The FDA has upgraded a December recall of Lay’s potato chips to its highest risk level, “Class I.”

Originally affecting over 6,000 bags of 13 oz. classic chips in Washington and Oregon, the recall was prompted by the presence of undeclared milk, which poses a serious risk to individuals with severe allergies.

The upgraded recall now warns that exposure to the product could cause serious health consequences or even death, NPR has reported.

Written by B.C. Begley