Mammalian toxicology overview and human risk assessment for sulfosulfuron

Sulfosulfuron is a low-use rate sulfonylurea herbicide. A review of the toxicity database for sulfosulfuron indicates that the molecule has a low order of acute toxicity. It is not genotoxic and is not a reproductive, developmental, or nervous system toxicant. There were no indications of endocrine disruption in any study performed with the molecule. The only findings considered to be an adverse effect in mammalian laboratory animals following prolonged subchronic or chronic exposure to sulfosulfuron were isolated to the urinary tract. These findings occurred in conjunction with findings of urolith formation following high-level chemical dosing, resulting in epithelial hyperplasia that, in a few cases, progressed to tumor formation. Mode-of-action information supports the conclusion that these tumors result from a non-genotoxic, threshold-based process that is well established and widely considered to be not relevant to humans. Based on its short-term, infrequent application pattern and very low use rate and crop residues, aggregate and cumulative risk assessments indicate that sulfosulfuron has substantial margins of exposure and does not represent a significant risk to human health.