Used as an intermediate in the synthesis of organophosphorus compounds, particularly in the production of pesticides and flame retardants. It serves as a reducing agent in organic reactions and participates in the preparation of phosphonate esters through Arbuzov-type reactions. Its reactivity makes it valuable in pharmaceutical manufacturing and agrochemical research for building phosphorus-carbon bonds. Also employed in radical reactions as a source of phosphite anions. Requires careful handling due to its moisture sensitivity and potential decomposition.