At 02:29 AM 12/8/2012, Eric Walker wrote:
On Fri, Dec 7, 2012 at 10:51 PM, Eric Walker
<<mailto:eric.wal...@gmail.com>eric.wal...@gmail.com> wrote:
The problem is that you don't find out if it
what you did was safe for five years, and then
you have a 1/3 chance of dying or being disabled.
More accurately, I think it would be something
like this -- for each interaction with the
beryllium, there is a probability b that an
adverse beryllium event B occurs. Â You'll then
find out five years on average, with some amount
of variation, whether B occurred. Â If B isn't
seen one or two standard deviations out from
five years from 2017, you will have been
cleared, as far as the initial beryllium
interaction went. Â If B does occur, you'll have
a 1/3 chance of dying and a 2/3 chance of
disability. Â But I assume you will need to
repeat this process for each interaction that you have with the beryllium.
I would not go near it.
That's a personal choice. From what I've seen,
the adverse event, B, simply does not happen with
contact with pure beryllium metal, as a solid
piece, nor with contact with BeO as a ceramic. It
does happen with inhalation of Be, BeO, and other
Beryllium compounds, if they are airborne (i.e.,
suppose one is machinging the metal, and it is
being ground away. Or one is working the
beryllium brakes, a real place where people have
been seriously exposed -- i.e., mechanics).
BeO is very dangerous if crushed. Don't crush
beryllium oxide insulators!!! If I whack my piece
of beryllium with a hammer, it might make a few
very small particles. I'm not going to do it.
Turns out I don't need to. But if there was a
good reason, it would be *highly* unlikely to generate a case of berylliosis.
It appears that a single adverse event that even
produces an acute reaction only very rarely ends
up causing chronic berylliosis. Much more
dangerous is continued low-level exposure, which
may produce no immediate symptoms at all, but
which can then show up as much as twenty years
later, as very serious chronic berylliosis.
Okay, my package arrived. No warning signs on it,
and I don't think they are required. Opening it
up, inside a plastic bag, is a piece of metal,
6.55 x 19.45 x 25.88 mm. (It is not cut perfectly
squarely, those are averages.) It is indeed very
light, it weighs 6.02 grams. (It was sold as 5.85
grams). Thus the density (from measured weight)
is 1.83 g/cm^3. The density of Be is reported as
(Wikipedia) 1.85 g/cm^3. Pretty close. (The
surface is scored, and my dimensions are pushed
as to accuracy, I only could find my vernier
caliper, so the actual material there might be slightly less volume).
I scratched it with the point of a scissor, a
short scratch. It made a clean shallow groove.
Aong the edges, particularly corners, it is
broken, tiny pieces are missing. That's how I'd
expect beryllium to look, it's brittle.
It seems to have a bit of grey film or dark dust
on the surface, on one or two edges. That's
worrisome. I wiped some off on a piece of tissue
paper, and examined it under a microscope. It
looks like a fine powder. Each side of the piece
is scratched with parallel lines, apparently from when it was cut.
I will now write the seller and find out more
what I have. If that's machining dust, i.e.,
finely powdered beryllium, or mixed with
beryllium, and maybe with an oil used to keep
dust from flying when machining, it's a bit
dangerous. The material is not readiliy airborne,
though. It would not blow off, for example, I
don't think -- and I'm not about to try it. None
of this material fell off the piece in its plastic bag.
