There exists a need for enhanced decontamination systems which are non-corrosive, non-toxic and environmentally safe; suitable for a timely clean-up of CB agents on all materials and surfaces. These materials may be used on personnel, individual equipment, tactical combat vehicles and equipment, sensitive equipment, interior and exterior areas of aircraft, ships, and wide areas such as military bases and shore based naval installations. This requirement includes decontaminants that both remove and neutralize CB agents and procedures to apply these decontaminants as well as techniques that help prevent the spread of CB contamination. These decontamination systems will enable forces to reconstitute personnel and equipment rapidly to increase combat efficiency and lessen the logistic burden.
3.3.2 CB Decontamination Overview
3.3.2.1 Goals and Timeframes. The goal of this subarea is to develop effective, environmentally safe CB decontamination systems to clean-up toxic materials without damaging the contaminated surface or affecting the performance of the equipment being decontaminated. Mid-term requirements are to replace DS2 and develop concepts for aircraft interior decontamination. Long term efforts focus on sensitive equipment and wide area decontamination.
3.3.2.2 Major Technical Challenges. The challenge in this area is finding materials that will meet all the criteria established for a field decontaminant, yet be applicable to the widest range of threat agents. Materials being studied include mild nucleophilic reactants, nucleophilic catalysts, stable oxidants, oxidative catalysts, catalytic enzymes, and organic oxidants. Nucleophilic reagents promote decomposition of G and V agents, while oxidative processes are suitable for H and V agents. The fundamental chemistry of the different chemical classes of agents is a major challenge to overcome. Catalytic enzymes are under investigation are intended to detoxify G, V and H agents. This approach is promising for G and V-agents, but is a technical barrier for H-agents. The requirement that decontaminants be supplied pre-mixed negatively impacts the shelf life of the chemical reagents useful for decontamination.
Another major challenge is finding suitable liquid decontamination media including surfactant systems or environmentally acceptable organic solvent to serve as the vehicle to carry decontaminants. New decontamination materials need to be stabilized in an appropriate media. In addition, all materials must not interfere with other fielded systems, such as detectors.
Sorbents are an effective way of removing CB contamination from surfaces. However, they do not neutralize the CB contamination removed and thus tend to release absorbed contamination over time. Research into reactive sorbents is an area of potential investigation.
Recent studies have identified interior space decontamination as a critical requirement. This need is especially true in the case of cargo aircraft which may experience interior contamination of critical avionics and other electronic components. The requirement also applies to other interior spaces such as shipboard areas, combat vehicles and buildings.
Decontamination of large areas is not practical during on-going operations. However, post-operational decontamination is desirable. The feasibility and potential methods and technology are currently being examined.
3.3.2.3 Related Federal and Private Sector Efforts. Demilitarization research is being done cooperatively with the U.S. Army Chemical Demilitarization and Remediation Agency in two major programs. In conjunction with the Program Manager for Chemical Demilitarization, alternative methods of destroying the U.S. chemical weapons stockpile are being investigated, in consonance with recommendations from the National Research Council. Also under the office of the Program Manager for Non-Stockpile Chemical Materiel, methodologies for the destruction of non-stockpile chemical items and related environmental remediation are being developed. The Defense Nuclear Agency (DNA) is sponsoring a program to evaluate the effectiveness of a methodology proposed by Russia to destroy their chemical warfare agents stockpile. The DNA also has a related program in the area of Treaty Verification where analytical chemistry sampling and analysis methodology is being developed to perform trace level analysis of chemical agents, agent precursors and degradation products in assorted environmental matrices. The U.S. Environmental Protection Agency, U.S. Army Environmental Center and the private sector are performing research on and are developing technologies for site remediation and restoration. The U.S. is the lead nation for NATO Project Group 31 which is seeking to develop an enzyme-based decontaminant for nerve agents and mustard. The planned decontaminant (based on the U.S. model) is intended for use by all service on equipment, vehicles, facilities and large areas.
3.3.3 CB Decontamination S&T Investment Strategy
3.3.3.1 Technology Demonstrations. The effort to develop Quarternary Ammonium Complexes is scheduled to transition to 6.4 in FY98. Also, the potential exists for the transition of supercritical carbon dioxide technology followed by decontamination treatment of the resulting solutions to serve as a two step procedure to decontaminate sensitive equipment. The 6.3 transition could occur in FY00. Proposed FY97 work on commercial detergents as a DS2 replacement, could lead to an FY00 6.3 transition. Finally, technology utilizing fire suppressant and other foams to deliver catalytic enzymes and other materials to effect multi-agent decontamination will be demonstrated against a broad spectrum of agents in FY06.
3.3.3.2 Technology Development. There is limited funding for Decontamination S&T efforts such that the commodity area is essentially at a technology watch status. Available resources are focused on decontaminants, operational materials, and contamination control.
Biochemical investigations in this area are directed toward finding reactive enzymes which will be effective against all CB threat agents. These must be stable in storage and environmentally acceptable. Various approaches are being taken to optimize the use of enzymes. Studies continue into the use of enzymes incorporated into various foam systems. This would allow for the use of fielded fire fighters' equipment for surface application. Tests will also be conducted using new formulations of quaternary ammonium complexes against CW agents with emphasis on devising ways to control viscosity and develop means to optimize efficiency and effectiveness.
There exists a requirement to replace DS2 with a significantly less corrosive and more environmentally acceptable material. For this purpose, a study is planned to be initiated in FY97 using commercially available oxidizing detergents. Also, in a recent Decontamination Workshop, new technology for future investigation was identified. The most promising approach is the use of supercritical carbon dioxide technology. This approach would require a two step procedure, using the supercritical carbon dioxide to remove the agent from surfaces, such as sensitive equipment, and following that with destruction of the collected contaminant. Investigations are planned for FY97.
Preventing the spread of contamination or preventing combat equipment from becoming contaminated greatly eases the later decontamination process and permits equipment to be used much more quickly after a CB attack. This technology effort is investigating procedures and materials that will prevent contamination from spreading to the interiors of combat equipment and aircraft or aid in rapid clean-up of contamination to reduce the spread of contamination. Work to date has concentrated on aircraft interiors. In addition, by the end of FY97, a plan will be completed to assess the feasibility of large area decontamination and, if deemed worthy of further investigation, a road map and funding plan will be detailed.
3.3.3.3 Basic Research. The chemistry at organized interfaces
in solutions (micelles, emulsions, microemulsions, vesicles, liposomes)
has proved to be extremely useful for enhanced reactivity needed
for decontamination technology advances. Recently, novel types
of polymeric support termed "starburst" dendrimer polymers
have been developed. The ability to attach substances that can
serve as catalysts to the surface of dendrimers has been shown.
Studies are planned to examine the use of such systems to decontaminate
CB agents in environmental matrices.