Statement on the active substance flupyradifurone

Following Regulation, Imidacloprid Persists and Flupyradifurone Increases in Nontarget Wildlife

After regulation of pesticides, determination of their persistence in the environment is an important indicator of effectiveness of these measures. We quantified concentrations of two types of systemic insecticides, neonicotinoids (imidacloprid, acetamiprid, clothianidin, thiacloprid, and thiamethoxam) and butenolides (flupyradifurone), in off-crop nontarget media of hummingbird cloacal fluid, honey bee (Apis mellifera) nectar and honey, and wildflowers before and after regulation of imidacloprid on highbush blueberries in Canada in April 2021. We found that mean total pesticide load increased in hummingbird cloacal fluid, nectar, and flower samples following imidacloprid regulation. On average, we did not find evidence of a decrease in imidacloprid concentrations after regulation. However, there were some decreases, some increases, and other cases with no changes in imidacloprid levels depending on the specific media, time point of sampling, and site type. At the same time, we found an overall increase in flupyradifurone, acetamiprid, thiamethoxam, and thiacloprid but no change in clothianidin concentrations. In particular, flupyradifurone concentrations observed in biota sampled near agricultural areas increased twofold in honey bee nectar, sevenfold in hummingbird cloacal fluid, and eightfold in flowers after the 2021 imidacloprid regulation. The highest residue detected was flupyradifurone at 665 ng/mL (parts per billion [ppb]) in honey bee nectar. Mean total pesticide loads were highest in honey samples (84 ± 10 ppb), followed by nectar (56 ± 7 ppb), then hummingbird cloacal fluid (1.8 ± 0.5 ppb), and least, flowers (0.51 ± 0.06 ppb). Our results highlight that limited regulation of imidacloprid does not immediately reduce residue concentrations, while other systemic insecticides, possibly replacement compounds, concurrently increase in wildlife. Environ Toxicol Chem 2024;43:1497-1508. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Metabolites in the regulatory risk assessment of pesticides in the EU

A large majority of chemicals is converted into metabolites through xenobiotic-metabolising enzymes. Metabolites may present a spectrum of characteristics varying from similar to vastly different compared with the parent compound in terms of both toxicokinetics and toxicodynamics. In the pesticide arena, the role of metabolism and metabolites is increasingly recognised as a significant factor particularly for the design and interpretation of mammalian toxicological studies and in the toxicity assessment of pesticide/metabolite-associated issues for hazard characterization and risk assessment purposes, including the role of metabolites as parts in various residues in ecotoxicological adversities. This is of particular relevance to pesticide metabolites that are unique to humans in comparison with metabolites found in in vitro or in vivo animal studies, but also to disproportionate metabolites (quantitative differences) between humans and mammalian species. Presence of unique or disproportionate metabolites may underlie potential toxicological concerns. This review aims to present the current state-of-the-art of comparative metabolism and metabolites in pesticide research for hazard and risk assessment, including One Health perspectives, and future research needs based on the experiences gained at the European Food Safety Authority.

Modification of the existing maximum residue levels and setting import tolerances for flupyradifurone and difluoroacetic acid (DFA) in various crops

In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant Bayer AG, Crop Science Division submitted a request to the competent national authority in the Netherlands to modify the existing maximum residue levels (MRL) and to set import tolerances for flupyradifurone and its metabolite difluoroacetic acid (DFA) in various plant commodities. The data submitted in support of the request were found to be sufficient to derive MRL proposals for flupyradifurone and DFA in avocados, mangoes, papayas, asparagus, sesame seeds, sunflower seeds, sugar beet roots and chicory roots. Adequate analytical methods for enforcement are available to control the residues of flupyradifurone and DFA in plant matrices under consideration at the validated limits of quantification (LOQs) of 0.01 and 0.007 mg/kg, respectively. Based on the risk assessment results, EFSA concluded that the short-term and long-term intake of flupyradifurone and DFA residues resulting from the use of flupyradifurone according to the reported agricultural practices is unlikely to present a risk to consumer health.

Modification of the existing maximum residue levels and setting of import tolerances for flupyradifurone and DFA in various crops and animal commodities

In accordance with Article 6 of Regulation (EC) No 396/2005, the applicant Bayer CropScience SA-NV submitted a request to the competent national authority in the Netherlands to modify the existing maximum residue levels (MRLs) and to set import tolerances for the active substance flupyradifurone and its metabolite difluoroacetic acid (DFA) in various plant and animal commodities. The data submitted in support of the requests were found sufficient to derive MRL proposals for flupyradifurone and/or DFA in the crops under consideration. The calculated EU livestock dietary burden indicated that for several animal matrices the EU MRLs for flupyradifurone and/or DFA would need to be modified. Adequate analytical methods for enforcement are available to control the residues of both compounds in the plant and animal commodities under consideration, and in honey. Based on the risk assessment results, EFSA concluded that the proposed and authorised uses of flupyradifurone on various crops and subsequent residues of flupyradifurone and DFA in plant and animal commodities will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a risk to consumers' health.

Revised guidance on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees)

The European Commission asked EFSA to revise the risk assessment for honey bees, bumble bees and solitary bees. This guidance document describes how to perform risk assessment for bees from plant protection products, in accordance with Regulation (EU) 1107/2009. It is a review of EFSA's existing guidance document, which was published in 2013. The guidance document outlines a tiered approach for exposure estimation in different scenarios and tiers. It includes hazard characterisation and provides risk assessment methodology covering dietary and contact exposure. The document also provides recommendations for higher tier studies, risk from metabolites and plant protection products as mixture.