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dioxine in kaolin

updated sat 8 apr 00

 

Jeff van den Broeck on thu 6 apr 00

Hi,
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.

Jeff van den Broeck - P.O.Box 1099
Baguio City 2600 - Philippines
jvdb@skyinet.net

Bruce Girrell on fri 7 apr 00

Jeff van den Broeck wrote:
>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...

Dioxin is a term used to refer to many different compounds - 75 dioxins, 135
furans and 209 PCBs. The most dangerous is
2,3,7,8-tetrachlorodibenzo-p-dioxin, but they all share the characteristic
of being halogenated hydrocarbons (chlorine atoms attached to benzene
rings).
Halogenated hydrocarbons do not appear in nature. If there is a
contamination of this kaolin, it most likely came from waste products
associated with the mining operations.

For me, a statement such as "According to available information, this could
be a contamination of geological origin..." calls into question the veracity
of the entire report.

Bruce Girrell