search  current discussion  categories  safety - toxicity 

acers and dioxine in ball clays

updated mon 18 sep 00


Jeff van den Broeck on sun 17 sep 00

Dear Karen Terpstra,
I read with a particular interest what you are telling about dioxines in
ball clay and would like to read more about the results of the research of
I was probably too early with my information (April 5, 2000) from the
European Union (Nov.99) about dioxines in German and American kaolins and
ball clays. I would like to reprint my original message that got one
negative reaction of Bruce Girrell who wrote that 'a statement as
"According to available information this could be a contamination of
geological origine..." calls into question the veracity of the entire report'.
I 'm not a specialist in this matter, but although you have to determine
the source of contamination, this doesn't change the problem of using
contaminated clay.
Here my email of April 5:

recently I read an information that I would like to share.
In a regulation of 17 november 1999 the European Commission "on the
conditions for the authorisation of additions belonging to the group
'binder, anti-caking and coagulants' in feedingstuffs" states that
"...kaolinitic clays originating from certain mines situated in the Federal
Republic of Germany have been found to contain extremely high levels of
dioxine. According to available information, this could be a contamination
of geological origin... The use of feedingstuffs contaminated with dioxines
may contaminate foodstuffs of animal origin... The acceptable level of
dioxins in kaolinitic clays should be restricted to the analytical limit of
determination... The contamination could in fact also concern other
authorised additives, as indicated by the fact that ball clay, sedimentary
clays containing other minerals besides kaolin, originating from a mine in
the United States has also been shown to be heavily naturally contaminated
by dioxin of geological origin..."
I imagine no greater risk for potters than for other citizens. What happens
to dioxine in the firing?
Greetings, Jeff.

At 11:27 09/16/2000 -0500, you wrote:
>Membership in this organization provides you with pertinent information
>regarding the latest information, material, products and services. For
>example, a topic that has me very concerned came to my attention via the
>legislative committee of ACerS: the issue of the EPA planning to
>classify dioxins in ball clay as carcinogens. What would this do to the
>ceramic industry, our suppliers, teaching ceramics at an institutional
>level, making ceramics in your private home or studio?
>Karen Terpstra
>Vice-Chair, Art Division
>The American Ceramic Society
>Assistant Professor of Art
>University of Wisconsin-La Crosse

Jeff van den Broeck - P.O.Box 1099
Baguio City 2600 - Philippines