Ron Roy on fri 22 nov 02
There are two ways to get manganese into you system - fumes from firing and
breathing the dust. If there is dry powdered clay in your studio - and
there always is - and that dust is in the air - and it always is - then
exposure may be greater from the dust.
Many of the clay bodies I have seen have a lot of Manganese in them - they
sometimes fire black - that requires a lot of MnO2.
I predict most of us will see the requriment that materials containing
manganese be labled.
Any clay manufacture who produces clays with manganese in them should be
concerned about this - and lable such products as having possible side
effects - and it will have to be included on the MSDS - by law.
RR
>As for the manganese-bearing bodies: the toxicity
>from manganese is primarily due to fumes, and NO
>kiln fumes are good, so I don't really feel that
>such clays need special labeling.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Bobbruch1@AOL.COM on sat 23 nov 02
<<<<<Manganese in them - they sometimes fire black - that requires a lot of MnO2.
I predict most of us will see the requriment that materials containing
manganese be labled.
Ron: Are the clays with manganese only those which fire black, or are there
stoneware bodies which contain MnO2 in which the manganese would be hard
detect?
Thanks for your help,
Bob Bruch
Ron Roy on tue 26 nov 02
Hi Bob,
I suspect many clays have at least a small amount - I have analysis for SGP
#1 and Albany that show a very small amount. Barnard (Black Bird) has 3.3%.
It is wise to ask for MSDS on the clays you use - by law they must be
provided and they must list the oxides present.
I am not concerned with small amounts in a body - but if there is a lot
anyone working with them is going to be exposed to the dust and the fumes.
><<<<<>Manganese in them - they sometimes fire black - that requires a lot of MnO2.
>I predict most of us will see the requriment that materials containing
>manganese be labled.
>
>Ron: Are the clays with manganese only those which fire black, or are there
>stoneware bodies which contain MnO2 in which the manganese would be hard
>detect?
>
>Thanks for your help,
>
>Bob Bruch
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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