Over the past few weeks, concern has been growing regarding the contamination of eggs for sale in a number of EU countries with the chemical Fipronil. Currently seven different countries have discovered contaminated eggs, and it has led to large number of eggs being withdrawn from sale. So, what is Fipronil, how has it gotten into eggs, and should consumers be worried?
The chemical culprit behind the contamination, Fipronil, is an insecticide which can be used against a wide range of pests, and it is commonly used in veterinary products to remove fleas, lice, and ticks. It’s also used in agricultural products for insecticidal purposes. It interferes with the central nervous systems of insects by blocking certain ion channels, leading to overstimulation of nerves and muscles. It doesn’t affect mammals as some of the ion channels it targets in insects do not exist in mammals.
Though Fipronil is widely used, there are certain regulations surrounding its utilisation by farmers. In particular, it is not permitted for it to be used on, or even around, food-producing animals. This is because it can be absorbed through animal skin, and it can have toxic effects on humans if ingested. So how has it ended up in eggs for human consumption?
While the exact details are still unclear, it’s been discovered that Fipronil had been added to a red mite treatment, Dega-16, presumably in order to enhance its effectiveness. Red mites are common poultry pests, and if left untreated can cause hens to become anaemic and stop laying eggs. A criminal investigation into how Fipronil came to be added to Dega-16 is underway; in the meantime, 180 farms in the Netherlands were temporarily shut down after traces of Fipronil were found.
Many eggs from these farms had already been exported, however. Belgium, Germany, France, Switzerland, Sweden, and the United Kingdom* have all previously imported affected eggs, and millions of these eggs have had to be recalled and withdrawn from sale. It was warned that one particular batch of eggs, with the serial code 2-NL-4015502, contained levels of Fipronil high enough to constitute an acute risk to human health. Other batches contained lower levels of Fipronil, which pose less of a risk, though it was warned that it was still above the daily recommended intake levels for children. The batch numbers affected were as follows (where X represents any number): X-NL-41679XX, X-NL-42071XX, X-NL-42659XX, X-NL-42766XX, X-NL-43113XX, X-NL-43326XX, X-NL-43514XX , X-NL-43640XX, X-NL-43835XX, X-NL-43879XX.
The World Health Organisation classifies Fipronil as ‘moderately toxic’. Human ingestion of large amounts of the insecticide can lead to kidney, liver, and thyroid damage. However, the amounts present in contaminated eggs are much lower than this level, and are unlikely to represent a risk to public health. A toxicologist from Utrecht University, Martin van den Berg, has been quoted in Dutch media as saying that the contaminated eggs would only be dangerous “if you eat them every day throughout your life.” In addition, the ongoing investigation has ascertained that any affected eggs have already been withdrawn from sale in the countries to which they had been exported.
The investigation into the exact story behind the contamination is still ongoing. The Dutch farms affected will be hit by being temporarily closed down, but the good news is that there may not be a need to slaughter all the affected chickens. Fipronil exits chicken systems within 6-8 weeks, so as long as the facilities are cleaned to remove traces of Fipronil, it should be possible for the farms to eventually get back into business, free from contamination. However, other reports suggest that chickens may still face culling.
This graphic and article are based on news and studies to date (9 August 2017). It will be updated if there are further developments that contradict current information.
*Update 11 August 2017: Reports have stated that as well as the original seven countries identified as having imported contaminated eggs, a further 8 countries have since been implicated. These are Luxembourg, Romania, Italy, Austria, Slovenia, Slovakia, Denmark, and Ireland. Hong Kong is also reported to have imported a number of the contaminated eggs. Two people have been arrested as part of the investigation into how the eggs came to be contaminated, with a Belgian pest control firm and a Dutch poultry farm cleaning company in the spotlight.
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References & Further Reading
- Fipronil fact sheet – National Pesticide Information Centre
- Fipronil – What is it and how did it get into our eggs? – G Heise, Deutsche Well
- Millions of ‘bad eggs’ recalled in contamination scandal – N Stafford, Chemistry World
- Update on Fipronil in eggs – Food Standards Agency
- Fipronil: Environmental fate, ecotoxicology, and human health concerns (£) – C C D Tingle and others
- Health assessment of individual levels of Fipronil levels detected in foods of animal origin in Belgium – Bundesinstitut für Risikobewertung