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CFLs and their Hg Content

Discussion in 'Lighting' started by Paul M. Eldridge, Mar 10, 2007.

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  1. There seems to be a genuine concern over the mercury contained within
    CFLs and the potential health and environmental risks this represents.
    Looking at reader feedback to various media coverage you see this come
    up time and time again, and you get the impression some folks view
    CFLs much like toxic nuclear waste.

    So with that in mind, I wanted to get a better sense of how the major
    lamp manufactures compare, but this hasn't been as easy as I had
    expected.

    As a starting point, the EPA tells us a typical CFL contains 4
    milligrams of Hg.

    Source:
    http://www.nema.org/lamprecycle/epafactsheet-cfl.pdf

    According to GE's website, the average is 5 milligrams (close enough).

    Source:
    http://www.gelighting.com/na/home_lighting/ask_us/faq_compact.htm

    The data for Osram Sylvania suggests mercury content can vary
    considerably (i.e., from less than 1.8 mg to just under 15 mg) but,
    for the most part, it falls within the range of 3 mg to 5 mg.

    Source:
    http://www.sylvania.com/content/display.scfx?id=003690938

    Lastly, we have Philips and in the case of their "Extreme Low Mercury"
    line, these numbers are reported to all fall below 2 mg.

    Source:
    http://www.lighting.philips.com/gl_...main=global&parent=4390&id=gl_en_news&lang=en

    But here's where things get a bit murky for me. I had initially
    thought the "Extreme Low Mercury" line might be the same thing as
    Alto, but that's not the case. For example, the 25-watt Marathon
    Universal, which proudly wears the Alto badge, contains 2.64 mg of Hg.

    So are these "Extreme Low Mercury" lamps available only in Europe and
    is this designation something different from Alto? Or is it a case
    that the numbers for Alto will eventually drop over time?

    Philips has kindly listed the mercury content of specific Alto and
    non-Alto CFLs, but not all (e.g., their popular "Twister" line). It
    would be helpful if manufacturers were a little more forthcoming with
    this information, so that we, as consumers and specifiers, could make
    better-informed choices.

    Cheers,
    Paul
     
  2. Are you sure the ball is not a mercury amalgam?

    --
    Vic Roberts
    http://www.RobertsResearchInc.com
    To reply via e-mail:
    replace xxx with vdr in the Reply to: address
    or use e-mail address listed at the Web site.

    This information is provided for educational purposes only.
    It may not be used in any publication or posted on any Web
    site without written permission.
     
  3. Yes, there surely are. I have some where this little ball is solid, and
    bounces around with a rattling sound if I shake the lamp vigorously.
    Only if the amalgam component other than mercury leads to a vapor
    component with concentration no less than maybe 3 orders of magnitude
    below that of the concentration of the mercury vapor.
    I doubt the amalgam has an alkali metal since alkali metals react with
    the usual grades of glass enough to cause problems in lamps. Even sodium,
    potassium and lithium can't produce enough vapor to show up much in a
    spectrum at even 80 degrees C or so. I give similar to worse prospects
    for thallium, indium, gallium, aluminum, cadmium, zinc, barium, strontium,
    and calcium. I say no better for tin, lead and magnesium since these fare
    worse for visible and near-UV. Cadmium may achieve only 2 orders of
    magnitude weaker in vapor concentration than mercury at a given
    temperature, but it is noted as a toxic material. I also doubt use of
    less-common rubidium and cesium and radioactive francium and radium -
    along with probably all metals in the first column of the periodic table
    probably having some ability to react with most glass in a bad way within
    lamps even at hardly above room temperature. Almost any other metal
    produces even less vapor than any of the above at fluorescent lamp bulb
    inner surface temperatures.

    - Don Klipstein ()
     
  4. Yes, Many if not most CFLs use mercury amalgams. You can
    usually tell by looking at the shape of the bulb. Lamps
    without amalgams use cold chambers, typically small bumps in
    the glass at the ends of the tubes that are outside the path
    of the discharge. Without either a cold chamber or an
    amalgam the mercury pressure would be too high since the
    tubing is so small.
    No. The goal is to change only the mercury pressure, not
    the spectrum. Anything that competes with Hg for energy
    from the electron cloud will decrease efficacy . Typical
    amalgam materials are led, tin, or bismuth.

    --
    Vic Roberts
    http://www.RobertsResearchInc.com
    To reply via e-mail:
    replace xxx with vdr in the Reply to: address
    or use e-mail address listed at the Web site.

    This information is provided for educational purposes only.
    It may not be used in any publication or posted on any Web
    site without written permission.
     
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