Monona Rossol on fri 12 mar 99
---------- Forwarded message ----------
Date: Thu, 11 Mar 1999 07:48:49 EST
From: June Perry
To: CLAYART@LSV.UKY.EDU
Subject: Question on Barium
----------------------------Original message----------------------------
Has anyone got the information on the typical leachate concentration is in
mcg/dl for a typical worst case scenario for barium? < SNIP
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There's no "typical" anything with barium glazes. I have seen tests from
below 1 ppm and above 4000 ppm. And I have seen much variation in different
samples glazed with the same glaze fired at slightly different temperatures.
> Also, do we know what the epa regulations are for barium release in
> glazes?<
EPA has nothing to do with glazes. FDA does. And they don't regulated
barium--only lead and cadmium.
> I have the numbers for water but can't find anything relating to ceramics.
> I've been having a interesting discussion with someone on this who seems to
> have quite a lot more knowledge than I in these matters and he just can't
> see that Ba alumino silicates as being very dangerous. <
If barium leaches from ceramics on the standard acetic acid FDA leach test,
it has to be in a soluble form--probably a barium acetate. It wouldn't
be in an insoluble barium alumino silicate mineral form at all. What is your
friend thinking?
> He requested that I ask the list about the typical leachate concentrations
> as mentioned above. I checked out the EPA site and found a paper on Barium
> toxicology but it was in pdf format and after an hour of downloading it I
> got an error message and could only print out the title page. AARGH! <
You need the barium toxicology information from EPA's rationale for the
setting of their 2ppm maximum contaminant level for drinking water. This
will give you an idea for the safety margin for chronic low level exposure.
It is this level that I am suggesting be used for barium glaze leaching tests
as a safe level. This is admittedly not good toxicology, but it is good
common sense. If a pot doesn't leach more into food and drink than EPA
allows in a rather poor quality water supply, consumers should be assured
that they can use the ware without worry.
> Also, has anyone had any of their barium glazes tested, and if you have
> could you please post the results to the list. <
The lab director at Alfred Analytical is collecting test data from the
pottery he is testing for many people and will be trying to make sense out of
it when there is enough data to draw conclusions. Asking people to provide
you or your friend a few lab results wouldn't be very useful at this point.
Monona Rossol
ACTS
181 Thompson St., # 23
NYC NY 10012-2586 212/777-0062
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