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lead glazes?....and studio space

updated wed 28 may 03

 

May Luk on mon 19 may 03


Hi there;

A friend of mine just rented a studio space with this potter who uses lead
glaze (low sol). Her space is right next to a bath tube size kiln and
there's no kiln vent. I'm concerned with her health. I had asked a teacher
regarding this and he said lead ingestion is a problem but not so much about
the fume. I had read the digital fire article twice and I don't see much
regarding studio ventilation with firing lead glaze. Is there another source
I can read up on?

Thank you in advance
May
London, UK

on 5/18/03 10:50 pm, J. B. Clauson at jclauson2@EARTHLINK.NET wrote:

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Previous message in part
>
> Seriously, lead poisoning is a sneaky, insidious b------! It first robs you
> of your energy, then you IQ eventually leading to irreparable brain damage
> and will eventually rob you of your life. We potters have been taking the
> rap for the fall of the Roman Empire for centuries because of the lead
> glazes so popular during that period (So, who knew back then?). Yes, it
> produces beautiful reds - but at what price!
>
> Jan C.
>

May Luk on tue 20 may 03


Dear Janet;

Thank you for the sound advice.

In my search, I had found more information at The Health and Safety
Executive
www.hse.gov.uk
www.coshh-essentials.org.uk

This lady is making and selling food safe dinnerware glazed with lead base
glaze. Her studio is her private lease. We are not interested in upsetting
her livelihood. We are trying to have some leverage because she is imposing
some unfair studio rental practise after my friend has moved in. She is
trying to charge her extra and it was not agreed upon before moving in. And,
the studio is in a very bad part of town for a single japanese girl.
Nevertheless, my friend's health is the main concern.

A side bar. I'm always confused with the attitude to lead in the UK. What is
food safe with lead based glaze? (the low sol variety) Does slapping a lemon
on for a few days is sufficient to prove that it's food safe? Also with the
encapsulated red stain, which I love. Tutors and working potters and some
suppliers that I've talked to all seem to think that's fine enough. Being a
paranoid american that reads too much, I'm not convinced.

Anyways, thanks again

Best regards
May

on 5/20/03 12:21 am, Janet Kaiser at janet@the-coa.org.uk wrote:

> Dear May Luk
>
> There is not the same attitude to lead in the UK as some other countries,
> HOWEVER before you panic, you need to look at what exactly this "lead
> glaze" is. You are in a shared studio situation... Is this a school or
> college? Are you absolutely certain this glaze is not a pre-mixed communal
> glaze from some supplier, in which case it will be lead bi or trisillicate?
> Or is it mixed on site? Is it really a "lead glaze", or is it actually a
> substitute which is still referred to as a "lead glaze"?
>
> And just a little word of advice... Be very careful how you approach the
> whole situation. You do not want it to become an internal "political
> problem"... I know of whole departments which were closed down permanently,
> because they did not have the resources to change. And once an issue has
> been raised, it cannot be ignored by the authorities. Be very such of your
> facts before you do or say anything "official".
>
> Sincerely
>
> Janet Kaiser
>
> *** IN REPLY TO THE FOLLOWING MAIL:
>> A friend of mine just rented a studio space with this potter who uses lead
>> glaze (low sol). Her space is right next to a bath tube size kiln and
>> there's no kiln vent. I'm concerned with her health. I had asked a teacher
>> regarding this and he said lead ingestion is a problem but not so much
>> about
>> the fume. I had read the digital fire article twice and I don't see much
>> regarding studio ventilation with firing lead glaze. Is there another
>> source I can read up on?
>>
>> Thank you in advance
>> May
>> London, UK
>>

John Hesselberth on tue 20 may 03


Hi May,

No, absolutely not! The only way to assure lead glazes meet the
proscribed standards is to have them professionally leach tested. In
the US (and many other countries) there are specific leaching levels
that are allowed for lead and cadmium. The potter is responsible for
assuring these levels are not exceeded.

Regards,

John
On Tuesday, May 20, 2003, at 06:18 AM, May Luk wrote:

> Does slapping a lemon
> on for a few days is sufficient to prove that it's food safe?
http://www.frogpondpottery.com
http://www.masteringglazes.com

Ron Roy on wed 21 may 03


Hi May,

I would tell her to get out or start having her blood tested for lead to
see how fast it is accumulating.

Lead volatilizes during firing - especially if it is reduced at all - and
this can happen even in an electric kiln. This means the fumes are coming
out of the kiln and condensing in that area.

You are correct to be concerned.

RR


>A friend of mine just rented a studio space with this potter who uses lead
>glaze (low sol). Her space is right next to a bath tube size kiln and
>there's no kiln vent. I'm concerned with her health. I had asked a teacher
>regarding this and he said lead ingestion is a problem but not so much about
>the fume. I had read the digital fire article twice and I don't see much
>regarding studio ventilation with firing lead glaze. Is there another source
>I can read up on?
>
>Thank you in advance
>May
>London, UK

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513

Brian Haviland on wed 21 may 03


Roy
Does this mean that that the lead settles out on all surfaces in
the studio, to later be picked up off of those surfaces by touch and
possibly be ingested or absorbed into the skin.If this is the case you
should never put your kiln in the studio where you work and sometimes eat
while you work (bad habit..but sometimes nessasary if you want to get
anything done).. :<( ..due to the fact you could be ingesting poison.WOW
I dont use leaded glazes except for a clear glaze over underglazes at low
fire once and awhile.So am i not practicing a safe studio role for me and
my clay buds ??? Guess i had better get out the safe studio book and read
it again !!!!

Brian Haviland








At 01:37 AM 5/21/03 -0500, you wrote:
>Hi May,
>
>I would tell her to get out or start having her blood tested for lead to
>see how fast it is accumulating.
>
>Lead volatilizes during firing - especially if it is reduced at all - and
>this can happen even in an electric kiln. This means the fumes are coming
>out of the kiln and condensing in that area.
>
>You are correct to be concerned.
>
>RR
>
>
> >A friend of mine just rented a studio space with this potter who uses lead
> >glaze (low sol). Her space is right next to a bath tube size kiln and
> >there's no kiln vent. I'm concerned with her health. I had asked a teacher
> >regarding this and he said lead ingestion is a problem but not so much about
> >the fume. I had read the digital fire article twice and I don't see much
> >regarding studio ventilation with firing lead glaze. Is there another source
> >I can read up on?
> >
> >Thank you in advance
> >May
> >London, UK
>
>Ron Roy
>RR#4
>15084 Little Lake Road
>Brighton, Ontario
>Canada
>K0K 1H0
>Phone: 613-475-9544
>Fax: 613-475-3513
>
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karen gringhuis on thu 22 may 03


For a concise summary of lead hazards, refer to
Cushing's HANDBOOK or his article published in
Ceramics Monthly between 1990-95. (They might have an
on-line archive??? Sorry I can't be more precise at
the moment.) Also refer to Monona Rossol's writings.
IMHO too many people think using a fritted lead source
is enough safety and they are wrong.

I know nothing about fallout from vapor onto surfaces.
My personal opinion (and practice) is that any kiln
should be ventilated regardless of what is being
fired. I do not use lead glazes of any sort (I fire
C/10) and in a prior life in a community art center,
they were not allowed at any temperature for any
reason period.

=====
Karen Gringhuis
KG Pottery
Box 607 Alfred NY 14802

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Ron Roy on tue 27 may 03


Hi Brian,

I suppose that advice that you should not eat or smoke in the studio comes
mainly from the days when lead was so commonly used.

I am not so concerned with the amount potters could ingest but children
might be a different story - or pets.

I would be more concerned about the dust factor - every time the hot or
cold air system comes on dust is stirred up - and then there is the fuming
from any lead containing kiln. It is common to have some reduction even in
an oxidizing kiln and lead is easily reduced.

I also think you are right to include absorption through the skin -
according to some recent info I am aware of.

I don't know if you are in a dangerous situation - a blood test will tell
you if you need to be concerned.

I am not saying no one should use lead by the way - but the problem is -
many are simply not aware of the danger and certainly most of us don't know
enough to make sure the glazes are safe.

Lead and Cadmium are both controlled now - I would not want to be the
potter who is putting out unsafe glazes that contained those materials.

I was at a work shop this last weekend - one presenter - a teacher - said -
once the Cadmium is in a glaze it is safe - and he was using 15% - utter
nonsense by the way. He did at least say the danger was more to the potter
and he was right about that. But still - he should have been the one taking
a workshop.

A sorry state of affairs when those teaching our craft are so ignorant in
simple basic understanding of the technical part of what we do - it looks
like they will be the last to learn.

I do spend some time wondering how so much ignorance has been allowed to
exist for so long and why it is so difficult to change the attitudes.
Perhaps it's time to hire teachers who are still willing to learn.

RR

> Does this mean that that the lead settles out on all surfaces in
>the studio, to later be picked up off of those surfaces by touch and
>possibly be ingested or absorbed into the skin.If this is the case you
>should never put your kiln in the studio where you work and sometimes eat
>while you work (bad habit..but sometimes nessasary if you want to get
>anything done).. :<( ..due to the fact you could be ingesting poison.WOW
>I dont use leaded glazes except for a clear glaze over underglazes at low
>fire once and awhile.So am i not practicing a safe studio role for me and
>my clay buds ??? Guess i had better get out the safe studio book and read
>it again !!!!
>
> Brian Haviland

Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513