Joseph Herbert on thu 29 nov 07
One MSDS for Barium Carbonate found on line indicated a fatality of a human
adult upon ingesting 4 grams of the material. This was a 150 pound person.
4 grams of barium carbonate is a really small amount by volume because the
material is rather heavy. I expect that a relatively careless person could
transfer and ingest this amount of barium carbonate to as few as 4
cigarettes, or by laying a sandwich down in a light layer of dust. It is
really not much stuff.
In addition, the MSDS states that the material can be absorbed through the
skin. Breathing, eating, touching - all a path into the body.
I agree with Ron on this issue. While it is true that the particular
materials can be used safely, the amount of care necessary may exceed the
ability (or motivation) of the casual user. I would expect that a person
who had a through technical indoctrination on ceramic materials, like that
available to every ceramics MFA candidate or elementary education art
teacher, would be able to use whatever material they wanted safely. Not all
of our correspondents come to clay by that path. After all, it is probably
easier (although slightly more expensive) to participate in producing
ceramic objects than to operate a meth lab. In some cases, the two
activities hold nearly the same level of danger to the participants and the
people surrounding them. Given the difference in income, it is surprising
that there are not fewer ceramics producers.
I asked the counter person at Santa Fe clay why they didn't have any
warnings of any kind on any of the glaze materials they repackaged and sold.
Their response was that they could determine if the purchaser needed any
coaching, perhaps by intuition. I have often made the statement that glaze
"chemicals" are mostly ground up rocks. This is true in large part but
there are exceptions and those exceptions can be dangerous to the
uninformed. Lead oxide, Barium Carbonate, Uranium oxide, for a few
examples.
A responsible training program for ceramics production at any level should
include specific warnings about the materials used. Many people who are
using clay have not had that education and may have purposely avoided it.
We don't have to be paranoid but we do need to be informed.
Joe
Joseph Herbert
Technical Writer
Irving, Texas
214-725-8305 (Cell)
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Checked by AVG Free Edition.
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11:10 AM
Edouard Bastarache Inc. on fri 30 nov 07
Bastarache E. Barium and compounds/toxicology
(CASRN 7440-39-3).
Integrated risk information system, IRIS
toxicological review,
US Environmental protection agency (EPA).
You may also check my text on the Net EPA talks
about...
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
----- Original Message -----
From: "Joseph Herbert"
To:
Sent: Thursday, November 29, 2007 6:47 PM
Subject: barium poisoning
> One MSDS for Barium Carbonate found on line
> indicated a fatality of a human
> adult upon ingesting 4 grams of the material.
> This was a 150 pound person.
> 4 grams of barium carbonate is a really small
> amount by volume because the
> material is rather heavy. I expect that a
> relatively careless person could
> transfer and ingest this amount of barium
> carbonate to as few as 4
> cigarettes, or by laying a sandwich down in a
> light layer of dust. It is
> really not much stuff.
>
> In addition, the MSDS states that the material
> can be absorbed through the
> skin. Breathing, eating, touching - all a path
> into the body.
>
> I agree with Ron on this issue. While it is
> true that the particular
> materials can be used safely, the amount of care
> necessary may exceed the
> ability (or motivation) of the casual user. I
> would expect that a person
> who had a through technical indoctrination on
> ceramic materials, like that
> available to every ceramics MFA candidate or
> elementary education art
> teacher, would be able to use whatever material
> they wanted safely. Not all
> of our correspondents come to clay by that path.
> After all, it is probably
> easier (although slightly more expensive) to
> participate in producing
> ceramic objects than to operate a meth lab. In
> some cases, the two
> activities hold nearly the same level of danger
> to the participants and the
> people surrounding them. Given the difference
> in income, it is surprising
> that there are not fewer ceramics producers.
>
> I asked the counter person at Santa Fe clay why
> they didn't have any
> warnings of any kind on any of the glaze
> materials they repackaged and sold.
> Their response was that they could determine if
> the purchaser needed any
> coaching, perhaps by intuition. I have often
> made the statement that glaze
> "chemicals" are mostly ground up rocks. This is
> true in large part but
> there are exceptions and those exceptions can be
> dangerous to the
> uninformed. Lead oxide, Barium Carbonate,
> Uranium oxide, for a few
> examples.
>
> A responsible training program for ceramics
> production at any level should
> include specific warnings about the materials
> used. Many people who are
> using clay have not had that education and may
> have purposely avoided it.
> We don't have to be paranoid but we do need to
> be informed.
>
> Joe
>
>
> Joseph Herbert
> Technical Writer
> Irving, Texas
> 214-725-8305 (Cell)
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database:
> 269.16.10/1159 - Release Date: 11/29/2007
> 11:10 AM
>
> ______________________________________________________________________________
> Clayart members may send postings to:
> clayart@lsv.ceramics.org
>
> You may look at the archives for the list, post
> messages, or change your
> subscription settings here:
> http://www.acers.org/cic/clayart/
>
> Moderator of the list is Mel Jacobson who may be
> reached at melpots2@visi.com
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.503 / Virus Database:
> 269.16.9/1157 - Release Date: 2007-11-28 12:29
>
>
Michael Wendt on fri 30 nov 07
Consider this:
My Chun recipe has 400 grams of Barium
Carbonate in a standard 10,000 gram
batch (enough glaze to fill a 5 gallon
bucket). If I could glaze 100 cups with this,
each would contain the listed 4 grams of
Barium Carbonate (see below), but 5 gallons
is enough to glaze 300-400 cups so even if
every speck of Barium leached from one cup
at one sitting, it would be below the danger level.
Also consider that the solubility of Barium
Carbonate at 16 degrees C in water is
7 X 10^-9 ( a miniscule amount) as
listed by the CRC handbook of Chemistry
and Physics. The Barium in glazes is even
harder to take into solution since it is
in the form of a silicate melt and is
protected by the glaze.
Bottom line...
I had Alfred Analytical acid test this glaze
for release and their results show what they
termed "trace" too small to assign a
percentage value.
Use some sense when addressing these issues
unless you want to see all the materials that
"might" harm someone banned from studio
use.
How do you feel about clear glazes only?
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501
U.S.A.
208-746-3724
wendtpot@lewiston.com
http://www.wendtpottery.com
http://UniquePorcelainDesigns.com
>snip:
One MSDS for Barium Carbonate found on line indicated a
fatality of a human
adult upon ingesting 4 grams of the material. This was
a 150 pound person.
4 grams of barium carbonate is a really small amount by
volume because the
material is rather heavy. I expect that a relatively
careless person could
transfer and ingest this amount of barium carbonate to
as few as 4
cigarettes, or by laying a sandwich down in a light
layer of dust. It is
really not much stuff.
A responsible training program for ceramics production
at any level should
include specific warnings about the materials used.
Many people who are
using clay have not had that education and may have
purposely avoided it.
We don't have to be paranoid but we do need to be
informed.
Joe
Joseph Herbert
Paul Lewing on fri 7 dec 07
On Nov 30, 2007, at 9:51 PM, Michael Wendt wrote:
Use some sense when addressing these issues
unless you want to see all the materials that
"might" harm someone banned from studio
use.
How do you feel about clear glazes only?
Sorry, MIchael, you can't use clear glazes either. They have silica
in them which, as everybody knows, causes silicosis.
Michael makes the really essential point here. Risk equals toxicity
times exposure. There can be no such thing as zero tolerance for
toxic materials in the clay studio, because the clay itself is a
hazard under the right (wrong?) conditions. So every one of us has
to draw the line somewhere as to how much of what we are willing to
live with. You can draw your lines based on hearsay and buzzwords,
or you can do the research and find out what's what. Only with
information like what Michael and Edouard are laying out can you make
a realistic decision.
So draw your line wherever you feel comfortable drawing it and we
will all respect it. Just know that there is no way you're going to
completely avoid all risk, and that there is almost nothing in the
ceramic supply list that you can't use safely with proper
precautions. Sunshine, water, and fire will all kill you if you're
not careful and don't handle them properly, but we all deal with them
every day with no ill effects.
Paul Lewing
www.paullewingtile.com
Steve Slatin on fri 7 dec 07
Michael --
You're right as far as your example goes, but:
1) I've seen glaze recipes with barium carb
being more like 40% of the recipe than 4%;
2) The problem's not with leaching at one
sitting; it's cumulative exposure to
the user;
3) The solubility of the carbonate in water
may be moot to the final user, as the
carbonate form is most likely not the
form the barium is in when the glaze
is fired;
4) Even though the carbonate is largely
insoluble in water, it's highly soluble
in acids, so if the carbonate remains
in the final glaze there may be hazards
if a cup is used for, say, orange juice; and
4) The 'user' may be the potter -- and I
read Joe H's comment to be directed
to exposure to a potter.
For what it's worth, I don't suspect that
barium is nearly as much a risk to the
user of pottery as it is to the potter. That's
no reason to diminish the significance of
that risk, however. Smart use is called for;
avoiding use of barium glazes on food-
contact surfaces where possible, testing
for leaching, and so on.
Best wishes -- Steve Slatin
Michael Wendt wrote:
Consider this:
My Chun recipe has 400 grams of Barium
Carbonate in a standard 10,000 gram
batch (enough glaze to fill a 5 gallon
bucket). If I could glaze 100 cups with this,
each would contain the listed 4 grams of
Barium Carbonate (see below), but 5 gallons
is enough to glaze 300-400 cups
---------------------------------
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June Perry on sat 8 dec 07
Steve,
You said in point 2 that you were worried about barium accumulation. That
isn't a problem with barium. The body doesn't store it like it does other
materials according to the toxicology reports I've researched. Check barium
toxicology on google. There are some reports, test results, and other information
on it.
Regards,
June
_http://www.shambhalapottery.com_ (http://www.shambhalapottery.com/)
_http://shambhalapottery.blogspot.com_
(http://shambhalapottery.blogspot.com/)
_http://groups.yahoo.com/group/sodasaltfiring_
(http://groups.yahoo.com/group/sodasaltfiring)
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Terrance Lazaroff on sat 8 dec 07
I was just told by my prof. Not to lick my fingers if I am using barium
carbonate. Otherwise get ready for a lot of time sitting on the white
telephone.
Food for thought.
Edouard Bastarache Inc. on sat 8 dec 07
"The body doesn't store it like it does other
materials according to the toxicology reports
I've researched."
(June)
Right June,
The biological half-life of barium varies
between 2 and 20 hours.
Gis la revido,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/librairie/
http://www.flickr.com/photos/30058682@N00/
http://myblogsmesblogs.blogspot.com/
June Perry on sat 8 dec 07
That's good advice for any ceramic materials. Gheesh! LOL
Regards,
June
_http://www.shambhalapottery.com_ (http://www.shambhalapottery.com/)
_http://shambhalapottery.blogspot.com_
(http://shambhalapottery.blogspot.com/)
_http://groups.yahoo.com/group/sodasaltfiring_
(http://groups.yahoo.com/group/sodasaltfiring)
**************************************Check out AOL's list of 2007's hottest
products.
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Steve Slatin on sat 8 dec 07
June -- The body doesn't deliberately 'store' barium, no. But it does
sometimes deposit it in bones (demonstrated in human remains) and
in some soft tissues (found in the beta cells in the islets of langerhans
of rats deliberately exposed to barium, for example).
Metabolization may well depend on the molecule to which you're
exposed -- the acetate, which is highly water soluble will give one
set of results, and I believe quite a bit of the testing has been done
with it, but barium salts, AFAIK, are all acid soluble and I've run
across far less testing (could be there's more and I've missed it).
I do respect the fact that you've researched this, but as the wiser
heads will tell us, there's always more to know than is known.
Because there are fewer legitimate needs for human exposure to
barium than to say, lithium, lithium is far better studied. We know
quite a bit about human metabolization of lithium. It makes me
more comfortable to work with lithium in my glazes than with
barium.
I still mix my glazes with a mask and wear those nitrile gloves,
though.
Best wishes -- for the holiday season and for safe and healthy
potting -- Steve
June Perry wrote:
Steve,
You said in point 2 that you were worried about barium accumulation. That
isn't a problem with barium. The body doesn't store it like it does other
materials according to the toxicology reports I've researched. Check barium
toxicology on google. There are some reports, test results, and other information
on it.
Regards,
June
_http://www.shambhalapottery.com_ (http://www.shambhalapottery.com/)
_http://shambhalapottery.blogspot.com_
(http://shambhalapottery.blogspot.com/)
_http://groups.yahoo.com/group/sodasaltfiring_
(http://groups.yahoo.com/group/sodasaltfiring)
**************************************Check out AOL's list of 2007's hottest
products.
(http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001)
______________________________________________________________________________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, or change your
subscription settings here: http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
---------------------------------
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Ron Roy on mon 10 dec 07
Paul,
Equating Barium in glazes with silica is silly.
If potters want to continue to use barium with no restrictions we are going
to have to inject some sense into the issue.
There are many grossly unstable barium glazes in use and they should not be
used as liner glazes.
I'm repeating myself again but - someone brought a mug into Tuckers - many
years ago now. It was glazed inside and out with a barium matte glaze
colored dark blue with cobalt. About three quarters up - including the
bottom - there was no color left - white matte in other words.
The person who had purchased the mug had left some neo citron (anti cold
drink you mix with hot water) in the mug over night. The acidic solution
had removed all the colour from the glaze.
Is there anyone on this list who recommends that type of glaze be used as a
liner glaze on functional ware?
As I have already pointed out - barium leaching is controlled in Austria -
it's just a mater of time before other countries do the same thing.
As for the argument that the material will be banned - nonsense - is lead
banned? Is cadmium banned?
RR
>Use some sense when addressing these issues
>unless you want to see all the materials that
>"might" harm someone banned from studio
>use.
>How do you feel about clear glazes only?
>
>Sorry, MIchael, you can't use clear glazes either. They have silica
>in them which, as everybody knows, causes silicosis.
>Paul Lewing
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Paul Lewing on tue 11 dec 07
On Dec 9, 2007, at 11:13 PM, Ron Roy wrote:
Paul,
Equating Barium in glazes with silica is silly.
I never equated barium and silica. I said that both can be
considered hazardous under certain (wildly different) conditions. My
point there was that no one can have a zero tolerance for materials
in the clay studio that might be hazardous under some condition,
because there is no way to avoid silica in the clay studio.
If potters want to continue to use barium with no restrictions we are
going
to have to inject some sense into the issue.
I agree.
someone brought a mug into Tuckers - many
years ago now. It was glazed inside and out with a barium matte glaze
colored dark blue with cobalt.
Is there anyone on this list who recommends that type of glaze be
used as a
liner glaze on functional ware?
Of course not. I certainly wouldn't.
As Dick Aerni said, "I guess I would say, as has Jeff Zamek and
others, that one should educate
oneself, use materials carefully, and keep up with the current
literature.
But to make a blanket statement that it is OK to use barium, or
absolutely a
problem is to oversimplify and cut off discussion and research."
All these posts we've seen this week on this subject just reinforce
what I said - that each of us has to decide for him or herself where
we are willing to draw the line on each of these materials. But draw
a line we each absolutely must. I'm just saying that where you draw
the line for yourself should be based on scientific information.
Paul Lewing
www.paullewingtile.com
Ron Roy on sat 15 dec 07
Hi Paul,
Well I think releying on the scientific facts is not good enough. There are
some things we cannot test for and we will never know the all the answers.
What I am saying is - if there is room for doubt we should fall on the safe
side - at least those of us who make functional work.
What we do to ourselves is one thing - what we do to our customers is another.
RR
>Paul,
>Equating Barium in glazes with silica is silly.
>I never equated barium and silica. I said that both can be
>considered hazardous under certain (wildly different) conditions. My
>point there was that no one can have a zero tolerance for materials
>in the clay studio that might be hazardous under some condition,
>because there is no way to avoid silica in the clay studio.
>
>If potters want to continue to use barium with no restrictions we are
>going
>to have to inject some sense into the issue.
>I agree.
>
> someone brought a mug into Tuckers - many
>years ago now. It was glazed inside and out with a barium matte glaze
>colored dark blue with cobalt.
>Is there anyone on this list who recommends that type of glaze be
>used as a
>liner glaze on functional ware?
>Of course not. I certainly wouldn't.
>
>As Dick Aerni said, "I guess I would say, as has Jeff Zamek and
>others, that one should educate
>oneself, use materials carefully, and keep up with the current
>literature.
>But to make a blanket statement that it is OK to use barium, or
>absolutely a
>problem is to oversimplify and cut off discussion and research."
>All these posts we've seen this week on this subject just reinforce
>what I said - that each of us has to decide for him or herself where
>we are willing to draw the line on each of these materials. But draw
>a line we each absolutely must. I'm just saying that where you draw
>the line for yourself should be based on scientific information.
>
>Paul Lewing
>www.paullewingtile.com
>
>______________________________________________________________________________
>Clayart members may send postings to: clayart@lsv.ceramics.org
>
>You may look at the archives for the list, post messages, or change your
>subscription settings here: http://www.acers.org/cic/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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