SEPA www.epa.gov/research Technical BRIEF INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE Decontamination of Indoor Porous and Permeable Surfaces Contaminated with Persistent Chemical Warfare Agents VX and sulfur mustard, HD Practical data regarding decontamination and disposal of contaminated building materials Background An intentional and nefarious attack or unintentional release of a chemical warfare agent (CWA) is expected to trigger a significant effort to clean up a contaminated area. Such effort becomes more complex when considering the permeability of common indoor building materials to some CWAs. While surface decontamination options exist for nonporous or nonpermeable materials that are contaminated with some of the more persistent CWAs [1-5], such as VX, HD, and FGAs, information about applying these options to porous or permeable materials is limited. Permeable materials include painted surfaces, which account for 60% to 70% of exposed surfaces in residences [6], Past EPA research has demonstrated that CWAs such as VX and sulfur mustard (HD) can permeate into paint and various materials [7], Studied surface decontamination technologies consist of an oxidative or hydrolytic active ingredient (sometimes created by onsite mixing of two chemicals), water, and sometimes surfactants. These types of solutions tend to remain on the surface with minimal to no absorption into a permeable material. This can leave unreacted/nondegraded chemical agent remaining in or below the permeable material, leading to the likelihood that the unreacted chemical will eventually diffuse back to the surface, reappearing as a surface contact hazard and potential vapor emission source. This potential to diffuse back to the surface has not been verified for CWAs; however, it has likely occurred in remediation efforts following organophosphate pesticide misuse cases in which initial decontamination efforts are deemed successful followed by reappearance of the same pesticide in follow-up surface sampling. U.S. Environmental Protection Agency's Homeland Security Research Program (HSRP) develops scientific products based on research and technology evaluations. Our products and expertise are widely used in preventing, preparing for, and recovering from public health and environmental emergencies that arise from terrorist attacks or natural disasters. Our research and products address biological, radiological, and chemical contaminants that could affect indoor areas, outdoor areas, and water infrastructure. The HSRP provides these products, technical assistance, and expertise to support EPA's roles and responsibilities under the National Response Framework, statutory requirements, and Presidential Directives. Purpose This technical brief serves as a summary that compiles data from recent EPA HSRP bench-scale studies [1-4, 8] that assessed decontamination efficacies for porous and permeable materials contaminated with VX and HD. This summary includes decontamination studies intended to overcome the initially observed lower efficacy results through modifications in decontamination strategy (e.g., extended dwell times, double applications, etc.) or introduction of chemicals intended to cause migration of permeated contaminate back to the surface. The purpose of this summary is to provide decision-makers with practical information on potential percent of remaining residuals after decontamination, efforts to improve efficacy, and identification of material types that are impractical, if not impossible, to clean to the intended clearance level. This practical information will inform the remediation strategy for the decontamination of contaminated interior areas. U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Definitions and Descriptions A recent technical summary on transport of VX and HD [7] identified built environment materials in four different groups based on their porosity and permeability: (I) Nonporous, impermeable materials. Glass, metal, and glazed ceramic tiles belong to this category. VX and HD tend to remain on the surface of this type of material and can be degraded without concerns that the chemical agent is inaccessible to the decontaminant [1-5]. (II) Nonporous, permeable materials. Organic materials such as rubber, silicone, vinyl, or laminate belong to this category. VX and HD can diffuse into these materials. This group also includes painted or sealed materials that can be porous. While paints and sealants are intended to prevent water absorption, VX and HD behave differently than water in terms of material permeability. (III) Porous, low permeability materials. Concrete, limestone, and various types of unsealed wood belong to this category. VX and HD can be absorbed quickly into the material by filling the pores. VX and HD are not expected to chemically adsorb into and diffuse through the material (at the molecular level) but remain on the interior surface of the pores. (IV) Porous, high permeability materials. Carpet, upholstery, and ceiling tile belong to this category. For these materials, a liquid CWA may fill the porous spaces by capillary action, followed by adsorption and diffusion into the material. Experimental Methods The decontamination studies followed a generic contamination approach: Contaminating the material via application of neat CWA droplet(s) (1 — 2 |j.L volume) followed by a defined contact time prior to decontamination. This contact time varied among the studies from 30 min to three days (72 h). Decontamination was conducted via application of the liquid decontaminant. Earlier studies [1,2,4] used a pipette to apply the decontaminant; later studies [3,5,7] used a spray application. The dwell time of the decontaminant among the individual studies varied between 30 min and 120 min. Several studies [1,2,5,7] extended testing by including modifications to decontamination procedures such as longer dwell times, repeated application of the same decontaminant, or application of a chemical prior to decontamination intended to cause the CWA to migrate back to the surface. Such chemicals are marketed as "stain removers" for painted surfaces, so the intent was to investigate if they could serve this function of VX and HD. Earlier decontamination studies, that included permeable or porous materials, determined efficacy by measuring residual CWA on a material via extraction [1,2]. Low efficacy (especially when compared to efficacy for nonporous materials) could be attributed to some absorption of the CWA into a material where it would not come into contact with the decontaminant at the surface. Later studies [3-5] separated residual CWA on the surface from what permeated into a material by first wiping the surface, followed by the extraction of the material coupon to determine how much agent remained inside. The transport of chemical agent in paint and sealant layers followed by decontamination was the subject of one study [8] which used a low volatility agent permeation (LVAP) method. This method allowed for measurement of residual CWA on the paint or sealant surface via surface wipe sampling; measurement of residual agent in the paint or sealant by extraction of the paint or sealant layer; and measurement of CWA that permeated through the paint or sealant. This was accomplished by using a simulated porous subsurface below the paint or sealant. Prior to each of the decontamination efficacy studies, surface wipe sampling methods and material extraction methods were verified, as applicable, with regard to their efficiency to sample the targeted CWA from all materials. Permeation Results Each decontamination study included positive controls (contaminated materials not exposed to the decontaminant but otherwise handled in the same manner as the test material) such that changes in mass recovered after decontamination can be separated from other fate and transport mechanisms such as evaporation, permeation, natural degradation, etc. These positive controls provide a first insight in the degree to which VX and HD permeate into a material. Figure 1 illustrates CWA permeation for some of the materials that are discussed in more detail below. This graph is limited to those materials for which the CWA on the surface could be separated from the amount that was absorbed into the material. U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Decontamination Results The observed decontamination efficacy results are provided per material, ordered according to the four previously defined material groups. Table 1 (HD) and Table 2 (VX) provide information on recoveries for tested materials. Tables 3 and 4 contain relevant information on the tested decontaminants and materials, respectively. Additional details can be found in the referenced decontamination study reports [1-4,8], Figure 1. Percent of HD and VX permeated into various permeable materials after specific contact times based on positive control recoveries for decontamination studies. ABS - Acrylonitrile Butadiene Styrene I. Nonporous, impermeable materials Results on the decontamination of nonporous, impermeable materials are outside the scope of this summary. Decontamination efficacies are typically the highest for this type of materials and can be better than 99.9%. See references [1-4] for efficacy data for surfaces such as glass, stainless steel, galvanized steel, aluminum, and glazed ceramic tiles that are contaminated with VX or HD. II. Nonporous, permeable materials Laminate: Decontamination by chemical degradation of VX and HD from (decorative) laminate was included in an EPA study that evaluated household and industrial cleaning products [1], Better than 99% efficacy was obtained with full strength bleach for VX and HD contaminated laminate after a 60-min dwell time. In this study, the contact time between the CWA and the laminate was only 30 min. This study did not differentiate between VX or HD on the surface layer (and accessible by surface wiping) and VX or HD that permeated into the laminate since the whole material coupon was extracted. Rubber: Rubber (wall base molding) was part of a decontamination study which separated out VX and HD before and after decontamination by wipe sampling the material followed by extraction of any residual chemical [3], The study included prolonged exposure to HD and VX (4h and 24h, respectively) on the rubber prior to decontamination with various technologies. HD residuals on the surface of rubber after decontamination with full strength bleach, 3% hydrogen peroxide, or EasyDECON DF200 were low, with high (>90%) efficacies at the surface. However, significant amounts of unreacted HD were recovered when extracting the material (40-70% of applied amount recovered). Similarly, residual VX on the surface was low after decontamination (except for 3% hydrogen peroxide product) leading to >95% efficacy, but the recovered VX mass from inside the material was about equal to the amount recovered from a nontreated rubber coupon. Painted/Sealed Materials. Interpretation of the decontamination results for painted or sealed surfaces is complex, as it requires interpretation of changes in CWA mass at the surface, in the paint or sealant layer, and in permeated CWA mass in the subsurface material below the paint or sealant layer [7], This research showed that none of the tested decontaminants (bleach, Dahlgren Decon, and Decon7) can degrade HD and VXthat has permeated through the paint or sealant into a porous subsurface material. The HD mass that permeated through the paint or sealant layer to the subsurface material accounted for 64%-73% or 80%-85%, respectively, of the applied HD. Similarly, for VX, 38%- 47% or 0.1%-16% of the applied amount on the paint or sealant, respectively, was found in the porous subsurface material below the paint or sealant layer. Changes such as reapplication of the decontaminant combined with a doubling of the dwell time on the U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- surface or by pretreating the surface with a pre- decontamination chemical (i.e., a stain remover) did not make a difference in the CWA mass recovered from the material below the paint or sealant. Extraction of the paint and sealant layers after treatment with bleach, Dahlgren Decon, and Decon7 showed some positive effect in that these decontaminants degraded VX and HD that had permeated into these layers. These reductions varied by layer type and chemical agent. Further, significant amounts remained in the layer (34% - 97%) with respect to positive controls and across decontamination tests including both CWAs and all three decontaminants. There was also some improvement when the decontaminant was reapplied, when the dwell time was doubled, or when a stain-remover chemical was added. However, the broad range in measured CWA recoveries from extracted materials made it impossible to determine whether these improvements were statistically significant. Results for the stain remover applications were inconclusive and not shown in Tables 1 and 2 but can be found in the EPA report [8], Decontamination of VX and HD that resided on the paint and sealant surface was generally efficacious, but the remaining amounts (4% - 76%) would still pose a hazard. These results are limited in interpretation due to the small amount of CWA remaining on the surface under most of the test conditions due to the high degree of permeation. ABS plastic. The decontamination study that included ABS plastic included measurement of VX and HD from the surface after decontamination plus residual chemical mass that was associated with the bulk material [4], Positive controls for ABS plastic contaminated with VX showed that at most 2% of the applied amount had permeated into the material after one hour, which likely is within inherent experimental error of the surface sampling technique. By contrast for HD, the positive controls indicated that about 40% of the total recovered mass was found within the ABS plastic after one hour. Table 1 (HD) and Table 2 (VX) show percent recoveries when ABS plastic was decontaminated with EasyDECON DF200, Dahlgren Decon, and chlorine dioxide containing liquid. Acrylic plastic. Acrylic plastic was part of the decontamination study described for the ABS plastic [4], For acrylic plastic, the amounts of VX and HD that permeated into the material were less than 1% and 1.5%, respectively, after one hour. The reported efficacy data are limited to the surface decontamination by the inherent experimental error of the wipe sampling method. Table 1 (HD) and Table 2 (VX) show percent recoveries when acrylic plastic was decontaminated with EasyDECON DF200, Dahlgren Decon, and chlorine dioxide containing liquid. III. Porous, low permeability materials Plywood. CWAs may absorb into bare plywood, resulting in lower decontamination efficacy for full strength and 10% diluted bleach for VX [1] and HD [1,2], compared to nonporous materials (glass, galvanized metal) under otherwise identical conditions. Since the whole material coupon was extracted, these studies did not address the possible partitioning between VX or HD that remained on the surface (after 30 min contact time) and VX or HD that permeated into the plywood material as the material coupon was extracted. Components of the plywood (e.g., cellulose) probably also created a material demand (i.e., a loss in active ingredient concentration due to interactions with the material) for oxidant in the bleach decontamination solution, leading to lower efficacy. In addition, plywood contains glues and other substances that may have their own adsorptive properties, and these may vary among manufacturers. The plywood studied was pine or fir, common in many applications; other species are possible. IV. Porous, high permeability materials Carpet. Decontamination efficacy for VX and HD contaminated industrial nylon carpet with full strength bleach was found to be considerably high (77% and 73% for VX and HD, respectively) [1], with >99% for galvanized metal (both CWAs) for reference. One explanation may be the short (30 min) contact time between VX or HD and carpet prior to decontamination, during which diffusion of the CWA into the material at the molecular level is limited. Also, permeation of HD and VX into the nylon fibers may be low. Actual cleanup responses are likely to occur days after a CWA release. This study did not address the possible partitioning between VX or HD that remained on the surface (and possibly accessible by surface wiping) and VX or HD that permeated into the carpet since the whole carpet coupon was extracted. U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Table 1. Summary of Surfaces, Test Parameters, and Percent Recoveries for HD Decontamination Studies. Contact HD percent recovered on surface and Surface Subsurface Material Function Time (h) Decontaminant, Dwell Time in other layers of material (as applicable) Ref. 1. Nonporous, impermeable materials Not included in this summary II. Nonporous, permeable materials Laminate Miscellaneous; none included in testing; sheet only Workspace surfaces, 0.5 Full strength bleach, 1 h <1% (whole material extraction) 1 flooring, furniture 10% diluted bleach, 1 h 69% (whole material extraction) Full strength bleach, 1 h 0.013% (surface); 39% (in material) Rubber Bulk Wall base molding 4 3% Hydrogen Peroxide, 1 h 7% (surface); 71% (in material) 3 EasyDECON DF200, 1 h 10% (surface); 52% (in material) Full strength bleach, 1 h 18% (surface); 34% (layer) Paint-Semi-Gloss Enamel Solid Phase Extraction (SPE) disk (surrogate for porous material) To protect and/or color materials (which can be porous or nonporous) Full strength bleach, 2 h (double application) 11% (surface); 10% (layer) 24 Dahlgren Decon, 1 h 18% (surface); 97% (layer) 8 Decon7,1 h 36% (surface); 75% (layer) Decon7, 2 h (double application) 11% (surface); 17% (layer) Full strength bleach, 1 h 0% (surface; below LOQ); 100% (layer) SPE disk (surrogate for porous material) To protect materials Full strength bleach, 2 h (double application) 0% (surface; below LOQ); 52% (layer) Sealant - Polyurethane (which can be porous or nonporous) 24 Dahlgren Decon, 1 h 0% (surface; below LOQ); ND (layer) 8 Decon7,1 h ND (surface); ND(layer) Decon7, 2 h (double application) ND (surface); 72% (layer) EasyDECON DF200, 1 h 56% (surface); 99% (in material) Electronic cases, 3D printing material Dahlgren Decon, 1 h 60% (surface); 65% (in material) ABS Plastic Bulk 1 Electrochemically generated aqueous chlorine dioxide (eCI02), 1 h 35% (surface); ND (in material) 4 Acrylic Plastic Bulk Protective covers, 1 EasyDECON DF200, 1 h 79% (surface); <1% (in material) 4 Liquid Crystal Display Dahlgren Decon, 1 h 46% (surface); <1% (in material) U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Contact HD percent recovered on surface and Surface Subsurface Material Function Time Decontaminant, Dwell Time in other layers of material (as Ref. (h) applicable) (LCD) screens, furniture eCI02,1 h 38% (surface); <1% (in material) III. Porous, low adsorption materials Fir Plywood Bulk Supporting wood flooring under e.g., carpet 0.5 Full strength bleach, 0.5 h 24% (whole material extraction) 1 Full strength bleach, 1.0 h 34% (whole material extraction) 10% Diluted bleach, 0.5 h ND (whole material extraction) 10% Diluted bleach, 1.0 h ND (whole material extraction) Pine Plywood Bulk Supporting wood flooring under e.g., carpet 0.5 Full strength bleach, 0.5 h 24% (whole material extraction) 10% Diluted bleach, 0.5 h ND (whole material extraction) 2 10% Diluted bleach, 1.0 h 88% (whole material extraction) 3% Hydrogen Peroxide, 0.5 h 70% (whole material extraction) IV. Porous, high adsorption materials Carpet Not considered Flooring material 0.5 Full strength bleach, 0.5 h 23% (whole material extraction) 1 Full strength bleach, 1.0 h 3% (whole material extraction) 10% Diluted bleach, 0.5 h 82% (whole material extraction) 10% Diluted bleach, 1.0 h 79% (whole material extraction) ND: No significant difference between recoveries from test coupon and positive control LOQ: Limit of Quantification U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Table 2. Summary of Surfaces, Test Parameters, and Percent Recoveries for VX Decontamination Studies. Contact VX percent recovered on surface Surface Subsurface Function Time Decontaminant, Dwell Time and in other layers of material (as Ref. Material (h) applicable) post decon (vs positive control) 1. Nonporous, impermeable materials Not included in this summary II. Nonporous, permeable materials Laminate Miscellaneous Workspace surfaces, 0.5 Full strength bleach <1% (whole material extraction) 1 flooring, furniture 10% Diluted bleach 77% (whole material extraction) Escalator handrail, wall base molding Full strength bleach, 1 h 4.5% (surface); 105% (in material) Rubber Bulk 24 3% Hydrogen Peroxide, 1 h 83% (surface); 102% (in material) 3 EasyDECON DF200, 1 h 7% (surface); 108% (in material) Full strength bleach, 1 h ND (surface); 79% (layer) SPE disk To protect and/or color materials (which can be porous or nonporous) Full strength bleach, 2 h (double application) 17% (surface); 62% (layer) Paint - Semi-Gloss Enamel (surrogate for 24 Dahlgren Decon, 1 h 50% (surface); 79% (layer) 8 porous material) Dahlgren Decon, 2 h (double application) 20%(surface); 77% (layer) Decon7,1 h 76% (surface); 66% (layer) Full strength bleach, 1 h 4% (surface); 51% (layer) SPE disk To protect materials Full strength bleach, 2 h (double application) 0.01% (surface); 57% (layer) Sealant - Polyurethane (surrogate for (which can be porous 24 Dahlgren Decon, 1 h 3% (surface); 89% (layer) 8 porous material) or nonporous) Dahlgren Decon, 2 h (double application) 1% (surface); 76% (layer) Decon7,1 h ND (surface); 70% (layer) Electronic cases, 3D printing material EasyDECON DF200, 1 h 16% (surface); ND (in material) ABS Plastic Bulk 1 Dahlgren Decon, 1 h 0.7% (surface); 6% (in material) 4 eCI02,1 h 94% (surface); ND (in material) Protective covers, LCD screens, furniture EasyDECON DF200, 1 h 1.4% (surface); <1% (in material) Acrylic Plastic Bulk 1 Dahlgren Decon, 1 h 1.0% (surface); <1% (in material) 4 eCI02,1 h 70% (surface); <1% (in material) III. Porous, low adsorption materials Fir Plywood Bulk 0.5 Full strength bleach, 1 h 42% (whole material extraction) 1 U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Contact VX percent recovered on surface Surface Subsurface Function Time Decontaminant, Dwell Time and in other layers of material (as Ref. Material (h) applicable) post decon (vs positive control) Supporting wood flooring under e.g., 10% Diluted bleach, 1 h 29% (whole material extraction) carpet IV. Porous, high adsorption materials Full strength bleach, 0.5 h 24% (whole material extraction) Carpet Not considered Flooring material 0.5 Full strength bleach, 1.0 h 23% (whole material extraction) 1 10% Diluted bleach, 1.0 h 47% (whole material extraction) ND: Not determined as amount recovered from test coupon exceeded amount recovered from positive control Table 3. Decontamination Technologies Supporting Information Table 4. Material Supporting Information Study Decontaminant Information references 1,2 Full strength bleach Household Bleach (sodium hypochlorite, 5.25%) 1,2 10% Diluted bleach 10-fold diluted Household Bleach 2,3 3% Hydrogen Peroxide 3% Hydrogen Peroxide 3 Full strength bleach Bleach (sodium hypochlorite, 7.3%) 3,4 EasyDECON EasyDECON DF200 (Intelagard), n-Alkyl(C12-C16) DF200 N, N-dimethyl N-benzylammonium chloride, 8.0% hydrogen peroxide, diacetin; active ingredient is activated hydrogen peroxide 4,8 Dahlgren Decon Dahlgren Decon (First Line Technology), water & surfactant, sodium hydroxide, peracetyl borate; active ingredient is peroxyacetic acid 4 eCI02 eCI02 solution (TDS Research, Inc.) 8 Full strength bleach Bleach (sodium hypochlorite, 6%) 7 Decon7 Decon7 (Decon7 Systems), surfactants/inorganic salts (Part 1), hydrogen peroxide (Part 2), and diacetin (Part 3); active ingredient is activated hydrogen peroxide Study Material Information reference 1 Laminate Decorative laminate (phenolic), Pionite, matte finish 1 Carpet Industrial grade carpet Shaw Industries Inc.; Style #M7832 (Nylon) 1 Fir Plywood Fir plywood flooring (bare) 2 Pine Plywood Pine plywood flooring (bare) 3 Rubber ROPPE Pinnacle rubber black wall cove base 4 ABS Plastic Common thermoplastic 4 Acrylic Plastic Acrylic, poly(methyl methacrylate) (PMMA), Plexiglas 8 Paint Behr Premium plus low odor, paint and primer in one. Semi-gloss enamel, 100% acrylic 8 Sealant Rust-Oleum 6711 system waterborne oil-modified polyurethane floor coating U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- Impact of CWA Transport into Permeable Materials on Decontamination Efficacy The observed transport of the CWAs VX and HD into permeable materials impacts the ability to decontaminate these materials. I. Nonporous, impermeable materials VX and HD will remain on the nonporous or impermeable surface. These types of surfaces can be relatively straightforward to clean/decontaminate. These materials are expected to remain in place and would not enter the waste stream. II. Nonporous, permeable materials The observed transfer of CWAs into this group of materials is agent and material specific as illustrated in Figure 1 for different plastics, rubbers, paints, and sealants. Full decontamination of these materials is expected to be complex considering the limited ability of water-based decontaminants to react with CWAs in the material layer(s). Tested modifications to decontamination approaches such as the use of a stain remover [7] did not improve overall efficacy. For materials such as rubber, ABS, acrylic, or laminate, residual CWA after decontamination may diffuse back to the surface from which it could volatilize and become an airborne and contact hazard. Currently, effective decontamination of these types of materials remains near impossible. In many cases, these materials may become part of the waste stream. III. Porous, low adsorption materials Based on the limited number of materials that were tested (only two species of plywood), it is expected that significant amounts of VX or HD would remain after decontamination with full strength bleach or 10- fold diluted bleach. Absorption of these CWAs into porous materials is highly likely. Degradation through interactions with the material should not be excluded either, especially for materials known to be reactive in nature, such as cellulose. Applied decontaminants may not be able to reach deep into pores. Currently, decontamination of these materials is difficult. In many cases, they may become part of the waste stream. IV. Porous, high adsorption materials Decontamination studies for this group of materials have been limited. The impact on decontamination is expected to be like those for the porous, low adsorption materials described under (III). Limitations of Decontamination Studies • All decontamination studies were conducted with representative, new and clean surfaces and materials. Soiling, degradation, hardening, cracking or other deteriorations by wear and tear over time would impact the transport and permeation as well as the decontamination of contaminated materials. • Other materials with similar names to the ones studied here can be expected to behave differently than described in this summary. This is based on the large number of materials used historically and currently marketed compared to the limited numbers of these products investigated in these studies. This also applies to decontamination products such as household bleach. • While some, unstudied materials may be resistant to VX and HD permeation, at an actual contaminated site, it may be impossible to determine what the composition of all contaminated materials may be. This will profoundly influence the role of decontamination in overall site remediation and disposition. • Some of the decontamination studies [1,3] included decontaminants that were less efficacious than bleach on nonporous materials and were not included in this summary. Contact Information Technical Contacts Lukas Oudejans, oudejans.lukas(5)epa.gov General Feedback/Questions Contact CESER(a)epa.gov Disclaimer: This document is for informational purposes only. It was subject to administrative review but does not necessarily reflect the view of the U.S. Environmental Protection Agency (EPA). Any mention of or reference to commercial products, processes, or services by trade name, trademark, manufacturer, or otherwise does not imply an endorsement by the U.S. Government or the U.S. Environmental Protection Agency and shall not be used for advertising or product endorsement purposes. EPA does not endorse any commercial products, services, or enterprises. U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- References 1. U.S. EPA. Evaluation of Household or Industrial Cleaning Products for Remediation of Chemical Agents. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-11/055, 2011. 2. Stone, H, D See, A Smiley, A Ellingson, J Schimmoeller, and L Oudejans. Surface decontamination for blister agents Lewisite, sulfur mustard and agent yellow, a Lewisite and sulfur mustard mixture. J Hazard. Mater., 314: 59-66, 2016. 3. Oudejans, Land S. Chattopadhyay. Remediation Options for Porous Materials Contaminated with Persistent Chemical Warfare Agents VX and HD. U.S. Environmental Protection Agency, Washington, DC, EPA/660/R-17/348, 2017. 4. Oudejans, L, D See. Efficacy and Compatibility of Decontamination Options for Sensitive Equipment-Related Materials Contaminated with Persistent Chemical Warfare Agents. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-19/075, 2019. 5. Oudejans, L, M Magnuson, J Sherrieb, R Fitzpatrick, and K Rindfusz. Decontamination Options for Sensitive Equipment-related Materials Contaminated with a Fourth Generation Agent (FGA). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-22/164, 2022. 6. Manuja, A, J Ritchie, K Buch, Y Wu, CMA. Eichler, JC Little and LC Marr. Total surface area in indoor environments. Environ. Sci.: Processes & Impacts, 21: 1384-1392, 2019. https://doi.org/10.1039/C9EM00157C. 7. U.S. EPA. Transport of Persistent Chemical Warfare Agents HD and VX into Porous Materials and Permeable Layers: Practical data for remediation of contaminated building materials. U.S. Environmental Protection Agency, Washington, DC, EPA/600/S-21/155, 2021. 8. U.S. EPA. Decontamination Options for Surface Layers Containing Permeated Chemical Warfare Agents HD and VX and Pesticides Malathion and Fipronil. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-22/037, 2022. U.S. Environmental Protection Agency - Office of Research and Development EPA/600/S-23/198 | September2023 ------- |