Methylene Iodide

It is toxic. See the MSDS...

It is photosensitive, and will degrade into Methyl Iodide (see the
MSDS for that also) * it will break down in the presence of light*

It must be used in a fumehood, or use a respirator. Gloves must be
worn. It will cause painful swelling of the hands otherwise. It is
also a nuerotoxicant. It also causes cancer in rats. There is some
indication that the nerve damage is permanent.

On Fri, 06 Apr 2007 19:34:49 -0700, in rec.crafts.jewelry
wrote:

It is toxic. See the MSDS...

It is photosensitive, and will degrade into Methyl Iodide (see the
MSDS for that also) * it will break down in the presence of light*

It must be used in a fumehood, or use a respirator. Gloves must be
worn. It will cause painful swelling of the hands otherwise. It is
also a nuerotoxicant. It also causes cancer in rats. There is some
indication that the nerve damage is permanent.


That's all very nice, and true, of course. Did you have a point to make other
than stating already pretty well known facts? Or a specific type of use you
wished to warn us about?

Keep in mind that as relates to jewelry use (ie, this group), pretty much the
only significant uses for methylene iodide are in gem identification and
examination. Most notably, when modified by dissolving sulfur in it, as the
rather costly refractive index fluid used one tiny drop at a time, with
refractometers. In that use, the amounts used are so small as to be essentially
unimportant for most users. And most gemologists using the stuff know already
that it's dangerous, needing to be handled with care. For gemological uses,
most of them any way, fume hoods are not required (as I said, the amounts
normally used are one very tiny drop at a time (like about the size of a period
at the end of this senance.) We're not drinking the stuff, you know. And
normally, not only is it used in only very small quantities, but it's used only
briefly at any one time. And, while I'm not soaking my hands in it, I've never
noted any skin irritation from the tiny exposure potentially caused when I clean
the drop off the stone after taking a reading, with a fingertip instead of a
cloth...

Now, when methylene iodide is used for things like gem immersion fluid, or
specific gravity fluids, then larger amounts are indeed used, and the time the
jar is open may be somewhat longer.. But again, normal gemological training
includes the information that the stuff is toxic and to be handled with care.
The same can be said to one degree or another by a large number of other
volatile solvents, including others used in gemology and jewelry work, some of
which are suspected of being much more potent carcinogens. With MI, for most
uses, normal hygene and reasonable room ventillation will suffice.. Even in
these above noted uses where one is using an open small jar instead of a tiny
droplet, simply the high cost of the stuff will lead most users, even ones who
weren't paying too much attention in safety lessons, to be careful with the
stuff, I'd hope. Those users running a gem laboratory, or in another situation
where exposure is of longer duration or more frequent, will probably wish to
take a closer look at their ventillation. But even then, an actual fume hood is
probably unnecessary overkill for most gemological situations. the GIA labs,
for example, don't use fume hoods when doing RI determinations or using an
immersion cell on the microscope, at least they didn't last time I visited the
place a few years ago. If it were required, they'd have been doing it.

Larger industrial uses and exposures, of course, are a totally different
situation, and as with any chemical or toxic material, the safety measures
needed and used will be in part dictated by the nature of the situation.
Reasonable caution suggests it's better to err on the side of caution. But this
does not indicate the need for paranoid overkill. An MSDS sheet can be a source
of valuable information, but they sometimes also can be misleading or overly
alarming. Keep in mind that too much of anything can kill a rat, or give it
cancer, etc. Even table salt. But giving a lethal dose statement about orally
ingested table salt might lead a lot of people to avoid it altogether in their
diets. Oh. Wait. maybe that wouldn't be so bad after all, in view of peoples
blood preassures. But that's another discussion.

Yes, Methylene Iodide is toxic, and needs to be handled with care. But please,
lets not devolve into unreasoned paranoia without taking the circumstances of
use into consideration. It CAN be used quite safely enough in gemology,
without needing to jump through all sorts of costly or tiresome hoops.

Peter

On Sat, 07 Apr 2007 02:35:03 GMT in rec.crafts.jewelry
, intended to write something intelligible,
but instead wrote :

It is toxic. See the MSDS...

It is photosensitive, and will degrade into Methyl Iodide (see the
MSDS for that also) * it will break down in the presence of light*

It must be used in a fumehood, or use a respirator. Gloves must be
worn. It will cause painful swelling of the hands otherwise. It is
also a nuerotoxicant. It also causes cancer in rats. There is some
indication that the nerve damage is permanent.

I had planned on just killing my rats, but causing cancer in them may
send a message to other rats that might be considering moving into my
space.
So thanks for the heads-up on this GeoLocks!

Frosty wrote:
On Sat, 07 Apr 2007 02:35:03 GMT in rec.crafts.jewelry
, intended to write something intelligible,
but instead wrote :

It is toxic. See the MSDS...

It is photosensitive, and will degrade into Methyl Iodide (see the
MSDS for that also) * it will break down in the presence of light*

It must be used in a fumehood, or use a respirator. Gloves must be
worn. It will cause painful swelling of the hands otherwise. It is
also a nuerotoxicant. It also causes cancer in rats. There is some
indication that the nerve damage is permanent.

I had planned on just killing my rats, but causing cancer in them may
send a message to other rats that might be considering moving into my
space.
So thanks for the heads-up on this GeoLocks!




BTW
Did you know that is has a distinctly sweet taste?

In rec.crafts.jewelry almost on Sun, 30 Sep 2007 22:09:48 -0700 a
smoke signal from Manmountain Dense rang out,
which was heard to say :

Frosty wrote:
On Sat, 07 Apr 2007 02:35:03 GMT in rec.crafts.jewelry
, intended to write something intelligible,
but instead wrote :

It is toxic. See the MSDS...

It is photosensitive, and will degrade into Methyl Iodide (see the
MSDS for that also) * it will break down in the presence of light*

It must be used in a fumehood, or use a respirator. Gloves must be
worn. It will cause painful swelling of the hands otherwise. It is
also a nuerotoxicant. It also causes cancer in rats. There is some
indication that the nerve damage is permanent.

I had planned on just killing my rats, but causing cancer in them may
send a message to other rats that might be considering moving into my
space.
So thanks for the heads-up on this GeoLocks!




BTW
Did you know that is has a distinctly sweet taste?

No, I didn't know that.
Hmm. Interesting. So then I should prepare a meal for these rodents
based upon this sweet taste? That's good to know. I'd hate to make,
say a Thai dish that they expect to taste salty and spicy, and have it
instead taste sweet. No, that would never do. Maybe a tart would be
more in order. Do you think it would go well with strawberry?