The invention relates to oil-in-water emulsions based on fatty alcohols and mono- or diesters of glycerol and the use thereof as antifoams or deaerators for aqueous compositions. The oil phase of the emulsions according to the invention consists to at least 95% by weight of the following constituents: a) 40 to 95% by weight, based on the total weight of the oil phase, of a mixture of at least two alcohols as component A, consisting of: a1) at least one alkanol having 12 to 30 carbon atoms as component A1, a2) at least one mono- or diester of glycerol with at least one fatty acid having 14 to 24 carbon atoms as component A2; b) 0.1 to 10% by weight, based on the total weight of the oil phase, of at least one further component B, which is selected from esters of C12-C36-alkanecarboxylic acids with polyglycerol, amides of C12-C36-alkanecarboxylic acids with alkylenediamines or oligoalkyleneamines, and esters of C12-C36-alkanecarboxylic acids with C12-C36-alkanols, and mixtures thereof, c) 4.9 to 50% by weight, based on the total weight of the oil phase, of at least one further component C, which is selected from organic substances which are liquid at 50° C. and 1013 mbar, at atmospheric pressure have a boiling point above 200° C., and at 25° C. and 1013 mbar have a solubility in water of less than 0.1 g/l.