Diethyl phosphite

Diethyl phosphite (CAS 762-04-9, EC 212-091-6), also known as diethyl phosphonate or NSC 2665, is an organophosphorus compound supplied as a colourless liquid under HS code 29209014. It carries no E-code designation and is not classified as a food additive.

In polymer stabilisation, diethyl phosphite acts as a hydroperoxide decomposer, interrupting oxidative chain reactions to extend the service life of plastics and lubricants. In pharmaceutical synthesis, it serves as a reactive intermediate for constructing phosphonate-containing active ingredients. Agricultural formulators use it as a building block for organophosphorus pesticide synthesis.

Diethyl phosphite is available in technical and synthesis grades and is subject to REACH registration requirements within the EU. It is typically supplied in drums or IBC containers. Buyers should confirm purity specifications and SDS documentation prior to procurement to ensure compliance with applicable handling and transport regulations.