7068-83-9: N-Nitroso methyl butyl amine
N-Nitroso Methyl Butyl Amine (CAS No: 7068-83-9) labeled with deuterium in the methyl group or at the alpha position of the butyl group, were given to rats in drinking water at equimolar doses, it was more effective carcinogen causing tumors of the esophagus in animals.
Lijinsky, W., et al. “The Effect of Deuterium on the Carcinogenicity of Nitroso-Methyl-n-Butylamine.” Carcinogenesis, vol. 1, no. 2, 1980, pp. 157–60, https://doi.org/10.1093/carcin/1.2.157.?