The invention relates to a method for producing high purity 1,2-dichloroethane using a liquid reaction medium that is circulated and that is essentially composed of 1,2-dichloroethane and a catalyst. At least ethylene and chlorine are added to the reaction medium and a mainly chlorine-containing gas flow is dissolved in a part of the reaction medium which is essentially devoid of dissolved ethylene. The gaseous components not dissolved in this solution are removed from the solution by means of a gas-separation device and the solution from which the undissolved gas components were removed is contacted with ethylene which is present in dissolved form.