On October 5, 2023, the interim relief judge of the Amiens Administrative Tribunal refused to grant the application for interim measures filed on September 7, 2023 by the ROSO association (Regroupement des organismes de sauvegarde de l'Oise). The association's aim was to obtain the imposition of measures restricting the consumption of water in certain municipalities where the health value ("valeur sanitaire") for metabolites of chloridazone, a substance banned from sale and use since 2021, has been exceeded.

ROSO complains that the National Health Agency (Agence Régionale de Santé or ARS) has not taken any measures to restrict water consumption after discovering that the results of tests carried out on water in the communes of Ecuvilly and Margny-sur-Matz exceed the 3µg/l limit set by the Ministry of Public Health in an instruction dated June 15, 2022. The association objects to the ARS's method of calculating chloridazone concentration, based on an annual average, and calls for the health value to be taken into account on a regular basis, in accordance with current regulations.

ROSO is also asking ARS to be more transparent in publishing readings of water concentrations of the chlorothalonil metabolite R471811, another pesticide-derived molecule whose levels are close to the 3µg/l limit.

In a counter-memorial filed on September 22, 2023, ARS argues on the contrary that the 3µg/l limit is an indicative value, a risk management tool adopted in a context of uncertainty in application of the precautionary principle, but not a mandatory limit. ARS also considers that the urgency required to qualify a request for interim relief is not characterized, in that the effects of exposure exceeding 3µg/l remain uncertain. Furthermore, ARS points out that analysis results vary enormously on the same point, and that restrictive measures are therefore unnecessary.

The interim relief judge upheld the ARS's argument, noting that the Minister of Health's instructions did not require the ARS to recommend restrictions on water use in the event of the transitory health value being exceeded, but simply to "rely on the transitory health values [to] manage local situations while awaiting the opinion of ANSES". It is only when the 3µg/l limit is exceeded over a "sufficiently representative" period of time that the ARS must recommend that the prefect impose restrictions on water use.

In view of the reinforced monitoring measures already adopted by the ARS, the absence of a regulation requiring the ARS to recommend restrictive measures automatically when the transitional health value is exceeded, and the fact that the ROSO has not provided proof that "[the] exceedances of the transitional health value would be such as to entail particular health risks", the application for interim relief is rejected.