Graphitising of carbon products emits many gaseous substances into the air, with the following having the highest emissions: CO, CO2, SO2, H2S, and CS2; aliphatic hydrocarbons (CH4, C2H4, C2H6 and C3H8); and benzene, toluene, ethylbenzene and xylenes (BTEX). These emissions are of a time-variable nature and depend on technological parameters, e.g. weight and assortment of charge, furnace heating curve, type and amount of insulation packing, and efficiency of air pollution control devices. Presented are concentrations of selected gaseous substances emitted from Castner graphitising furnaces (equipped with installations of catalytic afterburning and flue-gas desulphurisation), and corresponding mass flow rates and emission factors related to carbon charge weight.