[Assessment of human tolerance for local pressures on the head and an objective statement of the requirements for the hygienic characteristics of protective helmets].

To obtain reference data for a statistically substantiated evaluation of man's tolerance to the local pressure on the head (as applied to protective helmets kept on for a long time), 86 experiments were carried out in which 11 test subjects participated. The local pressure of 0.05-0.5 kg/cm2 was applied to 8 areas of the head. The tolerance time was measured as the time interval from the beginning of the exposure to the emergence of localized sensations of the type: unpleasant, painful, very painful or intolerable. As a result, statistically significant relationships between the tolerance time and the level of the local pressure were obtained for the 8 locations and 3 grades of subjective sensations. These data can be used in evaluating protective helmets to be worn for a long time as well as in developing hygienic requirements for the advanced helmet-like devices.