ACUTE AND SUBACUTE TOXICITY OF DDT (2,2,-bis(p-CHLOROPHENYL)-1,1,1-TRICHLOROETHANE) TO LABORATORY ANIMALS

¹ Division of Pharmacology, Federal Security Agency, Food and Drug Administration, Washington, D. C.

DDT, a synthetic insecticide, is acutely toxic by mouth to small laboratory animals (rats, mice, guinea pigs, rabbits, and chicks) in doses ranging from 150 to 750 mgm./kgm. Acute doses may produce anorexia, tremors, depression and death.

DDT is capable of causing subacute toxicity when given in small amounts in the diet for periods of from 3 days to 20 weeks. Definite signs of toxicity are produced by levels in the diet of 0.05% (500 ppm.) for rats and mice, 0.1% for guinea pigs, and less than 0.05% for growing chicks.

Characteristic of DDT poisoning is the wide variation in individual susceptibility, making the estimate of a safely tolerated dose extremely difficult.