Bust a pigtail bulb? Don’t freak out

Q: Given the toxicity of mercury, why in the world would light-bulb manufacturers have chosen to use this in the CFL light bulbs that replaced the incandescents? 

So let me ask you this: Do you have any of those long fluorescent light tubes in your house? Perhaps a couple in a fixture over a workbench, or, like me, in a desk light that’s been in my family for 60 years? Did you know there’s mercury in those things — possibly two or three times more than in these newer bulbs? Have you ever worried about it before? Probably not.

You have to understand that compact fluorescent lights, or CFLs, are simply those old-fashioned tubes repackaged for a new purpose — to replace inefficient incandescents while saving energy and, although I don’t know if I can convince you, money. They work the same way: Instead of electricity heating up a wire that glows, the current in fluorescents is driven through a tube containing argon and a tiny bit of mercury vapor. This generates invisible ultraviolet light, which, in turn, excites a coating (phosphor) on the inside of the tube, which produces the light we see.

As for the mercury, you just can’t make any fluorescent bulb without it, whether it’s a black light or a bug zapper, the experts say.

“At present, it is scientifically and technically impossible to produce mercury-free compact fluorescent lamps,” according to a report by Europe’s Scientific Committee on Health and Scientific Risks. “But new technologies can reduce the amount of mercury contained, and the authorized content will be gradually lowered.”

Years ago, thermometers we hung around the house or took our temperature with contained far more mercury than any CFL bulb — perhaps as much as 500 milligrams. We didn’t give them a second thought. Yet when CFL bulbs started to proliferate, warnings made it sound like we might want to start writing our last will and testament if we broke one. Having once been properly chastised for spreading this alarm myself, let me try to set the record straight now:

According to a 2008 article in Environmental Health Perspectives, CFLs typically contain from 3 to 5 milligrams of mercury — about 1 percent of the amount found in older HVAC thermostats that still may be found in some homes. Moreover, a 2011 study found that if you break one, only a tiny fraction of that mercury will escape even if you don’t clean it up for 24 hours. As a result, these researchers found it could take weeks for the levels of mercury vapor in the room to reach a point that might be hazardous to a child.

Even more good news: Some lightbulb makers have dropped the amount of mercury to as little as 1.4 milligrams per bulb, compared to as much as 8 milligrams in those longer fluorescent tubes. (There are more than 28,000 milligrams in an ounce.)

And here’s the real kicker: The electricity required to power one of those old 60-watt incandescent bulbs over its lifetime would require a coal-fired generating plant to release an estimated 4.4 milligrams of mercury into the atmosphere, much more than a broken CFL bulb that is cleaned up promptly. By comparison, the electricity required to power a 13-watt CFL bulb over an 8,000-hour lifetime releases about 1 milligram of mercury into the atmosphere, again assuming that coal supplies about 40 percent of that electricity (the national average as of 2014).

Remember that every year, both natural events (volcanoes, rock weathering, etc.) and human activities (mining, fuel use, etc.) release not a few milligrams but perhaps as much as 10,000 tons of mercury into the environment. So call me a tree-hugger, but every little bit of conservation helps. And the experts still swear it’s good for your bank account as well: Although the initial outlay is more, they estimate that each CFL bulb will save you $30 to $50 over its lifetime.

If you do break one, there’s no need to grab the oxygen masks. First, leave the room (calmly) and air it out for five to 10 minutes. Then, scoop up the waste with stiff paper or cardboard, use sticky tape to pick up remaining residue and put it all in a sealable glass jar if possible. (Do not vacuum.) If practical, continue to air out the room and leave the HVAC system off for several hours. Otherwise, please recycle burned-out but intact CFLs at a home improvement store like Home Depot or Lowe’s so the mercury doesn’t wind up in a landfill.