Eggs, coming mainly from the Netherlands, have been found to contain a fipronil, a substance used to kill lice and ticks on animals that is banned by the European Union for use in the food industry.
It is thought that fipronil was added to disinfectant used on some chicken farms.
The contaminated eggs have mainly come from the Netherlands, followed by Belgium and Germany.
In large quantities, the insecticide is considered to be "moderately hazardous" according to the World Health Organization, and can have unsafe effects on people's kidneys, liver and thyroid glands. However, food standards agencies played down the risks for anyone who already had the tainted eggs.
The FSA said as this represents 0.007% of the eggs we consume in the United Kingdom every year, there is unlikely to be 'any risk to public health from consuming these foods'.
The FSA said investigations indicated it was "very unlikely" that the eggs posed a risk to public health but nonetheless said they were urgently investigating where they may have been sold.
These would likely be mixed with other eggs that were not from affected farms, making "Fipronil residues highly diluted", the FSA said.
Two people have been arrested in connection with the latest food scandal to hit Europe, Dutch prosecutors said.
The British Egg Industry Council said shell eggs on sale to consumers in the United Kingdom were not affected.
The Netherlands is one of the largest exporters of eggs and egg products in the world.
FSA chairwoman Heather Hancock said: "I'm confident that acting quickly is the right thing to do".
The spiralling scandal also spread to an eighth country, Luxembourg, which announced that it too had found eggs containing the insecticide fipronil, which can be harmful to human health.
Dutch and Belgian police have been investigating reports of contamination in their jurisdictions while some supermarkets in Germany withdrew stocks of eggs earlier this month.
The FSA said 85% it had "no evidence" that any eggs laid in the United Kingdom were contaminated.
Van der Molen says the Dutch raids on Thursday are part of a joint action with Belgian authorities.