Air—Water and Ether—Water Distribution of N—Nitroso Compounds: Implications for Laboratory Safety, Analytic Methodology, and Carcinogenicity for the Rat Esophagus, Nose, and Liver 2

Abstract

The air—water distribution ratio K₁, ether—water distribution ratio K₂, and solubility in water were measured for 17 nitrosamines, 3 nitrosamides, and 1 nitrosocyanamide. For K₁, air was analyzed either by UV absorption of ethanol extracts or by gas chromatography. K₁ at 37° C varied from less than 2×10⁻⁶ to 4.5×10⁻³, with 11 compounds showing K₁ greater than 10⁻⁴. A literature analysis provided data on the carcinogenicity of these N-nitroso (NNO) compounds toward the esophagus, nose, and liver of the rat. This compilation of data on physical properties and carcinogenicity of NNO compounds was then analyzed in terms of: a) safety of workers handling either solutions of volatile NNO compounds or animals treated with these compounds, b) analytic methodology, and c) possible correlations between K_l-, K₂-, and solubility-characteristics, and carcinogenicity. Overall correlations were not observed. However, within each of five chemical groups, K_l and K₂ tended to be associated positively with esophageal and nasal carcinogenicity and negatively with hepatic carcinogenicity. Water solubility showed the opposite associations.