October 5th, 2011, By Matthew Van Dusen

It’s a zombie myth that just won’t stay down: Yes Compact Flourescent Lamps contain toxic mercury. There is about as much truth to that statement as there is mercury in CFLS — which is to say, trace amounts. CFLs do contain mercury, but in quantities so small that breaking one exposes you, in most cases, to less mercury than eating tuna fish. 

Then they consulted the USEPA and contacted a lighting specialist from General Electric (their sponsor) in order to take on the issue of mercury in CFLs.

How does mercury help produce light in CFLs?  CFLs are glass tubes that are filled with argon gas and mercury vapor. When an electric current passes through the tube, the mercury emits ultraviolet light that excites a phosphor coating on the tube. The coating then emits light.

Are we talking about high levels of mercury?  No. And the amount of mercury in CFLs has dropped steadily since they first made inroads into the market 15-20 years ago. As recently as 2007, CFLs contained about 5 milligrams, enough to cover a ballpoint pen tip. Since then, regulations in the European Union, which have also been adopted in California and other areas, have mandated that the amount of mercury in CFLs be limited to 3.5 mg by 2012 and 2.5 mg by 2013.