The object of this study is a selective average of the dangerous parameters of the gas environment during the ignition of materials. Theoretical substantiation of the fire detection method based on testing the null hypothesis regarding the current difference of the specified selective averages of an arbitrary dangerous parameter of the gas environment has been performed. In this case, the significance of the current difference with respect to selective averages allows detection of ignition in real-time observation of an arbitrary dangerous parameter of the gas environment. The method makes it possible to set the level of significance for the current difference and at the same time provide for the maximum power of fire detection. Laboratory experiments were conducted to verify the proposed method for detecting ignition based on the current difference of the selective averages of the measured dangerous parameters of the gas environment corresponding to the training and control general population. The results of verification showed that at a given level of significance, the method allows detecting current fires of materials based on significant differences in sample means. It was established that the current difference in the concentration of carbon monoxide during ignition and after ignition of alcohol, paper, wood shavings, and textiles is –0.459 and 8.296, –0.152 and 4.299, –0.027 and 6.9, –0.262 and 2.3, respectively. Current smoke density differences are 0.043 and 0.391, 0.012, and 0.923, –0.139, and –0.235, 0.034, and 0.129, and temperatures are –0.01 and 10.635, 0.53 135 and 2.726, respectively. This means that the current difference is significant and is due not to a random nature but to the appearance of a persistent effect from the ignition of the material. In practice, research results can be used to detect fires in real time in order to prevent them from growing into an uncontrolled fire