[Clayart] Clayart Digest, Vol 104, Issue 19 Manganese
ronroy at ca.inter.net
ronroy at ca.inter.net
Thu Aug 1 16:41:47 UTC 2024
I agree mostly with Vince. I suppose it is a stretch but maybe
possible if clay containing granular manganese was ground underfoot
enough - perhaps? - the particles could be reduced to the danger
point. I have been in such studios!
I doubt if the fumes from granular manganese would be much of a
problem. If you are breathing kiln fumes there are much more serious
issues.
We have not had a go around on studio air quality for a while. Anyone
have some something outrageous to say about that?
RR
Quoting Vince Pitelka via Clayart <clayart at lists.clayartforum.com>:
> I'm traveling and haven't followed this thread very close. As I
> understand it, in oxidation claybodies, speckles are achieved with
> granular manganese, while in reduction bodies, they are achieved
> with iron. Because the manganese is granular, I have always
> understood that it poses no threat in handling the raw clay. Of
> course, in firing, your kiln needs to be outdoors or equipped with a
> proper kiln vent system installed and operating.
> - Vince
>
> Vince Pitelka
> Potter, Writer, Teacher
> Chapel Hill, NC
> vincepitelka at gmail.com
> www.vincepitelka.com
> https://chathamartistsguild.org/
>
> -----Original Message-----
> From: Clayart <clayart-bounces at lists.clayartforum.com> On Behalf Of
> trina281--- via Clayart
> Sent: Sunday, July 28, 2024 10:20 AM
> To: clayart at lists.clayartforum.com
> Cc: trina281 at aol.com
> Subject: Re: [Clayart] Clayart Digest, Vol 104, Issue 19 Manganese
>
> Coming in late to the discussion. Standard Clay body #112 aren't
> the speckles Manganese?
> On Thursday, July 25, 2024 at 08:02:38 AM EDT,
> clayart-request at lists.clayartforum.com
> <clayart-request at lists.clayartforum.com> wrote:
>
> Send Clayart mailing list submissions to
> clayart at lists.clayartforum.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
> https://lists.clayartforum.com/mailman/listinfo/clayart
> or, via email, send a message with subject or body 'help' to
> clayart-request at lists.clayartforum.com
>
> You can reach the person managing the list at
> clayart-owner at lists.clayartforum.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Clayart digest..."
>
>
> Today's Topics:
>
> 1. Manganese toxicity - RR (ronroy at ca.inter.net)
> 2. Joining ClayArt? (ronroy at ca.inter.net)
> 3. join clayart instructions (mel jacobson)
> 4. Re: Manganese toxicity - RR (Dragonbelly Ceramics)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 24 Jul 2024 11:35:38 -0400
> From: ronroy at ca.inter.net
> To: clayart at lists.clayartforum.com
> Subject: [Clayart] Manganese toxicity - RR
> Message-ID: <20240724113538.17063fllw1ml9bgq at webmail.ca.inter.net>
> Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
> format="flowed"
>
> Below is a letter sent to Mathhew Katz over a month ago by a
> Canadian potter who pots in a community setting that does not think
> manganese is a problem. To date he has not responded.
>
> Sent: Friday, June 14, 2024 10:48 AM
> To: Matthew Katz (matt at ceramicmaterialsworkshop.com)
> <matt at ceramicmaterialsworkshop.com>
> Subject: Manganese information from Monona Rossol
>
> Dear Matt:
>
> I am reaching out to you to provide you with some information from
> Monona Rossol about manganese. Monona is an industrial toxicologist
> specializing in materials used in the Arts and Theatre, and used to
> write about toxicology in Clay Times.
>
> In your podcast, "Should I be afraid of manganese", you mentioned
> that dust is not soluble and that only soluble materials could pass
> from the lungs to the blood stream. I found a lot of articles about
> manganism in miners exposed to dust. Closer to ceramic use, is the
> case (Hine CH, attached) of a worker who developed manganism in a
> relatively short time from cleaning up dry glaze powder spills
> without a mask or proper ventilation. These sources show that
> manganese dust does pass into circulation.
>
> Monona was able to shed some more light on this. According to the
> SDS, the TLV for manganese dioxide by inhalation in the respirable
> particle size (fumes and dusts under 10 microns in diameter) is 0.02
> mg/m3. She says that this is very low, indicating that manganese
> dust is very toxic to inhale.
> She also wanted me to share with you the attached published review
> that concluded that there are multiple environmental sources of
> manganese that can be additive. This means that the small amount we
> might be exposed to even if we use PPE and ventilation in ceramics,
> could be a tipping point over time.
>
> You also mentioned that manganese does not fume until it reaches
> temperatures well in excess of kiln firing. Were you referring to
> the boiling point of manganese dioxide? I looked up the melting and
> boiling points of chrome and copper oxides, and even their melting
> points are above cone 10. Yet chrome and copper are known to fume
> in low firings.
>
> Monona explained that fume generation does not begin at the boiling
> point of manganese dioxide, but at its melting point (under 1000
> degrees F) and that fume generation from heating manganese compounds
> is a risk factor. Also, interactions with other materials in a
> glaze may enhance melting and subsequent fuming.
>
> Monona also shared that an earlier sign of manganese toxicity is
> essential tremor rather than full-blown Parkinson-like symptoms.
> The majority of welders today have essential tremor attributed to
> manganese exposure, and early effects are subtle but likely to be
> irreversible and progressive.
>
> We might hope that people will be diligent in using PPE and damp
> mopping, or will always vent their kilns effectively, but there will
> always be those who do not know any better. I hope you will teach
> through your courses and podcasts that manganese does confer risks
> from dust as well as fume inhalation at kiln temperatures. I have
> no problem with people using manganese. I can only hope that they
> become aware of risks that you can help disseminate.
>
> Thank you for your time. I would appreciate hearing back from you.
>
> Yours in health,
>
> I have omitted the potters name but she has allowed me to include it
> if anyone is interested,
>
> RR
>
> ronroy at ca.inter.net
> Web page ronroy.net
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 24 Jul 2024 11:37:33 -0400
> From: ronroy at ca.inter.net
> To: clayart at lists.clayartforum.com
> Subject: [Clayart] Joining ClayArt?
> Message-ID: <20240724113733.71201vxos350av25 at webmail.ca.inter.net>
> Content-Type: text/plain; charset=ISO-8859-1; DelSp="Yes";
> format="flowed"
>
> I can't find the instructions for joining ClayArt - could someone
> send them to me please - thanks RR
>
>
> Ron Roy
> ronroy at ca.inter.net
> Web page ronroy.net
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 24 Jul 2024 13:24:26 -0500
> From: mel jacobson <melpots at mail.com>
> To: "clayart at lists.clayartforum.com" <clayart at lists.clayartforum.com>
> Subject: [Clayart] join clayart instructions
> Message-ID: <0MOPpb-1sbvSB0ywP-00AkJD at smtp.mail.com>
> Content-Type: text/plain; charset="utf-8"
>
>
> https://lists.clayartforum.com/mailman/listinfo/clayart
> www.melpots.com
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <https://lists.clayartforum.com/pipermail/clayart/attachments/20240724/10358142/attachment.htm>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 24 Jul 2024 18:17:23 -0400
> From: Dragonbelly Ceramics <lisa at dragonbellyceramics.com>
> To: Clayart international pottery discussion forum
> <clayart at lists.clayartforum.com>
> Subject: Re: [Clayart] Manganese toxicity - RR
> Message-ID:
> <CAMxmGNai6fajfO7Ji2fWfpBvwgMCCj0x-GX5aW0=RLahm0PejQ at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Thank you for sharing this. I do hope Matt responds.
>
> Lisa
>
> On Wed, Jul 24, 2024, 11:35 AM ronroy--- via Clayart <
> clayart at lists.clayartforum.com> wrote:
>
>> Below is a letter sent to Mathhew Katz over a month ago by a Canadian
>> potter who pots in a community setting that does not think manganese
>> is a problem. To date he has not responded.
>>
>> Sent: Friday, June 14, 2024 10:48 AM
>> To: Matthew Katz (matt at ceramicmaterialsworkshop.com)
>> <matt at ceramicmaterialsworkshop.com>
>> Subject: Manganese information from Monona Rossol
>>
>> Dear Matt:
>>
>> I am reaching out to you to provide you with some information from
>> Monona Rossol about manganese. Monona is an industrial toxicologist
>> specializing in materials used in the Arts and Theatre, and used to
>> write about toxicology in Clay Times.
>>
>> In your podcast, "Should I be afraid of manganese", you mentioned that
>> dust is not soluble and that only soluble materials could pass from
>> the lungs to the blood stream. I found a lot of articles about
>> manganism in miners exposed to dust. Closer to ceramic use, is the
>> case (Hine CH, attached) of a worker who developed manganism in a
>> relatively short time from cleaning up dry glaze powder spills without
>> a mask or proper ventilation. These sources show that manganese dust
>> does pass into circulation.
>>
>> Monona was able to shed some more light on this. According to the
>> SDS, the TLV for manganese dioxide by inhalation in the respirable
>> particle size (fumes and dusts under 10 microns in diameter) is 0.02
>> mg/m3. She says that this is very low, indicating that manganese dust
>> is very toxic to inhale.
>> She also wanted me to share with you the attached published review
>> that concluded that there are multiple environmental sources of
>> manganese that can be additive. This means that the small amount we
>> might be exposed to even if we use PPE and ventilation in ceramics,
>> could be a tipping point over time.
>>
>> You also mentioned that manganese does not fume until it reaches
>> temperatures well in excess of kiln firing. Were you referring to the
>> boiling point of manganese dioxide? I looked up the melting and
>> boiling points of chrome and copper oxides, and even their melting
>> points are above cone 10. Yet chrome and copper are known to fume
>> in low firings.
>>
>> Monona explained that fume generation does not begin at the boiling
>> point of manganese dioxide, but at its melting point (under 1000
>> degrees F) and that fume generation from heating manganese compounds
>> is a risk factor. Also, interactions with other materials in a glaze
>> may enhance melting and subsequent fuming.
>>
>> Monona also shared that an earlier sign of manganese toxicity is
>> essential tremor rather than full-blown Parkinson-like symptoms. The
>> majority of welders today have essential tremor attributed to
>> manganese exposure, and early effects are subtle but likely to be
>> irreversible and progressive.
>>
>> We might hope that people will be diligent in using PPE and damp
>> mopping, or will always vent their kilns effectively, but there will
>> always be those who do not know any better. I hope you will teach
>> through your courses and podcasts that manganese does confer risks
>> from dust as well as fume inhalation at kiln temperatures. I have no
>> problem with people using manganese. I can only hope that they become
>> aware of risks that you can help disseminate.
>>
>> Thank you for your time. I would appreciate hearing back from you.
>>
>> Yours in health,
>>
>> I have omitted the potters name but she has allowed me to include it
>> if anyone is interested,
>>
>> RR
>>
>> ronroy at ca.inter.net
>> Web page ronroy.net
>>
>>
>>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <https://lists.clayartforum.com/pipermail/clayart/attachments/20240724/f4a78089/attachment.htm>
>
> End of Clayart Digest, Vol 104, Issue 19
> ****************************************
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <https://lists.clayartforum.com/pipermail/clayart/attachments/20240728/bba9a3e1/attachment.htm>
>
>
Ron Roy
ronroy at ca.inter.net
Web page ronroy.net
More information about the Clayart
mailing list