The US Food and Drug Administration (FDA) upgrades a voluntary recall for multiple popular potato chip brands to its most serious alert level due to a potential risk of salmonella contamination. The action follows an earlier voluntary recall issued by Utz Quality Foods in May covering select varieties of Zapp’s and Dirty potato chips. The company traces the concern to seasoning ingredients that may contain salmonella, specifically dry milk powder sourced from a third-party supplier used in the production of the seasoning.

The FDA estimates that about 650,000 bags of the affected potato chips are involved. The recall concerns particular product varieties rather than all items under the brands. CNET and The Guardian report that the FDA’s most serious classification is used when there is a reasonable probability that exposure to the product will cause serious adverse health consequences or death. Consumers are advised to check their purchases against the recall information issued by the FDA and the manufacturer and to follow return or disposal guidance provided as part of the recall.