Acute oral and percutaneous toxicity of phosalone in the rat, in comparison with azinphosmethyl and parathion

Abstract

The acute oral and percutaneous toxicities and in vivo anticholine-sterase activities of phosalone (RP 11 974), azinphosmethyl, and parathion (organophosphorus esters with insecticidal properties) are compared. The oral LD50 in female rats for phosalone was about 110 mg/kg, while those of azinphosmethyl and parathion were, respectively, 4 and 18 times lower. At time of peak effect, the oral ID50 of phosalone for erythrocyte choline-sterase was about 10 mg/kg; azinphosmethyl and parathion were 2 and 10 times more inhibitory, respectively. The differences in percutaneous toxicity of the three compounds were more marked than by the oral route. The acute percutaneous LD50 of phosalone in female rats was about 1500 mg/kg, while those of azinphosmethyl and parathion were close to 90 and 8 mg/kg, respectively. The oxygen analogue of phosalone (RP 12 244) was about 4 to 5 times more toxic than the parent compound after a single oral or percutaneous administration to female rats.