Gas mixture explosions and fires are responsible for most of the largest property loss events worldwide in the chemical and power industry. In this contribution, a theoretical analysis was performed of explosion behavior for CO/O2/N2, CO/O2/N2/H2O and CO/O2/N2/CO2 mixtures. Presented explosions based on real scenarios of accidents associated with transport and storage facilities with flammable chemicals. While explosions of pure flammable chemicals are well described in the literature, the information about explosions of toxic flammable substances is rather scarce. This work aims at studying the explosion behavior of pure mixture and of the inerted carbon monoxide-air mixtures at different initial temperatures and pressures. The results of mathematical modeling of the calculated maximum explosion pressure are presented.