Plant protection products containing chlorothalonil remain banned

After a targeted review in December 2019, the Federal Office for Agriculture (FOAG) revoked the authorisation for plant protection products based on the active substance chlorothalonil. According to the FOAG, the use of chlorothalonil could result in harmful chlorothalonil metabolic products entering groundwater and drinking water. The ban was imposed with immediate effect, meaning there was no grace period for selling off and using up existing stock. The FOAG proceedings and decision had been preceded by proceedings in the EU that led to the decision by the European Commission in April 2019 not to renew the authorisation for the active substance, due to contamination of groundwater and drinking water and the risk to fish and amphibians (frogs, newts, etc.). This decision was upheld as lawful in the last instance.

In January 2020, Syngenta Agro AG, a supplier of a plant protection product with the disputed active substance, lodged an appeal with the Federal Administrative Court (FAC) against the FOAG decision. Syngenta objected that the metabolites repeatedly detected in groundwater – R471811 (M4) and R417888 (M12) – were not harmful to human health (not toxicologically relevant) at all. These had been qualified as "not relevant" in an expert opinion issued by the Federal Food Safety and Veterinary Office (FSVO), the competent authority which had participated in the FOAG review. In the appeal proceedings, the FSVO, as the new authorising body and first instance, argued that, despite the expert opinion, all chlorothalonil metabolites were to be considered ‘relevant’ and that, irrespectively, it should be assumed that limit values had been exceeded and that the use of chlorothalonil was a risk to human health. The FSVO was supported by similar and independent arguments by the WWF Switzerland.

Assessments under the new law
In its judgment, the FAC first determines which law is applicable. It states that the completely revised Plant Protection Products Ordinance (PPPO) which came into force on 1 December 2025 does not apply in the case at hand. On the other hand, however, amendments to individual articles of the law that came into force after the decision was issued but before the complete revision was enacted must be taken into account. One of these, Article 24(2)bis PPPO, requires the adoption of the assessment results from the EU procedure. In this procedure the European Food Safety Authority (EFSA) had concluded in its recommendation to the European Commission, and the Commission had noted in its decision, that the use of chlorothalonil posed a significant risk to amphibians and fish. On the basis of this finding alone, the Federal Administrative Court concludes that the withdrawal of the authorisation for the chlorothalonil-based plant protection product was lawful and that the appeal must be dismissed.

Non-compliance with limit values 
The Court also examines the withdrawal of the authorisation (essentially due to groundwater contamination) under the previous law and reaches the same conclusion. It firstly rejects the argument that all chlorothalonil metabolites are relevant. On the contrary, the classification of four metabolites as non-relevant, including metabolites R471811 (M4) and R417888 (M12) which are detected relatively frequently in groundwater, must be upheld. The presence of these non-relevant metabolites at levels exceeding 0.1 micrograms per litre of groundwater would not per se justify the withdrawal of the authorisation since this drinking water protection limit only applies to relevant metabolites (harmful to human health). However, considering that relevant chlorothalonil metabolites have also been detected in isolated cases at concentrations exceeding 0.1 micrograms per litre of groundwater, compliance with the limit values cannot be demonstrated. Therefore, in addition to the aforementioned environmental risk aspect, the withdrawal of the authorisation for the appellant’s chlorothalonil-based plant protection products is lawful for reasons of groundwater and drinking water protection.

Lawfulness of the refusal to grant a clearance and a use-up period
The Court also rejects the appellant’s arguments against not granting a grace period. A key factor here is the threat to amphibians and fish.

This judgment may be appealed to the Federal Supreme Court.