title: Bioassay of sodium diethyldithiocarbamate for possible carcinogenicity.
abstract: A bioassay of sodium diethyldithiocarbamate for possible carcinogenicity was conducted by administering the test chemical in feed to F344 rats and B6C3F1 mice. Groups of 50 rats of each sex were administered sodium diethyldithiocarbamate at one of two doses, either 1,250 or 2,500 ppm, for 104 weeks. Groups of 50 mice of each sex were administered sodium diethyldithiocarbamate at one of two doses, either 500 or 4,000 ppm, for 108 or 109 weeks. Matched controls consisted of 16 untreated male rats, 20 untreated female rats and 20 untreated mice of each sex. All surviving rats and mice were killed at the end of administration of the test chemical. Mean body weights of all dosed groups of rats and mice were lower that those of corresponding controls and were dose related throughout the bioassay except those of the low-dose male rats, which were essentially unaffected by administration of the test chemical. Survivals of the rat and mice were unaffected, and no other clinical signs could be related to administration of the test chemical; thus, the animals may have been able to tolerate higher doses. Sufficient numbers of dosed and control animals of each species and sex were at risk for the development of late-appearing tumors. No tumors occurred in the rats or mice of either sex at incidences that were significantly higher in the dosed groups than in the control groups. It is concluded that under the conditions of this bioassay, sodium diethyldithiocarbamate was not carcinogenic for F344 rats or B6C3F1 mice of either sex.