CHRONIC ORAL TOXICITY OF FERRIC DIMETHYLDITHIOCARBAMATE (FERBAM) AND ZINC DIMETHYLDITHIOCARBAMATE (ZIRAM)

¹ Division of Pharmacology and Toxicology, University of Rochester School of Medicine and Dentistry, Rochester, New York

When administered in the diet for a period of 2 years, growth and mortality in the rat were not affected by 0.025 or 0.0025 per cent of ferbam or ziram, respectively. Growth was reduced by diets containing 0.25 per cent and life-span was shortened by this amount of ferbam but not by ziram. Neurological changes appeared after two months or more in the rats given the 0.25 per cent diets.

Periodic hematological examinations and urine analyses gave normal values. Organ weights lay in normal ranges.

Cystic brain lesions were found in many of the female rats and a few of the male rats given the 0.25 per cent ferbam diet. Certain rats on the higher percentage diets exhibited atrophic testes. Thyroid tissue was normal. Ferbam and ziram are not cancerogenic.

Ferbam and ziram in trace amounts were found in rat liver and in dog brain, liver and fat; the compounds are not stored. In the rat, skeletal stores of iron and of zinc increased slightly but regularly with increasing dietary concentrations of ferbam and ziram, respectively.

Ferbam and ziram were administered in doses of 0.5, 5 and 25 mgm./kgm./ day for 1 year to groups of 2 young adult dogs each. Ill effects were observed only in the dogs given 25 mgm./kgm.; with one exception these suffered convulsive seizures and 2 dogs given this dose of each compound died during the year period. Urine analyses, periodic hematological examinations and organ weights were normal. Histological studies revealed no tissue injury induced by ferbam or ziram.