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Fluorescent lighting's proven benefits make it an attractive technology, but lamp disposal has become a political issue with real financial impact. How do you separate the truth from the half-truths and hyperbole? What's the real story?
Why so much furor over fluorescent lamps? It's because each one contains a very small quantity of mercury. Without the mercury, you get no fluorescence (light). Though the mercury exists in miniscule quantities, the fact that it exists is enough to draw the pens and political swords of the regulators from their blotters and scabbards.
Federal and state regulations governing fluorescent lamp disposal have become increasingly complex in recent years. Environmental issues concerning overall mercury releases to the air and water have created a blizzard of regulations; so have state goals to increase recycling rates. The myriad of differing disposal regulations, which vary by state, continues to grow.
States continue to evolve and change their preferred regulatory approach to lamp disposal. In fact, regulators are trying to balance economic impact with environmental impact in an environment filled with unknowns; thus, the frequent changes. Among the unknowns is how much mercury it takes to pose a health risk. Until we have a clear answer as to how much mercury is too much, the regulatory briar patch will continue to grow.
These costly and confusing regulations may tempt you to avoid fluorescents altogether, but that, too, is costly-and not just in terms of dollars.
Why do fluorescent lamps need mercury? A typical fluorescent lamp is composed of a phosphor-coated glass tube with aluminum end caps and cathodes located at either end. The tube contains milligram levels of mercury, of which a fractional amount is vaporous. Current flowing through the lamp energizes the mercury vapor. This energization causes the vapor to emit ultraviolet energy. As the ultraviolet energy passes through the phosphor coating, it's transformed into visible light. Without the mercury vapor to emit ultraviolet energy, the lamp would not emit light.
A 4-ft fluorescent lamp has an average rated life of 20,000 hours. To achieve this long life, the lamp must contain some mercury in addition to the vapor. As the mercury is energized, it slowly absorbs into the phosphor and glass. If the lamp contains too little mercury,...