The eggs may contain (low) levels of the toxic substance Fipronil, used in chicken batteries to tackle parasites living on poultry. Fipronil is officially banned but apparently it was used after all.
The FAVV didn't notice until very late, because standard tests on eggs with regards to possible contamination, do not include Fipronil. In fact, the FAVV was informed by an egg producer and didn't find out itself. At present, investigations are going on in 57 different businesses.
However, there is no reason to panic. Preliminary results show there is no real problem like in the Netherlands. Fipronil levels in eggs, if any, are low and do not pose a threat to public health, the authorities repeat. This being said, official results of the news tests have not been released yet.
Experts estimate that with the present levels found in some companies in Belgium, a child of 23 kilos should eat five eggs, and adults weighing 70 kilos more than a dozen eggs in 24 hours to experience any ill effect from Fipronil, like on the liver or the thyroid gland. Belgium is hardly importing eggs from the Netherlands.