ʻOku malava makehe ʻa e efu ʻuliʻuli ke ignition ʻi ha vekiume, tauʻataina mei he ʻosikena atmospheric.
Koloaʻia ʻi he sotiume naituleiti, hono decomposition liberates ʻosikena, ʻa ia ʻoku ne toe ngaue malohi ʻaki ʻa e malala mo e sulfur. ʻOku ʻomi ʻe he tali malohi ko ʻeni ha vela lahi, kasa nitrogen, mo e kaponi taiokisaiti, fakaʻaliʻali ʻa e malohi ʻo e efu exothermic ngaahi koloa.