The FDA has issued a Class I recall for Lay’s Classic Potato Chips due to undeclared milk, warning of severe allergic reactions or death.

The FDA issued a product recall on Lay's Classic Potato Chips in two states. The recall was upgraded to the highest risk factor over undeclared milk.

The Food and Drug Administration has upgraded a December recall of Classic Lays Potato Chips to Class 1, the highest priority designated by the agency.

The problem ingredient identified was "undeclared milk," which poses a risk to those with severe sensitivities or allergies.

A previous FDA recall on certain Lay's potato chip products has now been updated to the category with the highest risk for consumers. What to know

Class I, according to the FDA, means exposure to or consumption of the product could cause "serious adverse health consequences or death."

Those with an allergy or severe sensitivity to milk run the risk of a serious or life-threatening allergic reaction if they consume the recalled product,” the FDA said in its initial notice on Dec. 16.

Lay’s voluntary recall from December has been increased to the U.S. Food and Drug Administration’s highest risk level classification. On Dec. 13, Frito-Lay recalled more than 6,000 bags of 13 oz. Lay’s Classic Potato Chips due to “undeclared milk.” The affected chips were sold in Oregon and Washington.

Urgent class 1 recall affects thousands of Lay's Classic Potato Chips bags due to undeclared milk allergen, posing severe health risks to sensitive consumers.

A December recall on Lay’s Potato Chips sold in two states has been escalated to the FDA’s highest risk level, but no allergic reactions have been reported.

After Frito-Lay issued a recall for some of its Lay's Classic Potato Chips last month, the the U.S. Food and Drug Administration has determined the select bags of snacks pose a serious health hazard.