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Where is the mercury contained in a CFL

  1. Nov 9, 2009 #1
    Hello all,

    This evening, I broke a hole near the tip of a spiral CFL similar to this one while screwing on a glass cover over a ceiling light fixture in what will become a new baby's room:
    http://upload.wikimedia.org/wikipedia/en/thumb/0/0b/Compact-Flourescent-Bulb.jpg/180px-Compact-Flourescent-Bulb.jpg" [Broken].

    I spoke to poison control and was told that the amount of mercury contained in a CFL (3-5mg) is nothing to be alarmed about.

    The poison control rep also told me that I may not have even released the mercury at all because I broke the bulb at the end furthest away from the ballast. She stated that the mercury is actually contained in an enclosed area on the ballast end...is that true?

    Thanks :smile:
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 9, 2009 #2

    I would assume that the mecuy vapour is present within an enclosed space close to the ballast, so that the eletric current can be fed through it easily, but I guess it would depend on manufacturer and design.

    They reckon that the amount in a tube is only a chronic hazard, so it should only present a problem if you break a bulb every day.
  4. Nov 9, 2009 #3
    The mercury is actually contained as elemental vapor in the gas, not condentrated near the ballast. The plasma discharge excites a UV level (I think around 3800 Angstroms) in mercury, which is not visible. The white coating on the inside of the glass absorbs this radiation and reemits visible (longer wavelength) light.
    Bob S
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