Strategies to Protect the Health of Deployed U.S. Forces Force Protection and Decontamination (1999) / Chapter Skim
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5 Decontamination
5 Decontamination
Pages 108-137
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From page 108... ...
Most current decontamination systems are labor and resource intensive, require excessive amounts of water, are corrosive and/or toxic, and are not considered environmentally safe. Current R&D is focused on developing decontamination systems that would overcome these limitations and effectively decontaminate a broad spectrum of CB agents from all surfaces and materials.
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From page 109... ...
Because the shortcomings of all current decontamination methods can be slightly mitigated but not eliminated through effective training, advances in technology will be necessary to increase the effectiveness of decontamination methods. The skin decontamination technologies currently used make personnel more vulnerable to injury by increasing percutaneous absorption.
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From page 110... ...
The following problems are common to current and potential decontaminants: irritation of the skin, toxicity, ineffectiveness, and high cost. R&D to develop a skin decontaminant with the following traits is continuing (Chang, 1984; Hurst, 1997~: · capability of neutralizing chemical and biological agents · safety (i.e., nontoxic and noncorrosive)
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From page 111... ...
Another decontamination kit, the M295, contains the same resin as the M291 and may be used to decontaminate personal equipment but not the skin. At present, the most universal chemical agent decontamination methods continue to be washing with water or water and soap, oxidation,
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From page 112... ...
Because several biological agents pose a percutaneous threat to a contaminated individual, respiratory protection alone may not provide adequate protection, although in most instances respiratory protection will be sufficient for short-term protection, provided decontamination of the skin is initiated relatively quickly (Johnson, 1990; LeDuc, 1989; Mikolich and Boyce, 1990~. The 0.5 percent hypochlorite solution, which has been used since World War I, is currently recommended for decontamination of all biological agents (All et al., 1997~.
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From page 113... ...
In addition, decontamination equipment for use in buildings must fit in a conventional elevator. Technologies Self-Decontaminating Materials and Protective Equipment Self-decontaminating coatings, which could facilitate the rapid reuse of contaminated equipment, could be formulated with components capable of catalyzing the conventional hydrolysis and oxidation reactions of agents (Albizo et al., 1988; Medema et al., 1987~.
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From page 114... ...
Once the agent is absorbed into the sacrificial coating, the contaminated coating can either release itself from an uncontaminated substrate or it can be stripped off using relatively mild decontaminants, such as soapy water. Self-decontaminating coatings absorb deposited chemical agents to reduce vapor hazards.
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From page 115... ...
DS2, introduced in 1960, is a nonaqueous liquid composed of 70 percent diethylenetriamine, 28 percent ethylene glycol monomethyl ether, and 2 percent sodium hydroxide (Beaudry et al., 1990; Richardson, 1972~. The reactive component is the conjugate base CH3OCH2CH2O-.
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From page 116... ...
cell structures, such as ribosomes and a nucleoid. Many bacterial pathogens, some of which are biological warfare agents (e.g., Bacillus anthracis)
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From page 117... ...
Another product designed to eliminate the use of chlorinated solvent, called decontamination agent multipurpose (DAM) , contains N-cyclohexyl-2-pyrolidone, calcium hypochlorite, and a surfactant mixture.
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From page 118... ...
The compound was also functionalized to introduce surface activity and surfactant character to the active groups (Moss et al., 1986~. Metal ionamine complexes, with a surface active moiety, were also developed and shown to exhibit catalytic effects in substitution reactions (Courtney et al., o O2 N `~4 ll o o o 11 / P' IP'o_: ~ l\ -Hi O2 N j~OH off To o ~0 // O-P~ ~ /+OH O O 11 / o' IP'o_\ FIGURE 5-2 Catalytic acceleration of soman by iodobenzoate.
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From page 119... ...
Recently, hydroperoxycarbonate anions produced by the reaction of bicarbonate ions with hydrogen peroxide, both relatively nontoxic compounds, have been shown to oxidize sulfur mustard and VX (Richardson et al., 1998; Tadros et al., 1998; Wagner and Yang, 1998~. Polyoxymetalates are being developed as room-temperature catalysts for the oxidation of chemical agents, but the rates are reported to be slow at this stage of development (Rhule et al., 1998a, 1998b)
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From page 120... ...
Decontaminant Decontaminated Decontaminant Status Sodium hypochlorite (bleach) all liquid available Calcium hypochlorite G agents, VX, HD liquid available High-test hypochlorite GB, VX, HD liquid available Dutch powder GB, VX, HD powder in develc Supertropical bleach GB, VX, HD liquid available Activated solution of hypochlorite not specified liquid available Fichlor VX liquid available Self-limiting activated not specified liquid available solution of hypochlorite Chloramine B HD, VX liquid available Chloramine T G and H agents liquid available Chlorine gas (C12)
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From page 121... ...
, a nitrogenchloro oxidant that is commercially available; used in sanitizing, disinfecting, and bleaching agents in commercial bakeries and swimming pools Bleach system composed of 0.5% Ca(OCl) 2 + 1.0% sodium citrate + 0.2% citric acid + 0.05% detergent in water C6H5ClNNaO2S, also known commercially as Neomagnol, an oxidant commonly used as an antibacterial agent; for decontaminating/detoxifying military chemical agents, chloramine-B is impregnated into a wetted towelette Information not available C12, a very reactive gas that readily reacts with all elements except the rare gases and nitrogen; has been successfully used in the large-scale decontamination of VX K2O4S, a component of oxone (a mixture of 2:1:1 [molar ratio]
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From page 122... ...
VX gas available Sodium carbonate not specified liquid available BX24 not specified liquid in develc Source: CBIAC, 1999. oxidation and substitution reactions become slower as the polarity of the solvent decreases.
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From page 123... ...
Modern techniques for causing selective mutations and screening could reveal families of enzymes with broader applications. The use of biological processes to destroy chemical warfare agents is at an early stage of development.
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From page 124... ...
Several methods of developing enzymes with enhanced activity and/ or the capability of deactivating multiple agents have been developed. These methods use directed mutations and rapid screening techniques to manipulate the genes that code for decontaminating enzymes (Longchamp, 1999~.
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From page 125... ...
The decontamination of both real chemical warfare agents and biological warfare agent simulants by the combination of foam and additives
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From page 126... ...
Using the bacterium Erwinia herbicola as a biological simulant for vegetative cells, a 7-log kill in the foam within 15 minutes has been achieved. However, this bacterium may not be a good simulant for the biological agents of concern.
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From page 127... ...
Some tests have been less successful, however. For example, GD was effectively removed from carpet but was less effectively removed from painted surfaces.
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From page 128... ...
All of these are known to be effective against biological agents. Reports by SBCCOM have shown that ozone is not effective as a decontaminant for GD (Bartram et al., 1998~.
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From page 129... ...
Los Alamos National Laboratories has developed an atmospheric-pressure plasma source to generate chemically reactive effluent for neutralizing chemical and biological agents (Selwyn and Currier, 1999~. This approach is "dry," requires no subsequent cleanup or waste disposal, and can potentially decontaminate surfaces and equipment.
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From page 130... ...
SBCCOM has initiated a program to extract chemical agents from contaminated sensitive equipment using supercritical carbon dioxide (joint Science and Technology Panel for CB Defense, 1999~. Supercritical fluids exhibit very high mass-transfer rates because of their liquid-like density, gas-like viscosity, and negligible surface tension.
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From page 131... ...
High-energy radiation could provide a method for destroying agent while it is still inside a bomb-type canister, which would be an effective way of dealing with terrorist threats of most biological agents and some chemical agents. Radiation might also be used to decontaminate large areas, such as airstrips, highways, and seaports.
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From page 132... ...
With some miniaturization of the superconducting elements, conventional radio-frequency accelerators could fit on a truck bed. Feasibility studies are being conducted at Sandia National Laboratories to validate the concept that electromagnetically induced alteration of tertiary molecular structure is sufficient to deactivate biological agents.
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From page 133... ...
Commanders are also advised to decontaminate chemical agents first because decontamination methods for chemical agents are also believed to be effective for neutralizing or removing biological contamination, but not vice versa. Decontamination is only briefly mentioned in Joint Doctrine for Nuclear, Biological and Chemical Defense (joint Chiefs of Staff, 1995~.
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From page 134... ...
. No decontamination standards were available for certifying that contaminated equipment could be returned to operational status.
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From page 135... ...
The MAGs for chemical warfare agents listed in Table 5-5 are for concentrations that produce minimal and severe effects after 1-day and 14-day exposures. Relating doctrine to risk in the area of decontamination will first require establishing guidelines for what constitutes acceptable risk and then TABLE 5-5 Military Air Guidelines for Chemical Warfare Agents 1-hour MAGs (ppm)
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From page 136... ...
Therefore, it is difficult to know when it is safe to return equipment to operational status and impossible to "certify" that previously contaminated equipment can be transported to a new location, especially a location in the United States. Recommendation.
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From page 137... ...
should coordinate and prioritize the chemicalibiological research and development (R&D) defense program, focusing on the protection of deployed forces and the development of environmentally acceptable decontamination methods.
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