A new set of safety rules went into effect July 9 aimed at curbing salmonella contamination in eggs. The rules, a coordinated strategy between the U.S. Food and Drug Administration (FDA) and the Food Safety and Inspection Service (FSIS) , requires egg processors having more than 50,000 laying hens to add preventive measures and use refrigeration when storing and transporting eggs, among other things.

Large producers that don’t sell all of their eggs directly to consumers and those who transport or hold eggs must comply with the rule’s refrigeration requirements. Producers with fewer than 50,000 but at least 3,000 laying hens whose shell eggs are not processed with a treatment like pasteurization must comply with the new rules by July 9, 2012, while producers having less than 3,000 hens are not covered by the rule.