Properties, mode of insecticidal action, environmental exposure pathways, and uses of the insecticide sulfoxaflor; sulfoxaflor environmental science review part I

Sulfoxaflor (SFX, CAS# 946578-00-3) is marketed by Corteva Agrisciences Inc. as Isoclast®. SFX is a Group 4C, nicotinic acetylcholine receptor agonist and is a systemic insecticide that is most active against sucking insects. This paper critically reviews and characterizes the physical and chemical properties of SFX to facilitate development of conceptual models that identify environmental compartments with the greatest potential concentrations and organisms most likely to be exposed. These conceptual models were assessed in a Weight of Evidence (WoE) framework to identify scenarios and organisms at greatest risk. The solubility of SFX in water is approximately 550 mg L^{− 1} and the P_OW of 0.8, so it will not bioconcentrate or undergo trophic transfer. It has the potential to move in soils, but this is unlikely because of the short half-life (hours to 2–5 days) in agricultural soils where bacteria mediate dissipation. Some of the transformation products of SFX have longer half-lives (months) in soil and are more mobile but are less toxic and not a concern for adverse effects. SFX does not undergo significant photolysis or hydrolysis in water, but this does not lead to a risk in aquatic systems because it is not approved for over-water use and the label recommends buffer zones to protect sensitive aquatic areas. Overall, use of SFX under good agricultural practices is unlikely to result in biologically relevant exposures in non-target species or areas in the environment.