Last week journalist revealed how the Dutch food and product safety board (Nederlandse Voedsel- en Warenautoriteit, or NVWA) banned 180 poultry farms from sending their eggs to market because they may be contaminated with the pesticide fipronil.

And on top of that, the NVWA warned consumers not to eat eggs with the code X-NL-40155XX, as these contain enough fipronil to present “an acute danger to public health.”

And now RIKILT - which is part of Wageningen University & Research and carries out independent research into the safety and reliability of food, specializing in measuring substances and examining their composition and effect on the human body and proving food fraud and conducting forensic research - is investigating further. 

Business Unit Manager Leen van Ginkel and Researcher Pesticides & Mycotoxins Theo de Rijk of RIKILT says that RIKILT has been asked to conduct part analyzes of Dutch eggs from several poultry companies over the holiday period. 

So far, his team has analyzed 230 boxes of ten or twelve eggs with more to come. 

Seeing as this was the first time that fipronil was found in eggs, Van Ginkel explains how RIKILT analysts had to first adapt the test so it was suitable for analysis on eggs before getting started. 

“We had to make the existing test for fixing fipronil in bees suitable for analysis on eggs so that the results of the analysis are 100 percent reliable and reproducible,” he says. 

How does the analysis work?
The eggs from a single box are chopped, bottled and shaken. A small sample is taken from which the solvent acetonitrile is added. Then this goes through centrifuge so that the bottom of the fat and protein is on top of the liquid. This fluid is analyzed by liquid chromatography and mass spectrometry. A graph will show peaks and analysts compare with known concentrations of fipronil, so that they can accurately determine how many micrograms of fipronil there were in kilograms per kilogram.

What was the outcome of the analysis?
“There were negative and positive results, so eggs above the internationally established standard of five micrograms of fipronil per kilogram of egg and eggs below that limit,” adds Van Ginkel.

“Because all samples are encrypted, the NVWA can reduce the results to the poultry house wher the eggs came from.”

The NVWA has also asked RIKILT to take into account the quality assurance of the analyses carried out by other, mostly commercial laboratories. 

It is expected that these laboratories will also carry out analyzes in the coming weeks. As a national reference laboratory, RIKILT assesses the quality of these analyzed.

Contamination fears
As news of the scandal ripples through Europe, retail discounter Aldi has removed its eggs from the shelves of German supermarkets amid safety concerns. 

Fipronil is used to treat lice and ticks in chickens and some tests show that it can harm kidneys, the liver and thyroid gland. 

While European supermarkets are believed to be stopping the distribution of eggs from the affected batches, Aldi, with approximately 4,000 supermarkets across Germany, is the first retailer to pull the eggs from sale as a precautionary measure. 

As Europe’s largest egg exporter, the Netherlands supplies around 65 percent of the 10 billion eggs it produces every year to overseas markets. 

Authorities in Belgium, Sweden and Switzerland are also understood to be tracking egg shipments and considering a removal from the shelves, as the impacts of the food safety scandal widened.