A systematic analysis of the occurrence of man-made emergencies due to a fire at the facilities is performed. It is established that in the event of fires, the gaseous medium in the premises of the facility serves as a means of transmitting hazardous effects to the facility. The object of influence may be maintenance personnel, technological equipment, units, the design of the room or the object itself. In this case, the state of the object of influence can be characterized by a certain scalar parameter, which in the general case represents the amount of loss (damage or risk) caused to the object by the influence of the danger object. It is shown that the scalar parameter is a certain functional of the states of the hazard object and the gas environment, characterizing the degree of emergency, numerically equal to the amount of losses caused to the object of exposure by the hazard object in the room. The possibility of preventing a man-made emergency due to a fire based on monitoring the parameters of the state of the gas environment in the premises of the facility is substantiated. It is noted that in real conditions there is no information about the indicated disturbances and the state of the hazard object. This is the main difficulty in reliably preventing a man-made emergency due to a fire in the premises of the facility. An experimental verification of the dynamics of the parameters of the state of the gaseous medium in the premises of an object during the combustion of alcohol, paper, wood and fabric in a model chamber is performed. The obtained data indicate that the real dynamics of the temperature, smoke, and CO content of the gaseous medium in the chamber upon ignition of the tested materials is not deterministic, but is clearly unsteady and non-linear with obvious signs of an unsteady trend and random disturbances. It is established that the nature of the random dynamics of the states of the gaseous medium at the time of ignition of materials changes dramatically. Moreover, these changes are of an unequal nature, depending on the type of combustible material. The obtained results indicate the possibility of preventing a man-made emergency due to a fire by means of operational monitoring of the parameters of the gas environment in the premises of the facility.