Bill Edwards on fri 12 dec 03
Many here know I have worked with chromium a good bit
in the past. Not to open a new topic but... I have
many white tin glazes that I fire with chromium and do
not get any red or ppink tinting when fired with
chrome. I have others that turn pink as white
underwear washed with a red shirt in hot water. The
tin whites needs to be balanced and what I have found
is the chemistry balance of AL203 and SIO2 play a role
here. Theres a ton of things that will alter a glaze
at any proportion enough to cause tinting including
adding rutile to one that didn't tint in the past. I
have done this! Lead and Chromium will linger in a
kiln for (?) firings. But the only way to know for a
fact if lead is still running around in there is to
test for it. Chromium if left will show its face with
some tin glazes and if under the right conditions. Go
back through the archives and I believe I have left a
rational on the chrome tin pinking. Got to run or
would pull it up myself.
I don't think I would get overly concerned as to the
potential for dangers with chromium just yet. We take
in in our bodies daily through food intake. Chromium
that potters use should be handled the same way all
products we use should. Its still a usefull product!
Copper got the mean green award not too long ago and
it winds up in several recipes that are being used
left and right and in highly published recipes. It
takes lots of testing and practical sense in the
studio no matter what. There are some much nastier
products out there like Jon's chitlins and Sponge-Bob.
If it causing you tin whites to tint pink examine and
make some recipes changes to the white and try
reducing the chrome content when and where possible.
It takes very little chrome to get a nice green.
Bill Edwards
=====
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http://www.tallapoosariverpottery.com/
Bill Edwards
PO Box 367
Camp Hill, Alabama. 36850
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Edouard Bastarache Inc. on fri 20 apr 07
BTW,
according to USA-EPA, "chromium (III) is essential
to normal glucose,
protein, and fat metabolism and is thus an
essential dietary element."
(...)
"with a daily intake of 50 to 200 µg/d recommended
for adults."
www.epa.gov/ttn/atw/hlthef/chromium.html - 40k
Later,
Edouard Bastarache
Le Français Volant
The Flying Frenchman
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/cerambooks/rayons/technologie.php
http://www.flickr.com/photos/30058682@N00/
Ron Roy on thu 26 apr 07
Hi Edouard,
Do they say what happens if you exceed the recommended limits?
RR
>BTW,
>
>according to USA-EPA, "chromium (III) is essential
>to normal glucose,
> protein, and fat metabolism and is thus an
>essential dietary element."
>
>(...)
>
>"with a daily intake of 50 to 200 =B5g/d recommended
>for adults."
>
>www.epa.gov/ttn/atw/hlthef/chromium.html - 40k
>
>
>
>Later,
>
>
>
>Edouard Bastarache
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Edouard Bastarache Inc. on fri 27 apr 07
Hello Ron,
sorry, these days I keep getting kicked out by
the system. In our small industrial region they
are probably not used to processing so many
e-mails daily from the same source.
I have not kept any copy of my answer to your
second question, it was refused by Listserv.
To make things short, there are no hazard by
inhalation
and ingestion of trivalent Green Chromium Oxide
It is only minimally absorbed by these route of
entries.
So, according to Quebec "OSHA" database, there is
no acute effcts due to exposure.
The only chronic effect is allergic dermatitis
following
chronic exposure.
Other authors say that trivalent salts are poorly
absorbed,
through intact skin but, once the dermal barrier
is broken,
however, absorption may occur.
I do not think this situation occurs in our trade,
or from
using wares covered by a chrome containing glaze,
and
also considering the very small amounts used in
such
glazes.
Later,
Edouard Bastarache
Le Français Volant
The Flying Frenchman
Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.ceramique.com/cerambooks/rayons/technologie.php
http://www.flickr.com/photos/30058682@N00/
http://perso.orange.fr/smart2000/blogs_edouard.htm
Ron Roy on sun 29 apr 07
Hi Edouard,
This is what I sent -
Hi Edouard,
Do they say what happens if you exceed the recommended limits?
RR
>BTW,
>
>according to USA-EPA, "chromium (III) is essential
>to normal glucose,
> protein, and fat metabolism and is thus an
>essential dietary element."
>"with a daily intake of 50 to 200 =B5g/d recommended
>for adults."
>www.epa.gov/ttn/atw/hlthef/chromium.html - 40k
>Later,
>Edouard Bastarache
>Hello Ron,
>
>sorry, these days I keep getting kicked out by
>the system. In our small industrial region they
>are probably not used to processing so many
>e-mails daily from the same source.
>
>I have not kept any copy of my answer to your
>second question, it was refused by Listserv.
>
>To make things short, there are no hazard by
>inhalation
>and ingestion of trivalent Green Chromium Oxide
>It is only minimally absorbed by these route of
>entries.
>
>So, according to Quebec "OSHA" database, there is
>no acute effcts due to exposure.
>The only chronic effect is allergic dermatitis
>following
>chronic exposure.
>
>Other authors say that trivalent salts are poorly
>absorbed,
>through intact skin but, once the dermal barrier
>is broken,
>however, absorption may occur.
>
>I do not think this situation occurs in our trade,
>or from
>using wares covered by a chrome containing glaze,
>and
>also considering the very small amounts used in
>such
>glazes.
>
>
>
>Later,
>
>
>
>
>Edouard Bastarache
>Le Fran=E7ais Volant
>The Flying Frenchman
>
>Sorel-Tracy
>Quebec
>http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
>http://perso.orange.fr/smart2000/livres.htm
>http://www.pshcanada.com/Toxicology.htm
>http://www.ceramique.com/cerambooks/rayons/technologie.php
>http://www.flickr.com/photos/30058682@N00/
>http://perso.orange.fr/smart2000/blogs_edouard.htm
>
>___________________________________________________________________________=
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Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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