|Preferred IUPAC name
Methylphosphonoyl difluoride, EA-1251
3D model (JSmol)
|MeSH||difluoride Methylphosphonic difluoride|
CompTox Dashboard (EPA)
|Density||1.359 g/mL (77°F)|
|Melting point||−37 °C; −35 °F; 236 K|
|Boiling point||100 °C; 212 °F; 373 K|
|Vapor pressure||36 mmHg (77°F)|
|Main hazards||Corrosive, toxic|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Methylphosphonyl difluoride (DF), also known as EA-1251, is a chemical weapon precursor. Its chemical formula is CH3POF2. It is a Schedule 1 substance in the sense of the Chemical Weapons Convention. It is used for production of sarin and soman as a component of binary chemical weapons; an example is the M687 artillery shell, where it is used together with a mixture of isopropyl alcohol and isopropyl amine, producing sarin.
Methylphosphonyl difluoride is both reactive and corrosive. It is absorbed through skin and causes burns and mild nerve agent symptoms. It reacts with water producing HF fumes and methylphosphonic acid as a result. It is also capable of corroding glass. It has a boiling point of only 55.4 °C at normal atmospheric pressure, and thus a fairly high vapor pressure at room temperature.
- Handbook of chemical and biological warfare agents (2nd ed.). CRC Press. ISBN 9780849314346.
- "Physical properties of standard agents, candidate agents, and related compounds at several temperatures" (PDF).