expert Julian P. Robinson at Sussex Univer sity in England, says: "It is quite interesting that CWC negotiators, some of whom would have known the nerve-gas applica pi S OCH2CH3 C l tions of EMPTA, did not put it on Schedule CH4 / S H/ CH3CH2OH 3 2 PCI3 • H3C-P. • H3C-P( » H 3 C-P=0 1 as they did QL. The very fact that they KQH N x ci ci I put it instead on Schedule 2 meant that Phosphorus Methylphosphonous Methylphosphonothioic SH someone thought it had commercial po trichloride dichloride (SW) dichloride (SWS) OEthyl methylphosphonothioic tential." Schedule 1 chemicals are banned, acid (EMPTA) and QL is the key precursor the U.S. used to make VX. The research literature shows V ό1 ' ^ NCH2CH2CI EMPTA's use in making fungicides, pesti (CHgfeCH^ cides, and antimicrobial agents. κΟΗ(ΟΗ3)2\ EMPTA's precursor chemicals are readi ^ Neutralize [ H 3 C — P — S — C H g C H ^ J ' · HCI ν χ ly available. Despite Sudan's claims that *C CH3)2 special equipment would be necessary to NC HH ( C(H icH2CH3 3>2 / make the VX precursor, Will D. Carpenter, a chemical weapons expert and former 0-Ethyl-S-(2-diisopropylaminoethyl) methylphosphonothiolate hydrochloride chemical company executive, says it is (VX · HCI, stable for storage) possible to make the small amount terror ists would need "in a wide range of avail money and mastermind behind the Weapons Convention (CWC). PC13 is so able glass-lined equipment that can be deadly Aug. 7 attacks on two U.S. embas widely used that it is listed in the treaty as tucked away in a small part of a building." sies in East Africa that triggered the Aug. a Schedule 3 chemical. CWC requires re- I In fact, the chemical industry would call - the amount of EMPTA that El Shifa might 20 retaliatory strikes aimed at impairing porting such data as production and im bin Laden's terrorist networks. port/export quantities for substances onι have been producing bench or pilot-plant VX, a viscous, amber-colored liquid, is both schedules, but the reporting thresh scale. Sudan has not signed, let alone ratified, highly lethal: One drop on the skin can olds are higher for Schedule 3. All Sched the chemical weapons treaty. Carpenter kill. Its precursors—EMPTA, methylphos- ule 2 facilities must be inspected, but be points out that if Sudan were a party to phonous dichloride (SW), methylphos- cause a lottery determines which Sched phonothioic dichloride (SWS), and phos ule 3 plants are to be inspected, some mayr the treaty, the U.S., which has ratified it, could have asked for a challenge inspecphorus trichloride (PC13)—are toxic as escape scrutiny. ) tion instead of launching a missile strike. well. All except PC13 are listed as dual-use Although the U.S. says EMPTA has no Lois Ember Schedule 2 compounds in the Chemical commercial application, chemical weapons5 I
Direct route from SW to VX precursor, EMPTA
nerve agent on his neck. He chased them for about 100 yards before collaps 100 to 200 g of VX and 20 to 30 kg of sa ing, dying 10 days later without ever com ing out of a deep coma. Doctors in the rin, he told C&EN. Both scientists took part in a sympo hospital suspected at the time he had sium on the Japanese incidents organized been poisoned with an organophosphate for the Division of Agricultural & Food pesticide. But the cause of death was Chemistry by Anthony T. Tu, professor of pinned down only after cult members ar biochemistry and molecular biology at rested for the subway attack confessed to the killing, Tsuchi Colorado State Uni hashi said. versity, Fort Collins. An expert on chemiAum Shinrikyo Found in Japanese cal weapons who members also unsuc murder victim served as an adviser cessfully tried to kill /CH(CH3)2 to Japanese police a lawyer who op CH3SCH2CH2N after the subway at posed them, Tokyo X CH(CH3)2 tack, Tu invited the police forensic toxi experts who treated cologist Noriko Tsuthe victims and in noda told C&EN. HO — P — C H 3 vestigated the crime They confessed to I to Boston for the squirting a mixture OCH2CH3 first briefing on of VX and hair oil their efforts outside into a keyhole, hop Japan. ing the lawyer would then touch the The 28-year-old VX victim, who ap nerve agent on his contaminated key. parently had soured on the cult, was at Police later found VX degradation prod tacked in December 1994 on the street ucts in the keyhole. Pamela Zurer in Osaka by two men who sprinkled the
Japanese cult used VX to slay member From the ACS meeting The Japanese cult whose homemade sa rin killed 13 people and sickened thou sands of commuters in the Tokyo sub way in March 1995 had earlier killed one of its own members with the even more deadly nerve agent VX. The murdered man is the "only victim of VX ever documented in the world," said Hitoshi Tsuchihashi, chief forensic toxicologist at the Osaka Police Forensic Science Laboratory, Osaka, Japan. In Bos ton, Tsuchihashi described how he found metabolites of VX in samples of the vic tim's blood seven months after his mur der, one of which is similar to the com pound found in the soil at the Sudanese plant the U.S. bombed recently. The Aum Shinrikyo sect had a small lab set up to make VX at a compound near Mount Fuji where it could also produce sarin on the ton scale, said Yasuo Seto, chief chemist with the National Research Institute of Police Science in Tokyo. The cult members succeeded in making only
AUGUST 31, 1998 C&EN 7
