Disclosed are novel active hydrogen compositions comprising: (1) a polymeric polyol; (2) a low equivalent weight cross-linking polyol; (3) optionally a second polyol having an equivalent weight up to about 500; and (4) a sufficient amount of a monohydric alcohol of equivalent weight up to about 1,500 to provide a monophase low viscosity blend.Also disclosed are the molded polyurethanes produced from the above compositions, and, particularly high strength mat molded reaction injection molded parts.