Toxicologic studies on 3′,4′-dichloropropionanilide

Abstract

Studies on 3′,4′-dichloropropionanilide (DCPA), a selective herbicide, are presented. For rats and dogs the single estimated po LD50 ± SD values are 1384 ± 99 mg/kg and 1217 ± 8 mg/kg, respectively. In subchronic (13 wk) studies in rats on 0, 100, 330, 1000, 3300, 10,000 and 50,000 ppm diets, survival of rats on the 50,000 ppm diet was affected, and at 10,000 and 3300 ppm, growth and feed consumption were depressed. Polychromatophilia was observed in rats on the 1000 and 330 ppm diets; the effect was marked in rats on the 10,000 and 3300 ppm diets. Significant decreases in hemoglobin values were found between controls and the 3 highest diet levels for 13 wk. In a chronic (2 yr) study in rats on 0, 100, 400 and 1600 ppm diets, significant decrease in growth and increase in organ-to-body weights ratio for spleen, liver of females, and testes of rats on the 1600 ppm diet were noted. No dose-related effects were noted on hemograms, except for significant decreases in hemoglobin values for females on the 1600 ppm diet, urinary findings and histopathology. In a 2 yr study in dogs on 0, 100, 600 and 4000 ppm diets, no adverse trends were noted on survival, hematology, urinary findings, liver function tests, organ-to-body weight ratios (with the exception of the heart of dogs on the 4000 ppm diet) and histopathology. However, body weight of dogs on 4000 ppm diets was significantly depressed. In multigeneration studies in rats on 0, 100, 300 and 1000 ppm diets, no apparent deleterious effects or adverse trends were noted. Histopathologic studies on F 3b weanlings revealed no lesions. In summary, this study establishes 400 ppm as the overall apparent no-effect level.