Acute Toxicity of Pesticides in Adult and Weanling Rats

Acute Toxicity of Pesticides in Adult and Weanling Rats. GAINES,T. B., AND LINDER, R. E. (1986). Fundam. Appl. Toxicol. 7, 299-308.LD50 values were determined for 57 pesticides administered bythe oral or dermal route to adult male and female Sherman rats.Thirty-six of the chemicals were also tested by the oral routein one sex of weanlings. Nine pesticides tested by the oralroute (bufencarb, cacodylic acid, dialifor, deltamethrin, dicamba,diquat, quintozene, phoxim, pyrazon) and four tested by thedermal route (bufencarb, chlordimeform, dichlofen-thion, leptophos)were more toxic to females than to males whereas famphur and2,4,5-T (oral route) were less toxic to females. Eighteen ofthe test chemicals were more toxic to the adult than to theweanling and four compounds (leptophos, methidathion, pyrazon,and sulfoxide) were more toxic to the weanling. In additionalstudies the variability of the LD50 value over a 1-year periodwas examined for two typical insecticides. Six consecutive bimonthlyoral LD50 determinations for parathion and DDT in adults ofboth sexes indicated that the LD50 values were little affectedby the time of year that the tests were done.