Nerve agents evaluating

Currently, there is no information on performance testing of chemical protective clothing against carbamate nerve agents. Evaluation of fabrics used to prevent exposure to carbamate pesticides may provide guidance on selection of appropriate protective clothing. 

The major gap in the available information on GA is the lack of snbchronic or chronic oral toxicity stndies from which to directly derive the RfD. The absence of oral data conld be addressed by conducting a subchronic oral toxicity study that assesses anti-ChE activity in RBCs and plasma. Study of two species would be preferable. If further research reveals that significant toxic effects can be induced by any of the nerve agents evaluated (i.e., GA, GB, GD, or VX) at doses below those that cause significant ChE inhibition, new smdies should be conducted to reassess the safety of the recommended RfD for GA. 

The G-series nerve agents evaluated are all toxie ester derivatives of phosphonie aeid eontaining either a eyanide... 

It is noted that the most complete experimental data set for the nerve agents evaluated in all species is that for... 

Airborne Exposure Limits (AEL) The permissible airborne exposure concentration for VX for an 8-hour workday of a 40-hour work week is an 8-hour time weighted average (TWA) of 0.00001 mg/m3. This value can be found in DA Pam 40-8, Occupational Health Guidelines for the Evaluation and Control of Occupational Exposure to Nerve Agents GA, GB, GD, and VX. To date, however, the Occupational Safety and Health Administration (OSHA) has not promulgated a permissible exposure concentration for VX. 

Although my own work at Edgewood was primarily dedicated to the evaluation of potenhal incapacitating agents, this book includes a discussion of nerve agents - the lethal substances that cause the greatest concern. It closes with a personal assessment of the current threat and a critique both of the facts released to the public, and the limitations of our government s information policies. 

Bay, E., Steinberg, G.M. 1973. Evaluation of chemotherapeutic compounds In nerve agent poisoning. EATR 4716. 

The Newport, Indiana, stockpile contains 1,269 tons of VX nerve agent, a relatively nonvolatile, persistent toxin that disrupts signal transmission in the central nervous system. VX can be hydrolyzed in hot aqueous sodium hydroxide solution. This process produces a strongly alkaline solution containing salts of methylphosphonic acid, its monoethyl ester, and a foul-smelling thiol amine compound. In 1996, the NRC recommended further evaluation of the Army s... 

U.S. Army. 1990. Occupational Health Guidelines for the Evaluation and Control of Occupational Exposure to Nerve Agents GA, GB, GD and VX. Pamphlet 40-8, December. Washington D.C. U.S. Army Medical Services. 

Bonhage MR, Chilcoat CD, Li Q, Melendez V, Flournoy WS (2008) Evaluation of two scopolamine and physostigmine pre-treatment regimens against nerve agent poisoning in the dog. J Vet Pharmacol Ther 32 146-153... 

Inclosure 30 shows the M55 GB Nerve Agent Rocket unpack area. In this area the individual rockets are removed from their packing of 15 rockets. The rockets are transported in the steel container shown in the center of the room. This operation is monitored by one of the new alarms - referred to as an RTM for Real Time Monitor and two bubbler stations. The detection systems are positioned to provide as representative a sample as possible (with a point sampling system). In addition one of the bubblers samples the room exhaust. The RTM is being evaluated in the Tooele operation and if successful could replace some of the bubbler requirements. 

The results of the subcommittee s evaluations are presented in Chapters 2 through 9. Chapter 2 reviews the method used by the Army to derive RfDs, and also inclndes a discussion of the benchmark dose method as a point of departure for calculating RfDs. Chapters 3 throngh 6 evaluate the RfDs for the nerve agents GA, GB, GD, and VX. Chapter 7 evalnates the RfD and slope factor for sulfnr mustard, and Chapter 8 provides an evaluation of the RfD for lewisite. Research recommendations are presented at the end of Chapters 3-8 for each of the specific chemical-warfare agents. 

Although there is the potential for nerve agents to have direct toxic effects on the nervous system, there is no evidence that such effects occur in humans at doses lower than those causing cholinesterase inhibition. For the purpose of evaluating potential health effects, inhibition of blood cholinesterase is generally considered the most useful biological endpoint. 

---