does not ingest any liquid that may come out of the bulb, they will not be exposed to toxic levels of mercury. Researchers have noted that it would take weeks for a child to be exposed to mercury vapor, which would mean a broken bulb would need to be left in a room for over a week. Provided you clean up the bulb promptly, and protect yourself by using rubber gloves (which are recommended for cleaning up incandescents as well to prevent cuts), there is no risk of mercury exposure. The Environmental Protection Agency (EPA) outlines very specific requirements for disposing of CFLs, since dumping them in landfills is harmful for the environment (http://www2.epa.gov/cfl). When a CFL stops working the easiest and safest way to dispose of it is to put it in a plastic bag and bring it to your local Home Depot or Lowes, where they will recycle it for you at no cost.