Decontaminating foams

Figure 16.4 Emergency responder in protective suit applying a decontaminating foam to a surface suspected of carrying a chemical or biological terror/warfare agent. From Sandia [973], Copyright 1999, Sandia National Laboratories.

Sandia National Laboratories decontaminating foam (licensed to Modec Inc., Denver, Colorado) is a solution (MDF-100) composed of two parts part a a solution of 6.6% V,VAUV"dV -penta-methyl,-V -tallow alkyl 1,3-prop-anamine diammonium 2.6% tallow pentamethyl propane quaternary ammonium compounds benzyl-C12-18 alkyl dimethyl 1% isopropyl alcohol, and part b a solution of 8% hydrogen peroxide. Mixing the two parts results in a foamlike product which lasts for up to 30 min (Figure 71.2). 

Sandia National Laboratory has developed two decontamination foams (1) MDF-100 and (2) DF-200 (Lukey et al. 2004). MDF-100 consists of two components that, when mixed, generate a foam that is used for decontamination. It has been reported that MDF-100 has the ability to neutralize anthrax spores. DF-200 is a faster acting foam than MDF-100 (Lukey et al. 2004). 

Though an ideal decontaminant may be difficult to attain, many alternatives exist that are readily available and meet many basic requirements, van Hooidonk et al. (1983) evaluated a variety of household products as decontaminants for VX, soman, and sulfur mustard. His paper provides an excellent comparison of these readily available decontaminants to include flour, soapy water, talcum powder, and tissue paper. We have selected several other candidate decontaminants that are under investigation, in advanced development, or currently fielded. These include the currently fielded U.S. Department of Defense skin decontaminants (M291 Skin Decontamination Kit [SDK], 0.5% hypochlorite, and 1% soapy water). Reactive Skin Decontaminant Lotion (RSDL), Diphoterine, Sandia Laboratory s Decontamination Foam, and the Decontamination Sponge. 

The first product developed was Mass Decontaminating Foam-100, licensed for manufacture to two companies Modec Inc. (Denver, Colorado) and Envirofoam Technologies Inc. (Draper, Utah). Modec marketed the product as Modec Decontamination Foam (MDF-lOO), stored in two separate containers. The first contains a solution of 6.6%-N,N,N,N, N -Pentamethyl,-N - fallow Alkyl 1,3-Propanamine Diammonium 2.6%-n-TaUow-Pentamethyl Propane Quaternary Ammonium Compounds Benzyl-C12-18 Alkyl Dimethyl 1%-lsopropyl Alcohol, and the other a solution of 8% hydrogen peroxide. When the two solutions are mixed and sprayed, they generate foam, which settles into a liquid in under 30 min. 

A researcher is spraying decontamination foam in a laboratory to test the neutralization of chemical weapons. 

FIGURE 76.2 Sandia decontamination foam for mitigation and decontamination of CWA. 

This idea has been utilized in elaboration of similar mixture of alkaline hydroperoxide with foam-generating detergents recently [10] but with a lower efficiency (tested only on GD - DI50 12.9). It is obvious that such emulsion cannot be used for primary decontamination in the first line due to a very limited stability (in the order of hours only) and also due to unsufficient effectiveness against HD. Such emulsion has thus limited utility. It could be used as a means of choice in stationary facilities to utilise its excellent effectiveness against V agents. 

The potential use of foams has also been demonstrated for the decontamination of nerve agents [80]. In these applications, the detoxification of the nerve agent was carried out by immobilizing the enzyme organophosphorous acid anhydrase within either a fire fighting or blast-containment foam carrier. 

The MDB is a two-story, steel-framed building with thick, reinforced-concrete floors and most interior walls made of concrete and foam-core sandwich panels. Explosion containment rooms have 2-foot-thick reinforced concrete floors, walls, and ceilings. Because concrete is a porous material capable of absorbing agent, all concrete surfaces in the JACADS process areas were sealed with an epoxy coating. A total of 134,153 square feet of concrete will require decontamination (U.S. Army, 1999d). 

Pentagone is an aqueous-based surface decontamination product developed for the cleanup of pentachlorophenols, creosote, petroleum hydrocarbons, chlorinated hydrocarbons, polynuclear aromatic hydrocarbons, and selected pesticide and herbicide spills. It can be used on concrete, asphalt, or metal and is capable of being applied as a foam, allowing treatment of overhead, vertical, and horizontal surfaces. It has been commercially available since 1993 and has been used in multiple applications. 

Moreover, liquid mustard agent often foamed up and overflowed the opened projectile casings, contaminating the MDM and the surrounding area. The MDM then had to be shut down and decontaminated with a neutralizing solution, after which it had to be cleaned and the corrosive effects of agent overflow and decontamination solution repaired. 

Bureaux, J.G. Purdon, J.G. Cowan, G. Cun-dasawmy, N.E. Decontamination and Dispersion Suppressing Foam Formulation, Canadian Patent Application 2,299,259, filed Feb. 25, 2000. 

Enzymes in skin and eye lotions, immobilized in foams and on tissues for skin and eye decontamination (Gordon et al, 2003), or in topical skin protectants (Braue et al, 2002), act under conditions where local OP concentrations can be very high. In these cases, enzyme reaction order in [OP] tends to zero, so that reaction rate is close to maximum velocity ... 

At the Walter Reed Army Institute of Research, an enzyme immobilized polyurethane foam sponge to decontaminate the skin of chemical warfare agents in a wide variety of... 

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