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#1 Pres

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Posted 26 February 2013 - 02:14 PM

The use of barium in the studio scares me, but I continued to read several articles and books that contain high amounts of barium in the glaze. I also understand that certain colors and surfaces are only accessible through the use of barium. When I was teaching, I was beginning glaze chemistry and went to the Science dept. to get materials and advice. They willingly gave me barium oxide(I believe) as they said they didn't want it around anymore, and did not have any use for it. After considerable research into the materials I had received, and the ones I was interested in ordering, barium was the one material that I decided I did not need due to its toxicity. Since then I have made it a rule to keep it out of my own studio also. I have found over the years, that accidents do happen, no matter how hard you try to be careful. Highly toxic materials can be a target for accidents. I take all of the precautions when making glazes, masks, gloves, washing surfaces afterward etc, but still know that a bump can knock an open container over.

I am reading the new publication developing glazes-Greg Daly and am amazed by the materials used in Australia, including the high barium content of some of the glazes. While I heartily agree with his approach, which follows much of the contemporary non empirical experimentation of glaze and glaze materials, I find the materials in use questionable. I guess in the end each person has to make up their own mind as to where they will go with their glaze formulation and material use.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#2 neilestrick

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Posted 26 February 2013 - 03:05 PM

I do not have any barium in my studio because as a small business I try to limit my liability as much as possible. As you said, accidents do happen.

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#3 Benzine

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Posted 26 February 2013 - 04:21 PM

I try not to keep anything toxic in my classroom studio. Not only am I worried about the students' health, but I'm worried about a group, like OSHA, coming in and telling me I can't teach certain classes anymore. I've talked to other teachers, who had to stop teaching film photography, simply because of the darkroom chemicals, and those relatively harmless. I have a couple glazes, from a previous instructor, that have some soluble copper and cobalt in them, but that's it. I just warn the students, and will not replace them, once they are gone.
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#4 JBaymore

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Posted 26 February 2013 - 10:34 PM

Pres,


To my knowledge, Australia does not have the "no-upfront fee" contingency lawsuit situation that drives tons of American litigation issues Posted Image.

best,

.............john
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#5 yedrow

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Posted 27 February 2013 - 12:38 AM

I would really like to know what Barium toxicity is as it applies to pottery studios. I'm told you would have to eat a tablespoon for it to kill you and that it doesn't build up in your body like some heavy metals do. In my studio I give cobalt the same respect I give barium.

Joel.

#6 Mark C.

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Posted 27 February 2013 - 01:01 AM

They still use Barium/wash as a drink for x-ray/scope stuff in hospitals

I tend to think of many of our chemicals we use in ceramics as toxics and to treat them with respect. That said its like driving it can get you but we need to get around.
The truth is in my view ceramics is about handling materials well and turning them into a safe outcome which can be enjoyed by others.
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#7 Pres

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Posted 27 February 2013 - 09:06 AM

The use of barium in the studio scares me, but I continued to read several articles and books that contain high amounts of barium in the glaze. I also understand that certain colors and surfaces are only accessible through the use of barium. When I was teaching, I was beginning glaze chemistry and went to the Science dept. to get materials and advice. They willingly gave me barium oxide(I believe) as they said they didn't want it around anymore, and did not have any use for it. After considerable research into the materials I had received, and the ones I was interested in ordering, barium was the one material that I decided I did not need due to its toxicity. Since then I have made it a rule to keep it out of my own studio also. I have found over the years, that accidents do happen, no matter how hard you try to be careful. Highly toxic materials can be a target for accidents. I take all of the precautions when making glazes, masks, gloves, washing surfaces afterward etc, but still know that a bump can knock an open container over.

I am reading the new publication developing glazes-Greg Daly and am amazed by the materials used in Australia, including the high barium content of some of the glazes. While I heartily agree with his approach, which follows much of the contemporary non empirical experimentation of glaze and glaze materials, I find the materials in use questionable. I guess in the end each person has to make up their own mind as to where they will go with their glaze formulation and material use.


I guess a lot of my concern is for the potter, myself. I know that a well balanced glass should be safe on ware, and that most absorbed materials are minimal through ingestion off of poorly made materials. However, in the studio the idea that barium can be absorbed in through the surface, not just ingested is bothersome. At the same time, when handling most other oxides of a poisonous nature, I can pretty well instantly tell when they are on a surface and what they are. Barium being white as it is looks like tin, or talc, or whiting or whatever. Even if it is safe to use in a private studio, I believe that in the long run it is best to not use in a Primary or Secondary school studio. I had students mixing glazes, and I really didn't want the liability of them being around it, even though I did use cobalt and chromium in my glaze mixing. All containers were marked with ingredient labels, and marked when anything was poisonous.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#8 JBaymore

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Posted 27 February 2013 - 10:49 AM

They still use Barium/wash as a drink for x-ray/scope stuff in hospitals


That is a different form of barium compounds.... based upon the compound barium sulfate I think, whjich is X-ray opaque. Different beast.

Barium carbonate is the main ingredient in the mouse and rat posion "Rit". It causes internal bleeding......and the rats die from blood loss. Acts a lot like the drug Warfirin.....a serious blood thinner.

LD50 is the dosage that will kill 50% of the specimins exposed to it. This is not "harm"..... but kill. So from the below......mice and rats are used to study the effects of toxins for potential application to humans. Let's say that the median here is 300 mg/kg. A 150 pound person is about 68 kilograms. So 68 x 300 = 20400 mg or 20 1/2 grams of barium carbonate. So about 20 grams of ingested barium carbonate will likely kill 50% of the people that might ingest it.


(If you happen to already be on blood thinners like Warfirin or are taking an asprin a day........ well..... your mileage may vary.)


From the MSDS.................ORAL (LD50): 200 mg/kg [Mouse]. 418 mg/kg [Rat]

Routes of Entry: Inhalation. Ingestion.

Toxicity to Animals: Acute oral toxicity (LD50): 200 mg/kg[Mouse].

Chronic Effects on Humans: CARCINOGENIC EFFECTS: A4 (Notclassifiable for human or animal.) by ACGIH.

Other Toxic Effects on Humans: Hazardous in case of skin contact (irritant),of ingestion, of inhalation.

Special Remarks on Toxicity to Animals: Not available.

Special Remarks on Chronic Effects on Humans: May cause adverse reproductive effects basedon animal test data

Special Remarks on other Toxic Effects on Humans:

Acute Potential Health Effects: Skin: May cause skinirritation. Eyes: May cause eye irritation. Inhalation: May cause respiratorytract irritation. May cause benign pneumoconiosis (baritosis). This is notincapacitating and is usually reversible with cessation of exposure. Inhalationmay have similar systemic effects as ingestion since Barium Carbonate iscleared from the lungs into the blood stream. Ingestion: Harmful of swallowed.May affect behavior/central nervous system/peripheral nervous system,gastrointestinal system, respiration, cardiovascular system, and kidneys. Symptomsmay include: weakness, nausea, vomiting, diarrhea, hypermotility, excessivesalivation, colic, convulsive tremors, giddiness, dilated pupils, increased bloodpressure, heart palpitations, hemorrhages in the gastrointestinal tract andkidneys, muscular paralysis, dryness of mouth, thirst, sweating, tinglingaround the mouth and neck, tightness in the throat, respiratory depression,dysarthria, headaches, muscle twitching, urinary retention, testiculartenderness. May also cause hypokalemia with associated electrocardiogramchanges. Serious cases may result in convulsions and death.

Chronic Potential Health Effects: Inhalation: Prolonged inhalation may cause benign pneumoconiosis (baritosis).


----------------------------------

So low doses over time liekly are not something that you want to have stressing your body in addition to all the OTHER stuff stressing your body.

With ALL potential toxins there are also issues with the concepts of total body burden, synergy, genetic predisposition, existing medical conditions, and so on. If someone does not understand all this stuff..... get a copy of "Artist Beware" by Dr. Michael McCann, "Keeping Claywork Safe and Legal" by Monona Rossol, and "Artists Health and Safety Guide" by Mononna Rossol.

best,

...............john
John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

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#9 JBaymore

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Posted 27 February 2013 - 11:00 AM

I guess a lot of my concern is for the potter, myself.


That is the prime concern. For the consumer it is less of an issue........ barium is used mainly as a secondary flux, and in low molecular equivalents. Unless the subject is barium matt glazes put on food wares. THEN there are some questions.


Even if it is safe to use in a private studio, I believe that in the long run it is best to not use in a Primary or Secondary school studio.


Read up on Mononna Rossols ideas on what is appropriate for kids in art programs to handle. It is VERY interesting. Contact her through the A.C.T.S. NY website.

I think the biggest issue for toxicological problems in school settings (of all grades) is not actually the exposure to most glaze chemsitry ....it is the broad exposure to CLAY DUST. This is because of the serious attention this gets from OSHA, the tightly defined workplace standards, and the fact that respirable free silica (in ALL clay bodies) is a known human carcinogen. DUST control in school st uidios should the absolute FIRST place to be looking at and to be worried about.


..................even though I did use cobalt and chromium in my glaze mixing. All containers were marked with ingredient labels, and marked when anything was poisonous.


The real issue with chromium is the hexavalent chromium compounds. Green chrome oxide is not one of them. Iron chromate is bad news. Cobalt chloride (used in some overglazes and underglazes) is absorbed directly through intact skin...and is also bad news.

best,

..............john
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Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

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#10 Pres

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Posted 27 February 2013 - 07:27 PM


I guess a lot of my concern is for the potter, myself.


That is the prime concern. For the consumer it is less of an issue........ barium is used mainly as a secondary flux, and in low molecular equivalents. Unless the subject is barium matt glazes put on food wares. THEN there are some questions.


Even if it is safe to use in a private studio, I believe that in the long run it is best to not use in a Primary or Secondary school studio.


Read up on Mononna Rossols ideas on what is appropriate for kids in art programs to handle. It is VERY interesting. Contact her through the A.C.T.S. NY website.

I think the biggest issue for toxicological problems in school settings (of all grades) is not actually the exposure to most glaze chemsitry ....it is the broad exposure to CLAY DUST. This is because of the serious attention this gets from OSHA, the tightly defined workplace standards, and the fact that respirable free silica (in ALL clay bodies) is a known human carcinogen. DUST control in school st uidios should the absolute FIRST place to be looking at and to be worried about.


..................even though I did use cobalt and chromium in my glaze mixing. All containers were marked with ingredient labels, and marked when anything was poisonous.


The real issue with chromium is the hexavalent chromium compounds. Green chrome oxide is not one of them. Iron chromate is bad news. Cobalt chloride (used in some overglazes and underglazes) is absorbed directly through intact skin...and is also bad news.

best,

..............john


Thanks for the rundowns, I knew most of this, but refreshers always help. Specially when the senior moments occur!

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#11 Benzine

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Posted 27 February 2013 - 10:29 PM

"I think the biggest issue for toxicological problems in school settings (of all grades) is not actually the exposure to most glaze chemsitry ....it is the broad exposure to CLAY DUST. This is because of the serious attention this gets from OSHA, the tightly defined workplace standards, and the fact that respirable free silica (in ALL clay bodies) is a known human carcinogen. DUST control in school st uidios should the absolute FIRST place to be looking at and to be worried about."

Very true. I had a run in with OSHA a few years back. Some one, made any "Anonymous" call complaining of clay dust in the Art Room. So OSHA came in and interviewed myself, and the other art teacher. We also had to wear these air sampling devices all day, that look like they were designed and built in the '50s, and no one saw fit to update and streamline the design. Anyway, the OSHA rep, reported that the dust, was well under the allowable limit. This was mainly because there wasn't a problem with dust.

But chemicals and airborne particles aren't OSHA's only concern. A colleague in a neighboring district, has OSHA stroll through and take a brand new, large paper cutter, because it didn't have the thin, metal "Don't put your fingers past here" bar. Of course the bar could have been added on, but that wouldn't make sense, so OSHA just took it.
"Anything worth believing, is worth questioning"

#12 JBaymore

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Posted 28 February 2013 - 09:42 AM

The interesting thing about OSHA and schools is that the issues have NOTHING directly to do with the STUDENTS welfare. It is the employees that work in the schools that are covered by the OSHA laws.

best,

...............john
John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

http://www.JohnBaymore.com

#13 clay lover

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Posted 28 February 2013 - 03:00 PM

The interesting thing about OSHA and schools is that the issues have NOTHING directly to do with the STUDENTS welfare. It is the employees that work in the schools that are covered by the OSHA laws.

best,

...............john



And in the local HIgh School, the questionably qualified " Art Teacher' has been know to fire bisque and glaze in the classroom with studnts present and no vert system at all, no windows even in the room.



#14 OffCenter

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Posted 28 February 2013 - 04:34 PM


The interesting thing about OSHA and schools is that the issues have NOTHING directly to do with the STUDENTS welfare. It is the employees that work in the schools that are covered by the OSHA laws.

best,

...............john



And in the local HIgh School, the questionably qualified " Art Teacher' has been know to fire bisque and glaze in the classroom with studnts present and no vert system at all, no windows even in the room.


Hopefully, you have done more about this than complain anonymously here!

Jim
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#15 Benzine

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Posted 28 February 2013 - 08:29 PM

The interesting thing about OSHA and schools is that the issues have NOTHING directly to do with the STUDENTS welfare. It is the employees that work in the schools that are covered by the OSHA laws.

best,

...............john



Rightfully so. Those careless, idiot teachers, might hurt themselves on their paper cutters and things of the like, if OSHA didn't step in. A cutter without a guard is a big deal, but dozen of scalpel sharp X-Actos, doesn't seem to concern them.....Dang, I may have said too much.
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#16 Pres

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Posted 28 February 2013 - 10:38 PM


The interesting thing about OSHA and schools is that the issues have NOTHING directly to do with the STUDENTS welfare. It is the employees that work in the schools that are covered by the OSHA laws.

best,

...............john



Rightfully so. Those careless, idiot teachers, might hurt themselves on their paper cutters and things of the like, if OSHA didn't step in. A cutter without a guard is a big deal, but dozen of scalpel sharp X-Actos, doesn't seem to concern them.....Dang, I may have said too much.


We could figure in the long run though that many teachers do and know much more and have made things safer for their students. I remember when I was reading in the 70's about the prevalence of radioactive enameling colors. Even though I was not the teacher I brought it to his attention. After discussing it with him I went up to the science department and got a Geiger counter. Checking we found that we had 5 or 6 containers of yellow enamels that were quite radioactive. They were removed from the school. So many times-times change. We become aware of hazards we did not know of 10 or even 5 years ago. The only way to really be careful is to stay current, and be proactive about your own health.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/


#17 clay lover

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Posted 01 March 2013 - 08:18 AM



The interesting thing about OSHA and schools is that the issues have NOTHING directly to do with the STUDENTS welfare. It is the employees that work in the schools that are covered by the OSHA laws.

best,

...............john



And in the local HIgh School, the questionably qualified " Art Teacher' has been know to fire bisque and glaze in the classroom with studnts present and no vert system at all, no windows even in the room.


Hopefully, you have done more about this than complain anonymously here!

Jim



#18 yedrow

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Posted 05 March 2013 - 12:02 AM

Thanks John, that was very helpful.

Joel.

#19 Marcia Selsor

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Posted 05 March 2013 - 07:37 AM

OSHA has provided a lot of good things to assist campuses in complying with better conditions.
The last campus where I taught provided containers for disposal of glazes chemicals or hundreds of unlabled glaze tests from years of prior classes.
They helped get the floors cleaned by the cleaning staff daily.
These are good things. I didn't like having the electric kilns in the same room that was 4250 sq. ft. but they were vented.
The glaze chemicals were in a separate mixing room. Once I explained there was a silica dust hazard more prevelent than
air born blood dangers ( we had a medical school and labs on campus), plus included MSDS info with chemical inventory for their records, they were very quick to respond to help improve the situation.

Marcia

#20 Pres

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Posted 11 March 2013 - 10:04 AM

OSHA has provided a lot of good things to assist campuses in complying with better conditions.
The last campus where I taught provided containers for disposal of glazes chemicals or hundreds of unlabled glaze tests from years of prior classes.
They helped get the floors cleaned by the cleaning staff daily.
These are good things. I didn't like having the electric kilns in the same room that was 4250 sq. ft. but they were vented.
The glaze chemicals were in a separate mixing room. Once I explained there was a silica dust hazard more prevelent than
air born blood dangers ( we had a medical school and labs on campus), plus included MSDS info with chemical inventory for their records, they were very quick to respond to help improve the situation.

Marcia


I had a person in the business offices that had been in lots of industry jobs before coming to the school district. He understood quality environmental control. He was always looking for ways to improve the quality of the air in my rooms. He was the one that got in the air filter system, insisted on high quality filters on my univents, and got me the two downdraft tables, and made certain the kiln area had an extra large vent fan. It was always funny that if the doors weren't shut when it started up, they soon would be from the draft. Otherwise the basement room had no windows two connected rooms and two doors.

Simply retired teacher, not dead, living the dream. on and on and. . . . on. . . .                                                                                 http://picworkspottery.blogspot.com/





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