Clay Times Back Issues Vol. 2 Issue 3 • Mar/Apr 1996 | Page 14

Studio Health & Safety

Testing for Barium Leaching
BY MONONA ROSSOL
Final Segment of a Three-Part Series
The EPA recognizes the toxicity of various metals by setting
standards for them in our drinking
water. There are two types of standards: 1) Maximum Contamination
Levels (MCLs) which are enforceable; and 2) Drinking Water Health
Advisories (HAs). The EPA standard for barium shows it is certainly not the most toxic metal we use.
Potters need to consider the toxicity of many different metals. The
EPA standards also can be used to
interpret leach testing data from
pottery. This is not a scientific
approach to leach tests, but it is
pragmatic in the absence of better
standards. Clearly, if our pottery
does not leach more metal on a 24hour acid leach test than is allowed
in drinking water, it is certainly
safe for the customer to use.
Substance

Current MCLs/HAs
in milligrams/liter

Aluminum . . . . . .