It is proved that the main prospects for improving the insulating means of respiratory protection are related to the chemical method of oxygen reservation. To increase the efficiency of its use, it is necessary to use the resource of the dead layer of the chemosorbent and prevent the sintering of the granules of the oxygen-containing product under the action of exothermic heat. This is achieved by faster pulsed passage of exhaled air through the frontal layers of the chemosorbent and its slow filtration through the rest of the regenerative cartridge. To evaluate the effectiveness of such a technical solution, a mathematical model of air regeneration in an insulating breathing apparatus with an uneven rate of exhalation filtration through a regenerative cartridge is constructed. The dependencies on the time and coordinate of the concentration of CO2 molecules in the air stream and the share of the use of the protective resource of the regenerative cartridge are obtained. Using numerical experiments, the optimal coordinate of the air flow filtration rate jump was determined to prevent sintering of the granules. Depending on the amount of pressure damping on exhalation and inspiration for the RHS respirator, an increase in the protective effect of the device was determined and a decrease in the power of exothermic heat sources in the frontal layers of the oxygen-containing product was calculated. The results obtained confirm the effectiveness of the considered improvements of the design, which make it possible to increase the reliability of insulating breathing apparatus on chemically bound oxygen and to increase the efficiency of using their protective resource.