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porcelain body and cobalt

updated wed 16 jul 03

 

Kendall deaton on tue 15 jul 03



I have heard of the same technique of adding Cobalt. I would advise against it to all, for health reasons. Cobalt is very toxic and even though it seems to be such a small amount one has to consider what intimate and frequent contact you have with wet clay.  If it is a concern with glaze leaching where the amounts are in the parts per million that makes that 1/4 teaspoon you are throwing with everyday a huge amount.


just a thought, Kendall



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Tony Hansen on tue 15 jul 03


Can you tell me why you think cobalt is high toxic?
I want completely unaware of this.

-------8<--------

I have heard of the same technique of adding Cobalt. I would advise against it to all, for health reasons. Cobalt is very toxic and even though it seems to be such a small amount one has to consider what intimate and frequent contact you have with wet clay.  If it is a concern with glaze leaching where the amounts are in the parts per million that makes that 1/4 teaspoon you are throwing with everyday a huge amount.




--------
Tony Hansen, Digitalfire Corp.

Snail Scott on tue 15 jul 03


At 02:47 PM 7/15/03 -0500, you wrote:

I have heard of the same technique of adding Cobalt. I would
advise against it to all, for health reasons. Cobalt is very toxic and
even though it seems to be such a small amount one has to consider what
intimate and frequent contact you have with wet clay...



Please support this. I was unaware of any significant

skin-absorption issues associated with cobalt as a

body stain. I would have no qualms about using this

modest amount of cobalt in a clay body.


-Snail

Kendall deaton on tue 15 jul 03







I now realize that toxic was the wrong term at least acutely and I also know that solubility is limited depending on what form. I should know better I am a pre-med dropout turned to the wonderful world of ceramics afterall. But I am not speaking without basis in truth. I am not concerned so much with skin absorption as dust inhalation and that snack some of us are prone to having at the wheel (not a good habit). I may be guilty of thinking in the long-term excessively but, I am a young guy and I want to work with clay for a long time and remain healthy. I think we should all be very careful of what we expose ourselves especially in relation to colorants. MSDS sheets are great things but I am not entirely convinced they are the end all in relations pertaining to health and safety, at least not mine. As we all know in the not too distant past lead, manganese, asbestos etc. were considered innocuous and we have lost some potters prematurely. Anyway, enou
gh of my defensive rantings here is some info. I can come up with more if you are interested.




I hope this cut and paste works


















 












 








 




 



Cobalt Toxicity is generally also not a concern since it doesn't develop from the normal consumption
of foods and beverages, unless - as with nickel - there is a natural tendency to retain too much cobalt,
in which case asthma, anxiety or cardiac symptoms may be experienced.  However, a number of years
ago, cobalt salts were added to beer as foam stabilizers which lead to an epidemic of cardiomyopathy
and congestive heart failure among beer drinkers.  Other effects of overdosing on cobalt (> 5mg / day)
include abnormal thyroid functions, polycythemia and overproduction of red blood cells (erythropoiesis),
with increased production of the hormone erythropoietin (EPO) from the kidneys.
Medically, EPO can increase the red blood cell count by 25-35% so it is used to treat certain forms of
anemia (i.e. in chronic kidney failure). It has also been used by athletes to improve athletic performance
by increasing the oxygen-carrying ability of their blood, and to fight fatigue.  The blood however thickens
with excessive use of EPO, so users can suffer blood clots, strokes, heart attacks and related deaths.























 












 








 




 



Cobalt Toxicity is generally also not a concern since it doesn't develop from the normal consumption
of foods and beverages, unless - as with nickel - there is a natural tendency to retain too much cobalt,
in which case asthma, anxiety or cardiac symptoms may be experienced.  However, a number of years
ago, cobalt salts were added to beer as foam stabilizers which lead to an epidemic of cardiomyopathy
and congestive heart failure among beer drinkers.  Other effects of overdosing on cobalt (> 5mg / day)
include abnormal thyroid functions, polycythemia and overproduction of red blood cells (erythropoiesis),
with increased production of the hormone erythropoietin (EPO) from the kidneys.
Medically, EPO can increase the red blood cell count by 25-35% so it is used to treat certain forms of
anemia (i.e. in chronic kidney failure). It has also been used by athletes to improve athletic performance
by increasing the oxygen-carrying ability of their blood, and to fight fatigue.  The blood however thickens
with excessive use of EPO, so users can suffer blood clots, strokes, heart attacks and related deaths.






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