BYK P 9908 is a polymeric emulsifier that prevents phase separation of polyol blends in storage tanks. BYK P 9908 promotes the compatibility of polyol blends that have a tendency to phase separate and that are used to produce special foams. The additive stabilizes the emulsion and therefore facilitates the handling of polyol blends. The reactive mixture and the final product are more homogenous. The easier and faster handling results in lower processing costs with better process control. The costs for packaging and complaint handling are reduced. BYK P 9908 increases process reliability and reduces application time on site.