Paul Herman on tue 20 jan 04
Edouard,
Thank you for posting the information below.
I have used diatomaceous earth as a kiln insulation, mixed with clay and
a little Portland cement. They sell it at the auto parts store as "floor
dry". As with all airborne materials, I try not to breath the dust
during mixing.
There is a page on my website "kiln plans" that shows how I used it.
It's named Insmud.
Grand feu,
Paul Herman
Great Basin Pottery
Doyle, California US
http://www.greatbasinpottery.com/
----------
>From: "Edouard Bastarache
> Amorphous silica, natural diatomaceous earth, is usually considered to
> be of low toxicity; however, pure amorphous silica is rarely found.
> Processing of amorphous silica by high-temperature calcining alters
> the silica from the benign amorphous to the pathogenic form (cristobalite),
> which causes lung fibrosis.
> Characteristically, natural diatomite contains no measurable cristobalite.
> Depending on the source, it may contain a low percentage of contaminating
> quartz, rarely over 2%.
>
> Natural diatomaceous earth can be altered by calcining, with or without
> the concomitant use of fluxing agents.
> Non-flux-calcined diatomite may contain from 20% to 30% cristobalite,
> flux-calcined diatomite may contain as much as 60% cristobalite.
> Calcined diatomite can produce a severe and disabling pneumoconiose,
> which is attributed to its cristobalite content. Altough a form of silicosis,
> it characteristically produces pathologic and radiographic changes,
> which are different from classical quartz silicosis.
> Diffuse rather than nodular changes are more common.
>
> There is no evidence to associate any form of diatomaceous earth
> with human cancer.
> The IARC concluded that evidence is inadequate to describe amorphous
> silica as carcinogenic in either experimental animals or humans.
> The IARC concluded that crystalline silica is a probable human carcinogen.
>
>
>
> Later,
>
>
>
> "Ils sont fous ces quebecois"
> Edouard Bastarache
> Irreductible Quebecois
> Indomitable Quebeker
Edouard Bastarache Inc. on tue 20 jan 04
Amorphous silica, natural diatomaceous earth, is usually considered to=20
be of low toxicity; however, pure amorphous silica is rarely found.=20
Processing of amorphous silica by high-temperature calcining alters=20
the silica from the benign amorphous to the pathogenic form =
(cristobalite),=20
which causes lung fibrosis.
Characteristically, natural diatomite contains no measurable =
cristobalite.=20
Depending on the source, it may contain a low percentage of =
contaminating=20
quartz, rarely over 2%.
Natural diatomaceous earth can be altered by calcining, with or without=20
the concomitant use of fluxing agents.=20
Non-flux-calcined diatomite may contain from 20% to 30% cristobalite,=20
flux-calcined diatomite may contain as much as 60% cristobalite.
Calcined diatomite can produce a severe and disabling pneumoconiose,=20
which is attributed to its cristobalite content. Altough a form of =
silicosis,=20
it characteristically produces pathologic and radiographic changes,=20
which are different from classical quartz silicosis.=20
Diffuse rather than nodular changes are more common.
There is no evidence to associate any form of diatomaceous earth=20
with human cancer.
The IARC concluded that evidence is inadequate to describe amorphous=20
silica as carcinogenic in either experimental animals or humans.
The IARC concluded that crystalline silica is a probable human =
carcinogen.
Later,
"Ils sont fous ces quebecois"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://perso.wanadoo.fr/smart2000/index.htm
http://www.digitalfire.com/education/toxicity/
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