For nearly a decade, freshness dating has been used by the dairy industry to indicate when a carton or bottle of milk should be pulled from the shelf or used. In January, the California egg industry began doing the same, reports Ralph Ernst, a UC Davis Cooperative Extension poultry specialist. "On the average an egg can maintain its freshness for up to 30 days after it leaves the processor," says Ernst. "Under a new state law, however, retailers now must stamp each egg carton with a highly visible 'pull-by' date." Consumers now can easily see for themselves when the product is to be sold before it loses its quality. In addition to the "sell by" dating, retailers also must maintain egg refrigeration levels at 45 degrees, the same temperature at which eggs should be stored in the home refrigerator, Ernst says.