The opinion, drawn up by EFSA’s Biohazards expert Panel, focused on the risk from Salmonella Enteritidis, which is able to multiply in eggs during storage. The Panel used a quantitative predictive model supplied by the Australian Egg Corporation to compare current egg storage practice in the EU with a number of different scenarios with varying sell-by and best-before dates.
They found that extending the sell-by date for eggs for domestic consumption from 21 to 28 days increased the risk of Salmonella infection by 40% for uncooked and 50% for slightly cooked eggs. The results for eggs used in catering establishments were similar. If the sell-by date was extended to 42 days and the best-before date to 70 days, the risk increased by a factor of three.
The Panel concluded that the only way to reduce the increased risk from extended storage would be to refrigerate all eggs. But extending sell-by and best-before dates for more than three weeks would still increase the risk even with refrigeration in shops.
The opinion was produced at the request of the European Commission to inform any future discussion on date marking eggs. It can be found in full on the EFSA website here.