Alma Pak International LLC issued a voluntary recall for 400 boxes of its organic blueberries on June 9 due to possible listeria contamination.

The FDA elevated the recall on Tuesday, July 1, to a Class I recall — the highest, most serious recall classification. This classification is defined as a situation where there's a “reasonable probability” that consuming the contaminated product could lead to serious health issues, including death.

The Food and Drug Administration (FDA) upgraded a blueberry recall this week to the highest risk level amid concerns of contamination. The FDA raised the recall of 400 boxes that weigh 30 pounds to Class I.