A process for reducing the content of free formaldehyde and formic acid in nonionic and anionic surfactants, comprising adding an amine compound selected from the group consisting of a) an alkanolamine containing 2 to 15 carbon atoms, b) an aminocarboxylic acid containing 2 to 8 carbon atoms, and c) an oligopeptide with an average molecular weight of 500 to 5000 to a surfactant comprised of a member selected from the group consisting of nonionic and anionic surfactants, said nonionic and anionic surfactants containing 1 to 100 ethylene oxide units in the form of at least one polyethylene glycol chain, wherein said amine compound is added in a quantity of 50 to 6000 ppm, based on active substance of said surfactant.