Low amounts of surfactants found on textile woven fabrics before water repellent impregnation exercise have only a slight influence on this finish, and have no influence at all on oil repellent effects. This phenomenon is explained by the fact that the surfactants are covered with hydrophobic silicone films, or by the brush-like structure of zirconium-paraffin or fluorocarbon emulsions. Their effect is more evident in a longer contact with water (permeability bag test). However, if surfactants are contained in the impregnation bath itself, their negative influence is greater, since in this case not all of the surfactants can be covered by the hydrophobic film produced by the water repellent impregnation. As a general rule, the negative effect of nonionic surfactants is greater than that of anionic types. -- AATA