Anyone putting out chips for some July 4th noshing might want to check the bags. The FDA has upgraded Utz's May recall of certain Zapp's and Dirty brand potato chips to its highest level of concern over the risk of salmonella, reports NBC News. The Class 1 alert is tied to dry milk powder used in seasonings. That powder, from California Dairies via a third-party supplier, tested negative before use, and Utz said in May that no illnesses have been reported. No details were given about the reason for the upgraded recall. USA Today lists the affected brands: