2014 Volume 2 Issue 1 Pages 16
The Food Safety Commission of Japan (FSCJ) conducted a risk assessment of an isoxazoline herbicide fenoxasulfone (CAS No. 639826-16-7). Major adverse effects observed are: degeneration in the peripheral nerves of dogs, renal papillary necrosis, chronic progressive nephrosis and others in the kidney, and increased organ weights, centrilobular hypertrophy of hepatocytes and others in the liver. No carcinogenicity, effects on reproductive ability, developmental toxicity or genotoxicity was observed. Nerve fiber degeneration and other effects in the peripheral nerves were observed in a 90-day subacute toxicity study and a one-year chronic toxicity study in dogs, indicating neurotoxicity of fenoxasulfone. Based on the results from various studies, FSCJ specified the residue definition for this dietary risk assessment in agricultural products and seafood to be fenoxasulfone (parent compound only). The lowest no-observed-adverse-effect level (NOAEL) in toxicological studies was 17.6 mg/kg body weight/day in an 18-month carcinogenicity study in mice. Applying the safety factor of 100 to this NOAEL, FSCJ specified the acceptable daily intake (ADI) to be 0.17 mg/kg body weight/day.