Succinate dehydrogenases are ubiquitous enzymes involved in cell respiration in a vast number of living organisms: bacteria, moulds and mammals, including humans. Blocking this essential cell function with inhibitors known as succinate dehydrogenase inhibitors (SDHIs) is the basis for the effectiveness of this class of compounds, which have been used over the past couple of decades to combat fungal plant diseases.
Because succinate dehydrogenases are known to be implicated in certain diseases in humans, several scientists formulated the hypothesis, in a recently-published press article, that there may be health risks associated with the use of SDHIs as fungicides in agriculture.
Like all active plant protection substances, SDHIs had to be assessed for their toxicity to mammals (including their genotoxicity and carcinogenicity) and the potential risks presented by their uses, before being approved at European level and before any products containing them could be placed on the market by the Member States.
After being contacted by the principal author of this alert last November, ANSES made available its toxicity assessment dossiers for these products, with a view to discussing any new data resulting from this research work. In accordance with its principles for dealing with alerts, the Agency has now set up a dedicated expert group that will be tasked with interviewing the researchers raising the alert, and examining the evidence mentioned in light of the scientific literature and any data provided by the phytopharmacovigilance scheme.
The main aim of this work will be to determine whether any new evidence should be presented at European level and, if necessary, to take any risk management measures that seem appropriate.
Reminder of the procedure for assessing risks prior to approving active substances and authorising plant protection products
Assessing the toxicity of active substances and plant protection products is a mandatory requirement prior to placing them on the market. It is mainly based on tests on animals, as well as in vitro tests on cell lines, including those from humans. It takes into consideration all the mechanisms liable to produce a harmful effect and determines the conditions for use, to ensure the absence of adverse effects for humans (workers, local residents and consumers of treated foods) and the environment.