Abstract: Process for the combustion of toxic gaseous effluents bereft of oxygen in a flame, comprising an inner cone (8) supplied with combustible gas (6) and with so-called primary combustion-suppporting gas (7). Said gaseous effluent (10) and a so-called secondary combustion-supporting gas (9) are introduced separately at the level of said inner cone, said secondary combustion-supporting gas being introduced in the form of at least one jet directed towards the axis (D) of said inner cone at a flowrate and speed sufficient to ensure an excess of combustion-supporting gas, the maintenance of temperature and to create a turbulent gaseous mass at the level of said inner cone; the toxic gaseous effluent (10) being introduced into said turbulent gaseous mass. Said process is carried out under a depression. It also relates to an installation for carrying out said process.