Monona Rossol on mon 26 may 97
---------- Forwarded message ----------
Date: Tue, 20 May 1997 12:00:09 EDT
From: Zoey K von Borstel
Resent-Subject: Lead in the classroom
I have been reading the lead discussion with great interest, and I am
beginning to be concerned. I am enrolled in a community college ceramics
class. The first week of class lead in glazes was addressed a number of
students were concerned. My instructor explained that there were some
leaded frits in the glazes used in the class but that properly used they
were safe. Initially I trusted that what he said was true in spite of
the fact that I have taken a number of ceramics classes other places and
the rule regarding lead has always been quite simply- don't use it. I am
beginning to question the safety of the glazes in my class.
A little history- apparently until a few years ago the firings were to
^10. The school wanted to save money and asked that the firing temp be
reduced to do so. The firings are now to officially to ^7 (I say
officially because the firings are anything but regular- I would guess
that they range from ^5-^9 at least). Some of the glazes were adjusted
to fire at ^7- others were found to look nice at ^7 with no change.
My instructor is burned out, inaccessible and prone to giving answers to
questions other than the one asked. So I ask you- Should I stop using
the lovely dishes that I made in this class? Should I warn other
students? Should I complain?
ps I think I can get the glaze recipes- I suppose that would help.
Fast and dirty answer:
1. Use of lead in the classroom places the teacher and her/his employer
under the jurisdiction of the OSHA Lead Standard. Each step in the
processes in which lead is used (mixing, clean up, glazing, etc.) should have
been monitored and the amount of air borne lead determined. The necessary
precautions are determined on the basis of these findings. Precautions often
include showers and changing rooms to prevent take home of lead dust, regular
blood lead tests, and special ventilation systems.
2. The OSHA Lead Standard (29 CFR 1910.1025) as well as the Hazard
Communication Standard (29 CFR 1910.1200) require formal documented training
in the hazards of the products used on the job and proper precautions.
Employers (school administrators) are obligated by the laws to provide
this training during paid working hours, by a competent person, and for the
employees (teachers) to demonstrate comprehension (usually by taking a quiz).
Most teachers are uneducated and most administrators are in violation of
3. OSHA makes no distinction between raw lead compounds and lead frits in
4. Although the OSHA rules do not extend to the students, failure to protect
students with precautions equal to or better than the OSHA standards has been
interpreted as negligence in some law suits.
5. It is now known in the ceramic industry that solubility (in acid) of
lead frits is unrelated to bioavailability (the amount that is taken up by
the body on inhalation or ingestion). Claims on the labels of older lead
commercial glazes that frits are a safe form of lead are unfounded.
6. At cone 7, there will be considerable burn off of lead resulting in lead
fume in the air and deposits of lead in the brick in the kiln.
7. Lead contaminated kilns can contaminate lead-free glazes during firing.
8. There is no way to tell if the lead glazes or the lead-free glazes fired
in the lead-contaminated kilns are safe for use with food except by testing.
You could get a rough idea by testing with the lead kits you can purchase at
certain hardware stores. Really accurate testing, however, is done only in a
9. Perhaps you can suggest your teacher be tested as well. He may not be
"burned out, inaccessible, and prone to giving answers to questions other
than the ones asked," but instead, he may be showing the irritability,
psychological symptoms and lowered mental acuity associated with low level
Monona Rossol, industrial hygienist
Arts, Crafts and Theater Safety
181 Thompson St., # 23
New York, NY 10012-2586 212/777-0062