AMGARD® 1243 is a phosphine oxide that is liquid at room temperature. AMGARD® 1243 has been exploited for a wide variety of applications. With high thermal stability, large liquid range and solubility in a variety of common solvents AMGARD® 1243 has many potential uses. AMGARD® 1243 retardant is a phosphine oxide and, consequently, is not air-sensitive. It is a colorless to pale yellow viscous liquid with no appreciable odor. It is specifically designed to be a “reactive” type flame retardant. The 13-13.5% phosphorus content and two reactive hydroxyl functional groups make it a candidate for this use.