There is provided herein a flame retardant liquid solution comprising a brominated flame retardant solute and a hydroxyl-functional phosphonate solvent of the general formula (I) described herein; and, wherein the solvent of the general formula (I) has a viscosity of less than 1,000 cps. In addition, there is provided a polyurethane foam-forming composition comprising a polyol, a catalyst and the flame retardant liquid solution, or alternatively, polyurethane foam-forming composition comprising an a catalyst and the flame retardant liquid solution, wherein the hydroxyl-functional phosphonate solvent of the general formula (I) functions as a hydroxyl-containing component and/or a flame retardant in the polyurethane foam-forming composition, as well as articles made from either of the polyurethane foam-forming compositions.