Abstract: The invention relates to a process for producing polyether carbonate polyols through an addition reaction of alkylene oxides and carbon dioxide onto one or more H-functional starter substances in the presence of a couble metal cyanide catalyst or in the presence of a metal complex catalyst based on the metals zinc and/or cobalt, characterized in that one or more H-functionalstarter substances containing at least 1000 ppm of component (K) is/are continuously metered into the reactor during the reaction, where component (K) is selected from at least one compound containing a phosphorus-oxygen bond and a phosphorus compound that can form one or more P—O bonds through reaction with OH-functional compounds.

Abstract: The invention is directed to a double-metal cyanide catalyst for the preparation of a polyether polyol by the polyaddition of an alkylene oxide on to a starter compound containing active hydrogen atoms, wherein the DMC catalyst comprises a) at least one double-metal cyanide compound; b) at least one organic complexing ligand which is not a polyether, polyester, polycarbonate, polyalkylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, ?,?-unsaturated carboxylic acid ester or ionic surfactant compound; c) at least one polyether; and d) at least one polyester, polycarbonate, polyalkylene glycol sorbitan ester, polyalkylene glycol glycidyl ether, glycidyl ether, glycoside, carboxylic acid ester of polyhydric alcohol, cyclodextrin, phosphorus compound, ?,?-unsaturated carboxylic acid ester or ionic surfactant compound.