At BSC Labs we can test leachates from glazes for metals specifically lead and cadmium to meet FDA and California Propostition rules.
Having your glazed tested is easy to do...
Make a small cup. The cup can be most any size: however, most labs have agreed to a standard size to make our results more consistent and comparable. Unless you have a special reason to use a different size, we recommend you throw cups that are straight-walled cylinders 4 inches in diameter by 3 inches tall (wet dimensions). This size cup can be thrown from less than 1 pound of clay by someone with modest throwing skills. Dry and Bisque fire the cup, glaze it and glaze fire it at your standard conditions. Make sure the glaze completely coats the inside of the cup. It is best to put a pyrometric cone pack right next to the cup so you will know exactly what temperature it saw during firing.
Package well to avoid breakage
Include a check (or call to pay with a credit card)
Instructions as to which analysis is to be performed
and all of your contact information
name, address, phone number, and email address