Review of ANSES’s work on prosulfocarb
Prosulfocarb is one of the most widely sold herbicidal active substances in France. For several years now, ANSES has been paying close attention to the problems posed by spray drift of prosulfocarb products. For example, the Agency has examined deposits on non-target crops following prosulfocarb treatments. It has also updated its assessment of products with regard to the exposure of local residents. Below we take stock of the work carried out by ANSES since 2017.
A highly volatile substance used in large quantities
Prosulfocarb is the second most widely sold herbicidal active substance in France. Products containing prosulfocarb are mainly used on cereal, potato, and some vegetable crops. ANSES has undertaken several actions in relation to these products since 2017, for two main reasons:
- The large quantities of prosulfocarb used in France, due to the large areas treated and the doses applied per hectare;
- The high volatility of the active substance, favouring its dispersion in the air even after application.
In light of the above, ANSES put prosulfocarb on the list of plant protection substances requiring particular attention in its 2020 report on substances of concern. From a toxicological standpoint, the substance is not classified as carcinogenic, mutagenic or reprotoxic. However, it can cause skin reactions in exposed individuals.
Several European countries, including France, have reported the presence of prosulfocarb residues in foodstuffs from untreated crops. Following its phytopharmacovigilance analysis, the Agency tightened the conditions for applying products in 2018. In particular, it required the use of nozzles that reduce spray drift by at least 66%.
The active substance prosulfocarb is currently being assessed at European level. The European Commission recently extended its approval until 31 January 2027.
Review of analyses of reports concerning prosulfocarb
- Residues on non-target crops
As part of its phytopharmacovigilance scheme, ANSES analysed several reports in France concerning the undesirable presence of prosulfocarb in apples, watercress and rocket in particular, even though this herbicide is not used on these crops. After the conditions of use of products were tightened, it updated this analysis with the latest data on levels of prosulfocarb in foodstuffs. In its analysis, it notes that the undesirable presence of prosulfocarb on non-target crops is still being observed. The concentration levels measured in foodstuffs do not exceed the risk thresholds for consumers. However, due to the abnormal presence of such residues on non-target crops, some products have been downgraded and can no longer be marketed.
- Concentration peaks in ambient air
In 2022, Atmo Nouvelle-Aquitaine, ANSES's partner for phytopharmacovigilance, reported that concentration peaks of prosulfocarb had been observed in the air in Plaine d'Aunis (Charente-Maritime) in autumn 2021. To analyse these measurements, ANSES used one of the methods implemented to interpret the results of the 2018-2019 national exploratory campaign to measure pesticides in ambient air. It concluded that these concentration levels in ambient air did not constitute a health alert.
What are phytopharmacovigilance reports?
The phytopharmacovigilance scheme collects reports of adverse effects related to the use of plant protection products. These reports come from declarations made by professionals, as well as from measurement systems and research work. Each report is analysed to decide whether it constitutes an alert requiring the implementation of risk management measures, or whether it needs to be further investigated, in particular via specific studies or increased surveillance.
Updating of the assessment of risks to local residents
In this context, ANSES carried out a new assessment of the risks to local residents, taking into account the most recent methodological developments relating to exposure due to the application of products. This update was produced in response to a formal request concerning prosulfocarb received from the French Ministry of Agriculture.
To estimate this exposure, the Agency used the exposure estimation methods updated in 2022 by the European Food Safety Authority (EFSA) to further strengthen the protection of residents and bystanders.
Following this assessment, ANSES could not rule out the possibility of safety thresholds being exceeded for children within 10 metres of the crop during treatment, mainly in the event of dermal exposure.
Therefore, in October 2023, the Agency decided to impose new conditions for the use of products, effective immediately:
- Reduction of at least 40% in the maximum authorised doses of prosulfocarb per hectare.
- Obligation to use agricultural equipment for the application of products (nozzles) enabling a 90% reduction in spray drift, and to maintain a buffer zone of 10 metres from residential areas, or to apply a buffer zone of 20 metres until these more efficient nozzles have been acquired.
By 30 June 2024, holders of marketing authorisations for these products will be required to submit data on the impact of these new conditions of use on reducing the exposure of local residents. If no convincing evidence is provided, authorisations will be withdrawn immediately.