[Clayart] barium

Randall Moody randall.moody at gmail.com
Sun Jan 26 15:09:59 EST 2014


I agree but I do have to say that the vast majority of people "freaking
out" about barium are potters and not the average consumer. Also, if the
pottery buying public is being fed dubious information by "bariumophobes"
then isn't it up to the potters to correct the misinformation or at least
point out that there is no concrete scientific data to support the phobia?
The issue of unstable glazes and their use isn't limited to simply those
with harmful chemicals in them. If you are using a non-toxic yet unstable
glaze as a liner glaze then you have other issues. As to the last part,
couldn't that be said for most every ingredient? There is no reason to use
... cobalt oxide unless you want a particular colour response.


On Sun, Jan 26, 2014 at 2:44 PM, <ronroy at ca.inter.net> wrote:

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


-- 
Randall in Atlanta
http://wrandallmoody.com



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