Research on species categorical authentication of accelerants based on flame characteristics analysis

Species categorical authentication of accelerants has traditionally relied on fire debris analysis. To explore a novel method for identifying the accelerants species, four commonly used accelerants for arson were loaded onto different substrates and ignited at different locations. The entire combustion process was recorded and flame characteristics were analyzed. The results showed that the probability density function (PDF) of flame apex angle counts within a certain period after ignition can be used to distinguish accelerant species, and this method is not affected by accelerant loading amount, ignition location, and substrate, demonstrating strong stability and universality, while the temporal variation of flame area and the value obtained by dividing half of the flame width by the flame height (tangent of flame cone angle) can effectively differentiate gasoline and diesel. The utilization of flame characteristics for identifying accelerants species holds significant implications for arson investigation. •A novel method for species categorical authentication of accelerants was established.•Species categorical authentication of accelerants can be obtained by flame characteristics analysis.•Probability density function of flame apex angle counts can distinguish accelerant species.•This method is independent of accelerant loading amount, ignition location, ventilation condition and matrix type.