The Expray Explosive Detection Kit is a unique, aerosol-based pre- and post-blast field test kit designed to detect and identify Group A explosives e.g. TNT, TNB, Group B explosives e.g. Semtex H, RDX, C4 and compounds containing inorganic nitrates used in improvised explosives e.g. ANFO. As a pre-blast tool, it screens against potential terrorist elements. As a post-blast tool, it can immediately analyze any residues at the site to determine whether explosives were present and if so, what kind or if the detonation was the result of some other phenomenon. Each kit includes three tests sprayed directly on the suspect surface or onto a collection wipe. Positive reactions result in an instantaneous color change.