Judy Musicant on sun 8 may 05
Ron Roy wrote:
"Watch out for Manganese - in clay or glazes - the dust is a real health
hazard as are the fumes from firing it."
Based on this statement, should we assume that the manganese in =
manganese speckled clay (such as the very poplular Standard 112) makes =
the clay dust in our studios even more dangerous to breathe? This =
subject has been discussed before, but I've never been clear on the =
answer (if there is a definitive one). =20
I seem to remember a statement that the managese particals in this type =
of clay are not dangerous other than when fired, as fumes, because they =
are heavier than the clay dust, and you wouldn't breathe them in. Am I =
dreaming that one up? =20
If this type of clay is more dangerous, is it worth increasing the risk? =
I doubt that anyone's studio (besides perhaps Lili's!) is pristine. I =
certainly know mine is not. If manganese increases the danger, perhaps =
it's stupid to ever use it.
Judy Musicant=20
Pottersguildnj.org
Louis Katz on sun 8 may 05
Lots of things to consider here. Everyone has their own level of
acceptable risk and skepticism. I am not a safety expert. At the same
time I have to make decisions regarding safety. I read about safety and
ask the following questions:
Is the information pertenant to me. ie if they are talking about
soluble organic chromium compounds and I am using insoluble inorganics
does the material have any applicability.
How much data are the likely to have. Are there lots of people being
exposed or are they drawing conclusions on five workers?
How long could the study have been. Is it a new material or process or
an old one?
Is our type of exposure not duplicated in industry, ie we throw with it.
What is our possible maximum exposure in our use and how does it
compare with the limits set by government.
In terms of manganese I would avoid throwing with much powdered
manganese in my clay, although the chance that this would poison you
seems to my non-expert eyes very small. I would vent my kilns, and I
would keep my studio clean and as free of dust as I can.
I would also read Edouard Bastarache and compare the limits for
Manganese and respirable quartz,
Manganese---http://ceramic-materials.com/cermat/education/155.html
Silica---http://ceramic-materials.com/cermat/education/170.html
If after that you decide to use or not use manganese you will make the
decision with more information.
Louis
On May 8, 2005, at 10:27 AM, Judy Musicant wrote:
> Ron Roy wrote:
>
> "Watch out for Manganese - in clay or glazes - the dust is a real
> health
> hazard as are the fumes from firing it."
>
> Based on this statement, should we assume that the manganese in
> manganese speckled clay (such as the very poplular Standard 112) makes
> the clay dust in our studios even more dangerous to breathe? This
> subject has been discussed before, but I've never been clear on the
> answer (if there is a definitive one).
> I seem to remember a statement that the managese particals in this
> type of clay are not dangerous other than when fired, as fumes,
> because they are heavier than the clay dust, and you wouldn't breathe
> them in. Am I dreaming that one up?
>
> If this type of clay is more dangerous, is it worth increasing the
> risk? I doubt that anyone's studio (besides perhaps Lili's!) is
> pristine. I certainly know mine is not. If manganese increases the
> danger, perhaps it's stupid to ever use it.
>
> Judy Musicant
> Pottersguildnj.org
>
> _______________________________________________________________________
> _______
> 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.
>
Rick Hamelin on sun 8 may 05
There is a direct link of developing Parkinson's Syndrome to manganese welding rods and manganese itself. This information is obtainable throughout the web. Yet, in my area of central Massachusetts, our toilet tanks are discolored by the accumulation of the manganese and iron found in our water. So, is there a cumulative poisoning taking place just from my town's well water, aggravated by the manganese in my vitamins? I don't know of any adverse health conditions; ie increased Parkonson Syndrome for my area. All of our metals can be toxic. We don't live in the dark ages anymore. Information is at hand
--
"Many a wiser men than I hath
gone to pot." 1649
-------------- Original message --------------
> Ron Roy wrote:
>
> "Watch out for Manganese - in clay or glazes - the dust is a real health
> hazard as are the fumes from firing it."
>
> Based on this statement, should we assume that the manganese in manganese
> speckled clay (such as the very poplular Standard 112) makes the clay dust in
> our studios even more dangerous to breathe? This subject has been discussed
> before, but I've never been clear on the answer (if there is a definitive one).
> I seem to remember a statement that the managese particals in this type of clay
> are not dangerous other than when fired, as fumes, because they are heavier than
> the clay dust, and you wouldn't breathe them in. Am I dreaming that one up?
>
> If this type of clay is more dangerous, is it worth increasing the risk? I
> doubt that anyone's studio (besides perhaps Lili's!) is pristine. I certainly
> know mine is not. If manganese increases the danger, perhaps it's stupid to
> ever use it.
>
> Judy Musicant
> Pottersguildnj.org
>
> ______________________________________________________________________________
> 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.
Earl Brunner on sun 8 may 05
My understanding is that the problem with manganese is mainly from breathing
it, particularly the fumes. If I'm not mistaken, this was discussed at
length, back when David Shaner became ill. He used LOTS of manganese in some
of his signature surface treatments. His symptoms were similar to Lou
Gehrig's disease. Having it in the water didn't seem to be as much of an
issue.
Earl Brunner
Las Vegas, NV
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Rick Hamelin
Sent: Sunday, May 08, 2005 11:26 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Manganese health risks
There is a direct link of developing Parkinson's Syndrome to manganese
welding rods and manganese itself. This information is obtainable throughout
the web. Yet, in my area of central Massachusetts, our toilet tanks are
discolored by the accumulation of the manganese and iron found in our water.
So, is there a cumulative poisoning taking place just from my town's well
water, aggravated by the manganese in my vitamins? I don't know of any
adverse health conditions; ie increased Parkonson Syndrome for my area. All
of our metals can be toxic. We don't live in the dark ages anymore.
Information is at hand
--
"Many a wiser men than I hath
gone to pot." 1649
Edouard Bastarache Inc. on mon 9 may 05
Louis,
According to Eduoard the Canadian limits on Manganese are in the
same order of magnitude as the limits on respirable quartz.(Louis)
"Not exactly so, Manganese has 2 sets of exposure limits (expressed as Mn),
1 for the dusts and compounds,
and
1 for the fumes (1mg/m).
Welding fumes have a limit of 5mg/m.
Respirable quartz has a limit of 0.1 mg/m."(EB)
My glaze kilns are outside.(Louis)
"No problem, the name of the safe game is ventilation. I have
already presented a report to this list of a canadian study
that took place in British Columbia (Canada) :
AUTHOR: Bob Hirtle; Kay Teschke; Chris van Netten; Michael Brauer
TITLE: Kiln Emissions and Potters' Exposures
SOURCE: American Industrial Hygiene Association Journal v59 no10 p706-14 O '98
The magazine publisher is the copyright holder of this article and it is
reproduced with
permission. Further reproduction of this article in violation of the
copyright is prohibited.
ABSTRACT
Some ten thousand British Columbia potters work in small private studios,
cooperative
facilities, educational institutions, or recreation centers. There has been
considerable
concern that this diffuse, largely unregulated activity may involve
exposures to
unacceptable levels of kiln emissions. Pottery kiln emissions were measured
at 50
sites-10 from each of 5 categories: professional studios, recreation
centers,
elementary schools, secondary schools, and colleges. Area monitoring was
done 76 cm
from firing kilns and 1.6 m above the floor to assess breathing zone
concentrations of
nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes,
aluminum,
antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt,
copper, gold,
iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium,
silver, vanadium,
and zinc. Personal exposures to the same metals were measured at 24 sites.
Almost
all measured values were well below permissible concentrations for British
Columbia
work sites and American Conference of Governmental Industrial Hygienists
(ACGIH)
threshold limit values (TLVs) with the following two exceptions. A single
firing duration
(495 minute) acrolein measurement adjacent to an electric kiln (0.109 ppm)
exceeded
these guidelines. One 15-minute sulfur dioxide measurement collected
adjacent to a
gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The fact
that
concentrations in small, ventilated kiln rooms ranked among the highest
measured
gives rise to concern that unacceptable levels of contamination may exist
where small
kiln rooms remain unventilated. Custom designed exhaust hoods and industrial
heating,
ventilating, and air-conditioning systems were the most effective
ventilation strategies.
Passive diffusion and wall/window fans were least effective.
As you all see, we live in a safe place if we use ventilation; and most of
the shops sampled already had ventilation"(EB)
I would suggest you read the entire articles he wrote on each of these
metals.(Louis)
"Very good point, I write them so ceramists have decent information.(EB)
I read government docs with some skepticism, but I see no reason to
assume that manganese dioxide is more hazardous than cobalt oxide
or chrome oxide. I wonder what he thinks.(Louis)
"It is always a matter of nature, level and duration of exposure, also
the nature of the chemical must be taken into account, its known
acute and/or chronic toxicity.
Cobalt oxide has an exposure limit of 0.02 mg/m (expressed as Co)
while the one of green chromium oxide is 0.5 mg/m (expressed as Cr)
I use the three of them in glazes and it does not scare the shit out of me.
I rarely use clays containing manganese just because I prefer brown
clays, coloured by iron oxide, to black ones. In the case of manganese-
containing clays the applicable limit is 5 mg/m before the clay is fired.
As we saw in the canadian study, there is no problem if you have
good ventilation while firing when it comes to the production of
manganese fumes, the exposure limit is then 1 mg/m.(EB)
By the way, Babelfish.altavista.com translates(Louis)
"You do not need to use Babelfish, all of my articles on the Net are
written in English and French, in the Old Europe(damn Rumsfeld),
in North America http://ceramic-materials.com/cermat/education/
and in Australia (Ceramics Today run by Steven Goldate)"(EB)
Later,
"Ils sont fous ces quebecois"
"They are insane these quebekers"
"Estn 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://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
Gayle Bair on mon 9 may 05
Rick,
Here's another one.......... after reading this thread I recalled
being told that manganese was/is used in fireworks!
BTW it's also in matches! Interesting eh?
Just think about 4th of July celebrations, the kids waving those
metal sparklers around, the big firework displays and all the fumes they are
breathing! Interesting.... very interesting....
If you want to read more do a search... "Manganese in fireworks"
Gayle Bair
-----Original Message-----
From: Rick Hamelin
There is a direct link of developing Parkinson's Syndrome to manganese
welding rods and manganese itself. This information is obtainable throughout
the web. Yet, in my area of central Massachusetts, our toilet tanks are
discolored by the accumulation of the manganese and iron found in our water.
So, is there a cumulative poisoning taking place just from my town's well
water, aggravated by the manganese in my vitamins? I don't know of any
adverse health conditions; ie increased Parkonson Syndrome for my area. All
of our metals can be toxic. We don't live in the dark ages anymore.
Information is at hand
--
"Many a wiser men than I hath
gone to pot." 1649
-------------- Original message --------------
> Ron Roy wrote:
>
> "Watch out for Manganese - in clay or glazes - the dust is a real health
> hazard as are the fumes from firing it."
>
> Based on this statement, should we assume that the manganese in manganese
> speckled clay (such as the very poplular Standard 112) makes the clay dust
in
> our studios even more dangerous to breathe? This subject has been
discussed
> before, but I've never been clear on the answer (if there is a definitive
one).
> I seem to remember a statement that the managese particals in this type of
clay
> are not dangerous other than when fired, as fumes, because they are
heavier than
> the clay dust, and you wouldn't breathe them in. Am I dreaming that one
up?
>
> If this type of clay is more dangerous, is it worth increasing the risk? I
> doubt that anyone's studio (besides perhaps Lili's!) is pristine. I
certainly
> know mine is not. If manganese increases the danger, perhaps it's stupid
to
> ever use it.
>
> Judy Musicant
> Pottersguildnj.org
>
>
____________________________________________________________________________
__
> 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.
____________________________________________________________________________
__
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.
--
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Checked by AVG Anti-Virus.
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Lee Love on mon 9 may 05
Gayle Bair wrote:
>Here's another one.......... after reading this thread I recalled
>being told that manganese was/is used in fireworks!
>
As a kid (and one of my neighborhood aspireing "Mad Scientists"), I used
to make ariel fireworks out of model rockets and MAGNESIUM shavings my
father procured for me when he worked at Magline (they made quanset huts
and magnesium hand trucks.)
I am guessing they might have manganese as a colorant (they probably use
many oxides to color the fires), but magnesium is one of the things that
makes them burn bright.
--
李 Lee Love 大
愛 鱗
in Mashiko, Japan http://mashiko.org
http://hankos.blogspot.com/ Visual Bookmarks
http://ikiru.blogspot.com/ Zen and Craft
Kate Johnson on mon 9 may 05
Hi all--I'm taking all this in, and thank you...DEFINITELY will be careful
with the manganese, and plan to phase it out.
Part of my original question is still up in the air...we discussed Mason
stains, but what about using something similar to Albany
slip/Arroyo/whatever? I know I'm splitting hairs here, but I'm still trying
to work as close as possible to the historical model, and I don't think
"they" had Mason stains. If there's another more natural solution I'd
probably choose it...
Best--
Kate Johnson
graphicart@epsi.net
http://www.cathyjohnson.info/
Art, History, Nature and More at Cathy Johnson's Cafepress--
http://www.cafepress.com/cathy_johnson/
Graphics/Fine Arts Press--
http://www.epsi.net/graphic/
Gayle Bair on mon 9 may 05
Hi Lee,
You're going to love this web site but check out...
http://www.onlinelawyersource.com/news/firecracker-manganese.html
more interesting info...
http://www.state.nj.us/health/eoh/rtkweb/1155.pdf
and.........
http://www.mineralgallery.co.za/manganese.htm
last paragraph states
"The most important manganese compound, pyrolusite or manganese dioxide, =
is also an oxidizing agent. Pyrolusite is used extensively in the =
electrodes of dry batteries, where it absorbs liberated hydrogen gas and =
then chemically bonds it. It is also used as an oxygen source in =
fireworks and as a chemical catalyst. All other manganese compounds are =
made from pyrolusite.=E2=80=9D
Gayle Bair......used to be a fireworks chaser
-----Original Message-----
From: Lee Love
Gayle Bair wrote:
>Here's another one.......... after reading this thread I recalled
>being told that manganese was/is used in fireworks!
>
As a kid (and one of my neighborhood aspireing "Mad Scientists"), I used
to make ariel fireworks out of model rockets and MAGNESIUM shavings my
father procured for me when he worked at Magline (they made quanset huts
and magnesium hand trucks.)
I am guessing they might have manganese as a colorant (they probably use
many oxides to color the fires), but magnesium is one of the things that
makes them burn bright.
--
=E6=9D=8E Lee Love =E5=A4=A7
=E6=84=9B=E3=80=80=E3=80=80 =E3=80=80=E3=80=80 =E9=B1=97
in Mashiko, Japan http://mashiko.org
http://hankos.blogspot.com/ Visual Bookmarks
http://ikiru.blogspot.com/ Zen and Craft
_________________________________________________________________________=
_____
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.
--=20
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 5/6/2005
Louis Katz on mon 9 may 05
I wonder why you are going to phase manganese out of your pantry. I =20
have kept a tight hand on manganese in my studio in the past using the =20=
safe until I knew more attitude. Now I know more. According to Eduoard =20=
the Canadian limits on Manganese are in the same order of magnitude as =20=
the limits on respirable quartz. Short of using it in my clay body I =20
see know way of even coming close to the limits for this metal. My =20
glaze kilns are outside.
What you might substitute is iron and cobalt, but cobalt is probably =20
(from my unskilled reading of Edouard) more hazardous. About these =20
materials he says(below). I would suggest you read the entire articles =20=
he wrote on each of these metals. I read government docs with some =20
skepticism, but I see no reason to assume that manganese dioxide is =20
more hazardous than cobalt oxide or chrome oxide. I wonder what he =20
thinks. All of his safety articles on Digital fire are available from =20=
http://ceramic-materials.com/cermat/education/.
By the way, Babelfish.altavista.com translates:
Valeur d'Exposition Moyenne Pond=E9r=E9e
as
Value of Weighted average Exposure
Quoted from digital fire. Note these are out of context. The full =20
articles should be read.
-------------------------
Exposure Limits :
=A0
In Quebec, the VEMP ( Valeur d'Exposition Moyenne Pond=E9r=E9e) is set =
at =20
0.02 mg/m3 (as Co) for metallic cobalt and inorganic compounds.
It has a C3 designation, which means it is a carcinogen in animals and =20=
the results of animal studies are not necessarily applicable to man,
------------------
1-The VEMP in Quebec for copper dust and mist is :
1mg/m3 expressed as copper
=A0
2-The VEMP for copper fumes is :
0.2mg/m3 expressed as copper.
-------------------
=A0
A-Quebec's exposure limits :
VEMP : Valeur d'Exposition Moyenne Pond=E9r=E9e :
=A0
=A0
Chromium compound
VEMP
Notes
Chromium (metal)
0.5 mg/m3
-
Chromium II, compounds,as Cr.
0.5 mg/m3
-
Chromium III, compounds,as Cr.
0.5 mg/m3
-
Chromium VI, certain water- insoluble compounds,as Cr.
0.05 mg/m3
C1, RP, EM
Chromium VI, water- soluble compounds,as Cr.
0.05 mg/m3
---------------
The threshold limit value for dusts of manganese metal and inorganic =20=
compounds actually proposed by the ACGIH is 0.2 mg/m3,as total dust.
------------
Silica
9-Exposure limits :
=A0
Quebec's exposure limits :
=A0
=A0
Substance
VEMP
Notes
Cristobalite
0.05 mg/m3
Pr
Quartz
0.10 mg/m3
Pr, C2, EM
Tridymite
0.05 mg/m3
Pr
Tripoli
0.10 mg/m3
Pr
=A0
Pr =3D Respirable dust.(Poussi=E8re respirable)
C2 =3D Suspected carcinogen to humans
EM =3D Substance that should be kept at the lowest practicable level
On May 9, 2005, at 9:02 AM, Kate Johnson wrote:
> Hi all--I'm taking all this in, and thank you...DEFINITELY will be =20
> careful
> with the manganese, and plan to phase it out.
>
> Part of my original question is still up in the air...we discussed =20
> Mason
> stains, but what about using something similar to Albany
> slip/Arroyo/whatever? I know I'm splitting hairs here, but I'm still =20=
> trying
> to work as close as possible to the historical model, and I don't =
think
> "they" had Mason stains. If there's another more natural solution =20=
> I'd
> probably choose it...
>
> Best--
> Kate Johnson
> graphicart@epsi.net
> http://www.cathyjohnson.info/
>
> Art, History, Nature and More at Cathy Johnson's Cafepress--
> http://www.cafepress.com/cathy_johnson/
>
> Graphics/Fine Arts Press--
> http://www.epsi.net/graphic/
>
> =
_______________________________________________________________________=20=
> _______
> 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 =20
> melpots@pclink.com.
>
Kate Johnson on mon 9 may 05
Hi Louis...
>I wonder why you are going to phase manganese out of your pantry. I
have kept a tight hand on manganese in my studio in the past using the
safe until I knew more attitude. Now I know more. According to Eduoard
the Canadian limits on Manganese are in the same order of magnitude as
the limits on respirable quartz.
I read most of the webpage you sent me offlist...some of it is a tad over my
head, technically, but percentages and numbers often are. I MUST have
discalclia...
In part I was wary of manganese for an entirely different reason from
discussions on this board...as a watercolorist, I am aware that most
manufacturers of pigments have discontinued manganese blue, and now
substitute manganese blue HUE...it was supposedly dangerous for the
manufacturers and miners, as I understand it. Edouard is on another list
I'm on, where he posts more frequently, it seems like--I may request his
advice for the layman's version...
> What you might substitute is iron and cobalt, but cobalt is probably
(from my unskilled reading of Edouard) more hazardous. About these
materials he says(below). I would suggest you read the entire articles
he wrote on each of these metals.
Will do, and thank you again...
> I read government docs with some
skepticism, but I see no reason to assume that manganese dioxide is
more hazardous than cobalt oxide or chrome oxide.
I was aware of chrome/chromium, again from my experience as a painter, but
unaware of any dangers with cobalt. Oy.
And Lili, thank you for the leads on safety articles. As yet I don't
subscribe to any magazines, having spent most of my disposable
research/reading income on books. Given what you know of my rather
focused interests from our offlist discussions, which of those magazines
would you recommend? I pick up an occasional copy of CM, when I'm anywhere
that has them, but that's been over a year now...I'm too old to worry about
the gene pool, but I'd rather keep my lungs in good working order.
Best--
Kate
graphicart@epsi.net
http://www.cathyjohnson.info/
Art, History, Nature and More at Cathy Johnson's Cafepress--
http://www.cafepress.com/cathy_johnson/
Graphics/Fine Arts Press--
http://www.epsi.net/graphic/
Dave Finkelnburg on mon 9 may 05
Louis,
Your post today on manganese is misleading at best, potentially
dangerous at least.
I am absolutely no expert on the environmental health effects of
exposure to manganese, cobalt or chromium oxides in a pottery. I do
understand enough about the subject to know that PATHWAYS are important.
I emphasize the word pathways because that is a scientific term that
refers to the way particular chemicals get into our body. The pathways for
silica, for example, are either to breathe in or to eat or drink silica dust
(possibly inadvertently, such as in food or drink sitting out in a studio).
Silica is not something we absorb through our skin. Silica does not get
heated at pottery temperatures to the point that it becomes a vapor that we
inhale. Silica is the most abundant material in all clay-based ceramics.
Besides following the same pathways as silica, manganese does vaporize
from a kiln during a firing and does get into our blood through our lungs if
we breathe manganese-contaminated air around a kiln.
Chrome is also vaporized to some extent at common pottery kiln
temperatures. To my knowledge, cobalt is not vaporized. Chrome and cobalt
are quite powerful colorants, so we tend to use relatively small percentages
of them. That helps to reduce our exposure to them.
Because manganese can get into our bodies by multiple pathways,
because we tend to use it in higher percentages than chrome or cobalt, and
because medical science does not yet fully understand the apparent cause and
effect relationship between manganese exposure and Parkinson's disease-like
disorders, any ceramic artist should use manganese with great caution.
Good potting,
Dave Finkelnburg
----- Original Message -----
From: "Louis Katz"
Sent: Monday, May 09, 2005 1:58 PM
Subject: Re: Manganese health risks
I wonder why you are going to phase manganese out of your pantry.
Kathi LeSueur on mon 9 may 05
Kate Johnson wrote:
> Hi all--I'm taking all this in, and thank you...DEFINITELY will be careful
> with the manganese, and plan to phase it out.>>>>>
While I think it is very important to use all chemicals with caution, I
believe that the discussion about manganese is getting alittle overboard
here. I have a cone 10 glaze that uses 3% manganese. It is my most
popular glaze and I use a lot of it. Several years ago, when I lost my
sense of smell, my use of manganese became a source of concern. Heavy
metal poisoning could have been one cause (along with brain tumor). My
doctor first check for the brain tumor since this was the most dangerous
concern. Tests showed that 1) I do have a brain, and 2) it is a
FUNCTIONING brain (there are some who had doubts). So, on to testing for
heavy metals, specifically manganese. Test showed that I had no problem
with manganese or any other heavy metal. This was a relief to know after
so many years of using this glaze. The culprit was nearly blocked nasal
passages. Surgery took care of that problem and a year later I was
almost back to normal.
So, I no longer obsess about my use of manganese. But I do still take
care with handling it and all glaze ingredients.
Kathi
>
>
>
Louis Katz on mon 9 may 05
LIke I said,
I wonder why you would phase manganese out of your pantry. If you are
firing outside, and you don't sit next to your kiln while it is firing,
and you have a clean studio, mix stuff with a respirator, where is your
exposure to come from? Pathways are important. yes. If you have little
respiratory exposure and the threshold limit is relatively high, you
should have little to worry about. Care, yes. If your studio is a mess,
you fire inside, you read a book outside next to your kiln your
exposure may be high. Even if you use a lot of Manganese Dioxide,
limiting it makes more sense than phasing it out entirely.
I would rather people be careful with materials, all of them. I just
got through explaining to the janitorial staff here that if they don't
keep the floor clean I have work study do it for them, and when the
work study students can't or won't I get the hose out. Many glaze
chemicals here are kept under a very short leash( Manganese Dioxide is
one of them.But, if I relied on clayart for my concerns about what
materials to use however I would have no colorants except iron. I have
to read other authoritative sources and follow those recommendations.
Usually this is limited to Keeping Clayart Safe and Legal and Edouard
Basarache.
Clearly medical science does not fully understand anything, nor do any
of the rest of us. But people have used manganese industrially for a
long time and if I read Edouard's sheet on manganese correctly he
says," Manganese can be very toxic, especially with regards to
inhalation of the fumes during kiln firing. This material must be
treated with care."
O.K. what does care mean in this circumstance? I treat all of my
materials with care. Some I fire outside or not at all. Some I keep my
hands out of. Some I don't allow students to use. Some I don't use.
Some I never mix with bases. Some I don't mix with acids. If you are
not firing with Mn in glazes because your kiln is glazes in your studio
and is un-vented, you have other problems to deal with. But in these
circumstances not using manganese makes sense. Getting your kiln
outside of your studio makes even more sense.
I am hoping that Edouard chimes in, although I expect that where he
stands will be the views expressed in his article. What I would like to
know is what does he mean by care in this circumstance.
Louis
On May 9, 2005, at 6:11 PM, Dave Finkelnburg wrote:
> Louis,
> Your post today on manganese is misleading at best, potentially
> dangerous at least.
> I am absolutely no expert on the environmental health effects of
> exposure to manganese, cobalt or chromium oxides in a pottery. I do
> understand enough about the subject to know that PATHWAYS are
> important.
> I emphasize the word pathways because that is a scientific term
> that
> refers to the way particular chemicals get into our body. The
> pathways for
> silica, for example, are either to breathe in or to eat or drink
> silica dust
> (possibly inadvertently, such as in food or drink sitting out in a
> studio).
> Because manganese can get into our bodies by multiple pathways,
> because we tend to use it in higher percentages than chrome or cobalt,
> and
> because medical science does not yet fully understand the apparent
> cause and
> effect relationship between manganese exposure and Parkinson's
> disease-like
> disorders, any ceramic artist should use manganese with great caution.
>
>
Edouard Bastarache Inc. on mon 9 may 05
" Edouard is on another list"
Wronk, I have been on this list since 1998.
Later,
"Ils sont fous ces quebecois"
"They are insane these quebekers"
"Estn 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://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
Gary Lee on tue 10 may 05
I fine it interesting that in all the posts here about manganese there has
been no reply from the people who should know about what degree manganese can or
could be harmful. That is a representative from any of the clay
manufactures that use manganese in their clay bodies. I find it strange the uproar
concerning manganese. Would Standard or Highwater be using a material that would
be so hazardous to the very customers they sell it too, since they could be
held liable for any illness proven to have been caused by such? Like with all
posts here we should not be alarmists unless we have documentation to show for
it. We all have opinions and we should do what each of us feels is best for
each of us. Lead is bad, I don't use it. Manganese, well, the jury is
still out.
Gary
Rising Sun Pottery
Lincolnton NC
Sam or Mary Yancy on tue 10 may 05
Do you tell your janitorial staff that theer are hazardous materials in your class/studio and that they should wear masks????? - amd if not, why not???? Sam in Daly City
Louis Katz wrote:LIke I said,
I wonder why you would phase manganese out of your pantry. If you are
firing outside, and you don't sit next to your kiln while it is firing,
and you have a clean studio, mix stuff with a respirator, where is your
exposure to come from? Pathways are important. yes. If you have little
respiratory exposure and the threshold limit is relatively high, you
should have little to worry about. Care, yes. If your studio is a mess,
you fire inside, you read a book outside next to your kiln your
exposure may be high. Even if you use a lot of Manganese Dioxide,
limiting it makes more sense than phasing it out entirely.
I would rather people be careful with materials, all of them. I just
got through explaining to the janitorial staff here that if they don't
keep the floor clean I have work study do it for them, and when the
work study students can't or won't I get the hose out. Many glaze
chemicals here are kept under a very short leash( Manganese Dioxide is
one of them.But, if I relied on clayart for my concerns about what
materials to use however I would have no colorants except iron. I have
to read other authoritative sources and follow those recommendations.
Usually this is limited to Keeping Clayart Safe and Legal and Edouard
Basarache.
Clearly medical science does not fully understand anything, nor do any
of the rest of us. But people have used manganese industrially for a
long time and if I read Edouard's sheet on manganese correctly he
says," Manganese can be very toxic, especially with regards to
inhalation of the fumes during kiln firing. This material must be
treated with care."
O.K. what does care mean in this circumstance? I treat all of my
materials with care. Some I fire outside or not at all. Some I keep my
hands out of. Some I don't allow students to use. Some I don't use.
Some I never mix with bases. Some I don't mix with acids. If you are
not firing with Mn in glazes because your kiln is glazes in your studio
and is un-vented, you have other problems to deal with. But in these
circumstances not using manganese makes sense. Getting your kiln
outside of your studio makes even more sense.
I am hoping that Edouard chimes in, although I expect that where he
stands will be the views expressed in his article. What I would like to
know is what does he mean by care in this circumstance.
Louis
On May 9, 2005, at 6:11 PM, Dave Finkelnburg wrote:
> Louis,
> Your post today on manganese is misleading at best, potentially
> dangerous at least.
> I am absolutely no expert on the environmental health effects of
> exposure to manganese, cobalt or chromium oxides in a pottery. I do
> understand enough about the subject to know that PATHWAYS are
> important.
> I emphasize the word pathways because that is a scientific term
> that
> refers to the way particular chemicals get into our body. The
> pathways for
> silica, for example, are either to breathe in or to eat or drink
> silica dust
> (possibly inadvertently, such as in food or drink sitting out in a
> studio).
> Because manganese can get into our bodies by multiple pathways,
> because we tend to use it in higher percentages than chrome or cobalt,
> and
> because medical science does not yet fully understand the apparent
> cause and
> effect relationship between manganese exposure and Parkinson's
> disease-like
> disorders, any ceramic artist should use manganese with great caution.
>
>
______________________________________________________________________________
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 tue 10 may 05
Hi Judy,
I don't think granular manganese is anywhere near the danger of powdered.
I wonder how much - if any powder comes with the granular - I would think
not much.
I don't think anyone should be breathing kiln fumes - granular manganese or
not - there are lots of other fumes to worry about and some of them are not
even covered in the analysis we get.
I really see Manganese as a dangerous material in the studio - and I have
very good reasons for believing that - so I feel it is necessary to pass on
my concerns.
The RR Black cone 6 glaze - glossy base #2 with 9%iron and 2% cobalt carb.
is black - and was developed to make a black glaze without any manganese.
Also without copper because - as we know - copper lowers glaze stability.
So the Licorice glaze (glossy base plus iron and cobalt) can be used as a
liner glaze and would be a relatively safe glaze to use around the studio.
Still not safe to breath the dust of because of the silica and cobalt.
RR
>"Watch out for Manganese - in clay or glazes - the dust is a real health
>hazard as are the fumes from firing it."
>
>Based on this statement, should we assume that the manganese in manganese
>speckled clay (such as the very poplular Standard 112) makes the clay dust
>in our studios even more dangerous to breathe? This subject has been
>discussed before, but I've never been clear on the answer (if there is a
>definitive one).
>I seem to remember a statement that the managese particals in this type of
>clay are not dangerous other than when fired, as fumes, because they are
>heavier than the clay dust, and you wouldn't breathe them in. Am I
>dreaming that one up?
>
>If this type of clay is more dangerous, is it worth increasing the risk?
>I doubt that anyone's studio (besides perhaps Lili's!) is pristine. I
>certainly know mine is not. If manganese increases the danger, perhaps
>it's stupid to ever use it.
>
>Judy Musicant
>Pottersguildnj.org
>
>______________________________________________________________________________
>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 Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Louis Katz on tue 10 may 05
Yes- to the pointed question about hazardous materials. I tell them to
use the hose. I hand new employees an MSDS for silica. I show them the
MSDS sheets kept by the main door in a bright colored and labeled
holder. I tell them about the dangers of clay dust. I tell them I don't
want brooms in my studio. I reinforce this frequently. When needed I
email their supervisor. Would you like copies? I tell them if they were
my employee and they came into my studio with a broom I would fire them
on the spot. I insisted that we get tested for airborne silica. We got
a second floor drain to make cleaning the doors easier.
Why would you think I act otherwise?Is this some sort of go after Louis
day?
Do you beat your wife? and if so why?
Louis
On May 10, 2005, at 9:15 AM, Sam or Mary Yancy wrote:
> Do you tell your janitorial staff that theer are hazardous materials
> in your class/studio and that they should wear masks????? - amd if
> not, why not???? Sam in Daly City
>
> Louis Katz wrote:LIke I said,
> I wonder why you would phase manganese out of your pantry. If you are
> firing outside, and you don't sit next to your kiln while it is firing,
> and you have a clean studio, mix stuff with a respirator, where is your
> exposure to come from? Pathways are important. yes. If you have little
> respiratory exposure and the threshold limit is relatively high, you
> should have little to worry about. Care, yes. If your studio is a mess,
> you fire inside, you read a book outside next to your kiln your
> exposure may be high. Even if you use a lot of Manganese Dioxide,
> limiting it makes more sense than phasing it out entirely.
>
> I would rather people be careful with materials, all of them. I just
> got through explaining to the janitorial staff here that if they don't
> keep the floor clean I have work study do it for them, and when the
> work study students can't or won't I get the hose out.
> I have
> to read other authoritative sources and follow those recommendations.
> Usually this is limited to Keeping Clayart Safe and Legal and Edouard
> Basarache.
>
> Clearly medical science does not fully understand anything, nor do any
> of the rest of us. But people have used manganese industrially for a
> long time and if I read Edouard's sheet on manganese correctly he
> says," Manganese can be very toxic, especially with regards to
> inhalation of the fumes during kiln firing. This material must be
> treated with care."
>
> O.K. what does care mean in this circumstance? I treat all of my
> materials with care. Some I fire outside or not at all. Some I keep my
> hands out of. Some I don't allow students to use. Some I don't use.
> Some I never mix with bases. Some I don't mix with acids. If you are
> not firing with Mn in glazes because your kiln is glazes in your studio
> and is un-vented, you have other problems to deal with. But in these
> circumstances not using manganese makes sense. Getting your kiln
> outside of your studio makes even more sense.
>
> I am hoping that Edouard chimes in, Louis
>
> On May 9, 2005, at 6:11 PM, Dave Finkelnburg wrote:
>
>> Louis,
>> Your post today on manganese is misleading at best, potentially
>> dangerous at least.
>> I am absolutely no expert on the environmental health effects of
>> exposure to manganese,
Jon Pacini on wed 11 may 05
Greetings all---Hi Gary
Well--- You wanted a response from a clay company so here it goes.
The Manganese dioxide that is used in a very few of the clays that Laguna
makes, is non soluble. It is not going to get into your system solely by
handling the clay containing it.
The dust is a hazard as are all clay and ceramic raw material dusts. If dust
is present, always wear a NIOSH approved respirator, and avoid inhaling or
ingesting the dust. ALWAYS clean up after working in your studio. Get out
of dirty clothes and shower if necessary.
The fumes when fired are hazardous as are all fumes from kilns when clay is
fired, appropriate precautions should be followed. Fire in a well
ventilated area.
The manganese dioxide may or may not leach out of an unglazed clay surface.
This is dependent on how the ware is fired. It is not likely to leach from
the clay through a glazed surface. If you have particular concerns in this
area, I recommend you have the ware tested by testing lab such as BSK
Analytical Laboratories in Fresno, CA.
Manganese is apparently the Hazardous Mineral of the Month. I am not trying
to make light of this subject, but, nearly all minerals used in ceramics if
not handled properly will do you harm.
Be aware of the hazards, but do not be afraid of your materials. Learn as
much as you can about them and act appropriately.
Best regards
Jon Pacini
Clay Manager
Laguna Clay Co.
Fonda Hancock on wed 11 may 05
So do we have a definitive answer to the question of 112 clay? Is it only
the fumes that we need to worry about, or is the dust more problematic
than other clays without manganese. I surely love those little speckles
and would miss them, but I really like 378 and could switch to it.
Ron Roy on wed 11 may 05
HI Rick,
Manganese is not a problem by ingestion.
I would doubt you would have anything to fear from say using that water for
glazes or clay - but as I said - breathing kiln fumes in an under
venlitated situation is to be avoided - manganese or not.
When they took the lead out of gas they replaced it with Manganese by the
way - so we all have more exposure to manganese because of that. Some
toxicologists think that adding manganese to gas is a bad idea.
There is plenty about all this on the internet by the way - there is no
doubt about the toxicity of Manganese - the question is - how much can you
stand and how much are you getting.
I doubt if anyone can answer the question - what is your own safe level of
manganese - my answer is - assume you already have enough.
RR
>There is a direct link of developing Parkinson's Syndrome to manganese
>welding rods and manganese itself. This information is obtainable
>throughout the web. Yet, in my area of central Massachusetts, our toilet
>tanks are discolored by the accumulation of the manganese and iron found
>in our water. So, is there a cumulative poisoning taking place just from
>my town's well water, aggravated by the manganese in my vitamins? I don't
>know of any adverse health conditions; ie increased Parkonson Syndrome
>for my area. All of our metals can be toxic. We don't live in the dark
>ages anymore. Information is at hand
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ron Roy on wed 11 may 05
Hi Gary,
Just a matter of time before they stop.
There is an ongoing court case involving welders - who have manganese
poisoning - if they win I predict you will not be able to buy clay with
manganese in it - or at least some pretty explicit warnings on the box.
It would make a lot more sense to use a manganese slip instead - simply
because there would be less dust and fumes and cost a lot less.
RR
>I fine it interesting that in all the posts here about manganese there has
>been no reply from the people who should know about what degree manganese
>can or
>could be harmful. That is a representative from any of the clay
>manufactures that use manganese in their clay bodies. I find it strange
>the uproar
>concerning manganese. Would Standard or Highwater be using a material
>that would
>be so hazardous to the very customers they sell it too, since they could be
>held liable for any illness proven to have been caused by such? Like with all
>posts here we should not be alarmists unless we have documentation to show for
>it. We all have opinions and we should do what each of us feels is best for
>each of us. Lead is bad, I don't use it. Manganese, well, the jury is
>still out.
>
>Gary
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Jon Pacini on thu 12 may 05
Greetings All --- Hi Fonda----you don't have to worry at all, what you need
to do is take precautions.
Best regards,
Jon Pacini
Clay Manager
Laguna Clay Co
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