Lung tumor response in strain A mice as a quantitative bioassay of carcinogenic activity of some carbamates and aziridines.

A'séfiesof 21 carbamates and 8 aziridines were compared for quantitative carcinogenic activity using the pulmonary tumorinduction method in Strain A mice foi bîoassay. Aziridines as a class were more active than the carbamates, with 3,4-dichlorophertyl-jV-carbamoylaziridine being over 20 times more active on a molecular dose basis than urethan, the most active of the carbamates. Three carbamates (jV-hydroxy ethyl, vV-cyanoacetyl ethyl, and ./V-acetyl ethyl) approached the activity, of ethyl carbamate. Methyl carbamate was completely inactive, suggesting an important role in carcinogenesis of the carboethoxy portion of the molecule. The pulmonary tumor response in Strain A mice is a rapid, reproducible, economic, quantitative bioassay for carcinogenic activity, and wider use of this method is recommended.