iandol on tue 7 aug 01
I picked up on a Cyber article in About.com Ceramics Newsletter about =
Water Media on Porcelain.
One of the soluble colorants was Uranyl Nitrate. Though it does say this =
is a toxic substance it make no mention of the radio activity usually =
associated with uranium compounds.
Is this a safe substance to use. My opinion is that it would be highly =
undesirable in a studio. Do I have support on this.
Best regards,
Ivor Lewis. Redhill, South Australia
Michael Dickman on tue 7 aug 01
Ivor,
Nothing is completely "safe".
The radioactivity from uranium is relatively low-risk and shouldn't be a
major consideration. But having said that, the toxicity of uranium is another
matter. I wouldn't use it for food items. Another issue is volatility. I
don't know how volatile uranium compounds are-- but someone must have data on
that. You wouldn't want your kiln walls contaminated with uranium without
your knowledge.
I'd treat it like lead. In other words I wouldn't use it myself... although
with proper precautions it could be used with minimum risk.
In a message dated 8/7/01 8:14:23 AM, iandol@TELL.NET.AU writes:
>I picked up on a Cyber article in About.com Ceramics Newsletter about Water
>Media on Porcelain.
>One of the soluble colorants was Uranyl Nitrate. Though it does say this
>is a toxic substance it make no mention of the radio activity usually
associated
>with uranium compounds.
>Is this a safe substance to use. My opinion is that it would be highly
>undesirable in a studio. Do I have support on this.
>Best regards,
>Ivor Lewis. Redhill, South Australia
Edouard Bastarache on tue 7 aug 01
Allo Iveur,
There are 2 entries in Sax's Dangerous Properties of
Industrial Materials.
1-Uranyl Nitrate, CAS: 36478-76-9
N2O8U, mw: 394.02
ACGIH TLV: TWA: 0.2 mg(U)/m3
STEL: 0.6 mg(U)/m3
SAFETY PROFILE: Poison by intraveinous route.
Experimental reproductive effects. When heated to
decomposition it emits toxic fumes of NOx and U.
2-Uranyl Nitrate(Solid), CAS: 10102-06-4
N2O8U, mw: 394.02
ACGIH TLV: TWA: 0.2mg(U)/m3
STEL: 0.6mg(U)/m3
SAFETY PROFILE: Poison by inhalation.Moderately
toxic by ingestion. Human mutation data reported.A corrosive
irritant to skin, eyes, and mucous membranes.
A radioactive material.
A powerful explosive and oxidizer
Ether solutions in sunlight may explode
When heated to decomposition it emts toxic fumes
of NOx.
Later,
Edouard Bastarache
Irreductible Quebecois
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://www.absolutearts.com/portfolios/e/edouardb/
----- Original Message -----
From: iandol
To:
Sent: Monday, August 06, 2001 2:29 PM
Subject: Uranium Again
I picked up on a Cyber article in About.com Ceramics Newsletter about Water
Media on Porcelain.
One of the soluble colorants was Uranyl Nitrate. Though it does say this is
a toxic substance it make no mention of the radio activity usually
associated with uranium compounds.
Is this a safe substance to use. My opinion is that it would be highly
undesirable in a studio. Do I have support on this.
Best regards,
Ivor Lewis. Redhill, South Australia
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Rick Monteverde on tue 7 aug 01
At 10:35 AM -0400 8/7/01, Michael Dickman wrote:
>I'd treat it like lead. In other words I wouldn't use it myself... although
>with proper precautions it could be used with minimum risk.
Two categories here: risk to the potter and risk to the consumer.
Having these kinds of things stored and used safely in the studio for
long term or extensive use might require a level of cleanliness that
probably doesn't come naturally to most of us. I don't mean clean
room negative air pressure kinds of things, but simply using real
storage and use diligence when it comes to dry powders and vapors at
least.
For the end use, I have no problem at all using toxic materials in
sculpture or other purely decorative pieces that by their nature
could *not* be used as a practical food contact article. The metals
in raku glazes, and leads and cadmiums - still very common. Is that a
problem? I love my old uranium ("vaseline") glass - up there on the
shelves looking pretty in the sunlight.
- Rick Monteverde
Honolulu, HI
Michael Dickman on wed 8 aug 01
Rick,
I agree completely. Also there are differences between keeping toxics
around in your own studio with complete control over their handling,
versus a teaching environment. I would recommend no uranium, lead or
cadmium in a school but these could be used (in your own studio,
with proper procedures) for sculpture.
In theory they can be used for food ware if leaching tests
were performed. But I get the impression that many people wouldn't
buy it if they knew it contains lead, whether it passes tests or not.
Mostly I wanted to point out that the toxicity hazard from uranyl nitrate is
greater than the radiation hazard. The type of radiation that uranium emits
is weak and you can continue to enjoy your uranium glass without concern.
Also there is a real radiation hazard from inhalation of uranium (metal)
dust, but potters/sculptors are not likely to encounter powdered
uranium metal. I'd avoid other insoluble forms such as the oxides too.
As for raku another consideration for the potter is volatility. I don't
know offhand the volatility of lead and cadmium at low-fire temperatures
typical for raku. I'd try to stay upwind of the kiln in any case!
That reminds me, there has been discussion of dioxins in clay lately.
This is also probably a very small risk compared with silica. On the
other hand if you use newspaper for raku postfire reduction, the smoke
is likely to contain all sorts of nasty things including dioxins. I don't
bring
this up to scare people, just that the relative risk of dioxins in clay
seems trivial in comparison.
- Michael Dickman
In a message dated 8/7/01 10:20:13 PM, rick@HIGHSURF.COM writes:
>Two categories here: risk to the potter and risk to the consumer.
>Having these kinds of things stored and used safely in the studio for
>long term or extensive use might require a level of cleanliness that
>probably doesn't come naturally to most of us. I don't mean clean
>room negative air pressure kinds of things, but simply using real
>storage and use diligence when it comes to dry powders and vapors at
>least.
>
>For the end use, I have no problem at all using toxic materials in
>sculpture or other purely decorative pieces that by their nature
>could *not* be used as a practical food contact article. The metals
>in raku glazes, and leads and cadmiums - still very common. Is that a
>problem? I love my old uranium ("vaseline") glass - up there on the
>shelves looking pretty in the sunlight.
>
>- Rick Monteverde
>Honolulu, HI
>
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