The fluorine surfactant-free, long-term-stable and biodegradable additive for chromium electrolytes lowers the surface tension and hence improves the chromium deposition process, especially in the application for the electrolytical chromium-plating. Preferred additives are CH3(CH2)nSO3H and the salts thereof with n from 10 to 18. These additives are also useful as component in polymer mordants as pretreatments for polymer metallizations.