Isopropyl methylphosphono-fluoridate

The first of the United States' seven standardized chemicals was agent (GB) Isopropyl Methylphosphonofluoridate, the trivial name of which is Sarin.

This nerve gas was first made in a 1,000 pound batch, in Germany during World War II. The German expertise in this line of chemicals developed from their earlier research on insecticides.

GB is colorless, odorless, fairly volatile liquid that is very soluble in water. It is intended to enter the body by inhalation, and the lethal airborne exposure is about 100 mg-min/m³ . GB is not very persistent; splashed on the ground it will quickly evaporate except in a very cold climate, where it may remain for up to two days.

GB is one of a family of volatile, liquid, anticholinesterase nerve agents that reacts irreversibly with the enzyme cholinesterase, thereby permitting a deleterious accumulation of acetylcholine at nerve endings, which can lead to rapid death.

Sarin is a nerve agent and causes running nose, maximal miosis, eye pain, twitching eyelids, difficulty in accommodation, chest tightness, salivation, coughing and sneezing, nausea, heartburn, fatigue, muscle fasciculation, insomnia, diarrhea, frequent urination, dyspnea, ataxia, slow reaction, convulsions and, ultimately coma, respiratory paralysis and death.