Cindy Strnad on tue 30 jan 01
Cadmium is not non-toxic, as you know. As to whether it's food safe, it's my
understanding that, in commercial glazes, this is dependent on the glaze
being fired exactly as instructed. Even then, I wouldn't sell or give away
pottery glazed with this substance which could be used for food. Not unless
I'd had it lab tested--and probably not even then. Commercial glazes are
subject to changes in formulation without notice. Just because bottle A is
safe under your firing conditions is no guarantee that bottle B is also
safe. The same goes for lead.
Lead can also fume during firing (not sure about cadmium, but I expect it's
likely to do the same). This means you're breathing it in the air when that
unventilated kiln is firing. That and, probably, other nasty things not
intended to inhabit human lung tissue. I don't know how long the fumes hang
around. I suppose it depends on how well-ventilated the building itself is.
When you walk through this glaze-strewn room, you kick up dust and you
breathe the glaze ingredients. This is bad enough with the silica alone, but
using ingredients such as lead and cadmium, manganese, cobalt, copper,
chromium, vanadium, etc., can only make it worse.
The fact that many commercial glazes use "encapsulated" stains does not pull
the teeth of toxic ingredients. These ingredients are still poisonous and
still capable, in their raw state, of wreaking their various forms of havoc
on the human body. Small children who are still putting things in their
mouths shouldn't be in the studio at all unless they're under very close
supervision. Having little ones walking around sucking on brush tips is
There are, undoubtedly, regulatory bodies in your area charged with
protecting customers and consumers. I don't know what they are, but it would
be easy enough to find out. Call government information--that might give you
As for OSHA, I don't like them. I think they're generally over-zealous,
arrogant, antagonistic, and superior. You don't have to have done anything
wrong to have these guys put you out of business. They just like doing
it--showing how powerful they are. However, if I were in your situation, I
would call them.
I don't like Health and Human Services, either, but I called them once when
I felt a patient wasn't receiving proper care at the hospital where I
worked. She was from a nursing home which had criminally neglected her, and
the hospital was covering for them. Sometimes you just gotta do what you
gotta do. I wasn't very popular, but oh well.
Of course, do what you can to encourage your employers to clean things up.
If, as we can probably predict, they don't listen to you, I expect you'll
have to bite your lip, start looking for another job, and make some phone
calls. These people are abusing the trust of their employees and customers,
and subjecting them, and themselves, to very real danger.
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
Dennis Mummert on tue 30 jan 01
A few points,
*Cadmium in the reds: we use duncan concepts underglazes, we are told to
tell our customers that all of our paints are non-toxic. Is it possible the
cadmium will leach into food? Also, what about toddlers sticking the
brushes of paint in the mouth. We also do kids' "handprints" on the
In a general way, if (and that is a big if) commercial glazes are applied
and fired strictly per the manufacturer's directions, the *fired* product is
safe to use. That includes using it on the right clay body and -verifying-
that the kiln is neither under- nor over-firing. But - there aren't very
many glazes you can safely consume via mouth. Don't let it happen.
*Lead in the clear glaze: we use a clear glaze by Campbells. The employer
states that the lead is completely safe, and we are to tell our customers
that the ceramics are food safe after firing. In my inquiries regarding
these, they have never informed me that any of their fired ceramics have
Unless you're not following directions on the label, even if the glaze does
contain lead, it should be safe. Look at the label on the Campbells'
container. If it says 'food safe' (or has the plate, knife, and fork icon)
then it should be ok. Even simpler - switch to a lead-free clear. There
are a number of products that will do the job.
*Fumes from the kiln: the kiln is not ventilated to the outdoors, the fumes
are expelled into our
Absolutely vent the kiln/kiln room. No exceptions. Most kiln sheds leak
air like a sieve, or don't have one or more walls. If the room is tight, you
have a problem. An electric kiln, while firing, puts out a large amount of
carbon dioxide and carbon monoxide. Depending on the bisque load, and the
size of the kiln, potentially 5-10 POUNDS of those gasses. Any glaze just
adds to the problem.
*Glaze: the cermaics are dipped into a rubbermaid container of glaze that
is mixed with a drill, then set out to dry. The glaze is spewn all over the
room, on the floor, on the walls. Only the employers are doing the glazing
at this point, and that is how I prefer it. But if these spots of glaze are
disturbed, isn't it possible the lead will be expelled into the air?
Possible. That's why responsible potters wet mop floors and sponge down
glaze mixing areas. The wash water can go in the slip bucket, but not in
the drain. Not even in the storm drain.
*Kiln safety: With the kiln on one side of the room, and a table on the
other, there is less than three feet of space to walk by the kiln. They
further complicate the problem by plugging in an upright fan under the table
so that the cord is in the path of the walkway. They act like I'm crazy
when I express my slip/fall concerns, right onto a kiln that gets over 1200
Buy another extension cord and a roll of duct tape.
*Lastly, and perhaps most scary is their lack of concern for safety in their
products or towards their employees. There are no MSDS's in the studio on
any products being used, my request for
You're entitled to them if you want them. All of them are available on the
web, too. Well... some of them are.
Sandra Fisher on tue 30 jan 01
I stumbled across your list in an effort to gather information regarding =
my concerns working in a contemporary studio-you know, those paint it you=
rself ones popping up all over the country. I will attempt to be brief h=
ere, and would appreciate any comments. I have a minor in environmental =
health and my education sparked some concerns while working in the studio=
, my partner is also an industrial hygeinist. We have been unable to fin=
d the information I have been seeking and my employer has been less than =
forthcoming in providing information for me.
*Cadmium in the reds: we use duncan concepts underglazes, we are told to =
tell our customers that all of our paints are non-toxic. Is it possible t=
he cadmium will leach into food? Also, what about toddlers sticking the =
brushes of paint in the mouth. We also do kids' "handprints" on the bisq=
*Lead in the clear glaze: we use a clear glaze by Campbells. The employe=
r states that the lead is completely safe, and we are to tell our custome=
rs that the ceramics are food safe after firing. In my inquiries regardi=
ng these, they have never informed me that any of their fired ceramics ha=
ve been tested.
*Fumes from the kiln: the kiln is not ventilated to the outdoors, the fum=
es are expelled into our kiln room, the size is about 20'-25' long, and 1=
2' wide, with one door. The only thing they have said about this is not =
to stay in there too long when the fumes are present. According to the e=
mployer, this kiln does not require ventilation, but I did not see any so=
rt of "downdraft" vent on it either. I am concerned about the vapors pro=
duced, do they contain lead, and it seems to me that if so, the lead has =
to settle somewhere.
*Glaze: the cermaics are dipped into a rubbermaid container of glaze tha=
t is mixed with a drill, then set out to dry. The glaze is spewn all ove=
r the room, on the floor, on the walls. Only the employers are doing the =
glazing at this point, and that is how I prefer it. But if these spots o=
f glaze are disturbed, isn't it possible the lead will be expelled into t=
*Kiln safety: With the kiln on one side of the room, and a table on the =
other, there is less than three feet of space to walk by the kiln. They =
further complicate the problem by plugging in an upright fan under the ta=
ble so that the cord is in the path of the walkway. They act like I'm cr=
azy when I express my slip/fall concerns, right onto a kiln that gets ove=
r 1200 degress.
*Lastly, and perhaps most scary is their lack of concern for safety in th=
eir products or towards their employees. There are no MSDS's in the stud=
io on any products being used, my request for them at our meeting sunday =
was met with great disapproval, but a promise to provide them. They also=
told me that according to their people at the CCSA-Contemporary studio a=
ssociation group, the people in the organization that handle safety conce=
rns have told them that because they have so few employees (8 in two stud=
ios) they are not required to follow the same regulations as other compan=
ies because they are so small. My partner clarified that one for me, all=
this does for them is exclude them from reporting occupational accidents=
to OSHA. My concern here though is that they have absolutely no concern=
over health and safety, for their customers or employees.
I would appreciate any information or resources available, and please fee=
l free to email me directly. These studios are very popular, and moms co=
me in with kids all the time. It disturbs me to think I may be giving ou=
t the wrong information about food safety. Thank you so much.
Sandra in Hampton, Virginia
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