Fensulfothion

Abstract

The acute oral LD₅₀ of both fensulfothion and fensulfothion sulphone was between 6 and 10 mg active ingredient (a.i.)/kg body weight for male rats and between 2 and 3 mg a.i./kg body weight for female rats. For ewe hoggets, the acute oral LD₅₀ of fensulfothion was between 3 and 4 mg a.i./kg body weight. Administration of fcnsulfothion daily at dose rates of 3, 2, I, and 0.5 mg a.i./kg body weight caused death in 2, 4,7, and 13 days respectively. Of 3 other ewe hoggets drenched daily for 20 days at the rate of 0.5 mg a.i./kg body weight, one died, one became moribund, and one survived. No residues of fensulfothion or its oxidation products were detected in samples of fat, muscle, and liver from the latter 3 sheep. In a replicated plot trial pasture was topdressed with pellets of 5% fensulfothion at rates of I Ib and 2 Ib a.i./acre. After 4 weeks the pastures contained residues of 0.4 and 1.0 parts per million fensulfothion respectively. In a second trial, pasture topdressed at the rate of 2 Ib a.i./acre contained 1.1 parts per million fensulfothion after 4 weeks.