<<Disclaimer: Verify this information before applying it to your situation.>> Frankly, I think the question of "how must gluten is too much" is one that burns in the minds of all celiac patients (or in may case, parent of a celiac patient) who are not so sensitive that any exposure causes an obvious adverse reaction. Our ongoing attempts to adhere to a "zero gluten tolerance" diet has quality of life implications, and it is perfectly natural and certainly not harmful to anyone to simply ask the question, is there a safe quantity? I myself have asked the question, and to my knowledge there is no answer to it.