Supermarket giant Aldi has withdrawn all eggs from its stores in Germany as they may have been contaminated by an insecticide.
Tests showed that the chemical fipronil, which can harm people's kidneys, liver and thyroid glands, was found in eggs imported from Netherlands.
Fipronil is used to treat lice and ticks in chickens.
One German official said that up to 10 million such eggs may have already been sold in Germany.
Christian Meyer, the Agriculture Minister for lower saxony, told German television that there was risk to children if they ate two infected eggs a day.
About 180 poultry farms in the Netherlands have been temporarily shut while investigations are carried out