Luxembourg, Denmark, Slovakia and Romania became the latest European countries hit by a scare over tainted eggs contaminated with the chemical fipronil, with supermarket chains pulling them from the shelves and other firms affected, authorities said. One batch in Luxembourg contained so much fipronil it was unsafe to be eaten by young children, said the government statement. Fipronil is commonly used in veterinary products to get rid of fleas, lice and ticks but it is banned by the EU from being used to treat animals destined for human consumption. In large quantities, the insecticide is considered by the World Health Organisation to be “moderately hazardous” and can have dangerous effects on people’s kidneys, liver and thyroid glands. In joint raids with Belgium, Dutch prosecutors said they had arrested “two managers at the company that allegedly used the substance at poultry farms”, with Dutch media naming the suspects’ firm as Chickfriend. Farmers in the Netherlands – one of Europe’s biggest egg exporters – and Belgium have previously identified Chickfriend as the company that they hired to treat their chickens to eradicate the parasite red lice. Belgium lashed out at the Netherlands for covering up the scandal, which it says Amsterdam knew about as early as November 2016. But at that time there was no indication of an acute danger to food safety. There was also no indication that fipronil could be present in eggs.