The dark residue observed after blasting is caused by which explosive?

• A. TNT
• B. Dynamite
• C. PETN
• D. RDX

Answer: (A)

When a blast leaves something behind, the visible residue often reflects the chemical makeup of the explosive and how its detonation products form solid byproducts. TNT tends to leave a dark, sooty residue because its decomposition produces carbon-rich soot that clings to surfaces and soil. This charred, black residue is a recognizable field clue pointing to TNT.

Dynamite, which contains nitroglycerin, generally leaves more oily or sticky traces rather than a dense black soot. PETN and RDX, being different nitro compounds used in plastic formulations, often yield cleaner burns with less dark soot and can appear as lighter powders or ash, depending on conditions. So the dark residue you observe aligns most closely with TNT’s typical detonation byproducts, making it the best fit among these options.