Earl Brunner on tue 28 nov 00
Do we know what it is about Ball clays that causes them to have the
dioxin in them in the first place?
I ask, only because I'm curious as to whether or not some of our other
chemicals might be contaminated as well. Specifically, but not limited
to, other clays that we use.
ACTSNYC@CS.COM wrote:
> Clayarters,
>
> In the current Ceramics Monthly there is a statement by Jeff Zamek that
>
> "....the typical ball clays from the four companies having mines in Kentucky
> in Tennessee have been tested and are dioxin free."
>
> This is not consistent with the information from FDA's John Matheson, Office
> of Surveillance and Compliance, Center for Veterinary Medicine,
> e-mail:jmatheso@cvm.fda.gov on 10/11/2000 (on Clayart) that [quote]:
>
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
ACTSNYC@CS.COM on tue 28 nov 00
Clayarters,
In the current Ceramics Monthly there is a statement by Jeff Zamek that
"....the typical ball clays from the four companies having mines in Kentucky
in Tennessee have been tested and are dioxin free."
This is not consistent with the information from FDA's John Matheson, Office
of Surveillance and Compliance, Center for Veterinary Medicine,
e-mail:jmatheso@cvm.fda.gov on 10/11/2000 (on Clayart) that [quote]:
1) Ball clay is mined in specific locations in the US (mostly Tennessee,
Kentucky and Mississippi) and marketed as a specific product, even though it
is geologically a mixture of various clay minerals. ...
2) Every ball clay that was tested in 1997 contained elevated levels of
dioxins. Clays from mines in all three states were sampled. As a result, no
ball clays are now in use in animal feeds, and as far as I know, no ball clay
has been shown to be free of dioxins. [end quote]
And third: in a joint statement on 11/6/99, FDA and EPA reported that that
the single dioxin for which ball clays were tested (2,3,7,8-TCDD) may not be
the primary congener. The two agencies think all the ball clays should be
retested for the whole congener group of dioxins.
In the light of these facts, I think Jeff Zamek and/or the suppliers he
suggests we contact should be asked to provide answers to four questions:
1) Are the ball clay suppliers willing to state in writing that their clays
are "dioxin-free?"
2) Are these companies supplying copies of the lab tests to back up their
assertions?
3) What is the detection limit of the tests used--keeping in mind that
dioxins are significant in the parts per trillion (ppt) range.
4) Are these labs testing only for 2,3,7,8-TCDD or are they analyzing for
the whole congener group of dioxins? (That is, the ppt toxicity
equivalents or TEQ.)
Having read Jeff Zamek for years, I tend to think that if he actually had
hard data showing that some of the ball clays we use are dioxin-free he would
be providing them in gleeful, gottcha detail. And while I hope he is right,
until I see this data I remain incredulous.
I think Clayarters should get busy and contact their suppliers as Jeff
suggests and see what kinds of responses are forthcoming.
Monona Rossol
ACTS
181 Thompson St., #23
NYC NY 10012-2586 212/777-0062
ACTSNYC@cs.com
Martin Howard on thu 30 nov 00
labelled "montmorillonite," "bentonite," "ground clay," "silicate" and
"lime.">
Fuller's earth, the current main cat litter in the UK, is montmorillonite
and bentonite (one is a subsection of the other). So, there are a lot of
people and cats in the UK at least who are taking in dioxins without
realising it.
If the theory is correct (always a big IF nowadays) then these would have
been caused by burning of animal and plant remains at high temperatures and
the dust from the volcanoes and surface fires would have caused the dioxins
to be preserved within the structure of the bentonite and montmorillonite. I
would assume that fireclays are equally suspect. Perhaps that is what is
meant by .
Each of my glazes contains cat litter, up to 20 percent. Ouch.
Of course, it might be that the testing was done on deposits which had been
contaminated by recent air borne dust, a subject of our making, rather than
the geologically older material.
Martin Howard
Webb's Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
England
martin@webbscottage.co.uk
| |
|
