[en] The flash temperatures of monoatomic alcohols of aliphatic series at various concentrations of nitrogen oxide vap ours in air have been determined. The decrease in the flash temperature of alcohols is assumed to depend on formation of more highly inflammable compounds in the gas phase. An empirical equation has been proposed for estimating the flash temperatures of aliphatic alcohols as a function of their boiling temperature and concentration of nitrigen oxides in air. Calculations according to Antuan equation has been conducted to evaluate the value of vapour pressure of alcohols of aliphatic series. Evaluation of behaviour of various materials in contact with air, contaminated with vapours of nitrogen oxide is of interest in connection with nitrogen oxide application in nuclear power engineering