Abstract
Vendex 50 WP (Fenbutatin oxide) are widely used for agriculture applications. To assess hazard potential of air-born Vendex 50 WP, the long-term inhalation study in male and female rats was performed according to OPPTS test guideline. The rats were nose only exposed to 0.002 mg a.i./L air (G2), 0.008 mg a.i./L air (G3), 0.016 mg a.i./L air (G4 and G6) for 6 h/d, 5 d/week for 4 weeks in the 28-day study, respectively. A variety of biological clinical chemistry, hematology, urine analysis, organ weight and histopathology were examined. The results of satellite group animals exposed for 28-days are available. In present study, The treatment of Vendex 50 WP was associated with decreased in prothrombin time, increased in absolute and relative weights of lungs, increased in volume and pH of urine and decreased in specific gravity of urine at 0.008 mg a.i./L air (intermediate concentration) and 0.016 mg a.i./L air (high concentration). In the absence of any histopathologic findings in organs associated with these findings, which were considered as an adaptive response to test item treatment in the absence of any histopathological findings. Therefore, the No Observed Adverse Effect Concentration Level (NOAECL) is 0.016 mg a.i./L air , when administered through inhalation for up to 28 days to in Wistar rats under the procedure and conditions followed in the present study. Whereas, the No Observed Effect Concentration Level (NOECL) of Vendex 50 WP is 0.002 mg a.i./L air.
