The presented research consisted in a series of field experiments and laboratory analyses of obtained samples. Their aim was to investigate how different factors influence the possibility of identification of accelerant traces in conditions that are as similar as possible to those of real fires. The studied factors were: type of burned material, type of accelerant, length of time between lighting and extinguishing of fire and the air availability level. The obtained results show that, among investigated factors, the type of burned material has the greatest influence. The other factors, with regard to their influence, could be ranked in descending order as follows: 'other' (hard to determine and regulate factors), type of accelerant, time of burning and air availability. 'Other' factors include arrangement of the burned material and dispersion of the accelerant.