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oldlady

"dangerous" glaze ingredients

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several recent posts have left me with a suggestion.  since i am not the only potter who is self-taught and therefore ignorant of chemistry interactions, could someone put a list of toxic ingredients in a list that could be easily accessed by all of us?

i do read lots of books and posts here and sort of have an idea of what toxic ingredients are but there are so many ways that those ingredients can hurt us, that i think a simple list with one or two words could help.   

something like  ingredient XXXXXX toxic  to POTTER by breathing dust, skin contact before firing.    after firing, USER leaching caused by acid foods.

or is this like asking for an encyclopedia? 

 

 

Edited by oldlady
correction

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Monona Rossol’s book is probably a good starting point.  It’s generally addressed to artists, not just ceramists, but it should help.

Then talk to your GP, talk about your concerns and maybe come up with a strategy.  Your doctor is your #1 go to for health info.   They may not know everything off the bat, but they know how to get you plugged in to where you need to be.  It helps if you know a little about the materials going in, so that you can help the doc orient themselves in the issue.

Pairing this with msds sheets (despite their limitations), and independent research will flesh out your knowledge.  It’s sortof incumbent on each potter to know about their materials and their risks.  But I totally understand how this could be an overwhelming task for some—the research is opaque, sometimes contradictory, and drawing conclusions from numbers can be a little abstract.

For those doing research, a general rule:  systematic reviews of evidence > meta-analyses > controlled studies > case studies.

The WHO puts out a large amount of literature on things like this and its easily accessible by web.

I know this isn’t the answer you were hoping for, but I do hope it helps.  

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I think thats like asking for an encyclopedia. every material we use in our clays and glazes has an MSDS sheet which will list practically all the information you mentioned. Another good source for information is digitalfire.com Tony does a killer writeup on all the materials and is a very knowledgeable guy! Potter's Encyclopedia is another good source of info.

    I essentially tell my students and others to consider ALL the materials we use in a ceramics studio as hazardous, many of the materials in the glaze lab as toxic, and others as lethal. All that we use is bad for our lungs (mainly silica), all the colorants are in forms and concentrations that we are not used to (even though our water pipes are Cu, and Fe is in just about everything we eat, etc, its not in the form (Carbonates), and concentrations are WAYY above normal levels) and shouldnt be handled without masks, and gloves when possible. Lastly there are materials which are just downright lethal; not commonly used any more,  but historically arsenic, mercury, uranium lead.......were all common glaze ingredients (ive found this and worse in numerous studios Ive worked in).

   yes, some materials need to be absorbed through our mucous membranes, and not just our skin, to be harmful, but why make exceptions. Treat everything with care and caution and prevent accidents. Ventilation should always be used whenever possible, especially when handling colorants/oxides, and dusty materials, but even when in your studio walking/working. I have an air filter which runs whenever I am in the studio, even when not making any work.

   Granted there are times when Ive got my bare handed skin in a bucket of glaze, but when possible I avoid. Safety first folks!

 

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I hate to be the voice of doom, but I've read enough valid research to state emphatically that we are already so poisoned, the whole species is morphing into fodder for the health care industry. At this point, I worry less about silica (good mask/practices) and more about what is in my food, the hyper-flammable materials in our furnishings...you get the picture.

 

@Old Lady--Another reference book is Artist Beware, by Michael McCann...I got it from a library rather than pay for the latest revised version, since most of it does not apply to ceramists. Easy to take-I didn't need a degree in chemistry/science to grasp what I needed to know.

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oldlady,

There are are several things that are problematic in the studio, most of which are involved with glaze formulation/making. I would have a short list of things I personally will not use in the studio such as Lead, Barium, and Uranium. I also am careful with manganese, chromium, and cobalt, using, but being careful. I realize that over the years I have had silica problems, using brooms in earlier years, having a shop crowded to mop well, but I do what I can.

 

best,

Pres

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preston, what is the problem with barium carbonate?  the only thing i can find online is the story of the cook who used it thinking it was flour.  two stories seem to be about this same event, that 65 soldiers ate fried sweet potatoes coated with this and all became very ill.  they were sick for 7 days and all recovered.  barium carbonate is rat poison.  there was a woman who attempted suicide using it but the outcome was not reported in what i found.

have i missed something that would indicate there is more to it than this?

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12 minutes ago, oldlady said:

 

have i missed something that would indicate there is more to it than this?

Chronic vs. acute poisoning.  The battered sweet potatoes were an incident of acute poisoning.  This is a studio hazard to be sure, but a less likely one than chronic.

Over time barium can cause problems with organ function eventually causing failure.  The big one being kidneys.  This can be the real hazard.

Edited by Tyler Miller

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thank you, tyler, that is a clarification that matters.  do you know how the barium causes problems, breathing, touching, etc?   i ask because my favorite glaze contains 8% barium carbonate and i do not know if i can ever find a better looking glaze.  

tried to move a photo from my gallery but did not make it.

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You shouldn’t eat or inhale it in its powdered form. But just to be clear, we should not eat or inhale any of the raw materials in our studio, not just barium. Some are worse than others, but our studio habits should involve this amount of care with all materials.

Barium glazes can be improperly formulated or fired, and therefore leach barium into our food. It’s also possible to have a barium glaze that is well-formulated and fired, which has all of the barium encased in glass where it cannot leach out. The only way to know is to have your glaze leach-tested. According to the Mastering Cone 6 Glazes book, you can have glazes leach-tested at:

Alfred Analytical Laboratory, 4964 Kenyon Road, Alfred Station NY 14803, (607) 478-8074

Brandywine Science Center, Inc., 204 Line Road, Kennett Square PA 19348, (610) 444-9850

I think this would be worth it for you, just for the peace of mind. Either you’ll know the glaze is safe, or you’ll know that you need to start looking for a replacement. Better than living with the doubt. 

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I've used Brandywine, cost is approx $30- to test for one material plus the cost of shipping a small test piece there. You get results by email in about a week.  Directions for making and sending in a test piece here. Agree with Mea, find out one way or the other. I'm not sure that Alfred Analytical is still around.

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Many materials are just fine as long as you handle them with cautions . I think Monona Rossol comes from things more like a lawyer and is more about an industrial situation than small studios. I would use maganesse dioxide as an example-very bad in wielding but less so in ceramics .

If you treat all dry materials as dust issues and maintain good ventilation you should be fine-I have a 1 micron air  ventilation system in my small studio.

I also have a central vacuum system for reaping the place less dusty

Use latex gloves while glazing-this is something I have done for decades-they grip pots just fine and are super cheap in boxes of 100.Your hands will thank you as they do not get wet and dry as they do washing the glaze off without them -plus you can take them off and get a few uses from them.

as Pres said (Lead, Barium, and Uranium) are all bad-the barium is also not good but I use some in one glaze at cone 10-I make sure its only on the outside surface and not where its touching your lip or fluids -I also take precautions on handling it in dry state

Since I have been exposed to ceramic dust and all these chemicals for 45 years  as a production potter and in the early days had zero protections its amazing that I'm fine. In the early days no one thought about masks and dust in collage as we mixed clay until we had to leave the building because of dust.No gloves-only brooms .

It took another 20 plus years before all the safety of these days kicked in.

My thoughts are just be careful and take precautions and do not over worry things-gloves and masks and wet mops or vacuum .

I also never eat  food in studio and thats another bad one.

 

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I had the pleasure of actually speaking to Monona Rossol in person about 15 years ago at a talk she did for the local union of theatre workers. (All those movies you see set in Montana or the "American" Rockies? All shot in my area because of the favourable exchange rate.)

She's an industrial hygienist that worked herself in the theatre for years, and has parents who were potters. She does indeed spend a lot of time advocating in court a for artists and entertainers and all the supporting people because for the most part, everything is all contract work and workers safety regulations are less easily enforced, or poorly defined. She does have some valuable insights, because she's familiar with day-to-day workings of an artist's life, but she's also seen where common practices go horribly awry.

The problem with declaring commonly used ceramics materials hazardous are numerous. First, because the information on how they react in the body,  like the materials themselves, comes from them being used in different ways in different industries. This is important, because the poison is in the dose, and some things clear your system eventually while some things are fat soluble and stay with you a long time.

Second, how scientists are obliged to gather information on what poisons folks at what rate isn't ideal from a coldly scientific perspective: you can't set up a double blind human trial to see exactly how much cobalt exposure will begin to make your kidneys fail. So they're obliged to gather information from accidents and incident reports from people who might not be totally truthful, and extrapolate some things from animal trials, which has its own set of problems. Information on silicosis, for example, is most easily obtained from instances occuring in people who operate sandblasting equipment. In that example,  the exposure levels to airborne silica over time are relatively easy to extrapolate out for those of us who work in ceramics studios, and are easily solved with good hygeine (no eating or drinking in the studio, wet cleanup, an appropriate respirator while glaze mixing, etc.). Manganese, however, the information comes largely from metal workers, and we as potters aren't breathing in heated manganese fumes for the most part. Unless you have an unvented kiln load of some kind of saturated glaze firing right next to you while you throw or doing loads of raku, you're not too likely to replicate comparable conditions. How much of it are you really absorbing through your hands as you're weighing out a glaze, or from sticking your bare hand in a glaze bucket? Again, good studio hygeine, like wearing gloves, not eating your sandwich at the dusty work bench and washing your hands thoroughly before eating said sandwich somewhere else will keep your exposure minimized. Safety equipment should be used around raku firings anyways.

Anther problem with dtermining which materials are toxic and via what means, is that MSDS sheets are designed to tell you how fast it would acutely poison the average, healthy Caucasian male. All well and good if you are one, but if you're 40 lbs lighter, six inches shorter, have some key differences in your endocrine system, or you aren't perfectly healthy to start with, well, things begin to get inaccurate and vague. Linking some substances to chronic exposure is tricky, because again, under what circumstances did that exposure occur?

Add to this one more thing: there are no leaching guidelines that are specific to pottery. The only thing we can compare to are drinking water quality levels for certain materials, and even those aren't available for all of the materials we use. They ARE there for heavy metals like most of the things we use for colourants or lead. 

Monona Rossol's method isn't perfect, but I think she takes probably one of the smarter approaches given the quality of information available. Yes, she errs on the side of caution, but she is a big fan of science and numbers.  She's also very approachable if you email her. 

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I wear a dust mask and wear latex gloves when I am mixing glaze,  I also wear gloves  when working with glaze.  I don't make very many function pieces but when I do, I will use a  formula from some one like Tony Hansen that is table safe.    Forty years ago the only thing they told us was not to eat a sandwich when we were mixing glazes.  I was in the Raku testing group and using Red Lead.  I shudder when I think about it.   I am still here so I guess one semester of mixing glazes with no gloves for masks didn't do me in.   Denice

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The three materials that I mentioned(lead, barium and uranium), can be absorbed by breathing, ingesting, and through the skin. They are also materials that cannot be removed from the system by the liver or other organs, thus building up in the body. Long term effects are terminal. I don't believe in subjecting myself to these materials when there are alternatives. My health has enough trouble with just the dust in the studio and other hazards in the studio, in the home, and out in public; therefore when I can, I take what steps I can.

 

best,

Pres

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Straw and camel's back come to mind.

So LeeU 's comment v. Relevant.

Barium is added to some clay to revent scumming.

Any way, this topic has been thoroughly discussed in previous posts 

J Baymore wrote sound advice based on his long experience as a practising ceramist and educator. 

The total load on self is what items relevant  An acute poisoning occurring at an accidental level one would hope would be rare in studio but the potter can certainly take the steps to avoid adding to existing body load whilst working 

Then go out dirtroad motor bikibg to just inhale a few pounds of silica:-/ 

Edited by Babs
Sp.

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