Earl Brunner on tue 5 jul 05
Don't put it on cereal?.......
Earl Brunner
Las Vegas, NV
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Paulette Carr
Sent: Tuesday, July 05, 2005 6:21 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Somebright Green ... barium carbonate question
Vince and Edouard,
I have eliminated BaCO3 from my glazing work due to this "toxic
scare." If there is some way to reinstall some of these barium
containing glazes into my palette, and not endanger myself or others,
I would be thrilled! How can I properly use it?
Many thanks!
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
Paulette Carr on tue 5 jul 05
Vince Pitelka writes:
"Barium carbonate is also harmless if properly used, but has fallen
victim to toxic scare."
Edouard Bastarache writes:
"Right on Vince,
I really like the expression "toxic scare"."
Vince and Edouard,
I have eliminated BaCO3 from my glazing work due to this "toxic
scare." If there is some way to reinstall some of these barium
containing glazes into my palette, and not endanger myself or others,
I would be thrilled! How can I properly use it?
Many thanks!
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
Edouard Bastarache Inc. on tue 5 jul 05
Paulette,
myself, I do not refrain from using Barium Carbonate in my studio and
my wife has been making salad in one of my bowls covered by a barium-
containing glaze for years.
See, I am still around even if she puts vinegar in the dressing.
Barium Carbonate per se is INSOLUBLE, it becomes SOLUBLE in contact
with the acidic gastric juice as explained later in my text.
It is an ACUTE toxicant if the amount ingested is sufficient to cause the
intoxication, which would be most surprising in your context unless
you confuse it with sugar when you prepare a cup of coffee; or with
flour in the case of cooking something, etc.
Read my text for more information.
There is no use of testing barium leaching in glazes since it is not
a chronic toxicant.
Exposure :
1-Environmental :
Barium naturally occurs at low concentrations in ambient air, usually < 0.05
µg/m3,
but is found at relatively high concentrations in soils , nearly 500 mg/kg.
In fresh surface water, concentrations may vary from < 5 to 15,000 µg/L.
and it
contributes to water hardness.
Foodstuffs provide also barium and the daily human intake has been estimated
to
be in the order of 1 mg.
2-Industrial :
The pulmonary route of entry is the most significant in the industrial
setting.
Routes of entry :
SOLUBLE barium salts are well absorbed by pulmonary and oral routes of
entry.
INSOLUBLE salts inhaled and deposited are eliminated only slowly and can
accumulate in the lungs as a result of long-term exposure.
Barium compounds are not reputed to penetrate by skin unless the cutaneous
barrier is broken as in chemical burns; a case has been described in the
relevant
medical literature which had been caused by barium chloride in fusion.
Toxicity :
1-Solubility :
The toxicity of barium salts is related largely to their solubility, which
conditions
their digestive absorption and bioavailability. Water and acid soluble salts
are very
toxic when ingested.
The carbonate BaCO3 is INSOLUBLE in water at neutral pH, it becomes SOLUBLE
in
acid environments, which is not without consequence in vivo because of the
gastric pH. There would be under this condition, production of barium
chloride
BaCl2 from the solubilized carbonate; barium chloride is one the most toxic
of soluble barium salts.
2-Metabolism :
The biological half-life of barium varies between 2 and 20 hours. Absorbed
barium is mainly deposited in bones, which accounts for 93% of the body
burden in man. It is mainly excreted in feces and a small part (1 to 10%)
in urine.
3-Exprimental toxicity :
In the case of barium carbonate, the Lethal Dose Fifty (LD50) is :
-mouse (ingestion): 200 mg/kg,
-rat (ingestion): 418 mg/kg,
which makes it a very toxic chemical by ingestion.
Barium stimulates the striated and cardiac muscles. This hyperstimulation
causes arrhythmias, myoclonus, digestive disorders and arterial hypertension
by direct effect on the smooth muscles of the arterial wall independently of
the renin-angiotensin system and catecolamines.
4-Acute intoxication by ingestion :
The lethal dose in man varies, according to the barium compounds involved,
between 1 and 15 g. by ingestion. Acute intoxications are rare and generally
due to suicidal attempts with the chloride or the carbonate.
Some cases of collective food intoxications were reported, related to food
contamination, and to confusion between carbonate and barium sulphate at
the time of radiological examinations. Barium carbonate having been
substituted accidentally for potato flour during the preparation of
sausages,
144 people were poisoned in Israel in 1963. Two patients died.
5-Local effects :
Aqueous solutions of barium hydroxide and oxide are strongly alkaline
and can cause significant ocular burns and skin irritation.
The carbonate and the sulphate of barium are irritating to the mucous
membranes of the upper airways, the carbonate can also be irritating to
the skin and the eyes.
Prevention :
Good housekeeping of your studio is important as for any other chemical.
Avoidance of processes generating unnecessary dust is also important.
Effective filter masks should be worn if the severity of exposure justifies
it during preparation of glazes and clays.
It would be good practice not to drink, eat or smoke in the workshop.
Especially, one should not confuse barium carbonate with table sugar
when preparing coffee.
Medical surveillance :
An electrocardiogram is recommended as part of the periodical examination
of workers exposed to SOLUBLE salts.
Periodical urinary and blood mesurements could also be carried out; in
subjects
not professionally exposed blood concentrations are lower than 10 µg/L,
and lower than 20µg/L in the urine.
Later,
"Ils sont fous ces quebecois"
"They are insane these quebekers"
"Están locos estos quebequeses"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://www.flickr.com/photos/30058682@N00/
http://www.ceramique.blogspot.com/
http://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
----- Original Message -----
From: "Paulette Carr"
To:
Sent: Tuesday, July 05, 2005 9:21 AM
Subject: Somebright Green ... barium carbonate question
> Vince Pitelka writes:
> "Barium carbonate is also harmless if properly used, but has fallen
> victim to toxic scare."
>
>
>
> Edouard Bastarache writes:
>
> "Right on Vince,
>
> I really like the expression "toxic scare"."
>
>
>
> Vince and Edouard,
>
> I have eliminated BaCO3 from my glazing work due to this "toxic
> scare." If there is some way to reinstall some of these barium
> containing glazes into my palette, and not endanger myself or others,
> I would be thrilled! How can I properly use it?
>
> Many thanks!
>
> Paulette Carr
> Paulette Carr Studio
> Member/Potters Council
> St. Louis, MO
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
>
Chuck Wagoner on tue 5 jul 05
I am curious to no what percentage of Barium Carbonate your salad bowl
has in it? What temp was it fired to?
Potter Wagoner
Edouard Bastarache Inc. on tue 5 jul 05
21 % Barium Carbonate and fired at cone 9˝
Later,
"Ils sont fous ces quebecois"
"They are insane these quebekers"
"Están locos estos quebequeses"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://www.flickr.com/photos/30058682@N00/
http://www.ceramique.blogspot.com/
http://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
Paulette Carr on wed 6 jul 05
Edouard and Vince,
Merci beaucoup! I will be cautious and reasonable in handling the
carbonate, but I am very excited about the prospect of enlarging my
glaze palette. I do fire to ^9, and prefer honey to sugar ... my
kitchen is upstairs.
I owe a deep debt of gratitude to this Clayart forum, where the
"urban legands/toxic scares" can be discussed. There is freedom in
knowing ...
My best,
Paulette Carr
Paulette Carr Studio
Member/Potters Council
St. Louis, MO
Edouard Bastarache writes:
Paulette,
myself, I do not refrain from using Barium Carbonate in my studio and
my wife has been making salad in one of my bowls covered by a barium-
containing glaze for years.
See, I am still around even if she puts vinegar in the dressing.
Barium Carbonate per se is INSOLUBLE, it becomes SOLUBLE in contact
with the acidic gastric juice as explained later in my text.
It is an ACUTE toxicant if the amount ingested is sufficient to cause
the
intoxication, which would be most surprising in your context unless
you confuse it with sugar when you prepare a cup of coffee; or with
flour in the case of cooking something, etc.
Read my text for more information.
There is no use of testing barium leaching in glazes since it is not
a chronic toxicant.
Edouard Bastarache Inc. on wed 6 jul 05
Right Earl !!!
----- Original Message -----
From: "Earl Brunner"
To:
Sent: Tuesday, July 05, 2005 11:37 PM
Subject: Re: Somebright Green ... barium carbonate question
> Don't put it on cereal?.......
>
> Earl Brunner
> Las Vegas, NV
> -----Original Message-----
> From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Paulette Carr
> Sent: Tuesday, July 05, 2005 6:21 AM
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Somebright Green ... barium carbonate question
>
> Vince and Edouard,
>
> I have eliminated BaCO3 from my glazing work due to this "toxic
> scare." If there is some way to reinstall some of these barium
> containing glazes into my palette, and not endanger myself or others,
> I would be thrilled! How can I properly use it?
>
> Many thanks!
>
> Paulette Carr
> Paulette Carr Studio
> Member/Potters Council
> St. Louis, MO
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
>
Ron Roy on wed 6 jul 05
In Austria and Slovenia Barium is under control - no more than 1 mg/L of
release under acidic conditions.
Perhaps they know something we don't?
I would never use a high barium glaze as a liner glaze unless I was sure it
was a stable glaze.
In fact I would not use any kind of Barium glaze as a liner glaze unless I
was sure it was a stable glaze.
We simply do not know how our pots will be used - and remember - toxicity
is always related to the weight of the victim - think about that and how it
may affect the unborn.
I have no problem with using barium on the outsides of functional
containers - or sculptural work. Just realize that Barium Carbonate is
slightly soluble and is a very effective rat poison. Don't let your pets
drink out of the glaze bucket for instance.
RR
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Edouard Bastarache Inc. on wed 6 jul 05
Hello Ron,
"and remember - toxicity is always related to the weight
of the victim - think about that and how it may affect the
unborn." (RR)
Barium Carbonate,
from my text "Pregnancy, Ceramics and Crystalware Making"
Effects on development :
In animals :
No harmful anatomical effect was observed in the off-springs of rats and
mice receiving up to 4000 ppm of barium chloride dihydrate in water, even if
the weight at birth of the young ones was reduced.
Effects on reproduction :
In animals :
In rats and mice receiving up to 4000 ppm barium chloride dihydrate in
water, the indices of reproduction were not altered.
Effects on breast milk :
There is no data concerning its excretion or detection in milk.
Now my credentials concerning my knowledge of barium compounds :
"Bastarache E. Barium and compounds/toxicology (CASRN 7440-39-3).
Integrated risk information system, IRIS toxicological review,
US Environmental protection agency (EPA)."
Later,
"Ils sont fous ces quebecois"
"They are insane these quebekers"
"Están locos estos quebequeses"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://www.flickr.com/photos/30058682@N00/
http://www.ceramique.blogspot.com/
http://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
Ron Roy on wed 6 jul 05
Hi Edouard,
If you care to send the recipe I would like to have some idea about how
stable the glaze is.
RR
>21 % Barium Carbonate and fired at cone 9=BD
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
=46ax: 613-475-3513=20
Ron Roy on sun 10 jul 05
Hi Edouard,
Do I understand from this that you do not believe there is any danger from
barium leached out of any glaze - to anyone - including a fetus?
The EPA sets their maximum contaminant level (MCL) for barium in drinking
water at 2 ppm because there is evidence that chronic exposure to amounts
above this can raise blood pressure in humans, probably due to kidney
damage. Would it not be prudent to at least try to make barium containing
liner glazes somewhat stable?
RR
>Barium Carbonate,
>
>from my text "Pregnancy, Ceramics and Crystalware Making"
>Effects on development :
>
>In animals :
>
>No harmful anatomical effect was observed in the off-springs of rats and
>mice receiving up to 4000 ppm of barium chloride dihydrate in water, even if
>the weight at birth of the young ones was reduced.
>
>Effects on reproduction :
>
>In animals :
>
>In rats and mice receiving up to 4000 ppm barium chloride dihydrate in
>water, the indices of reproduction were not altered.
>
>Effects on breast milk :
>
>There is no data concerning its excretion or detection in milk.
>Now my credentials concerning my knowledge of barium compounds :
>
>"Bastarache E. Barium and compounds/toxicology (CASRN 7440-39-3).
>
>Integrated risk information system, IRIS toxicological review,
>
>US Environmental protection agency (EPA)."
>Later,
>Edouard Bastarache
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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