Infant formula sold in Switzerland still contains traces of cereulide, a toxin that can cause vomiting and diarrhoea in babies, according to an investigation by RTS. Although the products comply with the emergency threshold adopted by European food-safety authorities, the broadcaster questions both the scientific basis of that limit and the testing methods used to measure the toxin.
In March 2026, laboratory tests carried out by the Geneva cantonal chemist detected cereulide in 10% of powdered infant formula samples. Six products tested positive. The testing followed the contamination scandal earlier this year, which triggered large-scale recalls across Europe.
Despite the findings, the products remained on supermarket shelves. The concentrations detected were below the maximum level established in February by the European Food Safety Authority (EFSA), leaving no legal basis for a recall. Responsibility for deciding whether the products could remain on sale rests with Switzerland’s Federal Food Safety and Veterinary Office (FSVO). The authorities have nevertheless instructed the manufacturers concerned to investigate the source of the contamination and strengthen their production processes where necessary. In the meantime, parents may still buy products containing the toxin without being informed.
The RTS investigation raises two broader concerns. First, products containing cereulide remain on sale because they fall below an emergency reference value introduced during the contamination crisis. Second, scientists may have underestimated the amount of toxin present because many laboratories initially tested the dry powder rather than the formula after it had been mixed with water.
How reliable is the safety threshold?
Safety limits are normally based on well-established evidence. Cereulide is unusual because no regulatory threshold existed before the contamination crisis. The EFSA established the current reference value through an expedited risk assessment conducted during the outbreak.
The FSVO says exposure below this level is not expected to harm healthy infants. However, correspondence obtained by RTS suggests the agency itself has adopted a more cautious interpretation.
In exchanges with Danone, the FSVO reportedly wrote that it did not share the company’s interpretation of the reference dose. It described the EFSA value as the result of a rapid risk assessment carrying the status of a recommendation rather than a definitive safety limit, adding that how other countries or the European Union interpreted the value was not binding in Switzerland.
Some researchers also question the effects of repeated exposure to small amounts of cereulide over time. For now, there is no scientific consensus.
Were laboratories measuring the toxin correctly?
The investigation also raises questions about the analytical methods used after the contamination scandal emerged.
According to RTS, manufacturers and regulators across Europe initially analysed the powdered formula itself. However, cereulide is encapsulated in microscopic oil droplets that are released only once the powder is mixed with water, as it is before feeding. Testing the dry powder can therefore significantly underestimate the amount of toxin actually consumed by infants.
According to Sciensano, the Belgian laboratory regarded as Europe’s reference centre for cereulide testing, analyses of reconstituted formula detect between 35 and 135 times more cereulide than tests performed on dry powder, depending on the sample.
European authorities formally acknowledged the problem on January 30th, when a senior European Commission official wrote to member states and Switzerland advising laboratories to change their analytical methods. The email, seen by RTS, stated that infant formula should first be reconstituted to ensure complete extraction of cereulide before analysis. It also urged laboratories to adopt the recommended procedures to improve the accuracy of testing. Switzerland did not need to revise its own protocol because national testing began only on February 6th, after the Commission had issued the guidance.
Nestlé acknowledged to RTS that current analytical methods have technical limitations but said it aims to eliminate cereulide entirely from its products. Hochdorf said it follows the same approach. Danone, despite repeated requests for comment, was less forthcoming.
Where did the contamination come from?
The contamination did not originate in the milk itself. Investigations by manufacturers and regulators traced the source to arachidonic acid (ARA) oil, an ingredient routinely added to infant formula because it supports brain, eye and immune development. The contaminated ARA oil was supplied by a Chinese manufacturer and incorporated into products made by several formula companies, explaining why recalls spread across multiple brands and countries.
More on this:
RTS article (in French) – Take a 5 minute French test now
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