The Bill Carty talk in Milwaukee last year addressed this. He suggested that the neurological effects are only an issue when exposed to vaporized forms of Manganese (The MSDS information is from the steel industry, where everything they handle is at high heat). Proper materials handling still applies, however the greatest risk is breathing the kiln fumes. Also, be aware that subsequent firings will still give off fumes, as all surfaces in the kiln will hold on to a bit of the Manganese. Be sure to wash all wares prior to use as well to take care of the residue. As for the leaching issue, a pro