Reid Harvey on mon 31 jan 00
Can anyone tell me the affects to the body of skin contact with salts of
silver nitrate? While boiling silver ingots in nitric acid, I find it
difficult to eliminate occasional contact with the salt. It seems that
contact with skin (and just about anything else) ends up a bit like a
photo emulsion, turning black, not wearing off the skin for a week or
so. It appears important to keep everything very clean, knowing what is
making contact with the salts, and gloves need to be taken off
carefully, then washed.
Reid Harvey
ferenc jakab on tue 1 feb 00
My father was a professional photographer for nearly 70 years. He did a 10
year apprenticeship back when they had to make their own glass plates and
mix their own chemicals. He did not suffer any problems until near the end
of his life when his skin, particularly on his hands and arms became very
sensitive to any chemicals he handled (rashes and sores), particularly old
fixative which contains a lot of silver nitrate. Individuals vary greatly in
their sensitivity. I do not know what problems Medical science knows of.
Feri
Cheryl L Litman on tue 1 feb 00
If you think you spilled silver nitrate on your skin, before you expose
it to sunlight which causes the darkening, wash well with potassium
iodide. You can buy KI in crystal form and make it into a solution in
water. I don't remember what concentration but I'll sure it's not
critical. The KI will neutralize the silver nitrate. Should work to
clean up non-organic surfaces as well.
Cheryl Litman ---------- Somerset, NJ --------- email:
cheryllitman@juno.com
***The problem with doing nothing is not knowing when you are finished***
On Mon, 31 Jan 2000 14:43:56 EST Reid Harvey
writes:
> ----------------------------Original
> message----------------------------
> Can anyone tell me the affects to the body of skin contact with
> salts of
> silver nitrate? While boiling silver ingots in nitric acid, I find
> it
> difficult to eliminate occasional contact with the salt. It seems
> that
> contact with skin (and just about anything else) ends up a bit like
> a
> photo emulsion, turning black, not wearing off the skin for a week
> or
> so. It appears important to keep everything very clean, knowing what
> is
> making contact with the salts, and gloves need to be taken off
> carefully, then washed.
> Reid Harvey
Cheryl Litman ---------- Somerset, NJ --------- email:
cheryllitman@juno.com
***The problem with doing nothing is not knowing when you are finished***
I.Lewis on fri 4 feb 00
------------------
I have no doubt that silver can be reclaimed from photographic chemical =
residues
but I doubt very much that the Acid Bath which is used as an intermediate =
step
ever reacts with either the developed silver or the undeveloped silver =
halides.
It's purpose is to arrest the reactions by changing the developing solution =
from
a basic state to acidic. Sodium thiosulphate is then used to dissolve =
unexposed
and undeveloped silver halides from the emulsion of the film. Spent =
solutions
should be returned to a refiner or professional chemical disposal unit for
reclamation. In large operations the value of the reclaimed silver is
significant and can be a valuable source of revenue which is all profit for
processing labs.
Making silver nitrate by reacting metallic silver with nitric acid is a
dangerous process. Nitrogen dioxide which evolves is a corrosive gas brown =
red
gas which causes severe irritation of the mucous membranes. This reaction =
should
be done in a fume cupboard. When handling concentrated acids wear =
appropriate
protective clothing including a face mask. Before you start, learn how to =
cope
with an emergency situation.
Best wshes to all for the New Year.
Ivor Lewis.
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