SUMMARY
The principal aim of the paper is to make a physiological and hygienic assessmentof the criterion “volume of operative memory” of the nervous system in vocationalaptitude of workers involved in hazardous activities. Memory functions defined by generally accepted method «Numeric square» which entered Testing Program "ProfRisk".The principle of this method is based on determining the amount of useful information that can be kept under the conditions studied active information searchin the lack of time. It was established that most people matched psychophysiological criteria (69%). At the same time, the indeterminate number of people was considered as conditionallysuitable for work (30%) and non-suitable (1%). The findings are considered as an experiment of confirmed principles of medicine as well as a ground for practicalapplication of the criteria for nosological diagnosis under conditions.