METHOD OF DIAGNOSTICS OF SECONDARY FIRE SPOTS IN THE STUDY OF POLYMETRIC MATERIALS BY THE METHOD OF SYNCHRONOUS THERMAL ANALYSIS

This article presents a methodology for differentiating primary and secondary fire sources during forensic fire examinations. It also examines the key stages of the secondary fire diagnostic method for examining polymeric materials using synchronous thermal analysis. The developed methodology applies to fires with signs of multiple fire zones, where the combustible load consists of polymeric materials of varying chemical nature, including thermoplastics, which can melt, spread, drip, and burn, forming secondary fire sources. 
The differentiation of primary and secondary fire sources is based on the duration of high-temperature exposure of the finishing material of the room where the fire occurred. An additional criterion is the temperature of exposure to the material during the fire. The temperature and duration of high temperature exposure to the material are calculated using empirical equations of multiple linear regression, obtained from preliminary testing of material samples using synchronous thermal analysis. The final conclusion about the location of the explosive hazard is made after assessing the possibility of ignition of the combustible load material from dripping burning masses of thermoplastics (for isolated focal zones) or after comparing the distribution of the fire load in the room with the location of the focal zones (in the presence of a fire connection).