Switzerland’s ban on chlorothalonil will remain in force, according to a ruling by the Federal Administrative Court published on Thursday. Judges dismissed an appeal by Syngenta, which had challenged the prohibition of fungicides containing the substance.
The ban dates back to December 2019, when the Federal Office for Agriculture withdrew approval for plant-protection products based on chlorothalonil. The decision, which took effect on January 1st 2020, meant that existing stocks could no longer be sold. The concern was that the chemical can break down into potentially harmful metabolites that seep into groundwater and drinking water.
Syngenta argued that these degradation products are not harmful to human health. The court disagreed.
Environmental risks decisive
The judges pointed to a significant risk to aquatic life, particularly amphibians and fish. That alone, they said, was sufficient to justify the ban.
They also noted that metabolites had been detected in groundwater at levels exceeding 0.1 micrograms per litre—the legal threshold. Even if such cases were isolated, their presence indicated that safety limits had been breached. The ban was therefore warranted on grounds of both environmental protection and water safety.
The environmental group WWF, which took part in the proceedings, argued that chlorothalonil posed a serious threat to wildlife and, through water contamination, to public health.
Switzerland’s stance mirrors that of the European Union, which banned the substance in 2019 over similar concerns.
The ruling is not final. Syngenta may still appeal to the Federal Supreme Court.
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