Llewellyn Kouba on tue 4 sep 01
Is Vanadium generally considered to be 'food safe' at cone 9? Any doubt
whatever I mark the back of the plate *not food safe. (7.5 grams to the
100 gram weight)
Llewellyn
Ron Roy on wed 5 sep 01
Vanadium is not food safe.
It depends on the glaze - how stable it is.
Even if the glaze is stable - you can upset the stability by using a lot of
any oxide and 7.5 is a lot.
Have it tested to be sure.
RR
>Is Vanadium generally considered to be 'food safe' at cone 9? Any doubt
>whatever I mark the back of the plate *not food safe. (7.5 grams to the
>100 gram weight)
>
>Llewellyn
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
Edouard Bastarache on wed 5 sep 01
Hello Llewellyn et all,
vanadium pentoxide is considered a poison by ingestion
and other routes of entry.
Vanadium compounds have a variable toxicity.
Though certain workers believe that it is only the pentoxide
which is harmful, other investigators have found that
patronite dust (chiefly vanadium sulfide) is quite toxic to
animals, causing acute pulmonary edema.
So, you must know the chemical state of vanadium in
your glaze leachate and the amount before making a final
statement.
Also, if you only apply your vanadium glazes on non-utilitarian
wares, you do not have to worry.
Later,
Edouard Bastarache
Irreductible Quebecois
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://www.absolutearts.com/portfolios/e/edouardb/
John Baymore on thu 6 sep 01
So, you must know the chemical state of vanadium in
your glaze leachate and the amount before making a final
statement.
Also, if you only apply your vanadium glazes on non-utilitarian
wares, you do not have to worry.
Well........ you do have to worry about handling it yourself in the studi=
o
.
Best,
.............................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JohnBaymore.com
JBaymore@compuserve.com
John.Baymore@GSD-CO.com
"Earth, Water, and Fire Noborigama Woodfiring Workshop 2002 Dates TBA"=
Edouard Bastarache on thu 6 sep 01
Hello John,
the original question was about vanadium leaching from a glaze,
not studio exposure.
I have already sent a text to this list on the toxicology of vanadium
compounds, a few times.
I am sending it again:
Vanadium pentoxide:
Fume is recognized as being generally more toxic than dust because of the
smaller particle size of fume, which allows more complete penetration to the
small airways of the lungs.
The absorption of V2O5 by inhalation is nearly 100%.
Poison by ingestion, inhalation, and other routes of entry(experimental)
like intraperitoneal,
sub-cutaneous,
intrathecal and
intravenous.
Human systemic effects by inhalation:
-bronchiolar constriction,
-including asthma,
-cough,
-dyspnea(shortness of breath),
-sputum,
-conjonctiva irritation.
A respiratory irritant.
It causes skin pallor, greenish-black tongue, chest pain, dyspnea,
palpitation, lung changes.
When ingested it causes gastrointestinal tract disturbances.
It may also cause a papular skin rash.
An experimental teratogen, experimental reproductive effects,
mutagenic data.
When heated to decomposition it emits acrid smoke and irritating fumes of
VOx.
References:
1-Dangerous Properties of Industrial Materials by Sax and Lewis.
2-Chemical Hazards of the Workplace by Proctor and Hughes.
As for delayed healing of skin wounds, I have not found anything in the
medical literature.
Later,
Edouard Bastarache M.D.( Occupational & Envirnmental Medicine)
Dans / In "La Belle Province"
edouardb@sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/~edouardb/"
Ron Roy on fri 7 sep 01
My references mention Anemia, Kidney Disfunction and Nervous System damage
as well.
Best to stay away from this one.
RR
>the original question was about vanadium leaching from a glaze,
>not studio exposure.
>I have already sent a text to this list on the toxicology of vanadium
>compounds, a few times.
>
>I am sending it again:
>
>Vanadium pentoxide:
>
>Fume is recognized as being generally more toxic than dust because of the
>smaller particle size of fume, which allows more complete penetration to the
>small airways of the lungs.
>The absorption of V2O5 by inhalation is nearly 100%.
>
>Poison by ingestion, inhalation, and other routes of entry(experimental)
>like intraperitoneal,
>sub-cutaneous,
>intrathecal and
>intravenous.
>
>Human systemic effects by inhalation:
>-bronchiolar constriction,
>-including asthma,
>-cough,
>-dyspnea(shortness of breath),
>-sputum,
>-conjonctiva irritation.
>
>A respiratory irritant.
>
>It causes skin pallor, greenish-black tongue, chest pain, dyspnea,
>palpitation, lung changes.
>
>When ingested it causes gastrointestinal tract disturbances.
>It may also cause a papular skin rash.
>
>An experimental teratogen, experimental reproductive effects,
>mutagenic data.
>
>When heated to decomposition it emits acrid smoke and irritating fumes of
>VOx.
Ron Roy
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
Ron Roy on sat 8 sep 01
Hello Edouard,
The Artists Complete Health & Safety Guide by Monona Rossol 2nd edition
Page 147.
She also mentions - have caused chemical pneumonia and can cause allergies.
McCann also mentions heart problems.
RR
> Hello Ron,
>"My references mention Anemia, Kidney Disfunction and Nervous System damage
> as well."
>
>
>I would like to know what your references are.
>
>I have not found what you are talking about in the following "state
>of the art and up to date" references:
>
>1-Sax's Dangerous Properties of Industrial Materials, Lewis C., last
>edition.
>2-Occupational Medicine, Zenz C., last edition.
>3-Occupational & Environmental Medicine, Ladoue J., last edition.
>4-Hazardous Materials Toxicology, Sullivan & Krieger, last edition.
>5-Chemical Hazards of the Workplace, Proctor & Hughes, last edition.
>6-Toxicologie Industrielle et Intoxications Professionnelles, Lauweris R.,
>last edition.
>7-Precis de Medecine du Travail, Desoille H., Scherrer J., Truhaut R., last
>edition.
>
>
>I will check some more soon and report to the list.
>
>
>Later,
>
>
>
>Edouard Bastarache
>Irreductible Quebecois
>Sorel-Tracy
>Quebec
>edouardb@sorel-tracy.qc.ca
>http://sorel-tracy.qc.ca/~edouardb/
>http://www.absolutearts.com/portfolios/e/edouardb/
>
>
>
>the original question was about vanadium leaching from a glaze,
>not studio exposure.
>I have already sent a text to this list on the toxicology of vanadium
>compounds, a few times.
>
>I am sending it again:
>
>Vanadium pentoxide:
>
>Fume is recognized as being generally more toxic than dust because of the
>smaller particle size of fume, which allows more complete penetration to the
>small airways of the lungs.
>The absorption of V2O5 by inhalation is nearly 100%.
>Poison by ingestion, inhalation, and other routes of entry(experimental)
>like intraperitoneal,
>sub-cutaneous,
>intrathecal and
>intravenous.
>
>Human systemic effects by inhalation:
>-bronchiolar constriction,
>-including asthma,
>-cough,
>-dyspnea(shortness of breath),
>-sputum,
>-conjonctiva irritation.
>
>A respiratory irritant.
>
>It causes skin pallor, greenish-black tongue, chest pain, dyspnea,
>palpitation, lung changes.
>
>When ingested it causes gastrointestinal tract disturbances.
>It may also cause a papular skin rash.
>
>An experimental teratogen, experimental reproductive effects,
>mutagenic data.
>
>When heated to decomposition it emits acrid smoke and irritating fumes of
>VOx.
>
>______________________________________________________________________________
>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
RR# 4
15084 Little Lake Rd..
Brighton,
Ontario, Canada
KOK 1H0
Residence 613-475-9544
Studio 613-475-3715
Fax 613-475-3513
Edouard Bastarache on sat 8 sep 01
.
Hello Ron,
"My references mention Anemia, Kidney Disfunction and Nervous System damage
as well."
I would like to know what your references are.
I have not found what you are talking about in the following "state
of the art and up to date" references:
1-Sax's Dangerous Properties of Industrial Materials, Lewis C., last
edition.
2-Occupational Medicine, Zenz C., last edition.
3-Occupational & Environmental Medicine, Ladoue J., last edition.
4-Hazardous Materials Toxicology, Sullivan & Krieger, last edition.
5-Chemical Hazards of the Workplace, Proctor & Hughes, last edition.
6-Toxicologie Industrielle et Intoxications Professionnelles, Lauweris R.,
last edition.
7-Precis de Medecine du Travail, Desoille H., Scherrer J., Truhaut R., last
edition.
I will check some more soon and report to the list.
Later,
Edouard Bastarache
Irreductible Quebecois
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://www.absolutearts.com/portfolios/e/edouardb/
the original question was about vanadium leaching from a glaze,
not studio exposure.
I have already sent a text to this list on the toxicology of vanadium
compounds, a few times.
I am sending it again:
Vanadium pentoxide:
Fume is recognized as being generally more toxic than dust because of the
smaller particle size of fume, which allows more complete penetration to the
small airways of the lungs.
The absorption of V2O5 by inhalation is nearly 100%.
Poison by ingestion, inhalation, and other routes of entry(experimental)
like intraperitoneal,
sub-cutaneous,
intrathecal and
intravenous.
Human systemic effects by inhalation:
-bronchiolar constriction,
-including asthma,
-cough,
-dyspnea(shortness of breath),
-sputum,
-conjonctiva irritation.
A respiratory irritant.
It causes skin pallor, greenish-black tongue, chest pain, dyspnea,
palpitation, lung changes.
When ingested it causes gastrointestinal tract disturbances.
It may also cause a papular skin rash.
An experimental teratogen, experimental reproductive effects,
mutagenic data.
When heated to decomposition it emits acrid smoke and irritating fumes of
VOx.
Edouard Bastarache on sat 8 sep 01
Hello Ron,
" My references mention Anemia, Kidney Disfunction and Nervous System damage
as well.
Best to stay away from this one.
RR"
Here is something interesting that could be applied to vanadium leaching
from ceramics glazes:
Vanadium salts are poorly absorbed in the intestine; only about 1% is
absorbed.
Of the vanadium that is absorbed , only a small amount enters bone and is
mobilized slower than in other tissues.
Vanadium is rapidly excreted through urine(91%), with 60% of an absorbed
dose
excreted within 24 hours. The remainder is excreted in the feces (9%).
That is why I said recently that chemical form is very important when
talking vanadium
toxicity in glaze leachates.
I believe the same goes for other metals, for instance, insoluble barium
compounds
are inefficient sources of barium ions to cause the intoxication.
Later,
Edouard Bastarache
Irreductible Quebecois
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://www.absolutearts.com/portfolios/e/edouardb/
References:
1-Hazardous Materials Toxicology, Sullivan & Krieger, last edition.
2-Chemical Hazards of the Workplace, Proctor & Hughes, last edition.
Wade Blocker on sun 9 sep 01
Ron,
We are fortunate to have Dr.Basterache, who gives so generously of his
time, to give definitive answers to the safety issues of ceramics,by
quoting chapter and verse from books that have been published by recognized
experts in the health field of several countries. Edouard is a scientist
by training and a practitioner in the public health field.
I simply do believe in quotes from someone's book in which the author
has neither the scientific training nor the background in medicine to be
an authority on the above subject. I wonder if there has been a serious
study to substantiate the ill effects of vanadium, or whether they are
just so much hear say. Mia in ABQ.
Dave Finkelnburg on tue 11 sep 01
Mia,
Vanadium has been studied extensively because it is widely used as,
among other things, a catalyst in producing sulfuric acid. Workers who
handle the catalyst can be exposed to the yellow vanadium dust. Yes, the
hazards are real.
Doesn't mean there is no way to avoid the hazards, of course.
Regards,
Dave Finkelnburg
Mia wrote, >I wonder if there has been a serious
study to substantiate the ill effects of vanadium, or whether they are
just so much hear say." Mia in ABQ."
>
>___________________________________________________________________________
___
>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.
John Baymore on wed 12 sep 01
I simply do believe in quotes from someone's book in which the author=
has neither the scientific training nor the background in medicine to be=
an authority on the above subject. I wonder if there has been a serious
study to substantiate the ill effects of vanadium, or whether they are=
just so much hear say.
Mia,
I assume from the context above that you meant to say "I do NOT
believe......", and it is a typo . Assuming that.......... =
Ron is quoting Monona Rossol's book, if I remember correctly. I suggest
you might get a copy of one of her books and check her credentials, or ju=
st
email her at her ACTSNY@CS.com address and ask her about her
qualifications. If I catch your drift... I think you are saying that you=
think she is "professionally unqualified" to write such books. Yes/no?
BTW........ would the above thought logically get extended to if you don'=
t
have a recognized high level professional degree in ceramics (usually an
MFA here in the USA) that you shouldn't believe anything such a person wa=
s
saying in a professional context about ceramics? That would be an
interesting concept.
As to "studies" on many of the materials handcraft potters use and the WA=
Y
that they use them.......... none have been done, to my knowledge....but
Monona might know of some since this is very much her field of study. =
Unfortunatly in most cases they probably won't BE done. We are a VERY
small population doing a very specialized thing affecting VERY few
people......... and the funding for such research work goes first to plac=
es
that "do the most good". Serious medical studies of things like the impa=
ct
of the leaching of chemical X out of handcraft potter's ceramic glazes on=
first trimester fetuses and the impact of craft potters personal studio
exposures to chemical Y and so on would cost a BUNDLE (to be done
effectively) and take a very long time. Clinical research is not usually=
fast. I just don't see it happening anytime soon that we will have what
you might call "definitive proof" about many of the questions we are aski=
ng
ourselves about all manner of health risks and impacts. Industrial studi=
es
for some overlapping issues exist.... but because so much depends on such=
things like duration of exposure as well as intensity...... you can't
necessarily directly extrapolate such information. And in many artist
studio situations... there are no figures established for even the
actual LEVELS of exposure. =
For example, can YOU tell me the actual level (in ppm....or even ANY
scientific unit of measure) of crystalline silica in the air of your stud=
io
when you are mixing glazes or clay or cleaning or whatever? Probably not=
. =
And probably 99.999999 percent of other potters can't answer that questio=
n
accurately either. Few have had any air sampling done. Lacking that kin=
d
of information...... you can't even begin to relate your personal situati=
on
to information presented in even the few studies there are available.
So in the "health and safety" issue we always seem to come down to the
"glass is half full / glass is half empty" type issue. Lacking definitiv=
e
information, do you believe that a material is safe until proven hazardou=
s
or do you believe that it is hazardous until proven safe? Some opt for t=
he
former ....some opt for the later.
Personally ........ I advise GREAT respect for all ceramic materials you
use. Be careful but don't be paranoid. And gather information from ALL
sources you can and then make the best decisions you can based on what
information you have found.
Probably one of the BIGGEST issues in all this health stuff is the role
that those of us who act as educator in one form or another take. I thin=
k
INFORMED CONSENT is really a huge issue in all this stuff. If you
communicate clearly that there are possible risks in working with materia=
ls
and processes, many of which might not be fully studied or understood....=
.
and THEN a person so informed still choses to work with those materials o=
r
processes....... that is a very different situation from when the person
has not been informed about the potential risks. Unfortunately, all too
often......... potential risks are NOT presented or discussed.
Best,
..............................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JohnBaymore.com
JBaymore@compuserve.com
John.Baymore@GSD-CO.com
"Earth, Water, and Fire Noborigama Woodfiring Workshop 2002 Dates TBA"=
| |
|
