Federal regulators have upgraded a product recall of Lay's Classic Potato Chips to the highest risk level for a batch that may contain undeclared milk ingredients. Last month, Frito-Lay issued a recall warning that more than 6,

The Food and Drug Administration is using its most severe notice in a recall of more than 6,000 bags of chips in two states because of “undeclared milk.”

The FDA classified the recall of Lay's Classic Potato Chips in Oregon and Washington state as a Class 1 recall, which means consumption could be fatal for people with a milk allergy.