The chick embryo test as used in the study of the toxicity of certain dithiocarbamates

Abstract

The toxicities of six dithiocarbamates: bis(dimethyl thiocarbamoyl) disulfide (thiram), zinc dimethyldithiocarbamate (ziram), ferric dimethyldithiocarbamate (ferbam), bis(dimethyl thiocarbamoyl) ethylene bis(dithiocarbamate) (triaram), sodium diethyl dithiocarbamate (NaDEDC), and sodium ethylene bis(dithiocarbamate) (nabam) were determined in the chick embryo. The substances were dissolved in propylene glycol and injected in the air chamber prior to incubation. Injection in the yolk sac on any day of development or in the air chamber after the first day was unsuitable for the assessment of an LD50. With the exception of nabam, the dithiocarbamates were extremely toxic for the early chick embryo. Cysteine injected simultaneously in the air chamber protected the embryos from the toxic effect of thiram or ziram but not from the action of triaram. It is suggested that the former two dithiocarbamates are reduced by cysteine to less toxic compounds.