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

A recall of one of America’s favorite snacks has been classified as high risk for people with milk allergies. Here’s everything you need to know.

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

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

The U.S. Food & Drug Administration has recalled a popular brand of potato chips saying the product may be high risk for some consumers.

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.

The FDA has upgraded a recall of Lay’s Potato Chips to the highest level possible, meaning consuming the chips will cause adverse health consequences. In December, Texas-based food manufacturer Frito Lay recalled a limited number of Lay’s Classic 13oz because the product could contain undeclared milk ingredients.

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

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.