Monona Rossol on sat 27 mar 99
---------- Forwarded message ----------
Date: Thu, 25 Mar 1999 07:39:15 EST
From: Leslie St.Clair"
To: CLAYART@LSV.UKY.EDU
Subject: glaze leach test results, C6glazes
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Leslie St. Clair
Ft. Mitchell, Kentucky wrote:
----------------------------Original message----------------------------
Hi everybody. I sent some glazes to Alfred Analytical Laboratory for leach
tests. Here are the results. All the glazes were fired to c 6 electric,
witness cones 6 at 3 o'clock.
TEMMOKU GOLD:
Cornwall stone 61; Whiting 8; Gerstley Borate 3; RIO 10; Lithium Carb
5.5; dolomite 7; Flint 5.5.
RESULT: lithium detected at 0.48 MG/L.
ANNIE'S TAN:
FLint 90; Potash spar 60; Talc 42; EPK 15; Gerstley 96; Rutile,powdered
6; RIO 15.1; granular manganese 2.5.
RESULT: manganese detected at 0.15 MG/L
FLOATING BLUE (yes it's the infamous floating blue) Neph sy 47.3; Gerstley
27; Silica 20.3; EPK 5.4; RIO 2; Cobalt Oxide 1; Rutile, milled 4;
bentonite 1.
RESULT: cobalt detected at 0.048 MG/L
> I believe that the low detection rates mean that these glazes are food
> safe. Does anyone have any comments? >
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A couple comments;
1. First: Congratulations on doing the right thing by yourself and your
customers.
2. There are no water standards for the metal you tested, so its hard to
judge. But they look like they are in the range of water standards for other
toxic metals and probably quite safe.
3. There is a standard for boron, and it is in a large percentage in the
the 2nd and 3rd glaze. I would have run Annies Tan and Floating Blue for
boron and seen if they were in the range of 0.6 mg/L
EPA is working on water quality standards for manganese and for vanadium.
Its a long process, but I will be watching for these and will let you all
know when they do come out.
Monona Rossol
Arts, Crafts and Theater Safety
181 Thompson St., # 23
New York NY 10012-2586 212/777-0062
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