FDA issues melamine risk assessment

The FDA says melamine in food at or below a level of 2.5 ppm (mg/kg) is unlikely to be harmful–except in infant formula.  This seems reasonable; on a per kg body weight basis, this would be a very low dose.  But what about when it is mixed with its by-product, cyanuric acid?  Nobody has yet defined the lowest dose of melamine which, when mixed with cyanuric acid, does not form kidney-blocking crystals.  Melamine should not be in the food supply at all, and especially not in infant formula, under any circumstances