Comparison of selected skin decontaminant products and regimens against VX in domestic swine

Abstract

<jats:p> An anesthetized domestic swine model was used to compare the efficacy and cross-contamination potential of selected skin decontaminant products and regimens against the chemical warfare agent, VX. Animals topically exposed to 2×, 3× or 5× LD<jats:sub>50</jats:sub> VX showed typical signs of organophosphate nerve agent poisoning, including miosis, salivation, mastication, dysrhythmias, and respiratory distress prior to death. Animals were exposed to 5× LD<jats:sub>50</jats:sub> VX and then decontaminated 45 min later with the reactive skin decontamination lotion (RSDL<jats:sup>®</jats:sup>), Fuller’s earth (FE), 0.5% hypochlorite, or soapy water. Survival was 100% when the reactive skin decontamination lotion or FE was utilized, although 50% of Fuller’s earth-decontaminated animals exhibited serious signs of VX poisoning. Decontamination of VX-treated animals with 0.5% hypochlorite was less effective but also increased survival. Soapy water was ineffective in preventing lethality. Blood cholinesterase levels were not predictive of clinical outcome in decontaminated animals. The potential of “decontaminated” VX in open wounds to cause poisoning was assessed by vigorously mixing 5× LD<jats:sub>50</jats:sub> VX with the test decontaminants for 5 min and then placing the mixture onto a full-thickness skin wound. Soapy water was ineffective in preventing lethality. Although treatment with dry Fuller’s earth prevented death and all signs of organophosphate poisoning, a significant proportion of treated animals decontaminated with Fuller’s earth in aqueous suspension exhibited serious signs of organophosphate poisoning, suggesting that live agent may be desorbed from Fuller’s earth when it is exposed to a liquid environment. Animals treated with reactive skin decontamination lotion or 0.5% hypochlorite-VX mixtures showed no signs of organophosphate poisoning during the 6- h test period. </jats:p>

Determination of threshold adverse effect doses of percutaneous VX exposure in African green monkeys

“…Subsequent histology revealed CNS pathology not unlike that seen following high dose exposure to the nerve agent soman (see Appendix A). While experimental procedures vary across studies, the absorbed dose administered to this subject is well below the LD50s of 79.6 g/kg for percutaneous VX in swine (Bjarnason et al, 2008), 60 g/kg reported for the white pig (from Chilcott et al, Fig. 3.…”

“…Finally, we decontaminated the site after exposure using reactive skin decontamination lotion (RSDL) to ensure sufficient safety of the exposures that is necessary to conduct moderately long-term evaluations with the subjects. RSDL is approved by the US Food and Drug Administration for chemical decontamination and its use has been shown to be an effective decontamination procedure for VX (Bjarnason et al, 2008;Lundy et al, 2004).…”

Percutaneous Toxicity and Decontamination of Soman, Vx, and Paraoxon in Rats Using Detergents

“…The response time is an important factor which infl uences the effectiveness of the decontamination (15,17,25,26). In this study, decontamination was performed 2 min after exposure and the effectiveness would have certainly been decreased had the treatment been delayed.…”

“…Deaths were either fewer or associated with higher doses of OPs. All of the detergents provided a low or modest level of protection, which was attributed to their low detoxifi cation potency (17,18) and the low solubility of lipophilic OPs in water solutions (2,17). The lowest decontamination effectiveness was achieved against paraoxon (PR=1.6 to 2.6), followed by soman (PR=2.6 to 3.6).…”

In Vitro Skin Permeation of Detergents and Detergent-Based Decontamination Mixture

“…Detergents and detergent-based mixtures are commonly used as additives to water for mass decontamination as an emergency response to mass chemical industrial accidents or terrorist attacks [1,2]. A generic method for mass casualty decontamination involves a whole body wash with water and/or detergent-based washing solutions.…”