That's interesting and seems to make sense (that it would be a reaction between the 2 chemicals, and not just melanmine).
Our Walmart (at least) already has a program in place, so that if you pick up something that has been recalled, and they missed it (or it had been stuck on another shelf when they pulled it, etc.) it either won't ring up, or rings up as recalled (I can't remember which). I would think that all stores (especially food stores) should already have a system like this- it's just common sense. If they can keep up with what we buy with a shopper's card, they can do that
I even read or heard somewhere that, since they already know what we bought in a database, they could also notify those with shopping cards if we have previously purchased a now recalled item. If they can send out coupons with the shopping card, they can do that. I bet they would have a lot
more people sign up for them, especially after all this...