Abstract: The invention relates to a degreaser for treating hides, skins, pelts and other intermediates in leather and fur manufacture and also wool or related proteinaceous materials that is based on nonionic surfactants of the type of alcohol alkoxylates, comprising alcohol alkoxylates obtained by reaction of at least one alcohol ROH with n mol of at least one alkylene oxide per mole of alcohol ROH, where R is an alkyl radical of 5 to 30 carbon atoms which has a main chain, of 4 to 29 carbon atoms that has at least one C1— to C10-alkyl branch attached in the chain middle; the alkylene oxide has 2 to 6 carbon atoms, and n is an integer from 1 to 100. The invention further relates to a process for degreasing hide, skins, pelts and other intermediates of leather and fur manufacture and wool or related proteinaceous materials, which comprises using a degreaser according to the present invention, and to the use of the degreasers.