Dimethyl methylphosphonate, or methylphosphonic acid dimethyl ester (DMMP), is a colorless liquid with chemical formula C3H9O3P or CH3PO(OCH3)2. Its melting point is -50 °C and its boiling point is 181 °C. It is combustible. In contact with water it slowly undergoes hydrolysis. May soften some plastics and rubbers. Its CAS number is [ ] and its SMILES structure is CP(OC)(OC)=O. Its EINECS number is 212-052-3.
Its other names are dimethoxymethyl phosphine oxide, dimethyl methanephosphonate, dimethyl methyl phosphonate, Fran TF 2000, Fyron DMMP, Metaran, NSC 62240, O,O-dimethyl methylphosphonate, and Reoflam DMMP.
The primary commercial use of dimethyl methylphosphonate is as a flame retardant. Other commercial uses are a preignition additive for gasoline, anti-foaming agent, plasticizer, stabilizer, textile conditioner, antistatic agent, and an additive for solvents and low-temperature hydraulic fluids. It can be used as a catalyst and a reagent in organic synthesis, as it can generate a highly reactive ylide. The yearly production in the United States varies between 91,000 and 910,000 kilograms.
Dimethyl methylphosphonate is not classified as toxic, but is harmful if inhaled, swallowed or absorbed through the skin; it is a Chemical Weapons Convention schedule 2 chemical used in the synthesis of Sarin nerve gas. It can also be used as standalone as a simulant for sarin training exercises and for calibration of detectors. It is a suspected carcinogen.
About 190 liters of dimethyl methylphosphonate, together with other chemicals, were released during the El Al Flight 1862 crash at Bijlmer, Amsterdam. People in the area and the rescue workers involved suffered health problems for years after.