Agriculture Members of the European Parliament (MEPs) said the EU must improve information sharing on food safety risks via the Rapid Alert System for Food and Feed (RASFF).
Concerns were raised on how an alert was only made in July when sampling took place in May and how it was possible that use of fipronil went undetected since last year.
Fipronil is an insecticide used to control fleas, cockroaches and ants but cannot be used for animals intended for the food chain.
The World Health Organization (WHO) has classified it as a moderately hazardous pesticide.
“The early warning system RASFF is not rapid enough or effective enough,” said Ulrike Müller (ALDE, Germany).
Michel Dantin (EPP, France) suggested fines for EU states who fail to share crucial safety information.
Millions of chicken eggs withdrawn and farms blocked
The Commission said it became aware of contaminated eggs on 20 July when Belgian authorities informed all Member States through RASFF. So far, 22 EU member states have been affected.
Millions of chicken eggs have been withdrawn and all farms where products containing fipronil could have been used have been blocked from placing potentially tainted products on the market. Most of these farms were in the Netherlands (281) and Belgium (93).
Illegal treatment with other unauthorised substances - such as amitraz - is also being investigated but testing by Belgium and the Netherlands in eggs did not find any such residues.
Sabine Jülicher, the director for food and feed safety, innovation at DG SANTE, said there is evidence illegal treatments took place in late 2016 but the scale of the issue has become clear since July this year.
“Farms in Germany (seven) and one laying hen farm in France are concerned. More recently illegally treated farms have been found in Italy and Hungary and there is further suspicion that also some farms in Poland, Romania and the Czech Republic were illegally treated,” she said.
“However, it seems that these are independent occurrences of the one that is around Netherlands, Belgium, Germany and France.
“Judicial investigations are ongoing…in Belgium, the Netherlands and Germany. The affected farms will only be unblocked once there is evidence that the eggs and the chicken meat coming from these farms are fully compliant with the EU maximum residue levels and relevant sanitary requirements.”
Countries ban imports
Ukraine has banned imports of eggs, egg products and poultry meat from Belgium, Netherlands, Germany and France from 21 August and Brazil has prohibited import of egg products from one establishment in Belgium and one in Netherlands.
Controls on the possible use of fipronil in laying hen farms in South Korea and Taiwan have found several instances on several farms. China is also looking into its possible use on domestic laying hen farms.
Other countries such as the US, Japan, Malaysia and Russia have requested more information but no restrictive measures have yet been put in place by these countries.
For eggs, European legislation sets the maximum residue level (MRL) at 0.005 mg/kg.
The European Commission proposed 0.72 mg/kg as the limit from which eggs contaminated with fipronil could present an acute health risk.
Levels up to 1.2 mg/kg have been detected in chicken eggs and meat in Belgium.
The Joint Research Centre is organising a proficiency test for official control labs to analyse fipronil in eggs, egg products and chicken meat.
A fact finding mission is planned for September or October in most concerned member states by the European Commission to gather information as part of future follow-up.