[Clayart] barium

ronroy at ca.inter.net ronroy at ca.inter.net
Sun Jan 26 14:44:23 EST 2014

Hi Randal,

I'm not saying that ingesting small amounts of barium can kill you,  
I'm not even saying that small amounts released from glazes can be a  

What I am saying is - it's not a good idea to use unstable glazes  
containing toxic materials as liner glazes because some of the pottery  
buying public will freak out and thats not good for hand made pottery  

Besides - there is little or no reason to use it unless you want  
particular colour responses.


Quoting Randall Moody <randall.moody at gmail.com>:

> Yes, barium carbonate is toxic but it is voided by the body and is not
> cumulative like lead. In addition the amount ingested even in poisoning
> cases is WAY more than anyone would get by leaching from a glaze."
> ...nephropathy was not observed in mice exposed to 205 mg barium/kg/day for
> an intermediate duration; at
> 450 mg barium/kg/day, 95% of the animals exhibited mild to moderate
> nephropathy."  H2O is can kill you if you drink enough of it.
> On Sun, Jan 26, 2014 at 1:29 PM, <ronroy at ca.inter.net> wrote:
>> Hi Randal,
>> The problem I see is what happens when someone uses a pot with an unstable
>> barium liner glaze and it changes colour in use. This can easily happen
>> with the high barium matte glazes coloured with cobalt or copper. I have
>> seen potters at shows selling dinnerware covered with these kinds of glazes.
>> There are toxicity issues with barium - it comes with a scull and cross
>> bones on the bag.
>> My concern is with the publics reaction to unstable glazes leaching toxic
>> material into food.
>> I just wish that those potters who have no interest in making stable
>> glazes would simply choose to avoid using toxic materials in liner glazes.
>> RR
>> Quoting Randall Moody <randall.moody at gmail.com>:
>>  If you have any data confirming the assumptions please provide it. All
>>> that
>>> I have read (and I have pulled as many sources as possible) rely on the
>>> assumption and extrapolation rather than concrete data. Also, given that
>>> barium is not cumulative in the body like lead but is evacuated from the
>>> body unless taken in large doses such as eating BaCO3 rodenticide, the
>>> amount leached from a functional pot under normal use would be negligible.
>>> I am not trying to tell anyone that they must have barium in their studio
>>> but rather that there is, as yet, no concrete data set to warrant the fear
>>> and loathing that many have against the ingredient. The topic of barium
>>> comes up regularly on clayart and there has never been any data which
>>> directly links barium carbonate as used in glazes and pottery to any
>>> illness.
> --
> Randall in Atlanta
> http://wrandallmoody.com

Ron Roy
ronroy at ca.inter.net

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