<unk>  (DF), also known as EA-1251 or difluoro, is a chemical weapon precursor. Its chemical formula is CH3POF2. It is a Schedule 1 substance under 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
Dimethyl methylphosphonate
Selenium disulfide
Hydrogen fluoride
Hermaphrodite 
Hydrogen selenide
Tetrachlorodecaoxide
Sucrosomial iron