Abstract: The invention relates in a first aspect to a process for producing a polyurethane foam, comprising the reaction of (a) an isocyanate composition comprising at least one polyisocyanate based on diphenylmethane diisocyanate; (b) a polyol mixture, wherein the polyol mixture comprises (b1) 50% to 85% by weight of at least one polyether polyol having a hydroxyl value in the range from 10 to 60 mg KOH/g, an OH functionality of more than 2, and an ethylene oxide proportion in the range from 50% to 100% by weight based on the alkylene oxide content of the at least one polyether polyol, and (b2) 15% to 50% by weight of at least one polyether polyol having a hydroxyl value in the range from 10 to 100 mg KOH/g, an OH functionality of more than 2, an ethylene oxide proportion in the range from 2% to 30% by weight based on the alkylene oxide content of the at least one polyether polyol, and a proportion of primary OH groups of 40 to 100% based on the total number of OH groups in the at least one polyether polyol, in each

Abstract: The present invention relates to polyol mixtures comprising (b1) at least one polyether polyol having a hydroxyl value of 10 to 60 mg KOH/g and having a high proportion of ethylene oxide, (b2) at least one polyether polyol having a hydroxyl value of 10 to 100 mg KOH/g, a low proportion of ethylene oxide, and not less than 40% primary OH groups, and (b3) at least one polyether polyol having a hydroxyl value of 10 to 100 mg KOH/g, a low proportion of ethylene oxide, and not more than 30% primary OH groups. The invention further relates to a process for producing flexible polyurethane foams using the mixtures according to the invention, to the thereby obtainable flexible polyurethane foams, and to the use of the thereby obtainable flexible polyurethane foams as a mattress or cushion, as a cushioning element for furniture or as a seat element.