United States sarin production

Diisopropyl methylphosphonate is an organophosphate compound that was first produced in the United States as a by-product of the manufacture of the nerve gas isopropyl methylphosphonofluoridate (GB, or Sarin) (ATSDR 1996 EPA 1989 Robson 1977, 1981). It is not a nerve gas and is not a metabolite or degradation product (Roberts et al. 1995). Diisopropyl methylphosphonate constitutes approximately 2-3% of the crude GB product, but it is neither a metabolite nor a degradation product of GB (EPA 1989 Rosenblatt et al. 1975b). Diisopropyl methylphosphonate is not normally produced except for its use in research. One method of producing diisopropyl methylphosphonate is to combine triisopropyl phosphite and methyl iodide. The mixture is then boiled, refluxed, and distilled, yielding diisopropyl methylphosphonate and isopropyl iodide (Ford-Moore and Perry 1951). Diisopropyl methylphosphonate may also be prepared from sodium isopropyl methylphosphonate by a reaction at 270° C, but a portion of the resulting diisopropyl methylphosphonate is converted to trimethylphosphine oxide at this temperature (EPA 1989). 

Production, Import/Export, Use, Release, and Disposal. The risk for exposure of the general population to substantial levels of diisopropyl methylphosphonate is quite low. GB (Sarin) and diisopropyl methylphosphonate have not been produced in the United States since 1957, and there is no indication that U.S. production of these chemicals will resume (EPA 1989). No information exists regarding the import or export of diisopropyl methylphosphonate. Diisopropyl methylphosphonate has no known commercial uses, but has been used by the military as a simulant for chemical warfare agents (Van Voris et al. 1987). 

The United States began to produce sarin in the early 1950s, and VX in the early 1960s, for potential military use production continued for about a decade.6 The U.S. munitions inventory today contains these two nerve agents in 30- to 45-year-old M55 rockets land mines 105-mm, 155-mm, and 8-in. projectiles 500-lb and 750-lb bombs wet-eye bombs (one of a family of eye bombs, which has liquid chemical [wet] contents) spray tanks and bulk containers.9 These munitions are stored at six depots within the continental United States (CONUS) and one outside the continent the locations of these depots are public knowledge.10 The six CONUS depots are near Tooelle, Utah Umatilla, Oregon Anniston, Alabama Pine Bluff, Arkansas Newport, Indiana and Richmond, Kentucky the seventh depot is on Johnston Island in the Pacific Ocean. 

---