EPA/600/R-19/075 | June 2019
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
&EPA
Efficacy and Compatibility of
Decontamination Options for
Sensitive Equipment-Related
Materials Contaminated with
Persistent Chemical Warfare Agents
Office of Research and Development
Homeland Security Research Program
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EPA/600/R-19/075
June 2019
Efficacy and Compatibility of Decontamination
Options for Sensitive Equipment-Related Materials
Contaminated with Persistent Chemical Warfare
Agents
U.S. Environmental Protection Agency
Office of Research and Development
National Homeland Security Research Center
Research Triangle Park, NC 27711
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DISCLAIMER
The U.S. Environmental Protection Agency (EPA) through its Office of Research and
Development funded and managed the research described herein under Contract Number EP-C-
15-002, Task Order 0015 with Battelle. It has been subjected to the Agency's review and has
been approved for publication. Note that approval does not signify that the contents necessarily
reflect the views of the Agency. Any mention of trade names, products, or services does not
imply an endorsement by the U.S. Government or EPA. The EPA does not endorse any
commercial products, services, or enterprises. The contractor role did not include establishing
Agency policy.
Questions concerning this document or its application should be addressed to:
Lukas Oudejans, Ph.D.
National Homeland Security Research Center
Office of Research and Development
U.S. Environmental Protection Agency (MD-E343-06)
109 T.W. Alexander Drive
Research Triangle Park, NC 27711
Phone: 919-541-2973
Fax: 919-541-0496
E-mail: Oudeians.Lukas@epa.gov
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ACKNOWLEDGMENTS
Contributions of the following individuals and organization to this report are gratefully
acknowledged:
U.S. Environmental Protection Agency (EPA) Project Team
Lukas Oudejans (Principal Investigator, Office of Research and Development, National
Homeland Security Research Center (ORD/NHSRC)
Catherine Young (Region 1)
Charlie Fitzsimmons (Region 3)
Lawrence [Larry] Kaelin (Office of Land and Emergency Management, Office of Emergency
Management, Consequence Management Advisory Division (OLEM/OEM/CMAD)
Shannon Serre (OLEM/OEM/CMAD)
Elise Jakabhazy (OLEM/OEM/CMAD)
Timothy Boe (ORD/NHSRC)
Paul Lemieux (ORD/NHSRC)
US EPA Technical Reviewers of Report
Leroy Mickelsen (OLEM/OEM/CMAD)
Stuart Willison (ORD/NHSRC)
US EPA Quality Assurance
Eletha Brady-Roberts
Battelle
Carissa Dodds
William Hayes
Amy Andrews
Anthony Ellingson
David See
The National Caucus and Center on Black Aging, Inc.
Joan Bursey (Technical Editing and Quality Assurance Review)
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EXECUTIVE SUMMARY
Under U.S. Environmental Protection Agency's Homeland Security Research Program (US EPA
HSRP), the National Homeland Security Research Center conducts research necessary to identify
methods and technologies that can be used for the decontamination of equipment and surfaces
contaminated with chemical warfare agents. Typical decontamination approaches such as those
using the chlorine oxidation approach can be efficacious in decontamination of chemical warfare
agents (CWAs) but can also often be destructive and leave items or surfaces to which the
approaches are applied damaged or deteriorated. Approaches for decontamination of CWAs from
sensitive equipment (SE) items such as computer server systems or other electronic equipment
have thus been identified as a critical knowledge gap, as SE is typically associated with high
procurement costs and long lead times, and the integrity and usability of the equipment must be
preserved following decontamination.
This project focused on the evaluation of selected technologies for their efficacy and
compatibility in decontamination of persistent CWAs from SE-related materials. Decontaminants
that were anticipated to be simultaneously efficacious and material-compatible were first
identified via searches of existing literature and secondary data. From the technologies identified
during the literature searches, three were selected for inclusion during decontamination efficacy
testing during this work: Dahlgren Decon from First Line Technology, EasyDECON DF200
from Intelagard, and the Handheld Decontamination Apparatus (HDA), which used
electrochemically-generated chlorine dioxide (eClCh) as the active decontaminant, by TDA
Research, Inc. Decontamination of O-ethyl S-(2-[diisopropylamino]ethyl)
methylphosphonothioate (VX) and sulfur mustard (bis(2-chloroethyl) sulfide, HD) from the SE-
related materials acrylonitrile butadiene styrene (ABS) molded plastic, acrylic, and aluminum
was evaluated. These materials were selected because they are frequently included in
construction of SE.
Based on measured efficacy values, Dahlgren Decon demonstrated the highest efficacy for
decontamination of VX from all three SE-related material types, achieving 99% efficacy on ABS
plastic and acrylic and 98% on aluminum. DF200 demonstrated similarly high efficacy in
decontaminating VX from acrylic (98%) and aluminum (97%), though DF200 decontamination
of VX from ABS plastic was slightly lower at 83%. A statistical comparison (Student's t-test)
showed that the recovered VX amounts for Dahlgren Decon and DF200 for the ABS Plastic and
aluminum were not significantly different (p<0.05). The TDA eClCh decontaminant
demonstrated the lowest VX decontamination efficacies, measuring 30% from aluminum, 29%
from acrylic, and only 4.4% from ABS plastic.
Conversely, eClCh demonstrated generally higher efficacies for decontamination of HD
compared to Dahlgren Decon and DF200. Efficacy of eClCh against HD was 37% from ABS
plastic, 39% from aluminum, and 61% from acrylic (which was also the highest HD
decontamination efficacy measured during this work). Dahlgren Decon measured 54% HD
decontamination efficacy from aluminum, 53% from acrylic, and 38% from ABS plastic while
DF200 demonstrated only 29% efficacy against HD on ABS plastic, 19% on acrylic, and 9.4%
on aluminum. A statistical comparison showed that recovered amounts on ABS plastic and
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acrylic were not significantly different among all three decontaminants. Figure ES-1 summarizes
the average percent decontamination efficacy measured for each decontaminant for VX and HD
from the surface of each of the three SE-related material types included during testing.
Average Percent Decontamination Efficacy
(50:1 decontaminant to CWA by vol., 60-minute contact)
10094
9094
B094
7094
re
£ 60%
u
K 50%
u
o.
g 40%
ij
3094
2094
1094
094
VX
HD
CWA
I DF200, ABS Plastic
DF200, Acrylic
DF200, Aluminum
l Dahlgren Decon, ABS Plastic
Dahlgren Decon, Acrylic
Dahlgren Decon, Aluminum
Ied02, ABS Plastic
eCI02, Acrylic
eCI02, Aluminum
Figure ES-1. Average Percent Decontamination Efficacy by
CWA/Decontaminant/Material
In summary, all three decontaminants evaluated demonstrated some degree of efficacy for
decontamination of both VX and HD from all three SE-related materials. Generally, Dahlgren
Decon and DF200 were much more efficacious in decontamination of VX than of HD.
Conversely, eClCh demonstrated greater efficacy in decontamination of HD than in
decontamination of VX.
With regard to VX and HD degradation/decontamination byproducts, the relatively toxic mustard
sulfone was detected in several samples, including four of five wipe sample extracts taken from
HD-contaminated aluminum coupons decontaminated with Dahlgren Decon, and all wipe
extracts taken from all three SE-related materials decontaminated with the eClCh decontaminant.
Mustard sulfone was also detected in extracts of HD-contaminated ABS plastic and acrylic
coupons decontaminated with the eClCh decontaminant. The toxic byproduct of VX degradation,
EA-2192, cannot be identified by GC/MS. Analysis for EA-2192 requires the use of liquid
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chromatography (LC)/MS, which was outside the scope of this testing. Thus, degradation of VX
into EA-2192 was not evaluated during this work.
Generally, Dahlgren Decon appeared to demonstrate the highest degree of compatibility with the
three SE-related materials included in this evaluation. Residual decontaminant was easily wiped
from the surface of all three material types, leaving no lasting observable effects on acrylic and
only very slight discoloration of ABS plastic and aluminum. In contrast, DF200 and eClCh
discolored ABS plastic to a greater degree and left residues on aluminum that were not easily
removed. Actual physical damage to/deterioration of the aluminum coupon surface was observed
after contact with eClCh. This suggests that the use of eClCh may not be suitable for
decontamination of sensitive equipment including electronic equipment.
Impact of the Study:
Based on the results obtained from this study, VX and to a lesser degree HD can be neutralized
using the Dahlgren Decon or DF200 decontamination products while maintaining a material
compatibility. Caution should be used in extrapolating from bench testing to field application of
these decontamination solutions. Measurable amounts of VX and HD were found to remain on
the surface following any of the decontamination solution applications. Hence, additional
decontamination may be required to further degrade the residual agent to reach a clearance level.
Such may be accomplished through an extended dwell time beyond 1 h or a reapplication of the
decontaminant. Neither approach was part of the test matrix and was not investigated as part of
this study. Decontamination research studies need to consider the quenching of the residual
decontamination reaction at the end of the intended decontamination contact time. Incomplete
quenching will result in a low bias in recovered agent from wipes and/or extracted materials,
resulting in a high bias in efficacy values.
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TABLE OF CONTENTS
DISCLAIMER II
ACKNOWLEDGMENTS Ill
EXECUTIVE SUMMARY IV
TABLE OF CONTENTS VII
LIST OF TABLES IX
LIST OF FIGURES X
LIST OF ACRONYMS XI
1. INTRODUCTION 1
1.1 Purpose 1
1.2 Proj ect Obj ectives 1
1.3 Test Facility Description 2
2. EXPERIMENTAL METHODS 3
2.1 Experimental Design 3
2.1.1 Method Demonstration 3
2.1.2 Decontamination Efficacy 6
2.1.3 Material Compatibility 6
2.2 Test Matrices 7
2.2.1 Method Demonstration Test Matrices 7
2.2.2 Decontamination Efficacy Test Matrix 9
2.3 Experimental Methods and Materials 10
2.3.1 Coupon Materials 11
2.3.2 CWA Application 13
2.3.3 Decontamination Technologies 14
2.3.4 Coupon Surface (Wipe) Sampling 17
2.3.5 Coupon and Wipe Solvent Extraction 18
2.4 Analytical Methods 18
2.4.1 VX and HD Quantitative Analysis 18
2.4.2 VX Byproduct Qualitative Analysis 19
2.4.3 HD Byproduct Qualitative Analysis 20
2.5 Calculations 21
2.6 Analysis of Variance 22
3. RESULTS 23
3.1 Method Demonstration 23
3.1.1 Wipe Sampling and Solvent Extraction Method Development Results 23
3.1.2 Quench Method Development Test Results 27
3.2 Decontamination Efficacy 35
3.2.1 VX Residual Contamination 35
3.2.2 HD Residual Contamination 38
3.2.3 VX and HD Decontamination Efficacy 42
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3.3 ANOVA Results 44
3.3.1 Comparison of Positive Control Results 44
3.3.2 Comparison of Test Sample Results 46
3.4 Material Compatibility 47
4. QUALITY ASSURANCE/QUALITY CONTROL 55
4.1 Control of Monitoring and Measuring Devices 55
4.2 Equipment Calibrations 55
4.2.1 Calibration Procedures and Schedules 55
4.2.2 GC/MS Calibration 56
4.3 Technical Systems Audit 57
4.4 Performance Evaluation Audit 57
4.5 Data Quality Audit 58
5. SUMMARY 59
6. REFERENCES 63
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LIST OF TABLES
Table 1. Surface (Wipe) Sampling and Solvent Extraction Method Demonstration Tests 8
Table 2. Quench Method Demonstration Tests 9
Table 3. Decontamination Efficacy Test Matrix 9
Table 4. SE-Related Materials 13
Table 5. CWA Purity 13
Table 6. Decontamination Technology Application Volumes and Contact Periods 17
Table 7. GC/MS Conditions for VX and HD Analysis 19
Table 8. Wipe Sampling and Coupon Solvent Extraction Average Mass Recoveries 24
Table 9. Wipe Sampling and Coupon Solvent Extraction Percent Recoveries 24
Table 10. Quench Method Test 1, Solvent Extraction Alone, Average Mass Recoveries 28
Table 11. Quench Method Test 1, Solvent Extraction Alone, Percent Recoveries 28
Table 12. Quench Method Test 2, 3M STS, Average Mass Recoveries 30
Table 13. Quench Method Test 2, 3M STS, Percent Recoveries 31
Table 14. Quench Sample Reanalyses Percent Differences, 1st Test 34
Table 15. Quench Sample Reanalyses Percent Differences, 2nd Test 34
Table 16. VX Frequency of Detection 35
Table 17. VX Average Recoveries and Residual Contamination 36
Table 18. HD Frequency of Detection 38
Table 19. Mustard Sulfone Detection 39
Table 20. HD Average Recoveries and Residual Contamination 40
Table 21. Average Percent Decontamination Efficacies 42
Table 22. ANOVA Results for ABS Plastic with HD (Positives) 45
Table 23. ANOVA Results for Acrylic with HD (Positives) 45
Table 24. ANOVA Results for Aluminum with HD (Positives) 45
Table 25. ANOVA Results for ABS Plastic with VX (Positives) 45
Table 26. ANOVA Results for Acrylic with VX (Positives) 45
Table 27. ANOVA Results for Aluminum with VX (Positives) 45
Table 28. ANOVA Results for ABS Plastic with HD (Test Samples) 46
Table 29. ANOVA Results for Acrylic with HD (Test Samples) 46
Table 30. ANOVA Results for Aluminum with HD (Test Samples) 46
Table 31. ANOVA Results for ABS Plastic with VX (Test Samples) 47
Table 32. ANOVA Results for Acrylic with VX (Test Samples) 47
Table 33. ANOVA Results for Aluminum with VX (Test Samples) 47
Table 34. Dahlgren Decon Material Compatibility 49
Table 35. EasyDECON DF200 Material Compatibility 50
Table 36. TDA Research HDA eC102 Material Compatibility 51
Table 37. Quality Control Requirements and Results 55
Table 38. Equipment Calibration Schedule 56
Table 39. GC Performance Parameters and Acceptance Criteria 57
Table 40. Performance Evaluation Audit Results 58
Table 41. Average Residual Contamination Summary 60
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LIST OF FIGURES
Figure ES-1. Average Percent Decontamination Efficacy by CWA/Decontaminant/Material v
Figure 1. Wipe Sampling and Coupon Solvent Extraction, VX Mass Recovery 25
Figure 2. Wipe Sampling and Coupon Solvent Extraction, HD Mass Recovery 26
Figure 3. Quench Method Test 1, Solvent Extraction Alone, Average Mass Recoveries 29
Figure 4. Quench Method Test 2, 3M STS, Average Mass Recoveries 32
Figure 5. Average Residual VX Contamination 37
Figure 6. Average Residual HD Contamination 41
Figure 7. Average VX Decontamination Efficacy 42
Figure 8. Average HD Decontamination Efficacy 43
Figure 9. Damage to ABS plastic caused by HD (1) 52
Figure 10. Damage to ABS plastic caused by HD (2) 53
Figure 11. Damage to ABS plastic caused by HD (3) 53
Figure 12. Damage to ABS plastic caused by HD (4) 54
Figure 13. ABS plastic debris on wipe sample 54
Figure 14. Average Percent Decontamination Efficacy by CWA/Decontaminant/Material 61
ATTACHMENTS
Attachment A - Environmental Data
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LIST OF ACRONYMS
ABS acrylonitrile butadiene styrene
amu atomic mass unit(s)
ANOVA Analysis of Variance
°C degree(s) Celsius
CAS Chemical Abstracts Services
CI critical infrastructure
cm centimeter(s)
cm2 square centimeter(s)
CoV coefficient of variation
CCV continuing calibration verification
CWA chemical warfare agent
DFTPP decafluorotriphenylphosphine
DIC N,N'-diisopropylcarbodiimide
eC102 electrochemically-generated chlorine dioxide
EMPA ethyl methylphosphonic acid
EPA U.S. Environmental Protection Agency
°F degree(s) Fahrenheit
GC/MS gas chromatography/mass spectrometry
HD sulfur mustard, bis(2-chloroethyl) sulfide
HDA Handheld Decontamination Apparatus
HMRC Hazardous Materials Research Center
HSRP Homeland Security Research Program
IPA isopropyl alcohol
IS internal standard
L liter(s)
LC liquid chromatography
M molar
mg milligram(s)
mL milliliter(s)
mm millimeter(s)
MQL minimum quantifiable limit
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NHSRC National Homeland Security Research Center
PE Performance Evaluation
PMMA poly(methyl methacrylate)
QA quality assurance
r2 coefficient of determination
RH relative humidity
RSD relative standard deviation
SE sensitive equipment
SS stainless steel
STS sodium thiosulfate
TDG thiodiglycol
TSA Technical Systems Audit
|iL microliter(s)
VX O-ethyl S-[2-(diisopropylamino)-ethyl] methylphosphonothioate
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1. INTRODUCTION
The U.S. Environmental Protection Agency (EPA) is responsible for preparing for, responding
to, and recovering from threats to public health, welfare, or the environment caused by actual or
potential hazardous materials incidents. Hazardous materials include chemical, biological, and
radiological substances, whether accidentally or intentionally released. The threat and potential
impact of a chemical warfare agent (CWA) release is driving EPA's Homeland Security
Research Program (HSRP) to systematically evaluate potential decontamination technologies for
CWAs.
In the event of either an accidental or intentional release of CWAs, or as the result of use during
response to a CWA incident, sensitive equipment (SE) that may be part of critical infrastructure
(CI) can become contaminated by the CWA. CI is essential in support of the response and
recovery following such release and the decontamination of CI would be of a high priority.
Meanwhile, the procurement of SE is often associated with high costs and/or long lead times.
Hence, the approach to decontamination of SE has the additional requirement that the
decontamination process does not impact the function of the SE. A decontaminant may degrade
the exterior or housing of the equipment or deter the functionality of the equipment. The intent of
the SE decontamination would be to retain it for future use.
Traditional decontaminants such as bleach products using the chlorine oxidation approach are
known to be corrosive and would impact the functionality of electronic equipment and similar
items. Alternative decontaminants against CWAs exist that have been developed in recent years
with the intended purpose of being more material-compatible. The efficacy of these newly-
developed decontamination technologies against CWAs on SE surfaces is relatively unknown.
Additionally, existing decontamination technologies with demonstrated efficacy against CWAs
that have not previously been evaluated for use with SE surfaces may demonstrate material
compatibility. EPA responders have identified this high-priority knowledge gap for the HSRP to
address.
1.1 Purpose
This project focused on the evaluation of selected technologies for their efficacy and
compatibility in decontamination of persistent CWAs from SE-related materials.
1.2 Project Objectives
The primary objective of this project was to quantitatively evaluate the efficacy of candidate
decontamination technologies to decontaminate CWAs from select SE-related materials through
performance of bench-scale laboratory studies using neat O-ethyl S-(2-[diisopropylamino]ethyl)
methylphosphonothioate (VX, Chemical Abstracts Services (CAS) 50782-69-9) and sulfur mustard
(bis(2-chloroethyl) sulfide, HD, CAS 505-60-2) and the SE-related materials acrylonitrile butadiene
styrene (ABS) molded plastic, acrylic, and aluminum. These materials were selected because they
are frequently included in construction of SE (refer to Section 2.3.1). VX and HD were selected
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as two of the more persistent CWAs. Decontaminants that were anticipated to be simultaneously
efficacious and material-compatible were first identified via searches of existing literature and
secondary data. From the technologies identified during the literature searches, three were
selected for inclusion during decontamination efficacy testing during this work: Dahlgren Decon
from First Line Technology, EasyDECON DF200 from Intelagard, and the Handheld
Decontamination Apparatus (FEDA) by TDA Research, Inc.
Additionally, during the decontamination efficacy evaluation, compatibility of the
decontamination technologies/methodologies with the SE-related materials were evaluated
qualitatively. This evaluation included visual assessment and documentation of any visible
deterioration or damage caused to the materials by application of the decontamination
technology or methodology.
1.3 Test Facility Description
All testing was performed at Battelle's Hazardous Materials Research Center (HMRC) located in
West Jefferson, Ohio. The HMRC is certified to work with chemical surety material through its
Bailment Agreement W911SR-10-H-0001 with the U.S. Department of the Army. Wherever
applicable and required, the reporting requirements for this Bailment Agreement were followed.
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2. EXPERIMENTAL METHODS
2.1 Experimental Design
Generally, multiple coupons (small representative samples; see Section 2.3.1) of SE-related
materials were contaminated with neat VX or HD. After a 60-minute CWA dwell period, one of
three candidate decontaminants was applied to the surface of the coupons over the CWA-
contaminated area at a decontaminant:CWA ratio of 50:1 by volume. The applied
decontaminants were allowed to react with the CWA on the surface of the coupons for a
predetermined period. Following the decontamination period (one hour), coupons were sampled
via surface wiping and subsequent extraction in solvent (both wipe and coupon separately). Wipe
and coupon extracts were then analyzed via gas chromatography/mass spectrometry (GC/MS) to
quantify residual CWA contamination and assess the efficacy of the decontaminants.
Prior to decontamination efficacy testing, the experimental methods planned for use were
demonstrated to ensure valid data were generated. Concurrently with decontamination efficacy
testing, compatibility of the decontaminants with the SE-related materials to which they were
applied was assessed qualitatively through visual inspection of decontaminated and not
decontaminated coupons.
The experimental designs for each of these phases of testing, including method demonstration,
decontamination efficacy testing, and decontaminant/materials compatibility evaluation, are
described in the following subsections.
2.1.1 Method Demonstration
2.1.1.1. Surface (Wipe) Sampling and Solvent Extraction of VX and HD from SE-Related
Materials
The methods for wipe-sampling of coupons and for solvent extraction of wipes and coupons
developed during previous CWA/material interaction studies 111 were evaluated for use during the
project using VX and HD and the SE-related materials selected for evaluation to ensure
sufficient recovery of CWA would be achieved from the materials.
The wipe sampling and solvent extraction methods were evaluated concurrently through the
execution of method demonstration tests that incorporated both methods. During each test, 2
microliters (|iL) of neat VX or HD was applied as a liquid challenge (spiked) onto designated
coupons as described in Section 2.3.2 and allowed to remain undisturbed during a 60-min dwell
period. Following the dwell period, coupons were either wipe-sampled (Section 2.3.4) and then
extracted in solvent (Section 2.3.5) or extracted in solvent alone without prior wipe sampling.
Wipe and coupon extracts were then analyzed for VX or HD via GC/MS (see Section 2.4).
Specific procedures and materials used for wipe sampling, including the specific wipe type that
was used, are described in Section 2.3.4. The wipe sampling method that was evaluated for use
during the project includes the following details:
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• 95% //-hexane (H306-SK4, Fisher Scientific, Pittsburgh, PA, hereafter "hexane") was
evaluated as the wipe wetting and extraction solvent.
• Wipes were wetted with 1.5 milliliters (mL) of hexane. This volume of hexane added to
the wipe was found during previous work 111 to be an amount that is approximately half-
saturating for the wipe, as determined gravimetrically by weighing three wipes before
and after soaking the wipes in hexane (half of the amount of solvent remaining on the
wipe 30 seconds after immersion in solvent and hanging vertically to allow excess
solvent to drip off).
The procedure and materials used for solvent extraction of wipes and coupons are described in
Section 2.3.5. As with wipe wetting and extraction, hexane was evaluated as the coupon
extraction solvent for all three SE-related material types.
The experimental methods were deemed acceptable for use in the subsequent decontamination
efficacy evaluation if the mean total recoveries from all SE-related materials were within the
range of 70% to 120% of the mean of the stainless steel (SS, refer to Section 2.2.1.1) evaporation
controls with a coefficient of variation (CoV) between replicates of less than 30%. Total
recoveries equaled the sum of the wipe and coupon extraction recoveries for samples that were
wiped, or coupon extraction recoveries alone for samples that were not wiped. Refer to Section
3.1.1 for results from the wipe sampling and coupon solvent extraction tests.
2.1.1.2. Decontamination Technology Neutralization (Quench)
During decontamination efficacy testing, the decontamination reaction had to be stopped at the
end of a specified contact period to determine how much decontamination occurred during the
period. Adequate decontaminant neutralization (quench) methods were required for each of the
three decontamination technologies and had to be effective for both VX and HD on the surface
of all three SE-related materials. Ultimately, two quench methods were evaluated and used
during decontamination efficacy testing to halt the decontamination reactions and allow for
assessment of decontamination efficacy as a function of decontaminant contact time: (1)
extraction in hexane alone, and (2) addition of a 3 molar (M) sodium thiosulfate (Na2S2C>3, STS)
solution to the wipe/coupon extraction solvent. The method used was dependent on the
CWA/decontaminant combination. Refer to Section 3.1.2 for quench method development test
results and discussion.
The adequacy of the quench methods was demonstrated by post-spiking the extracts of
procedural blanks with dilute solutions of VX and HD. Aluminum (see Section 2.3.1) procedural
blanks were generated using each of the three decontamination technologies by applying 100 |iL
of decontaminant to unspiked coupons and allowing the decontaminant to remain undisturbed on
the coupons for the required decontamination contact period (see Section 2.3.3.4). Following the
contact period, the coupons (with the decontaminant remaining on the coupon surface) were
wipe sampled using the method selected for testing (see Sections 2.1.1.1 and 2.3.4), and wipes
and coupons were extracted in solvent as described in Section 2.3.5. During tests evaluating the
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use of 3M STS as a quench method, 15 mL of the STS solution was added to the extraction
solvent in the jar prior to addition of the wipes or coupons. Additional aluminum procedural
blanks were generated as described above, but no decontaminant was applied to the coupons
(coupons were wipe sampled as described in Section 2.3.4, with wipes and coupons extracted in
solvent as described in Section 2.3.5; no decontaminant was applied to the coupons prior to
sampling).
Following extraction, select wipe and coupon extracts were spiked with a dilute solution of VX
or HD in hexane such that the final CWA concentration fell at approximately the mid-point of
the "low curve" that was used for GC/MS analysis. During the first test evaluating solvent
extraction alone as a quench method, extracts were post-spiked with either:
• 155 |iL of a dilute VX solution at 863 |ag/m L (134 |ig spiked), yielding a coupon extract
concentration of 5.3 |ig/mL and a wipe extract concentration of 5.0 |ig/mL.
• 70 |iL of a dilute HD solution at 1903 |ag/m L (133 |ig spiked), yielding a coupon extract
concentration of 5.3 |ig/mL and a wipe extract concentration of 5.0 |ig/mL.
During the second test evaluating 3M STS as a quench method, extracts were post-spiked with
either:
• 153 |iL of a dilute VX solution at 873 |ag/m L (134 |ig spiked), yielding a coupon extract
concentration of 5.3 |ig/mL and a wipe extract concentration of 5.0 |ig/mL.
• 70 |iL of a dilute HD solution at 1903 |ag/m L (133 |ig spiked), yielding a coupon extract
concentration of 5.3 |ig/mL and a wipe extract concentration of 5.0 |ig/mL.
For those extracts also containing 3M STS as a quench agent, the dilute solution of VX or HD
was added to the extraction solvent (top) layer.
Post-spiked extracts were vortexed for 10 seconds and allowed to stand for one hour. Following
the one-hour stand, an aliquot of each extract was taken and immediately analyzed (no later than
the same business day that the samples were generated) via GC/MS to evaluate whether
decontamination of the post-spiked CWA had occurred. For those extracts also containing 3M
STS as a quench agent, the aliquot was taken from the extraction solvent (top) layer.
Immediately following the initial analysis, the GC vials containing the extract samples were
recapped (with new, unpierced septa) and stored at -20 ±10 degrees Celsius (°C). Three days
following generation of the samples, the samples were retrieved from storage and analyzed again
via GC/MS to evaluate whether decontamination and/or degradation of the post-spiked CWA
had occurred. Samples were allowed to equilibrate to room temperature prior to the second
analysis.
Hexane was used for wipe and coupon extraction for the quench method evaluations. Quench
methods were considered sufficient if the amounts of VX and HD recovered from post-spiked
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extracts containing decontaminant were each at least 70% of the mean amount of CWA
recovered from post-spiked extracts that did not contain decontaminant.
2.1.2 Decontamination Efficacy
A post-test only control group experimental design was used for the decontamination efficacy
evaluation. Decontamination was the experimental variable. Test coupons were contaminated,
decontaminated, sampled, and analyzed for VX or HD. Positive control coupons were
contaminated but not decontaminated, and subsequently sampled and analyzed for VX or HD
along with the test coupons. The effect of decontamination (efficacy) was defined as the
percentage of CWA remaining on the test coupons compared to the positive control coupons
(refer to Section 2.5). The higher the efficacy, the greater the effect of decontamination by the
specific technology.
Procedurally, 2 |iL of neat VX or HD was spiked onto the center of each test coupon (five
replicates) and positive control coupon (three replicates) as described in Section 2.3.2. The
spiked coupons were allowed to remain undisturbed during a set CWA dwell period of 60
minutes. Following the CWA dwell period, 100 |iL of the decontamination technology under test
was applied as a liquid directly to the CWA challenge on each test coupon (applied on top of the
liquid CWA droplet on the coupon surface) and allowed to remain in contact with the CWA on
the coupon surface for a set decontamination period of 60 minutes. Decontamination technology
application procedures as well as specific application volumes and decontaminant contact
periods that were used for each technology are provided in Section 2.3.3. Following the
decontamination period, the test and positive control coupons were sampled for residual CWA
via wipe-sampling according to Section 2.3.4 and solvent extraction according to Section 2.3.5.
Wipe and coupon extracts were analyzed for VX or HD via GC/MS according to Section 2.4.
2.1.3 Material Compatibility
The effect of the decontamination technologies on the test coupons was evaluated qualitatively
during decontamination efficacy testing. During decontamination and following wipe sampling,
test coupons and procedural blanks were visually inspected and compared to other coupons of
the same SE-related material types that were not exposed to the decontamination technologies.
Comparison of the test coupons and procedural blanks to coupons to which no decontaminant
was applied allowed for assessment of damage to the coupons from application of the
decontamination technologies. Any obvious changes (any corrosion, deterioration, damage, or
any other effect) on the appearance of the coupons, for example in the color, reflectivity, or
apparent roughness of the coupon surfaces, were documented. Representative photographs were
taken to document any visually-obvious changes that occurred. Additionally, positive controls
were compared to other unspiked coupons (procedural and laboratory blanks). Comparison of the
positive controls, following wiping, to blank samples allowed for assessment of damage to the
SE-related materials from application of the CWA.
6
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Additionally, a second procedural blank for each decontamination technology/material type
combination was generated that was not wiped or extracted alongside the test coupons following
the decontamination period (see the footnote included in Table 3). Rather, the decontaminant
was allowed to remain undisturbed on the surface of the coupon in a covered Petri dish for a
period of one week. Photographs of the additional procedural blanks were taken at one day and
one week following application of the decontaminants to assess the effects of extended contact
between the decontaminants and the materials. For any residue remaining on the surface of the
materials following one week (following evaporation of the liquid decontamination
technologies), the effort required to wipe the residue from the material surface and the extent to
which the residue could be removed were investigated.
2.2 Test Matrices
2.2.1 Method Demonstration Test Matrices
2.2.1.1. Wipe Sampling and Coupon Solvent Extraction Test Matrix
Two method demonstration tests were conducted to evaluate the surface wipe sampling and
coupon solvent extraction methods. Each test included all three SE-related materials selected for
evaluation during the project and a single CWA. In addition to the test coupons, three wipe
sampling procedural blanks and a single laboratory blank per material type were included. The
procedural and laboratory blanks consisted of coupons of the same SE-related material type and
dimensions as the associated test coupons. Each blank type is further described as follows:
• Procedural Blanks - SE-related material coupons that were not spiked but that were wipe-
sampled and extracted in solvent alongside the test coupons.
• Laboratory Blanks - SE-related material coupons that were neither spiked nor wipe-
sampled; the coupons were maintained outside the test hood until placed into extraction
solvent.
Additionally, stainless-steel (SS) coupons of dimensions identical to the dimensions of the test
coupons and other controls were included as evaporation controls during each test to quantify the
amount of CWA lost to evaporation during the CWA dwell period. The SS evaporation controls
were spiked and sampled during the test alongside the test coupons using the same equipment
and procedures. Three SS evaporation controls were wipe-sampled with subsequent solvent
extraction of the coupons, and three were extracted in solvent alone (no wipe sampling). SS
procedural and laboratory blanks were included as well.
Three CWA challenge amount confirmation controls (spike controls) were included in each test
to confirm the CWA challenge application amount. Spike controls consisted of a spike of equal
amount of VX or HD directly into extraction solvent (see Section 2.3.2.2). When spiked, CWA
was applied to the inside surface of the glass spike control sample jar (60 mL jar, see Section
2.3.5). Submersion of the syringe needle into the solvent was avoided.
7
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Table 1 summarizes the coupon wipe sampling and wipe and coupon solvent extraction
demonstration tests that were performed.
Table 1. Surface (Wipe) Sampling and Solvent Extraction Method Demonstration Tests
CWA
Sample Type
Material
Spiked
CWA
Dwell
Period
Wipe
Sampled
Replicates
Test Coupon (wiping)
Yes
60 min
Yes
3
Test Coupon (extraction)
ABS
Yes
60 min
No
3
Procedural Blank
No
NA*
Yes
1
Laboratory Blank
No
NA
No
1
Test Coupon (wiping)
Yes
60 min
Yes
3
Test Coupon (extraction)
Acrylic
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
vx
Test Coupon (wiping)
Yes
60 min
Yes
3
Test Coupon (extraction)
Aluminum
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
Evaporation Control (wiping)
Yes
60 min
Yes
3
Evaporation Control (extraction)
SS
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
Spike Control
NA
Yes
NA
NA
3
Test Coupon (wiping)
Yes
60 min
Yes
3
Test Coupon (extraction)
ABS
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
Test Coupon (wiping)
Yes
60 min
Yes
3
Test Coupon (extraction)
Acrylic
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
HD
Test Coupon (wiping)
Yes
60 min
Yes
3
Test Coupon (extraction)
Aluminum
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
Evaporation Control (wiping)
Yes
60 min
Yes
3
Evaporation Control (extraction)
SS
Yes
60 min
No
3
Procedural Blank
No
NA
Yes
1
Laboratory Blank
No
NA
No
1
Spike Control
NA
Yes
NA
NA
3
* NA = Not Applicable
2.2.1.2. Quench Evaluation Test Matrix
Matrices for the quench method evaluations are provided in Table 2. As discussed in Section
2.1.1.2, two quench methods were evaluated: (1) extraction in organic solvent alone, and (2)
addition of 3M STS to the wipe/coupon extraction solvent. Solvent extraction alone was
evaluated initially as a quench for all six CWA/decontaminant combinations. A subsequent test
was then conducted to evaluate the adequacy of 3M STS as a quench for those combinations that
were not adequately quenched by solvent extraction alone.
8
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Table 2. Quench Method Demonstration Tests
Test
No.
Material
Type
Quench
Method
Decontaminant
Post-Spike CWA
(Wipe and Coupon
Extracts)
Replicates
1
Aluminum
Extraction
in 25 mL
ofhexane
only
EasyDECON DF200
VX
3
Dahlgren Decon
VX
3
eC102
VX
3
None
VX
3
EasyDECON DF200
HD
3
Dahlgren Decon
HD
3
eC102
HD
3
None
HD
3
EasyDECON DF200
None
1
Dahlgren Decon
None
1
eC102
None
1
None
None
1
2
Aluminum
Extraction
in 25 mL
of hexane
and 15 mL
3M STS
EasyDECON DF200
VX
3
Dahlgren Decon
VX
3
None
VX
3
Dahlgren Decon
HD
3
None
HD
3
EasyDECON DF200
None
1
Dahlgren Decon
None
1
None
None
1
2.2.2 Decontamination Efficacy Test Matrix
The complete matrix for decontamination efficacy testing is provided in Table 3. The matrix was
completed twice, once using VX as the challenge CWA and again using HD as the challenge
CWA, for a total of 18 decontamination efficacy tests. During each test, environmental
conditions (temperature and relative humidity (RH)) in the test hood were monitored and
recorded but not explicitly controlled.
In addition to the test and positive control coupons identified in Table 3, procedural blanks,
laboratory blanks, and spike control samples were incorporated into each test. Spike controls
were generated as described in Section 2.2.1.1. Procedural and laboratory blank samples
consisted of coupons of the same SE-related materials of the same dimensions as the test
coupons to which they were associated and are further described as follows:
• Procedural Blanks - SE-related material coupons that were not spiked but that were
decontaminated, wipe sampled and extracted in solvent alongside the test coupons using
the same equipment and procedures.
• Laboratory Blanks - SE-related material coupons that were not spiked, decontaminated,
or wipe sampled; the coupons were maintained outside the test hood until placed into
extraction solvent.
Table 3. Decontamination Efficacy Test Matrix
9
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Test
Sample Type
Material
Spiked
Decontamination
Technology
Wipe
Sampled
Replicates
Test Sample
ABS Molded Plastic
Yes
EasyDECON DF200
Yes
5
1
Positive Control
ABS Molded Plastic
Yes
None
Yes
3
Procedural Blank
ABS Molded Plastic
No
EasyDECON DF200
Yes
1 + 1*
Laboratory Blank
ABS Molded Plastic
No
None
No
1
Test Sample
Acrylic
Yes
EasyDECON DF200
Yes
5
2
Positive Control
Acrylic
Yes
None
Yes
3
Procedural Blank
Acrylic
No
EasyDECON DF200
Yes
1 + 1*
Laboratory Blank
Acrylic
No
None
No
1
Test Sample
Aluminum
Yes
EasyDECON DF200
Yes
5
3
Positive Control
Aluminum
Yes
None
Yes
3
Procedural Blank
Aluminum
No
EasyDECON DF200
Yes
1 + 1*
Laboratory Blank
Aluminum
No
None
No
1
Test Sample
ABS Molded Plastic
Yes
Dahlgren Decon
Yes
5
4
Positive Control
ABS Molded Plastic
Yes
None
Yes
3
Procedural Blank
ABS Molded Plastic
No
Dahlgren Decon
Yes
1 + 1*
Laboratory Blank
ABS Molded Plastic
No
None
No
1
Test Sample
Acrylic
Yes
Dahlgren Decon
Yes
5
5
Positive Control
Acrylic
Yes
None
Yes
3
Procedural Blank
Acrylic
No
Dahlgren Decon
Yes
1 + 1*
Laboratory Blank
Acrylic
No
None
No
1
Test Sample
Aluminum
Yes
Dahlgren Decon
Yes
5
6
Positive Control
Aluminum
Yes
None
Yes
3
Procedural Blank
Aluminum
No
Dahlgren Decon
Yes
1 + 1*
Laboratory Blank
Aluminum
No
None
No
1
Test Sample
ABS Molded Plastic
Yes
eC102
Yes
5
7
Positive Control
ABS Molded Plastic
Yes
None
Yes
3
Procedural Blank
ABS Molded Plastic
No
eC102
Yes
1 + 1*
Laboratory Blank
ABS Molded Plastic
No
None
No
1
Test Sample
Acrylic
Yes
eC102
Yes
5
Positive Control
Acrylic
Yes
None
Yes
3
O
Procedural Blank
Acrylic
No
eC102
Yes
1 + 1*
Laboratory Blank
Acrylic
No
None
No
1
Test Sample
Aluminum
Yes
eC102
Yes
5
9
Positive Control
Aluminum
Yes
None
Yes
3
Procedural Blank
Aluminum
No
eC102
Yes
1 + 1*
Laboratory Blank
Aluminum
No
None
No
1
Spike Controls
NA
Yes
NA
NA
3 per test
* "+1" refers to an additional procedural blank that was not wiped or extracted along with other test coupons and
controls following the decontamination period, to assess the effect of extended decontaininant contact with the
materials.
2.3 Experimental Methods and Materials
Experimental methods and materials used to conduct all testing are described in the subsections
below. Prior to the experimental research, literature searches were performed to identify
decontamination technologies and approaches that are simultaneously efficacious in
decontamination of CWA and compatible with materials often used in construction of SE.
Specific search criteria comprised of keyword lists and Boolean search strategies were developed
for use to execute the searches. The criteria and strategies were then applied to multiple
information repositories and scientific and technical literature databases to accumulate secondary
10
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data and information related to the decontamination efficacy and materials compatibility
characteristics of various decontamination technologies, methodologies, and approaches. For the
purpose of focusing the search, secondary data and information related to decontamination of the
CWAs VX and HD were prioritized.
In the context of this study, SE materials were identified by the EPA project team as materials
associated with the housing or exterior of larger sensitive equipment items. While these materials
by themselves may not be a sensitive material, they represent materials that would be used to
house sensitive equipment. Degradation of such materials would lead to exposure of the interior
components to these decontaminants with potential additional incompatibilities with highly
sensitive items such as optical components or electrical contacts.
2.3.1 Coupon Materials
The method demonstration, decontamination efficacy testing, and material/decontaminant
compatibility evaluations were conducted using the following types of SE-related materials:
ABS molded plastic, acrylic, and aluminum. These materials were selected because they are
frequently included in construction of SE. Test articles consisted of coupons of each of the SE-
related materials selected for the evaluation. Coupons measured 2.5 centimeters x 4 centimeters
(cm; 10 square centimeters [cm2] contamination/decontamination surface area), with thickness
dependent upon the specific material.
ABS molded plastic is a common thermoplastic made by polymerizing styrene and acrylonitrile
in the presence of polybutadiene. The proportions of the three constituents can vary from 15 to
35% acrylonitrile, 5 to 30% butadiene, and 40 to 60% styrene. ABS is generally regarded as a
strong, lightweight plastic used in several applications including automotive components,
protective cases, and kitchen appliances. Regarding SE, ABS is used in several applications
including construction of electrical enclosures, medical devices for blood access, keyboard
keycaps, and others. ABS plastic coupons used during this work had a thickness of
approximately 6.4 millimeters (mm; 0.25 inch), which is representative of the thickness of most
common electrical/electronics enclosures. 24 x 24-inch sheets (8586K471, McMaster-Carr®,
Cleveland, Ohio) were obtained and cut into individual coupons for use during testing.
Acrylic, or poly(methyl methacrylate) (PMMA), Plexiglas™, or Lucite™ by DuPont, is a
transparent thermoplastic often used as a lightweight, shatter-resistant alternative to glass.
Typical uses of acrylic include aircraft windows, hard contact lenses, and eyeglass lenses.
Regarding SE, acrylic is used in construction of semiconductors, dosimeters, liquid crystal
displays and optical media (compact discs and digital video discs). For this work, acrylic
coupons had a thickness of approximately 1.6 mm (0.0625 inch), which is representative of the
thickness of CDs and DVDs. The 24 x 24-inch sheets (8560K174, McMaster-Carr®, Cleveland,
Ohio) were obtained and cut into individual coupons.
Aluminum is a generally soft, light (low-density), corrosion-resistant metal used widely in the
aerospace, automotive, and building industries, as well as extensively in the construction of
11
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many types of SE. Type 6061 aluminum was used during this testing. Type 6061 aluminum is
comprised of 0.4% to 0.8% silicon, up to 0.7% iron, 0.15% to 0.4% copper, up to 0.15%
manganese, 0.8% to 1.2% magnesium, 0.04% to 0.35% chromium, up to 0.25% zinc, up to
0.15% titanium, 95.85% to 98.56% aluminum, and no more than 0.05% of any other single
element and no more than 0.15% total of other elements. The 6061 aluminum is one of the most
common alloys of aluminum for general purpose use, including the construction of handheld
electronic devices and mobile phones. Aluminum coupons used for this work had a thickness of
approximately 2 mm (0.08 inch), which is consistent with the thickness of most personal
computer PC case walls. The 24 x 24-inch sheets (9015T246, McMaster-Carr®, Cleveland,
Ohio) were obtained and cut into individual coupons.
As described in Section 2.2.1.1, stainless steel was also used for the wipe sampling and solvent
extraction method demonstration tests. Type 304 stainless steel (24-gauge, 0.5 mm thickness)
coupons precut by the supplier to the required 4.0 cm length and 2.5 cm width (custom part,
Adept Products, Inc., West Jefferson, Ohio) were obtained for use during testing.
All coupons were cut to a uniform length (4.0 cm) and width (2.5 cm), so the top surface area to
which the CWA challenge and decontamination technologies were applied measured 10 cm2.
Thicknesses were dependent upon the material type, as specified above. These dimensions
enabled the coupons to fit lying flat at the bottom of the 125-mL jars that were used for solvent
extraction (see Section 2.3.5). Following cutting, coupons were cleaned using dry air to remove
dust and debris prior to use in tests. Aluminum and stainless steel coupons were also wiped using
isopropyl alcohol (IPA)-soaked wipes to remove any machining/cutting grease residue. All
coupons were visually inspected prior to use during all phases of testing to confirm the integrity
and representativeness of the material. Coupons with irregular edges and/or damaged areas were
discarded.
Table 4 provides a summary of test coupon information, including the number of coupons of
each type that were prepared for use during testing.
12
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Table 4. SE-Related Materials
Material
Description
Supplier
Location
Coupon
Dimensions
Preparation
Coupon
Quantity
ABS
Molded
Plastic
Black plastic;
approximately 6.4 mm
thickness
(electrical/electronics
enclosures)
McMaster-Carr
Cleveland, OH
4.0 cm length
2.5 cm width
6.4 mm thick
Coupons cut from 61 x 61
cm (24 x 24 inch) sheet;
cleaned using dry air to
remove cutting debris
321
Acrylic
Clear plastic;
approximately 1.6 mm
thickness (CD/DVD
thickness)
McMaster-Carr
Cleveland, OH
4.0 cm length
2.5 cm width
1.6 mm thick
Coupons cut from 61 x 61
cm (24 x 24 inch) sheet;
cleaned using dry air to
remove cutting debris
308
Aluminum
6061 alloy aluminum;
approximately 2 mm
thickness (computer
case)
McMaster-Carr
Cleveland, OH
4.0 cm length
2.5 cm width
2 mm thick
Coupons cut from 61 x 61
cm (24 x 24 inch) sheet;
cleaned using dry air to
remove cutting debris,
wiped with IPA wipe
378
Stainless
Steel
Type 304 stainless steel;
24-gauge thickness
(approximately 0.5 mm)
Adept Products,
Inc.
West Jefferson
OH
4.0 cm length
2.5 cm width
0.5 mm thick
Coupons cut from 41 x 41
cm (16 x 16 inch) sheet;
cleaned using dry air to
remove cutting debris,
wiped with IPA wipe
125
2.3.2 CWA Application
2.3.2.1. CWA
All quantities of VX and HD used during this work were synthesized at Battelle's HMRC under
Chemical Weapons Convention program guidelines. All VX and HD originated from the same
synthesis lots. VX and HD were stored in the HMRC CWA vault until needed for testing in
accordance with HMRC security and CWA storage policies. To preserve CWA purity, VX was
stored in multiple sealed glass ampoules (one ampoule per test, based on the matrices provided in
Sections 2.2.1 and 2.2.2, with the sealed volume based on the anticipated need for a particular
test). As HD has been demonstrated to be much less susceptible to degradation when maintained
in accordance with the HMRC controlled storage policies, HD was stored in a single capped vial
from which quantities were drawn for use when needed. Table 5 provides purity information for
VX and HD used during testing and identifies the tests during which each CWA was used.
Table 5. CWA Purity
CWA
Purity
Tests Used
HD
99.9%
All methods development and decontamination efficacy
VX
95.1%
Methods development
VX
95.0%
DF200/ABS plastic, DF200/acrylic
VX
94.9%
DF200/aluminum, Dahlgren Decon/ABS plastic
VX
95.1%
eClCh/ABS plastic, eClCh/acrylic, eClCh/aluminum
VX
95.0%
Dahlgren Decon/acrylic, Dahlgren Decon/aluminum
2.3.2.2. Coupon Spiking
13
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Test and positive control coupons were inspected visually prior to contamination with neat VX
or HD, and any coupons with surface anomalies were not used. Neat VX or HD was applied to
the center of each designated test coupon or positive control as a single 2 |iL droplet
(approximately 202 |ig/cm2 of VX, or 254 |ig/cm2 of HD, based on the 10 cm2 coupon surface
area) using a Hamilton® repeating dispenser (83700, Hamilton, Reno, NV, or equivalent) and
100 |iL Hamilton Gastight® syringe (81085, Hamilton, Reno, NV, or equivalent). Spiked control
samples were generated by delivering the same quantity of CWA (2 |iL) directly into 25 mL of
extraction solvent, rather than onto a coupon surface. Following spiking, spike controls were
processed in a manner similar to wipe and coupon extracts (that is, spike controls were sonicated
and aliquoted as described for wipe and coupon extracts in Section 2.3.5).
2.3.2.3. CWA Dwell Period
Following application of CWA, the contaminated coupons were allowed to remain undisturbed
for a 60-minute CWA dwell period. During the dwell period, the coupons were subjected to the
ambient atmosphere within the test hood. Each coupon was covered with a Petri dish or other
loose cover to protect from air currents. Temperature and RH of the coupon environment within
the hood were monitored and recorded but not controlled. Typical ambient laboratory
temperature (and thus, temperature within the hood where the coupons were located) ranged
from 17 °C (64 degrees Fahrenheit [°F]) to 24 °C (75 °F). Testing was not initiated if the
ambient laboratory temperature was outside this range. Ambient RH in the laboratory was more
variable and was dependent on outdoor weather conditions and time of year, but typically ranged
from 5% to 70%. RH was not expected to have an impact on evaporation of the CWA.
Temperature and RH conditions within the hood were measured and recorded using a HOBO
UX100 Data Logger (UX100-003, Onset® Computer Corporation, Bourne, MA) on each day of
testing. Environmental conditions for each test are provided as Appendix A.
2.3.3 Decontamination Technologies
2.3.3.1. Dahlgren Decon
Dahlgren Decon (DD-006-RTU, First Line Technology, Chantilly, VA) is a three-component
decontaminant system including water and a surfactant package (Part A), sodium hydroxide (Part
Bl), and peracetyl borate (active ingredient; Part B2; releases peracetic acid upon dissolution in
water). Part A of Dahlgren Decon was obtained premixed and ready for use (normally Part A in
solid form must be dissolved in water before mixing with Parts Bl and B2). Prior to each test, a
200-mL quantity of Dahlgren Decon was prepared for use by mixing the three parts in
accordance with directions provided by the manufacturer. The decontaminant was then used
(applied to designated coupons) within 30 minutes of preparation. According to the
manufacturer, the unmixed components have a ten-year shelf life, and the decontaminant remains
efficacious for at least 6 hours after the components are mixed.
14
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Consistent with the manufacturer-recommended use instructions, a decontaminant to CWA ratio
of 50:1 (by volume) was used during decontamination efficacy testing. Thus, 100 |iL of
decontaminant was applied to designated coupons according to procedures described in Section
2.3.3.4, following the CWA dwell period.
According to the manufacturer, Dahlgren Decon is capable of 100% neutralization of HD in two
minutes and 95% neutralization of VX in 15 minutes. For this testing, a 60-minute
decontamination contact period was used.
2.3.3.2. EcisyDECON DF200
EasyDECON DF200 (200-5312, Intelagard, Lafayette, CO) is a commercial variant of Sandia
National Laboratories' decontamination foam DF200. EasyDECON DF200 is a three-component
decontaminant system containing water and water-soluble cationic surfactants (Part 1), hydrogen
peroxide (8% H2O2, active ingredient, Part 2), and diacetin (CAS 25395-31-7, catalyst, Part 3).
The decontaminant can be applied as a liquid or a foam (using compressed air systems that inject
air into the pumped liquid decontaminant to create the foam). For this testing, EasyDECON
DF200 was applied as a liquid. EasyDECON DF200 is not received premixed, but rather the
three parts are received packaged separately and need to be mixed prior to use (by combining the
complete volumes of all three parts).
EasyDECON DF200 was prepared daily (each day of testing) in small batches of 10 mL each by
combining 4.9 mL of Part 1, 4.9 mL of Part 2, and 200 |iL of Part 3 in the correct order and
manner specified by the EasyDECON DF200 use instructions. According to the manufacturer,
Part 2 of EasyDECON DF200 (hydrogen peroxide active ingredient) has a shelf life of up to five
years when stored at ideal conditions. Following preparation (proper mixing of the components
in accordance with manufacturer directions), the decontaminant then has a pot-life of eight hours
(per the manufacturer). Manufacturer-recommended use procedures require that the
contaminated surface to which the decontaminant is applied be kept wet for a period of no less
than 10 minutes. For this testing, 100 |iL of prepared decontaminant was applied to designated
coupons (directly on top of the liquid CWA droplet in the case of test coupons). During previous
EPA studies using EasyDECON DF200 to decontaminate HD from nonporous material coupons
(sealed concrete, glass, galvanized metal ductwork)[2], 60 [xL of EasyDECON DF200
decontaminant was applied to a 1 [j,L CWA challenge on coupons with 5.25 cm2 surface area.
Use of a 100 |iL decontaminant volume is just less than the 60:1 decontaminant to CWA ratio
used during that work and is consistent with the 50:1 ratio recommended by other decontaminant
manufacturers. A decontaminant contact period of 60 minutes was used.
2.3.3.3. TDA Research Inc. HDA
The Handheld Decontamination Apparatus (HDA) by TDA Research, Inc. is a developmental (not
yet commercially available) handheld sprayer system equipped with an electrode for
electrochemical generation of aqueous chlorine dioxide (eC102). The HDA is intended for use in
decontamination of CWAs and biological agents from hard nonporous surfaces. The system
15
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consists of the electrode-equipped sprayer, an active ingredient salt package (Part A), and a
surfactant package (Part B). The Part A salt package contains a mixture of sodium chlorite and
sodium bromide as active ingredients. Prior to use, the total contents of the two packages were
added to 1 liter (L) of distilled water in the sprayer system bottle. Following mixing and
reassembly of the sprayer system, the sprayer pump was primed for 10 to 15 seconds until the
sprayed solution turned a light shade of yellow (per manufacturer use instructions, this yellow
color indicates that the HDA is fully primed and ready for use). During use, the system dispenses
the prepared salt solution through the electrochemical cell, oxidizing the salts and generating
chlorine dioxide and hypobromite ions. According to the manufacturer, the mixed decontaminant
solution is stable for multiple months. The decontaminant is not "activated" until it is delivered
through the electrode-equipped sprayer, following which it must be used as soon as possible as
the concentration of the oxidant will decrease quickly.
TDA Research, Inc., recommended use instructions require that the HDA spray stream be held
perpendicular to the contaminated surface during application at a distance of no more than 12
inches. Per the manufacturer, it is also acceptable for experimental purposes to spray the
electrochemical decontaminant into a glass jar or beaker and aliquot the solution onto
contaminated surfaces. This "collect and aliquot" method was used during the decontamination
efficacy testing conducted during this work. Just prior to the required decontaminant application
time (approximately 20 to 30 minutes before the 60-minute CWA dwell period described in
Section 2.3.2.3 was complete), the HDA eClCh decontaminant was prepared. Then, just prior to
use during testing, a sufficient quantity was collected from the sprayer into a new, clean, and
unused glass jar for application to all designated coupons for the test being run. Immediately
after collection, the decontaminant was aliquoted from the jar onto the coupons according to
procedures described in Section 2.3.3.4, below. The manufacturer did not establish a requirement
to keep the contaminated surface to which the decontaminant is applied wet for a specific period.
To maintain consistency with the other decontaminants, 100 |iL of activated eClCh solution was
applied to the center of each required coupon (directly on top of the CWA contamination, if
applicable), and a 60-minute decontaminant contact period was used.
2.3.3.4. Decontaminant Application
The decontaminants were applied as liquids to test and procedural blank coupons using a positive
displacement pipette (M-250E [50-250 |iL pipette] and CP250 [tip], Gilson Inc, Middleton, WI).
Decontaminant (100 |iL) was applied to designated coupons in such a manner that the
decontaminant remained pooled/beaded on the coupon surface (did not run off the edges of the
coupon). In the case of spiked coupons (e.g., test coupons), decontaminant was applied directly
on top of the CWA challenge. Following application, the decontaminants were allowed to remain
undisturbed on the coupons (to react with the CWA challenge, in the case of test coupons) for 60
minutes. Coupons were left uncovered during the decontamination contact period. The air flow
across coupons was not directly measured. Decontaminants were not reapplied during the 60-
minute contact period as the 100 |iL application volume used for all three decontaminants was
16
-------
sufficient to keep the coupon surfaces wetted for the duration, even in the presence of the higher
air flow across the coupons. Following the decontaminant contact period, coupons were wipe-
sampled, extracted with solvent, or both according to procedures described in Sections 2.3.4 and
2.3.5. Decontaminant application volumes, contact periods, and rationale for each are
summarized in Table 6.
Table 6. Decontamination Technology Application Volumes and Contact Periods
Decontamination
Technology
Application
Volume
Decon
Contact
Period
Rationale
Dahlgren Decon
100 nL
(50:1
decontaminant
by volume to
' CWA)
60
minutes
Manufacturer recommended 50:1 decontaminant to
contaminant ratio.
Manufacturer claimed HD neutralization in two minutes
and VX neutralization in 15 minutes.
EasyDECON
DF200
100 nL
(50:1
decontaminant
by volume to
' CWA)
60
minutes
Application volume is consistent with the 50:1
decontaminant to CWA ratio recommended for other
decontaminants.
Manufacturer recommends that contaminated surface be
kept wet with decontaminant for at least 10 minutes.
TDA Research,
Inc. HDA
100 nL
(50:1
decontaminant
by volume to
' CWA)
60
minutes
Collection of decontaminant from the sprayer into
glassware and subsequent application via pipette onto
contaminated surfaces is a practice accepted by the
manufacturer for experimental purposes.
Manufacturer did not provide recommendation on the
time that the surface should be kept wet with
decontaminant.
2.3.4 Coupon Surface (Wipe) Sampling
The method for coupon surface wipe-sampling used during this work was evaluated prior to
decontamination efficacy testing to ensure adequate recovery of VX and HD could be achieved
from the SE-related materials included in testing (refer to Section 2.1.1.1). The method included
the following details:
• Wipes used were lint-free 2 x 2-inch (5x5 cm) four-ply rayon/polyester blend (gauze)
sponges (22-037-921, Fisher Scientific, Pittsburgh, PA).
• The wipe was initially folded, as necessary, for manageability during wiping. Each
coupon was wiped using an established wipe pattern (four horizontal and four vertical
strokes with no folding between changes in direction). Given the small surface area of the
coupons, strokes were short (coupon length) and placed on top of each other.
No blotting or rinsing of any excess liquid decontaminant remaining on coupons was performed.
The excess decontaminant was absorbed into the wipe during the wiping action. As previously
described, adequate methods for quenching the decontaminant reactions were demonstrated prior
to decontamination efficacy testing (Sections 2.1.1.2 and 2.2.1.2).
17
-------
Wipes were extracted in the same manner as coupons, as described in Section 2.3.5, using the
same solvent as used to wet the wipes. Wipe extracts were analyzed for VX or HD by GC/MS as
described in Section 2.4.
2.3.5 Coupon and Wipe Solvent Extraction
All coupons and wipes were extracted by placing each into a separate 60 mL glass jar (05-719-
257, Fisher Scientific, Pittsburgh, PA, or similar) containing 25 mL of hexane. Hexane with
internal standard (IS; 2.5 |ag/mL naphthalene-dx, AC17496-0010, Fisher Scientific, Pittsburgh,
PA) was prepared in 4-L batches prior to filling individual extraction jars to ensure a consistent
internal standard (IS) concentration in each sample. A stabilizer (N,N'-diisopropylcarbodiimide
(DIC), CAS 693-13-0, D125407-100G, Sigma Aldrich, St. Louis, MO) was also added to help
improve the sensitivity of the GC/MS analysis of VX samples. During previous studies, the DIC
stabilizer was demonstrated to provide the intended benefits to VX analysis (without drawbacks)
while not affecting analysis for HD [1].
Using the dimensions provided in Table 4, coupons of the SE-related materials fit lying flat
within the inside diameter of the extraction jars identified above. Extraction solvent (25 mL)
reached a height within the jar of approximately 2 cm. This jar and volume of solvent were
sufficient to submerge all coupon types fully. ABS plastic coupons were identified to float in the
extraction solvent and so were placed into the jars with the CWA-exposed/decontaminated side
facing downward (into the extraction solvent).
Following addition of wipes or coupons to the extraction solvent within each jar, the jars were
swirled by hand for approximately 5-10 seconds and then placed into a sonicator. Extraction jars
were sonicated at 40 - 60 kilohertz for 10 min. Within 30 minutes of completing this process,
aliquots of at least 0.5 mL from each extraction jar were transferred to individual GC vials
(21140 [vial], 24670 [cap], Fisher Scientific [Restek Corp.], Hanover Park, IL 60133) and
sealed. Samples that were not analyzed the same day were stored at -20 ± 10 °C.
2.4 Analytical Methods
2.4.1 VX and HD Quantitative Analysis
Wipe and coupon extracts were analyzed to quantify the amount of VX or HD present and to
semi-quantitatively assess the presence of degradation products3 (see Sections 2.4.2 and 2.4.3)
using GC/MS (6890 gas chromatograph and 5973 mass selective detector, Agilent Technologies,
Santa Clara, CA). Each sample set was analyzed in full scan mode for compounds ranging from
40 to 500 atomic mass units (amu) to quantify VX or HD and to determine the presence of
degradation products. VX was detected with ions 114, 72, 127, and 79. HD was detected with
ions 158, 109, 160, and 111. GC/MS parameters used for analysis are provided in Table 7.
18
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Table 7. GC/MS Conditions for VX and HD Analysis
CWA
Parameter
Description
Instrument
Hewlett Packard Model HP 6890 Gas Chromatograph equipped with HP
5973A Mass Selective Detector and Model 7683 Automatic Sampler
Data System
MSD ChemStation
Column
Rxi-5Sil MS (cross4inked methylsilicone), 30 meters x 0.25 mm, 0.25 (.un
film thickness (Restek Cat. No. 13653)
Liner Type
4 mm Split/Splitless
VX
Carrier Gas Flow Rate
1.2 mL/min
Column Temperature
50 °C initial temperature, hold 1 min, 30 °C/min to 280 °C, hold 0 min
Injection Volume
1.0 nL
Injection Temperature
250 °C
MS Quad Temperature
U\
o
o
O
MS Source Temperature
230 °C
Solvent Delay
3 min
Instrument
Hewlett Packard Model HP 6890 Gas Chromatograph equipped with HP
5973A Mass Selective Detector and Model 7683 Automatic Sampler
Data System
MSD ChemStation
Column
Rxi-5Sil MS, 30.0 meters x 0.25 mm, 0.25 |im film thickness
Liner Type
4 mm Split/Splitless
HD
Carrier Gas Flow Rate
1.2 mL/min
Column Temperature
40 °C initial temperature, hold 2.0 min, 30 °C/min to 310 °C, hold 0 min
Injection Volume
2.0 |j,L
Injection Temperature
250 °C
MS Quad Temperature
U\
o
o
O
MS Source Temperature
230 °C
Solvent Delay
3 min
See Section 4.2.2 for GC/MS calibration details. Samples with quantification results that fell
below the low standard were reported as the method minimum quantifiable limit (MQL). All
data were reported to two significant figures. Generally, accurate quantification of VX or HD
was prioritized over qualitative assessment of degradation products when selecting GC/MS
method parameters (i.e., quantitative VX or HD analysis capability was not sacrificed for
increased capability to qualitatively assess degradation products).
2.4.2 VX Byproduct Qualitative Analysis
Extracts were also analyzed to semi-quantitatively estimate the amount of diethyl
methanephosphonate and diethyl dimethylpyrophosphonate present. Diethyl
methanephosphonate and diethyl dimethylpyrophosphonate are degradation products of ethyl
methylphosphonic acid (EMPA) and sometimes impurities associated with VX [3]. EMPA is a
hydrolysis product of VX. During preliminary/unpublished testing, 10 pg/mL of EMPA in
hexane with naphthalene-ds (IS) and DIC and in acetone with naphthalene-ds (IS) and DIC was
not directly detected via GC/MS as described in Section 2.4.1 for the analysis of VX. The EMPA
may have reacted or degraded in the hot inlet of the GC; however, degradation products of
EMPA (diethyl methanephosphonate and diethyl dimethylpyrophosphonate) were detected.
19
-------
Thus, analyses for diethyl methanephosphonate and diethyl dimethylpyrophosphonate were
performed concurrently with analyses for VX during the full scan analysis of each sample set.
Diethyl methanephosphonate was detected with ions 79, 97, and 125, and diethyl
dimethylpyrophosphonate was detected with ions 203, 143, and 175.
An EMPA standard at 81 |ag/m L (equivalent to the maximum response from each EMPA
degradant if all the VX on a particular coupon were to degrade into EMPA) was included during
VX analytical runs (along with the VX calibration curve and the VX continuing calibration
verification [CCV] standards described in Section 4.2.2). An intermediate EMPA standard at 3
milligrams (mg)/mL was prepared first by addition of neat EMPA (98% purity, 386561-1G,
Sigma-Aldrich, St. Louis, MO) to hexane containing naphthalene-dx (IS) and DIC. The
intermediate was then diluted to the 81 jag/m L concentration standard that was included in the
analytical runs. The EMPA standard served as a single "calibration point" that was compared to
any EMPA-associated peaks in the test and control samples. Ratios of peak area response for
EMPA-associated byproducts in the test samples to the peak area response of EMPA-associated
byproducts in the single "calibration point" were reported for each test sample.
Note: the toxic byproduct of VX degradation, EA-2192, cannot be identified by GC/MS.
Analysis for EA-2192 requires the use of liquid chromatography (LC)/MS, which was outside
the scope of this testing. Thus, degradation of VX into EA-2192 was not evaluated during this
work.
2.4.3 HD Byproduct Qualitative Analysis
bis(beta-Chloroethyl) sulfone (mustard sulfone, CAS 471-03-4) and thiodiglycol (TDG, CAS
111-48-8) were the target degradation byproducts of interest during HD analysis runs. Semi-
quantitative analyses for mustard sulfone and TDG were accomplished in the same manner as the
semi-quantitative analyses of diethyl methanephosphonate and diethyl dimethylpyrophosphonate
during analyses for VX (Section 2.4.2). Analyses for mustard sulfone and TDG were performed
concurrently with analyses for HD during the full scan runs of each sample set. Mustard sulfone
was detected with ions 63, 65, 92, and 127, and TDG was detected with ions 61, 45, 91 and 104.
A single "calibration point" standard each of mustard sulfone and TDG, both at 102 |ag/m L
(equivalent to the maximum response from the byproduct if all the HD on a particular coupon
were to degrade), was included in each full scan GC/MS run for analysis of HD. Intermediate
standards for each byproduct at 3 mg/mL were prepared first by addition of mustard sulfone
(S741930-100MG, Sigma-Aldrich, St. Louis, MO) or TDG (1 mg/mL solution in methanol,
ERT-053-1.2ML, Sigma-Aldrich, St. Louis, MO) to hexane containing naphthalene-ds (IS) and
DIC. The intermediates were then diluted to the 102 |ig/mL concentration standards that were
included in the analytical runs.
Ratios of peak area response for mustard sulfone and TDG in the test samples to the peak area
response of mustard sulfone and TDG in the single "calibration point" were reported for each
test sample.
20
-------
2.5 Calculations
Test, control, and blank coupon and wipe extract concentrations were provided in units of |ig of
VX or HD per mL of extract by the GC/MS ChemStation software through comparison of
analyte peak areas to the calibration curve. Results less than the GC/MS MQL were set to the
MQL for the sake of decontamination efficacy calculations. Mass recovered from the
coupons/wipes via extraction was determined according to Equation 1:
MassRec = ConcExt x VolExt (1)
where: MassRec = CWA mass recovered from the coupon/wipe (|ig)
ConcExt = Coupon/wipe extract concentration provided by the GC/MS software
(|ig/mL)
VolExt = Volume of extraction solvent (mL)
Total mass recovered from the test, control, or blank coupons was the sum of the masses
recovered from the wipe sample taken from the coupon and from extraction of the coupon in
solvent, according to Equation 2:
McLSSfQt McLSSftec (wipe) MaSSRec (coupon) (2)
where: Massiot = Total CWA mass recovered (from wipe and coupon; |ig)
MassRec (wipe) = CWA mass recovered from the wipe (|ig)
MassRec (coupon) = CWA mass recovered from the coupon (|ig)
Residual CWA contamination for each coupon was determined using the calculated total mass
recovered (wipe and coupon) and the coupon contamination/decontamination surface area,
according to Equation 3:
ContRes = (3)
ACoupon
where: ContRes = Residual coupon contamination (|ig/cm2)
Massiot = Total CWA mass recovered (from wipe and coupon; |ig)
Acoupon = Contamination/decontamination surface area of the coupon (cm2)
Percent efficacy was then calculated for each individual test coupon according to Equation 4:
Efficacy = (Cont^sPos-contResTest\ x 1QQ% ^
\ Co^ltResPos '
where: ContResTest = Residual test coupon contamination (|ig/cm2)
ContResPos = Residual positive control coupon contamination (|ig/cm2)
For each CWA/SE-related material/decontamination technology combination, the mean of the
efficacy values was determined. Thus, the primary result from testing was a matrix table in
which each entry provided the mean and percent relative standard deviation (RSD) of efficacy
results for each combination.
21
-------
2.6 Analysis of Variance
For each CWA/decontamination technology/SE-related material type combination, arithmetic
mean and percent RSD of the CWA recovery from test coupon and positive control sample sets
were calculated, and test coupon CWA recovery means were compared to associated positive
control means to determine if statistically significant decontamination of CWA occurred. F-tests
were used to determine if the variances of results sets are equal or not. The null hypothesis that
the variances of two sets were equal was rejected if the F-test p-value was < 0.05. One-tailed,
two-sample Student's t-tests (homoscedastic or heteroscedastic based on the F-test result) were
then used to determine if the means of the test results were significantly less than the positive
controls or not. The null hypothesis that the sample set means were equal was rejected if the t-
test p-Value was < 0.05.
Results were tested to determine if the data were reasonably bell-shaped and normally
distributed. A natural logarithmic transformation of total mass recovery was performed to
generally improve adherence to the statistical assumptions of normality and constant variance. A
one-way analysis of variance (ANOVA) model was fitted separately for each CWA (HD or VX)
and material (ABS plastic, acrylic, or aluminum) combination to the log transformed test sample
total mass recovery with an effect for decontaminant (Dahlgren Decon, DF200, and eCICh) to
determine if there were significant performance differences among the different decontaminants.
The geometric means from the ANOVA model were presented for each CWA and material
combination. Tukey's multiple comparisons procedure was performed for each CW A/material
combination to determine which pairs of decontaminants had geometric mean total mass
recoveries that were significantly different from each other (however, the results are presented
only if significant differences were identified).
Within each CWA/material/decontaminant test, the characteristics of CWA application to the
positive controls are assumed to be the same as the characteristics of application to the test
coupons with regard to variability from coupon to coupon and in the average amount of CWA
applied. Acceptance criteria for the spike control results (average within 80% to 120% of
theoretical, corrected for CWA purity; <30% RSD) are intended to support this assumption. For
accurate comparison of the performance of the decontaminants within each CWA/material
combination as described above, the amount of CWA applied to the test coupons must be
consistent across all eighteen CWA/material/decontaminant combinations. To evaluate
consistency of CWA application across the three tests (one test per decontaminant) of each
CWA/material combination, the comparisons described above for the test samples were repeated
using the geometric mean total recoveries from the three positive control sets associated with
each CWA/material/decontaminant combination.
22
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3. RESULTS
3.1 Method Demonstration
3.1.1 Wipe Sampling and Solvent Extraction Method Development Results
As described in Section 2.1.1.1, the methods for coupon surface wipe sampling and coupon
solvent extraction were tested concurrently during two tests including both methods (one test per
CWA). Hexane was demonstrated in each test as the wipe wetting and wipe and coupon
extraction solvent. Also, as discussed in Section 2.1.1.1, stainless steel evaporation control
coupons were included in the wipe sampling and coupon solvent extraction method development
test matrices. Inclusion of the SS evaporation controls to account for the degree of evaporative
losses of CWA during the 60-minute CWA dwell period was assumed to allow the measured
recoveries from the test coupons to be attributed to the efficiency of the wipe sampling and
solvent extraction methods.
As defined in Section 2.1.1.1, successful demonstration of the wipe sampling and coupon solvent
extraction methods using hexane as the wipe wetting and wipe and coupon extraction solvent
was defined as average CWA recovery from the test samples within 70% to 120% of the average
of the stainless steel controls, with < 30% RSD between replicates. These criteria were achieved
for all three SE-related material types tested, successfully demonstrating the methods for use
during decontamination efficacy testing. Average total VX recoveries from ABS plastic, acrylic,
and aluminum measured 107%>, 120%, and 119%, respectively. Average total recoveries of 75%>
from ABS plastic, 97%> from acrylic, and 97%> from aluminum were measured for HD.
No VX or HD was detected in any procedural or laboratory blank sample included in the wipe
sampling and coupon solvent extraction method development tests. No degradation products for
either CWA (as identified in Sections 2.4.2 and 2.4.3) were detected in any of the test samples.
Table 8 provides the average masses, standard deviations, and percent RSD for each sample type
included during method development testing. Table 9 provides percent recoveries for each. As
indicated, spike control recoveries were based on the theoretical target values, corrected for
CWA percent purity (see Section 2.3.2).
23
-------
Table 8. Wipe Sampling and Coupon Solvent Extraction Average Mass Recoveries
VX
HD
Sample Description
Avg. Mass
Recovery
(Mg)
Std. Dev.
Avg. Mass
Recovery
(Mg)
Std. Dev.
Spike Controls
2034
193
2699
233
Stainless Steel (extraction only)
1983
117
2698
123
Stainless Steel (wipe)
1621
124
2772
131
Stainless Steel (extraction following wiping)
8.3
6.3
8.2
9.9
Stainless Steel (total mass; wipe and ext.)
1629
127
2780
136
ABS Plastic (extraction only)
1944
182
1178
139
ABS Plastic (wipe)
1736
195
1392
248
ABS Plastic (extraction following wiping)
4.4
3.2
687
123
ABS Plastic (total mass; wipe and ext.)
1740
195
2079
144
Acrylic (extraction only)
2119
183
2646
204
Acrylic (wipe)
1943
63
2700
30
Acrylic (extraction following wiping)
3.9
1.2
2.9
0.76
Acrylic (total mass; wipe and ext.)
1947
62
2703
29
Aluminum (extraction only)
2209
206
2682
113
Aluminum (wipe)
1932
31
2699
168
Aluminum (extraction following wiping)
3.2
0.70
2.5
0.00
Aluminum (total mass; wipe and ext.)
1936
31
2702
168
Table 9. Wipe Sampling and Coupon Solvent Extraction Percent Recoveries
Sample Description
VX
HD
Percent recovery
% Recovery
RSD
% Recovery
RSD
determined vs
Spike Controls
106%
9.5%
106%
8.6%
Theoretical
Stainless Steel (extraction only)
97%
5.9%
100%
4.6%
Spike controls
Stainless Steel (wipe)
82%
7.6%
103%
4.7%
Stainless steel (ext. only)
Stainless Steel (extraction following wiping)
0.42%
76%
0.31%
121%
Stainless steel (ext. only)
Stainless Steel (total mass; wipe and ext.)
82%
7.8%
103%
4.9%
Stainless steel (ext. only)
ABS Plastic (extraction only)
98%
9.3%
44%
12%
Stainless steel (ext. only)
ABS Plastic (wipe)
107%
11%
50%
18%
Stainless steel (total)
ABS Plastic (extraction following wiping)
0.27%
73%
25%
18%
Stainless steel (total)
ABS Plastic (total mass; wipe and ext.)
107%
11%
75%
6.9%
Stainless steel (total)
Acrylic (extraction only)
107%
8.7%
98%
7.7%
Stainless steel (ext. only)
Acrylic (wipe)
119%
3.2%
97%
1.1%
Stainless steel (total)
Acrylic (extraction following wiping)
0.24%
31%
0.11%
26%
Stainless steel (total)
Acrylic (total mass; wipe and ext.)
120%
3.2%
97%
1.1%
Stainless steel (total)
Aluminum (extraction only)
111%
9.3%
99%
4.2%
Stainless steel (ext. only)
Aluminum (wipe)
119%
1.6%
97%
6.2%
Stainless steel (total)
Aluminum (extraction following wiping)
0.20%
22%
0.09%
0.00%
Stainless steel (total)
Aluminum (total mass; wipe and ext.)
119%
1.6%
97%
6.2%
Stainless steel (total)
Figures 1 and 2 summarize average mass recovery from each SE-related material type for each
CWA. As indicated in the figures, the upper and lower limit bars correspond to 120% and 70%
(respectively) of the average total mass recovery from the stainless steel evaporation controls
associated with the test samples.
24
-------
Wipe Sampling and Coupon Solvent Extraction Methods Development
VX Mass Recovery
3000
2500
— 2000
uD
A
V
>
o
s 1500
re
CiL
<
1000
500
Extraction Only
Wipe
Ext following wipe
Total mass
Upper limit
Lower limit
Spike Controls
Stainless Steel
ABS Plastic
Material
Acrylic
Aluminum
Figure 1. Wipe Sampling and Coupon Solvent Extraction, VX Mass Recovery
(Error bars equal ± one standard deviation; upper limit equals 120% of mean total mass recovery from stainless steel, lower limit equals 70% of mean
total mass recovery from stainless steel; Ext is abbreviation for Extraction)
25
-------
Wipe Sampling and Coupon Solvent Extraction Methods Development
HD Mass Recovery
4000
3 5 CO
3000
3 2500
v
>
o
u
c
2000
ID
s
u
>
1500
1000
500
Extraction only
Wipe
Ext following wipe
Total mass
Upper linit
Lower limit
Spike Controls
Stainless Steel
ABS Plastic
Material
Acrylic
Aluminum
Figure 2. Wipe Sampling and Coupon Solvent Extraction, HD Mass Recovery
(Error bars equal ± one standard deviation; upper limit equals 120% of mean total mass recovery from stainless steel, lower limit equals 70% of mean
total mass recovery from stainless steel; Ext is abbreviation for Extraction)
26
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3.1.2 Quench Method Development Test Results
Based on method development data from previous EPA studies evaluating decontamination of
HD and also considering that the three decontamination technologies selected for evaluation
during this work are aqueous-based (refer to Section 2.3.3), extraction of wipes and coupons in
organic solvent alone (hexane) was anticipated to be sufficient to halt the decontamination
reaction via separation of any residual CWA from the decontaminant and preserve any residual
VX and/or HD following the decontaminant contact period.
Average mass recoveries obtained during the first quench method test evaluating extraction in
hexane alone are provided in Tables 10 and 11 and summarized in Figure 3. No VX or HD was
detected in any blank sample included in the test. No degradation products for either CWA (see
Sections 2.4.2 and 2.4.3) were detected in any of the samples.
As defined in Section 2.1.1.1, extraction in hexane alone would be considered adequate to
quench the reactions of the decontaminants if the amounts of CWA recovered from post-spiked
extracts containing decontaminant were at least 70% of the mean amount of CWA recovered
from post-spiked extracts that did not contain decontaminant.
As described in Section 2.3.4, residual decontaminant still present on the surface of coupons
after the 60-minute decontaminant contact period was absorbed into the wipe during the act of
wipe sampling (i.e., decontaminant was not poured or rinsed off, or removed by some other
means). The results provided in Tables 10 and 11 and in Figure 3 suggest that this practice led to
residual decontaminant being nearly completely collected in the wipe sample. For
decontaminants that were not quenched by extraction in hexane alone, recoveries of both CWAs
from coupon extracts still ranged as high as 85% to 102% of the associated positive controls.
Low recoveries were obtained only from the post-spiked wipe extracts for those samples. This
suggests that unquenched decontaminant was only present in the wipe extracts and not in the
coupon extracts.
27
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Table 10. Quench Method Test 1, Solvent Extraction Alone, Average Mass Recoveries
Quench
Method
Initial Analysis
Three- Day Storage at
20 °C
CWA
Sample Description
Avg. Mass
Recovery
(Mg)
Std.
Dev.
Avg. Mass
Recovery
(Mg)
Std.
Dev.
Spike Controls
109
43
109
41
Positive Control Wipe Extracts
134
1.3
136
2.7
Positive Control Coupon Extracts
135
1.5
137
3.8
Extraction
DF200 Wipe Extracts
45
24
53
24
vx
in 25 niL
DF200 Coupon Extracts
114
7.6
125
7.4
of hexane
Dahlgren Decon Wipe Extracts
2.6
0.00
2.6
0.00
Dahlgren Decon Coupon Extracts
131
6.6
129
8.7
eClC>2 Wipe Extracts
135
2.1
137
6.3
eClC>2 Coupon Extracts
131
8.0
132
7.2
Spike Controls
135
0.96
135
1.7
Positive Control Wipe Extracts
138
5.3
137
4.5
Positive Control Coupon Extracts
138
2.3
137
3.3
Extraction
DF200 Wipe Extracts
108
11
106
11
HD
in 25 mL
DF200 Coupon Extracts
136
4.6
135
4.2
of hexane
Dahlgren Decon Wipe Extracts
2.6
0.00
2.6
0.00
Dahlgren Decon Coupon Extracts
123
21
124
22
eClC>2 Wipe Extracts
133
1.5
134
1.6
eClC>2 Coupon Extracts
138
0.88
137
1.0
Table 11. Quench Method Test 1, Solvent Extraction Alone, Percent Recoveries
CWA
Quench
Method
Sample Description
Initial Analysis
% Recovery RSD
3 Day Storage at 20 °C
% Recovery RSD
Percent recovery
determined vs
VX
Extraction
in 25 rnL
of hexane
Spike Controls
81%
39%
82%
38%
Theoretical
Positive Control Wipe Extracts
123%
0.97%
125%
2.0%
Spike controls
Positive Control Coupon Extracts
124%
1.1%
125%
2.8%
Spike controls
DF200 Wipe Extracts
34%
52%
39%
45%
PC wipe extracts
DF200 Coupon Extracts
85%
6.7%
92%
5.9%
PC coupon extracts
Dahlgren Decon Wipe Extracts
2.0%
0.00%
1.9%
0.00%
PC wipe extracts
Dahlgren Decon Coupon Extracts
97%
5.1%
94%
6.7%
PC coupon extracts
eClC>2 Wipe Extracts
101%
1.6%
101%
4.6%
PC wipe extracts
eClC>2 Coupon Extracts
97%
6.1%
96%
5.5%
PC coupon extracts
HD
Extraction
in 25 rnL
of hexane
Spike Controls
101%
0.71%
101%
1.2%
Theoretical
Positive Control Wipe Extracts
102%
3.8%
101%
3.3%
Spike controls
Positive Control Coupon Extracts
102%
1.7%
102%
2.4%
Spike controls
DF200 Wipe Extracts
78%
9.8%
77%
10%
PC wipe extracts
DF200 Coupon Extracts
98%
3.4%
99%
3.1%
PC coupon extracts
Dahlgren Decon Wipe Extracts
1.9%
0.00%
1.9%
0.00%
PC wipe extracts
Dahlgren Decon Coupon Extracts
89%
17%
90%
18%
PC coupon extracts
eClC>2 Wipe Extracts
97%
1.1%
98%
1.2%
PC wipe extracts
eClC>2 Coupon Extracts
100%
0.64%
100%
0.73%
PC coupon extracts
PC = Positive Control
28
-------
1B0
Quench Method Development
Solvent Extraction Alone, Initial Analyses
160
140
120
> 100
e
U
V
oc
ro
>
<
so
60
40
20
I
vx
SHD
PC Wipe Extracts
PC Coupon Extracts
DF200 Wipe Extracts
DF200 Coupon Extracts
Dahlgren Wipe Extracts
Dahlgren Coupon Extracts
eCI02 Wipe Extracts
eCI02 Coupon Extracts
PC Wipe Upper Limit
pc Wipe Lower Limit
PC Coupon Upper Limit
pc Coupon Lower Limit
CWA
Figure 3. Quench Method Test 1, Solvent Extraction Alone, Average Mass Recoveries
(Error bars equal ± one standard deviation; upper and lower limit bars correspond to 70% and 120%, respectively, of the average mass recovery from
positive wipe sample extracts [red] and positive coupon sample extracts [purple])
29
-------
The data show that solvent extraction alone sufficiently quenched decontamination of VX and
HD by the TDA eClCh decontaminant (post-spiked VX and HD recoveries ranging from 96% to
101% from wipe and coupon extracts of decontaminated coupons, both initially and after three
days), as well as decontamination of HD by EasyDECON DF200 (post-spiked HD recoveries
ranging from 77% to 99% from wipe and coupon extracts of decontaminated coupons, both
initially and after three days). Conversely, extraction in hexane alone was not sufficient to
prevent decontamination of post-spiked VX by DF200 or of either post-spiked VX or HD by
Dahlgren Decon.
Based on these results, a second test was performed to evaluate the adequacy of a 3M solution of
STS as a quenching agent to prevent decontamination of VX by DF200 and of VX and HD by
Dahlgren Decon. As described in Section 2.1.1.2, the second test was performed in the same
manner as the first using the same procedures and equipment, with the only exception being that
15 mL of 3M STS was added with the 25 mL of hexane to each wipe/coupon extraction jar.
Average mass recoveries obtained during the second quench method test evaluating 3M STS as
an adequate quench are provided in Tables 12 and 13 and are summarized in Figure 4. No VX or
HD was detected in any blank sample included in the test. No degradation products for either
CWA (as identified in Sections 2.4.2 and 2.4.3) were detected in any of the samples.
Table 12. Quench Method Test 2, 3M STS, Average Mass Recoveries
Initial Analysis Three- Day Storage at 20 °C
CWA
Quench
Method
Sample Description
Avg. Mass
Recovery
(MS)
Std.
Dev.
RSD
(%)
Avg. Mass
Recovery
(MS)
Std.
Dev.
RSD
(%)
Spike Controls
145
17
12%
140
5.5
4.0%
Extraction
Positive Control Wipe Extracts
159
4.8
3.0%
144
1.3
0.87%
in 25 niL of
Positive Control Coupon Extracts
157
1.4
0.87%
144
1.5
1.0%
VX
hexane with
DF200 Wipe Extracts
142
3.5
2.4%
127
2.8
2.2%
15 mL 3M
DF200 Coupon Extracts
143
2.4
1.7%
141
2.4
1.7%
STS
Dahlgren Decon Wipe Extracts
161
10
6.1%
150
7.2
4.8%
Dahlgren Decon Coupon Extracts
159
7.8
4.9%
146
0.65
0.44%
Extraction
Spike Controls
134
1.0
0.77%
135
0.46
0.34%
in 25 niL of
Positive Control Wipe Extracts
135
1.1
0.84%
137
2.0
1.5%
HD
hexane with
Positive Control Coupon Extracts
136
0.94
0.69%
138
2.6
1.9%
15 niL 3M
Dahlgren Decon Wipe Extracts
135
3.1
2.3%
136
3.0
2.2%
STS
Dahlgren Decon Coupon Extracts
136
0.54
0.40%
137
1.1
0.83%
30
-------
Table 13. Quench Method Test 2, 3M STS, Percent Recoveries
CWA
Quench
Method
Sample Description
Initial Analysis
Three-Day Storage at
20 °C
Vs
% Recovery
RSD
% Recovery
RSD
Spike Controls
108%
12%
105%
4.0%
Theoretical
Extraction
Positive Control Wipe Extracts
110%
3.0%
103%
0.87%
Spike controls
in 25 niL of
Positive Control Coupon Extracts
109%
0.87%
103%
1.0%
Spike controls
vx
hexane with
DF200 Wipe Extracts
89%
2.4%
88%
2.2%
PC wipe extracts
15 niL 3M
DF200 Coupon Extracts
91%
1.7%
98%
1.7%
PC coupon extracts
STS
Dalilgren Decon Wipe Extracts
101%
6.1%
104%
4.8%
PC wipe extracts
Dahlgren Decon Coupon Extracts
101%
4.9%
102%
0.44%
PC coupon extracts
Extraction
Spike Controls
101%
0.77%
101%
0.34%
Theoretical
in 25 niL of
Positive Control Wipe Extracts
101%
0.84%
102%
1.5%
Spike controls
HD
hexane with
Positive Control Coupon Extracts
102%
0.69%
103%
1.9%
Spike controls
15 niL 3M
Dalilgren Decon Wipe Extracts
100%
2.3%
99%
2.2%
PC wipe extracts
STS
Dahlgren Decon Coupon Extracts
100%
0.40%
99%
0.83%
PC coupon extracts
PC = Positive Control
31
-------
Quench Method Development
3M STS Quench, Initial Analyses
200
ISO
160'
140
bfi
>* 120
>
o
«S 100
cc
in
in
IB
6L
>
BO
60
40
20
PC Wipe Extract:
PC Coupon Extract:
DF200 Wipe Extracts
DF200 CoLpon Extract:
DaNgrer Wipe Extract:
Dahlgren Coupon Extract:
PC Wipe Upper Limit
PC Wipe Lower Limit
PC Coupon Upper Limit
-PC Coupon Lower Limit
VX
HC
CWA
Figure 4. Quench Method Test 2, 3M STS, Average Mass Recoveries
(Error bars equal ± one standard deviation; upper and lower limit bars correspond to 70% and 120%, respectively, of the average mass recovery from
positive wipe sample extracts [red] and positive coupon sample extracts [purple])
32
-------
As demonstrated by the data, 3M STS was found to adequately quench decontamination of VX
by EasyDECON DF200 (post-spiked VX recoveries ranging from 88% to 98% from wipe and
coupon extracts of decontaminated coupons, both initially and after three days) and
decontamination of VX and HD by Dahlgren Decon (post-spiked VX and HD recoveries ranging
from 99% to 104% from wipe and coupon extracts of decontaminated coupons, both initially and
after three days). Thus, the quench methods used for each CWA/decontaminant combination
during decontamination efficacy testing were as follows:
• HD by EasyDECON DF200: Extraction in hexane alone (78% recovery of post-spiked
HD in wipe extracts, 98% in coupon extracts)
• HD by Dahlgren Decon: 3M STS added to extraction solvent (100% recovery of post-
spiked HD in wipe extracts, 100% in coupon extracts)
• HD by TDA eC102: Extraction in hexane alone (97% recovery of post-spiked HD in wipe
extracts, 100% in coupon extracts)
• VX by EasyDECON DF200: 3M STS added to extraction solvent (89% recovery of post-
spiked HD in wipe extracts, 91% in coupon extracts)
• VX by Dahlgren Decon: 3M STS added to extraction solvent (101% recovery of post-
spiked HD in wipe extracts, 101% in coupon extracts)
• VX by TDA eC102: Extraction in hexane alone (101% recovery of post-spiked HD in
wipe extracts, 97% in coupon extracts)
As described in Section 2.1.1.2, following the initial analyses of the samples generated during
each quench method test, samples were stored at -20 °C for three days, and then reanalyzed to
determine if decontamination of VX or HD in the samples occurred during storage. Tables 14
and 15 provide the wipe and coupon sample mass recoveries for the individual replicates
included in each test, both from the initial analyses performed immediately after generation of
the samples as well as during reanalyses of the samples following storage for three days at -20
°C. Calculated percent difference in mass recovery between the initial analysis and reanalysis is
provided as well for each sample. Results suggest that continued decontamination of VX and HD
in the samples did not occur.
33
-------
Table 14. Quench Sample Reanafyses Percent Differences, 1st Test
Wipe Sample Mass Recovered
Coupon Mass Recovered
Sample
Initial
Reanalysis
% Diff
Initial
Reanalysis
% Diff
Hinm
(M^g)
Hinm
(Mg)
VX Positive 1
135
134
-1.4%
137
134
-1.6%
VX Positive 2
133
139
4.4%
134
135
1.0%
VX Positive 3
133
136
2.2%
136
141
4.1%
VX DF200 1
38
48
28%
109
120
10%
VX DF200 2
72
78
9.1%
123
134
8.8%
VX DF200 3
27
32
19%
111
122
10%
VX DD 1
2.6
2.6
0.00%
128
126
-1.4%
VXDD2
2.6
2.6
0.00%
128
122
-4.0%
VX DD 3
2.6
2.6
0.00%
139
139
-0.14%
VX eC102 1
138
144
4.5%
133
136
2.5%
VX eC102 2
133
136
2.1%
137
136
-1.0%
VX eC102 3
135
131
-2.7%
122
124
1.5%
HD Positive 1
144
142
-1.2%
139
140
0.65%
HD Positive 2
136
134
-2.0%
135
134
-1.2%
HD Positive 3
133
134
0.72%
139
137
-1.7%
HD DF200 1
104
106
1.6%
131
131
-0.31%
HD DF200 2
99
94
-4.7%
136
136
0.11%
HD DF200 3
119
116
-2.6%
140
139
-1.0%
HD DD 1
2.6
2.6
0.00%
136
137
0.88%
HD DD 2
2.6
2.6
0.00%
99
98
-0.75%
HD DD 3
2.6
2.6
0.00%
136
136
0.10%
HD eC102 1
135
135
0.44%
137
138
0.71%
HD eC102 2
132
133
0.45%
138
136
-1.3%
HD eC102 3
134
133
-0.59%
139
136
-1.8%
Table 15. Quench Sample Reanafyses Percent Differences, 2nd Test
Wipe Sample Mass Recovered
Coupon Mass Recovered
Sample
Initial
Reanalysis
% Diff
Initial
Reanalysis
% Diff
(Mg)
(Mg)
(Mg)
(Mg)
VX Positive 1
164
145
-12%
159
145
-8.4%
VX Positive 2
156
143
-8.6%
156
143
-8.6%
VX Positive 3
156
144
-7.5%
157
145
-7.7%
VX DF200 1
141
128
0s
00
00
I
140
138
-1.0%
VX DF200 2
145
129
-11%
143
142
-1.0%
VX DF200 3
139
124
-11%
145
143
-1.0%
VX DD 1
149
143
-4.6%
151
146
-3.3%
VX DD 2
166
157
-5.3%
159
146
-7.9%
VX DD 3
167
152
-9.0%
167
147
-12%
HD Positive 1
136
140
2.6%
136
137
0.63%
HD Positive 2
134
136
1.3%
137
141
2.7%
HD Positive 3
134
136
1.7%
136
136
0.61%
HD DD 1
138
139
0.92%
136
136
0.23%
HD DD 2
132
133
1.0%
136
138
1.2%
HD DD 3
136
136
-0.41%
136
137
1.3%
-------
3.2 Decontamination Efficacy
3.2.1 VX Residual Contamination
Throughout all of the VX decontamination efficacy testing, no VX was detected in any
procedural or laboratory blank samples. Spike control samples were within specification for all
tests with one exception: during the test evaluating eClCh decontamination of VX from ABS
plastic, two spike control sample recoveries were measured at 122% and 123% of the theoretical
target value. The mean VX recovery value for spike controls during this test was 122% of
theoretical, with 1.0% RSD. Neither EMPA-associated VX degradant (diethyl
methanephosphonate or diethyl dimethylpyrophosphonate) was detected in any sample.
Frequencies of detection of VX in wipe and coupon sample extracts are provided in Table 16.
Table 16. VX Frequency of Detection
Material
Sample
EasyDECON DF200
Dahlgren Decon
TDA eClCfc
Description
Wipes
Coupons
Wipes
Coupons
Wipes
Coupons
ABS Plastic
Positive Controls
3/3
2/3
3/3
3/3
3/3
3/3
Test Coupons
5/5
4/5
1/5
0/5
5/5
5/5
Acrylic
Positive Controls
3/3
3/3
3/3
3/3
3/3
3/3
Test Coupons
5/5
2/5
5/5
1/5
5/5
5/5
Aluminum
Positive Controls
3/3
3/3
3/3
3/3
3/3
3/3
Test Coupons
4/5
1/5
5/5
0/5
5/5
4/5
Frequency of detection = samples with detection above the GC/MS MQL/total replicate samples
For positive control coupon sets, a frequency of detection less than 3/3 indicates that all CWA was recovered in the
wipe sample for one or more replicates.
Average mass recoveries from wipe samples and coupon extractions and calculated average
residual VX contamination for each decontaminant/SE-related material combination included
during testing are provided in Table 17 and summarized in Figure 5. Generally, the least VX was
recovered from test coupons decontaminated with Dahlgren Decon, with average residual
contamination values of 1.5 |ig/cm2 (ABS plastic), 2.4 |ig/cm2 (acrylic), and 3.2 |ig/cm2
(aluminum). Recoveries from coupons decontaminated with EasyDECON DF200 were slightly
higher, with average residual contamination values of 30 |ig/cm2 (ABS plastic), 3.3 |ig/cm2
(acrylic), and 5.3 |ig/cm2 (aluminum). Both are in contrast to the markedly higher recoveries
from test coupons decontaminated with TDA's eClCh decontaminant, with average residual
contamination values of 191 |ig/cm2 (ABS plastic) and 139 |ig/cm2 (acrylic and aluminum).
35
-------
Table 17. VX Average Recoveries and Residual Contamination
Decontaminant
Material
Sample
Description
Wipe
Average Recovery
Coupon
Total Mass
Avg Residual
Contaminatioi
l
Mass
fog)
St. Dev.
(fig)
RSD
(%)
Mass
(US)
St. Dev.
dig)
RSD
(%)
Mass
(US)
St. Dev.
(fig)
RSD
(%)
Avg.
(jig/cm2)
St. Dev.
(jig/cm2)
RSD
(%)
EasyDECON
DF200
ABS
Plastic
Positive Controls
1790
76
4.2%
3.3*
0.73
22%
1793
76
4.2%
179
7.6
4.2%
Test Coupons
295
188
64%
8.4*
9.0
107%
304
190
62%
30
19
62%
Acrylic
Positive Controls
1817
51
2.8%
12
9.1
76%
1829
56
3.1%
183
5.6
3.1%
Test Coupons
26
17
67%
7.2*
9.3
129%
33
25
75%
3.3
2.5
75%
Aluminum
Positive Controls
1832
151
8.3%
36
28
77%
1868
124
6.6%
187
12
6.6%
Test Coupons
50*
72
145%
2.8*
0.76
27%
53
73
138%
5.3
7.3
138%
Dahlgren
Decon
ABS
Plastic
Positive Controls
1823
102
5.6%
40
9.8
24%
1863
110
5.9%
186
11
5.9%
Test Coupons
13*
23
177%
2.5*
0.0
0.00%
15
23
148%
1.5
2.3
148%
Acrylic
Positive Controls
1971
67
3.4%
13
11
81%
1984
70
3.5%
198
7.0
3.5%
Test Coupons
20
18
90%
4.2*
3.7
90%
24
19
78%
2.4
1.9
78%
Aluminum
Positive Controls
1964
159
8.1%
41
9.2
22%
2005
154
7.7%
201
15
7.7%
Test Coupons
30
45
152%
2.5*
0.0
0.00%
32
45
140%
3.2
4.5
140%
TDA eC102
ABS
Plastic
Positive Controls
1965
178
9.1%
28
18
63%
1993
172
8.6%
199
17
8.6%
Test Coupons
1852
139
7.5%
54
25
46%
1906
141
7.4%
191
14
7.4%
Acrylic
Positive Controls
1941
45
2.3%
19
20
105%
1960
44
2.3%
196
4.4
2.3%
Test Coupons
1364
105
7.7%
29
23
79%
1393
94
6.7%
139
9.4
6.7%
Aluminum
Positive Controls
1924
44
2.3%
55
15
27%
1979
58
2.9%
198
5.8
2.9%
Test Coupons
1340
267
20%
50*
63
126%
1390
211
15%
139
21
15%
Average recovery value includes non-detects (see Table 16) that were set at the MQL value.
36
-------
250
Average Residual VX Contamination Following Decontamination
(202 ng/cm2 VX contamination, 100 \xL decontaminant, 60-min. contact)
,u 200
M
150
IDC'
re
c
"E
ro
-u
C
O
u
"Us
3
T3
v?
flj
EC
1'
OS
2 50
QJ
I Positive Controls
Test Coupons
DF200. ABS
DF20D,
Acrylic
DF200,
Aluminum
Dahlgren,
ABS
Dahlgren,
Acrylic
Dahlgren,
Aluminum
eCI02, ABS
eC102,
Acrylic
eCI02,
Aluminum
Decontaminant, Material
Figure 5. Average Residual VX Contamination
(Error bars equal ± one standard deviation)
37
-------
3.2.2 HD Residual Contamination
Throughout all of HD decontamination efficacy testing, no HD was detected in any procedural or
laboratory blank sample. Spike control samples were within specification for all tests. Frequency
of detection of HD in wipe and coupon sample extracts is provided in Table 18.
Table 18. HD Frequency of Detection
Material
Sample
Description
EasyDECON
DF200
Dahlgren Decon
TDA eClCfc
Wipes
Coupons
Wipes
Coupons
Wipes
Coupons
ABS Plastic
Positive Controls
3/3
3/3
3/3
3/3
3/3
3/3
Test Coupons
5/5
5/5
5/5
5/5
5/5
5/5
Acrylic
Positive Controls
3/3
2/3
3/3
3/3
3/3
2/3
Test Coupons
5/5
5/5
5/5
3/5
5/5
4/5
Aluminum
Positive Controls
3/3
3/3
3/3
1/3
3/3
3/3
Test Coupons
5/5
5/5
5/5
2/5
5/5
1/5
Frequency of detection = samples with detections above the GC/MS MQL/total replicate samples
For positive control coupon sets, a frequency of detection less than 3/3 indicates that all CWA was recovered
in the wipe sample for one or more replicates.
No TDG was detected in any sample. However, mustard sulfone was detected in several
samples. Table 19 lists samples in which mustard sulfone was detected and provides the peak
area response ratio for each. Since the HD sulfone standard concentration was equivalent to the
maximum response from this byproduct if all HD were to degrade to HD sulfone, these semi-
quantitative ratios can be interpreted by first approximation as the percent conversion of HD into
HD sulfone.
38
-------
Table 19. Mustard Sulfone Detection
Sample
Description
HD Sulfone
*
CWA
Material
Decontaminant
Wipe Extract
Coupon
Extract
HD
Aluminum
Dahlgren Decon
Test Coupon 1
-
-
Test Coupon 2
0.29%
-
Test Coupon 3
0.67%
-
Test Coupon 4
0.12%
-
Test Coupon 5
0.53%
-
HD
ABS Plastic
Dahlgren Decon
Test Coupon 1
0.43%
-
Test Coupon 2
-
-
Test Coupon 3
-
-
Test Coupon 4
-
-
Test Coupon 5
-
-
HD
ABS Plastic
eC102
Test Coupon 1
1.2%
0.40%
Test Coupon 2
1.4%
0.46%
Test Coupon 3
1.3%
0.64%
Test Coupon 4
1.1%
0.61%
Test Coupon 5
2.5%
0.76%
HD
Acrylic
eC102
Test Coupon 1
6.3%
1.0%
Test Coupon 2
7.9%
-
Test Coupon 3
8.7%
0.41%
Test Coupon 4
8.2%
0.15%
Test Coupon 5
8.7%
-
HD
Aluminum
eC102
Test Coupon 1
8.9%
-
Test Coupon 2
9.9%
-
Test Coupon 3
9.2%
-
Test Coupon 4
6.9%
-
Test Coupon 5
14%
-
* Percentage = Sample HD sulfone peak area response/HD sulfone standard peak area response (see Section
2.4.3).
Average mass recoveries from wipe samples and coupon extractions and calculated average
residual HD contamination for each decontaminant/SE-related material combination included
during testing are provided in Table 20 and summarized in Figure 6. HD recoveries from positive
controls were lower across all materials than recoveries recorded during the wipe sampling and
solvent extraction method development (Table 8). However, method development recoveries
were for a 60 min dwell time of the agent on the surface versus a 120 min contact time in the
decontamination study. The highest test coupon recoveries of HD came from acrylic and
aluminum decontaminated with DF200 (average residual contamination values of 177 |ig/cm2
and 210 |ig/cm2, respectively). The remaining decontaminant combinations ranged from 92
|ig/cm2 (acrylic/eClCh) to 137 |ig/cm2 (aluminum/eClCh).
39
-------
Table 20. HD Average Recoveries and Residual Contamination
Decontaminant
Material
Sample
Description
Wipe
Average Recovery
Coupon
Total Mass
Avg. Residual
Contamination
Mass
fog)
St. Dev.
(fig)
RSD
(%)
Mass
(US)
St. Dev.
(fig)
RSD
(%)
Mass
(US)
St. Dev.
(fig)
RSD
(%)
Avg.
(jig/cm2)
St. Dev.
(jig/cm2)
RSD
(%)
EasyDECON
DF200
ABS Plastic
Positive Controls
1027
81
7.9%
545
88
16%
1572
37
2.3%
157
3.7
2.3%
Test Coupons
570
215
38%
538
102
19%
1108
305
28%
111
31
28%
Acrylic
Positive Controls
2162
112
5.2%
7.9
8.9
113%
2170
112
5.2%
217
11
5.2%
Test Coupons
1712
198
12%
55
76
138%
1767
155
8.7%
177
15
8.7%
Aluminum
Positive Controls
2301
47
2.0%
13
6.7
53%
2314
48
2.1%
231
4.8
2.1%
Test Coupons
2055
63
3.1%
42
65
155%
2097
70
3.3%
210
7.0
3.3%
Dalilgren
Decon
ABS Plastic
Positive Controls
921
202
22%
607
59
9.7%
1528
259
17%
153
26
17%
Test Coupons
548
178
32%
394
134
34%
942
133
14%
94
13
14%
Acrylic
Positive Controls
2374
117
4.9%
6.1
4.6
76%
2380
122
5.1%
238
12
5.1%
Test Coupons
1087
272
25%
23
41
179%
1110
255
23%
111
25
23%
Aluminum
Positive Controls
2193
458
21%
5.7
5.5
97%
2199
462
21%
220
46
21%
Test Coupons
1011
248
25%
6.6
8.8
134%
1017
250
25%
102
25
25%
TDA eC102
ABS Plastic
Positive Controls
903
178
20%
620
93
15%
1524
241
16%
152
24
16%
Test Coupons
320
38
12%
647
125
19%
967
120
12%
97
12
12%
Acrylic
Positive Controls
2354
77
3.3%
37
37
101%
2390
46
1.9%
239
4.6
1.9%
Test Coupons
889
185
21%
32
31
96%
921
172
19%
92
17
19%
Aluminum
Positive Controls
2203
121
5.5%
24
23
96%
2227
125
5.6%
223
13
5.6%
Test Coupons
1366
176
13%
2.6
0.22
8.3%
1369
177
13%
137
18
13%
40
-------
300
Average Residual HD Contamination Following Decontamination
(254 |ig/cm2 HD contamination, 100 \xl decontaminant, 60-min. contact)
£ 250
u
*¦-
w
3.
.2 200
rc-
C
E
IC
O
u
150
tc
-
| 100
cc
Or'
M
rc
h_
QJ
>
<
50
I Positive Controls
Test Coup oris
CF200, ABS
DF200,
Acrylic
DF200,
Aluminum
Dahlgren, Dahlgren, Dahlgrenr eCI02, ABS eCI02, eCIQ2,
ABS Acrv'lic Aluminum Acrylic Aluminum
Decontaminant, Material
Figure 6. Average Residual HD Contamination
(Error bars equal ± one standard deviation)
41
-------
3.2.3 VX and HD Decontamination Efficacy
Average percent decontamination efficacies for each CWA/decontaminant/SE-related material
combination are provided in Table 21.
Table 21. Average Percent Decontamination Efficacies
Decontaminant
Material
Avg. VX
Decontamination
Efficacy
(%)
Avg. HD
Decontamination
Efficacy
(%)
EasyDECON DF200
ABS Plastic
83%
29%
Acrylic
98%
19%
Aluminum
97%
9.4%
Dahlgren Decon
ABS Plastic
99%
38%
Acrylic
99%
53%
Aluminum
98%
54%
TDA eC102
ABS Plastic
4.4%
37%
Acrylic
29%
61%
Aluminum
30%
39%
Dahlgren Decon achieved the highest efficacy for VX, with efficacy values of 99% from ABS
plastic and acrylic and 98% from aluminum. EasyDECON DF200 VX decontamination efficacy
was only slightly lower at 98% from acrylic, 97% from aluminum, and 83% from ABS plastic.
The TDA eClCh decontaminant demonstrated lower VX decontamination efficacy, measuring
30% from aluminum, 29% from acrylic, and only 4.4% from ABS plastic. VX decontamination
efficacies are summarized in Figure 7.
Average VX Decontamination Efficacy
100%-
>
O
03
O
y=
LU
80% -
60% -
-------
EasyDECON DF200 and Dahlgren Decon demonstrated lower efficacy in decontamination of
HD, ranging from only 54% (Dahlgren Decon decontamination of HD from aluminum) to only
9.4% (EasyDECON DF200 decontamination of HD from aluminum). Conversely, the TDA
eC102 decontaminant demonstrated generally higher efficacy in decontamination of HD than of
VX. HD decontamination efficacy for the eClCh decontaminant ranged from 37% from ABS
plastic to 61% from acrylic, which notably was the highest measured HD decontamination
efficacy. HD decontamination efficacies are summarized in Figure 8.
Average HD Decontamination Efficacy
100%-
>
O
03
O
y=
LU
80% -
60% -
I
ABS Plastic
Acrylic
Aluminum
-------
3.3 ANOVA Results
3.3.1 Comparison of Positive Control Results
Tables 22 through 27 present the geometric mean total recoveries of the positive controls for
each CWA/material/decontaminant combination and any significant differences in geometric
means identified from Tukey-adjusted comparisons based on ANOVA models. The character in
the "Similarity Designation" column indicates the statistical similarity of the geometric mean
total mass recovery of a decontaminant to the geometric mean total mass recovery of the other
decontaminants within the material/CWA combination (e.g., in Table 26, DF200 and eClCh are
statistically similar and thus both designated "A", eClCh and Dahlgren Decon are statistically
similar and thus both designated "B", DF200 and Dahlgren Decon are not statistically similar).
There was only one CWA/material combination with a significant pairwise comparison: for
VX/acrylic, the positive control geometric mean total mass recovery for DF200 was significantly
less than the positive control geometric mean total mass recovery for Dahlgren Decon.
Considering that the random probability of measuring a significant difference when none truly
exists is 0.05, one significant difference out of 18 pairwise comparisons (three comparisons for
each of the six CWA/material combinations) is not enough evidence to say there was a
difference between the sets of positive controls within each CWA/material combination. In this
case, the range of standard deviations for positive control total mass recovery for the three
VX/acrylic tests was smaller than the ranges for any other CWA/material combinations tested
(44 to 70 |ig; the next narrowest range was 46 to 122 |ig for HD/acrylic). This smaller variability
in geometric mean total mass recovery for the three positive control sets for VX/acrylic makes
the comparisons more sensitive, and smaller differences in the geometric means of the three sets
are thus identified as statistically significant.
While the statistical comparisons that were performed identified that a significantly lesser
amount of VX (subjectively small, but nonetheless statistically significant based on the analysis)
was applied to the DF200 positive controls than to the Dahlgren Decon positive controls (i.e.,
more VX was applied to the Dahlgren Decon positive controls), average VX decontamination
efficacy for Dahlgren Decon from acrylic was calculated at 99%, while average VX
decontamination efficacy for DF200 from acrylic was calculated at 98%. Comparison of the
geometric mean total mass recoveries for the VX/acrylic/DF200 and VX/acrylic/Dahlgren Decon
test coupon sets did not determine that the sets are significantly different (suggesting no
performance difference between the two decontaminants for VX/acrylic). However, given the
considerations discussed above, it is not anticipated that a significant difference in performance
between the two decontaminants would have been identified if the positive control geometric
mean total mass recoveries were not identified as different.
44
-------
Table 22. ANOVA Results for ABS Plastic with HD (Positives)
Decontaminant
Similarity
Designation
Positive Control Geometric Mean
Total Mass Recovery (jug)
Tukey-Adjusted p-Value *
eCI02
A
1511
No significant differences.
Dahlgren Decon
A
1513
DF200
A
1571
* There were no significant differences between any pairs of decontaminants.
Table 23. ANOVA Results for Acrylic with HD (Positives)
Decontaminant
Similarity
Designation
Positive Control Geometric Mean
Total Mass Recovery (jug)
Tukey-Adjusted p-Value *
DF200
A
2168
No significant differences.
Dahlgren Decon
A
2378
eCI02
A
2390
* There were no significant differences between any pairs of decontaminants.
Table 24. ANOVA Results for Aluminum with HD (Positives)
Decontaminant
Similarity
Designation
Positive Control Geometric Mean
Total Mass Recovery (jug)
Tukey-Adjusted p-Value *
Dahlgren Decon
A
2164
No significant differences.
eCI02
A
2225
DF200
A
2313
* There were no significant differences between any pairs of decontaminants.
Table 25. ANOVA Results for ABS Plastic with VX (Positives)
Decontaminant
Similarity
Designation
Positive Control Geometric Mean
Total Mass Recovery (jug)
Tukey-Adjusted p-Value *
DF200
A
1792
No significant differences.
Dahlgren Decon
A
1861
eCI02
A
1988
* There were no significant differences between any pairs of decontaminants.
Table 26. ANOVA Results for Acrylic with VX (Positives)
Decontaminant
Similarity
Designation
Positive Control Geometric Mean
Total Mass Recovery (jug)
Tukey-Adjusted p-Value *
DF200
A
1828
0.0374 (DF200 < Dahlgren
Decon)
eCI02
AB
1960
Dahlgren Decon
B
1983
* Pairwise comparisons that were significant at the 0.05 level. The format within each cell is: (1) the
Tukey-adjusted p-value, and (2) the relationship between the corresponding pair of decontaminants
shown in parentheses.
Table 27. ANOVA Results for Aluminum with VX (Positives)
Decontaminant
Similarity
Designation
Positive Control Geometric Mean
Total Mass Recovery (fig)
Tukey-Adjusted p-Value *
DF200
A
1865
No significant differences.
eCI02
A
1978
Dahlgren Decon
A
2001
* There were no significant differences between any pairs of decontaminants.
45
-------
3.3.2 Comparison of Test Sample Results
Tables 28 through 33 present the geometric means of the ANOVA models for the
decontaminants for each material/CWA combination ordered from lowest to highest, along with
the significant Tukey-adjusted comparisons. As in Tables 22 through 27, the character in the
"Similarity Designation" column indicates the statistical similarity of the geometric mean total
mass recovery of a decontaminant to the geometric mean total mass recovery of the other
decontaminants within the material/CWA combination. Simply based on the ordering, DF200
consistently had the largest geometric mean total mass recovery across all three materials for
HD. For VX, Dahlgren Decon consistently had the smallest geometric mean total mass recovery
while eCI02 consistently had the largest geometric mean total mass recovery across all three
materials.
There were no significant differences between decontaminants for ABS plastic and acrylic
materials with HD. For aluminum with HD and ABS plastic with VX, the geometric mean total
mass recovery for Dahlgren Decon was significantly less than the geometric mean total mass
recovery for DF200. For ABS plastic, acrylic, and aluminum with VX, the geometric mean total
mass recovery for Dahlgren Decon was significantly less than the geometric mean total mass
recovery for eCICh. For acrylic and aluminum with VX, the geometric mean total mass recovery
for DF200 was significantly less than the geometric mean total mass recovery for eCICh.
Table 28. ANOVA Results for ABS Plastic with HD (Test Samples)
Decontaminant
Similarity
Designation
Geometric Mean Total Mass
Recovery (jug)
Tukey-Adjusted p-Value *
eCI02
A
891
No significant differences.
Dahlgren Decon
A
985
DF200
A
1207
* There were no significant differences between any pairs of decontaminants.
Table 29. ANOVA Results for Acrylic with HD (Test Samples)
1 Decontaminant
Similarity
Designation
Geometric Mean Total Mass
Recovery (jug)
Tukey-Adjusted p-Value * 1
eCI02
A
1039
No significant differences.
Dahlgren Decon
A
1179
DF200
A
1682
* There were no significant differences between any pairs of decontaminants.
Table 30. ANOVA Results for Aluminum with HD (Test Samples)
Decontaminant
Similarity
Designation
Geometric Mean Total Mass
Recovery (jug)
Tukey-Adjusted p-Value *
Dahlgren Decon
A
1127
0.0345 (Dahlgren Decon <
DF200)
eCI02
AB
1469
DF200
B
2055
* Pairwise comparisons that were significant at the 0.05 level. The format within each cell is: (1) the
Tukey-adjusted p-value, and (2) the relationship between the corresponding pair of decontaminants
shown in parentheses.
46
-------
Table 31. ANOVA Results for ABS Plastic with VX (Test Samples)
Decontaminant
Similarity
Designation
Geometric Mean Total Mass
Recovery (jig)
Tukey-Adjusted p-Value *
Dahlgren Decon
A
14
<0.0001 (Dahlgren Decon < eCI02)
0.0060 (Dahlgren Decon < DF200)
DF200
B
286
eCI02
B
1435
* Pairwise comparisons that were significant at the 0.05 level. The format within each cell is: (1) the
Tukey-adjusted p-value, and (2) the relationship between the corresponding pair of decontaminants
shown in parentheses.
Table 32. ANOVA Results for Acrylic with VX (Test Samples)
Decontaminant
Similarity
Designation
Geometric Mean Total Mass
Recovery (jug)
Tukey-Adjusted p-Value *
Dahlgren Decon
A
17
0.0015 (Dahlgren Decon < eCI02)
0.0399 (DF200 < eCI02)
DF200
A
43
eCI02
B
635
* Pairwise comparisons that were significant at the 0.05 level. The format within each cell is: (1) the
Tukey-adjusted p-value, and (2) the relationship between the corresponding pair of decontaminants
shown in parentheses.
Table 33. ANOVA Results for Aluminum with VX (Test Samples)
Decontaminant
Similarity
Designation
Geometric Mean Total Mass
Recovery (jug)
Tukey-Adjusted p-Value *
Dahlgren Decon
A
14
0.0005 (Dahlgren Decon < eCI02)
0.0049 (DF200 < eCI02)
DF200
A
20
eCI02
B
842
* Pairwise comparisons that were significant at the 0.05 level. The format within each cell is: (1) the
Tukey-adjusted p-value, and (2) the relationship between the corresponding pair of decontaminants
shown in parentheses.
3.4 Material Compatibility
As described in Section 2.1.3, compatibility of the decontaminants with the SE-related materials
was assessed qualitatively (visually) during decontamination efficacy testing. Test coupons and
procedural blanks were visually inspected and compared to other coupons of the same SE-related
material types that were not exposed to the decontamination technologies.
Also, as described in Section 2.1.3, additional procedural blanks were included during
decontamination efficacy tests to which decontaminants were applied, but the blanks were not
wiped or extracted following the 60-minute decontaminant dwell period. Rather, the
decontaminant was allowed to remain on the coupon surface for one week to assess the effect of
extended decontaminant contact with the SE-related materials. Tables 34 through 36 depict the
additional procedural blanks at the time of decontaminant application, after one day of contact
with the decontaminants, one week of contact with the decontaminants, and then following
47
-------
wiping of the coupon surface with hexane-soaked and/or water-soaked wipes to assess the
possibility of and effort involved with removal of any remaining decontaminant or residue.
Acrylic appeared to be unaffected by extended contact with any of the three decontaminants.
After one week, Dahlgren Decon was still visibly wet/puddled on the surface of the acrylic
coupon, while DF200 and the TDA eClCh decontaminant had evaporated and left a white,
crystallized residue. In all three cases, however, remaining decontaminant/residue was
completely removed via wiping with a hexane-soaked wipe, leaving no observable damage or
deterioration.
Results similar to the results obtained for acrylic were observed for the ABS plastic blanks.
Liquid Dahlgren Decon was still visible on the coupon surface following one week, while DF200
and eC102 had evaporated, leaving a "crusty" white residue. Residual decontaminant and dried
residue were easily removed from the surface of all three material types using a hexane-soaked
wipe, but all three decontaminants were found to have slightly discolored the ABS plastic
coupon.
Aluminum was generally affected the most by extended contact with the three decontaminants.
Like the ABS plastic, only very slight discoloration of aluminum was observed following one
week of contact with Dahlgren Decon. DF200 and the TDA eClCh decontaminant did not
demonstrate the same degree of compatibility, however. Both DF200 and eClCh left residues on
aluminum that were not easily removed using either hexane or water-soaked wipes, and the
eC102 even left the surface of the aluminum coupon visibly discolored and pitted.
On all three materials, Dahlgren Decon remained wet even after the one-week dwell period.
Some evaporation may have occurred, as the Dahlgren Decon remaining on the surface of the
coupons seemed thicker/tackier than when initially applied, but this observation is in contrast to
the other two decontaminants that had both completely evaporated from all three materials after
one week, leaving behind dried residues.
In summary, Dahlgren Decon appeared to demonstrate the highest degree of compatibility with
the three SE-related materials included in this evaluation. Residual decontaminant was easily
wiped from the surface of all three material types, leaving no lasting observable effects on
acrylic and only very slight discoloration of ABS plastic and aluminum. In contrast, DF200 and
eC102 discolored ABS plastic to a greater degree and left residues on aluminum that were not
easily removed and/or actual physical damage to/deterioration of the aluminum coupon surface
(eC102).
48
-------
Table 34. Dahlgren Decon Material Compatibility
Material
ABS
Plastic
Following Application
Decontaminant pooled on coupon.
After One Day
After One Week
Decontaminant still appeared wet.
Decontaminant still wet but appeared
thicker/tackier when wiped.
Following Wiping/Removal
Decontaminant easily removed with
hexane-soaked wipe. Very slight
discoloration where decon dwelled.
Acrylic
Decontaminant pooled on coupon.
Decontaminant still appeared wet
Decontaminant still wet but appeared
thicker/tackier when wiped.
Decontaminant easily removed with
hexane-soaked wipe. No deterioration
of material observed.
Aluminum
Decontaminant pooled on coupon.
Decontaminant still appeared wet.
Decontaminant still wet but appeared
thicker/tackier when wiped.
Decontaminant easily removed with
hexane wipe. Very slight discoloration
where decon dwelled.
49
-------
Table 35. EasyDECON DF200 Material Compatibility
Material
ABS
Plastic
Following Application
Decontaminant pooled on coupon.
After One Day
After One Week
Decontaminant appeared slightly
wet/crystallized.
Crystallized/crusty residue
remaining.
Following Wiping/Removal
Residue easily removed with hexane-
soaked wipe. Discoloration where
decontaminant dwelled.
Acrylic
Decontaminant pooled on coupon.
Decontaminant spread and appeared
slightly wet/crystallized.
Crvstallized/crusty residue
remaining.
Residue easily removed with hexane-
soaked wipe. No deterioration of
material observed.
Aluminum
Decontaminant pooled on coupon.
Decontaminant spread and appeared
dn/crystallized.
Crystallized/crusty residue
remaining.
Residue not easily removed with either
hexane-soaked or water-soaked wipe.
Discoloration/white residue present
where decontaminant dwelled.
50
-------
Table 36. TDA Research HDA eCI02 Material Compatibility
Material
ABS
Plastic
Following Application
Decontaminant pooled on coupon.
After One Day
After One Week
Decontaminant still appeared wet.
White residue remaining.
Following Wiping/Removal
Residue easily removed with hexane-
soaked wipe. Very slight discoloration
where decontaminant dwelled.
Acrylic
Decontaminant pooled on coupon.
Decontaminant still appeared wet.
White residue remaining.
Residue easily removed with hexane-
soaked wipe. No deterioration of
material observed.
Aluminum
Decontaminant pooled on coupon.
Decontaminant appeared slightly
wet/crystallized.
White residue remaining.
Residue not easily removed with either
hexane-soaked or water-soaked wipe.
Discoloration/possible pitting present
where decontaminant dwelled.
51
-------
Damage to coupons due to contact with the CWAs was also assessed visually. Neither VX nor
HD appeared to damage or degrade the materials following the 60-minute CWA dwell period,
with one exception: HD was observed to damage/deteriorate the surface of ABS plastic coupons
Figures 9 through 11 depict damage to ABS plastic coupons caused by contact with neat HD.
The pictures below depict ABS plastic coupons included in the HD wipe sampling and coupon
solvent extraction methods development test (procedures described in Section 2.1.1.1).
Figure 9. Damage to ABS plastic caused by HD (1).
52
-------
Figure 10. Damage to ABS plastic caused by HD (2). Figure 11. Damage to ABS plastic caused by HD (3).
53
-------
Figures 12 and 13 depict an ABS plastic coupon and wipe sample included in the
decontamination efficacy test evaluating decontamination of HD by TDA's eClCh I IDA
decontaminant. As the pictures show, the eClCh decontaminant does not appear to have affected
the coupon material, but a prominent pit is present in the coupon surface where the HD was
applied. Additionally, ABS plastic debris can be seen on the wipe sample taken from the coupon
(Figure 13).
Figure 12. Damage to ABS plastic caused by HD (4). Figure 13. ABS plastic debris on wipe
sample.
As discussed in Section 3.1.1, during the HD wipe sampling and coupon solvent extraction
method development test, total HD mass recoveries from ABS coupons were generally lower
than the total FID mass recoveries from acrylic and aluminum (75% average total mass recovery
from ABS plastic, versus 97% from both acrylic and aluminum). Furthermore, approximately
two-thirds of the HD recovered from ABS coupons was recovered from the wipe, with the
remaining HD obtained from extraction of the coupons. This recovery scheme is in contrast to
the acrylic and aluminum coupons, which demonstrated recovery of nearly all HD in the wipe
sample with low or no recovery from the coupon solvent extraction (only one acrylic coupon
extraction sample was above the GC/MS detection limit, with the other two samples less than the
detection limit; no measurable HD was recovered from extraction of the aluminum coupons).
ABS plastic coupons that were extracted in solvent only (no prior wiping) demonstrated only
44% average recovery during the wipe sampling and solvent extraction method development
test, versus the 75% average total mass recovery from ABS plastic coupons that were sampled
via both wiping and coupon solvent extraction. This scenario possibly suggests that FID is
absorbed into the ABS plastic material, becoming unrecoverable by solvent extraction alone. The
act of wiping then disrupts the damaged ABS plastic coupon surface, allowing absorbed HD to
be accessed and recovered by wiping and solvent extraction.
54
-------
4. QUALITY ASSURANCE/QUALITY CONTROL
4.1 Control of Monitoring and Measuring Devices
Quality control requirements and results are provided in Table 37. In general, the data quality
indicator results were acceptable, including check of the measurement methods for temperature,
RH, time, volume, IS response, and VX recovery from spike controls and blank samples.
Attainment of these data quality indicator results limited the amount of error introduced into the
investigation results.
Table 3 7. Quality Control Requirements and Results
Parameter
Measurement
Method
Data Quality Indicators
Results
Temperature
(°C)
Calibrated
HOBO UX100
Data Logger
Compare against NIST-traceable
calibrated thermometer once before
testing; agree ±1 °C through one hour.
The HOBO UX100 Data logger reading
remained within 0.6 °C of the NIST-
traceable calibrated reference through
one hour.
Relative
Humidity
(%) '
Calibrated
HOBO UX 100
Data Logger
Compare against NIST-traceable
calibrated hygrometer once before testing;
agree ±10% through one hour.
The HOBO UX100 Datalogger reading
remained within 5.4% of the NIST-
traceable calibrated reference through
one hour.
Time
(sec)
Timer
Compare to time provided at
NIST.time.gov once before testing; agree
±2 seconds/hour.
No difference was observed between the
timer and NIST.time.gov after one hour.
Volume
(mL, |xL)
Syringe (CWA
delivery)
Calibrated
pipette (decon
delivery)
Syringes/pipettes were checked for
accuracy and repeatability one time before
use by determining the mass of water
delivered. The syringe/pipette was
acceptable if the range of observed masses
for five droplets was ±10% of expected.
100 |iL syringe verification - Percent
difference across five measurements
ranged from 0.24% to 5.25%.
Pipette verification - Percent difference
across five measurements ranged from
0.57% to 1.07%.
CWA amount
Extraction,
GC/MS
Calibration curve with linear or quadratic
regression (coefficient of determination
[r2] > 0.990)
Calibration curves were created at the
beginning of each batch of test samples.
Curves that did not pass criteria were re-
run.
Naphthalene-d8
IS Recovery
Extraction,
GC/MS
The mean of the IS included with each day
of testing will be within 50% to 120% of
the expected mass.
IS response of each sample was
compared to the mid-point standard.
Anything outside the specification was
flagged and re-run.
4.2 Equipment Calibrations
4.2.1 Calibration Procedures and Schedules
Instrumentation was maintained and operated according to the quality requirements and
documentation of Battelle's HMRC. All equipment was calibrated with appropriate standards.
Table 38 provides calibration schedules for instruments that were used during the evaluation.
55
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Table 38. Equipment Calibration Schedule
Equipment
Frequency
Calibrated pipette and
repeating dispenser/syringe
Prior to the investigation. Calibration/accuracy was verified as described
in Table 37.
Calibrated UX100 HOBO
Hygrometer/Thermometer
Calibrated by the manufacturer, and calibration was verified against a
separate, NIST-traceable calibrated instrument once before use during
testing as described in Table 37.
Timer
Calibrated by the manufacturer, and calibration was verified against
NIST.time.gov once before use during testing as described in Table 37.
GC/MS
Beginning of each batch of test samples (calibration curve) and a
calibration verification standard after every five samples and at the end
of a batch of samples (see Section 4.2.2).
4.2.2 GC/MS Calibration
Neat VX or HD (concentrations corrected for percent purity; see Section 2.3.2.1) was used to
create calibration standards encompassing the appropriate analysis range. Calibration standards
were kept and used for no longer than six months from the date of creation.
GC/MS calibration ranged from 0.1 |ag/mL to 125 |ig/mL. To cover the entire analysis range,
two overlapping five-point calibration curves were used (a "low curve" from 0.1 |ag/m L to 10
|ig/mL, and a "high curve" from 5.0 |ig/mL to 125 |ig/mL). A linear or quadratic regression
(coefficient of determination [r2] > 0.990) curve fit was applied to the calibration data. The
GC/MS was recalibrated if the r2 from the regression analysis of these standards was less than
0.990. Limits were also placed on the percent bias (Equation 5) observed in the standards.
Bias = x 100% (5)
where: Ev = expected value from calibration curve
Ov = observed value from standard
The percent bias for the low standard had to be less than or equal to 25%, and the percent bias
for the remaining standards had to be less than or equal to 15%.
The GC/MS was tuned initially and then as needed following manufacturer's guidelines. A tune
check was performed before running each set of samples using decafluorotriphenylphosphine
(DFTPP). A 12-hour tune time was not employed.
Following analysis of the calibration standards at the beginning of each analytical run, a solvent
blank sample was analyzed to confirm that no VX or HD carryover was occurring. Solvent blank
sample analysis results had to be below the value of the lowest calibration standard.
Independently prepared CCV standards were analyzed prior to sample analysis, following every
five test/control samples and at the end of each set of samples. Two CCV concentrations were
used, one equal to the low calibration standard and the other within the calibration range (5.0
|ig/mL for the low curve and 50 |ig/mL for the high curve). CCV response had to be within 35%
56
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of the nominal concentration for the low level CCV and within 20% of the nominal
concentration for the higher level CCV for VX or HD to be acceptable. Samples analyzed prior
to or following CCVs that were outside acceptance limits were re-analyzed (either within the
same analytical run or during a separate run for which a new calibration curve was established;
results from reanalysis were considered valid and reportable if analysis quality control
objectives, as described above for calibration curve standards and bracketing CCVs, were met).
CCV standards were kept and used for no longer than one month from the date of creation. GC
analysis performance parameter and acceptance criteria are provided in Table 39.
Table 39. GC Performance Parameters and Acceptance Criteria
Parameter
Criterion
Coefficient of determination (r2)
>0.990
% bias for the lowest calibration standard
< 25%
% bias for remaining calibration standards (except lowest standard)
< 15%
Solvent blank sample
< lowest calibration standard
% bias for the lowest CCV
< 35%
% bias for remaining CCVs (except lowest CCV)
< 20%
4.3 Technical Systems Audit
The Quality Assurance (QA) Officer performed a technical systems audit (TSA) at the HMRC
facility in West Jefferson, Ohio, during decontamination efficacy testing on February 20, 2018.
The purpose of the TSA was to ensure that testing was performed in accordance with the quality
assurance test plan. The QA Officer reviewed the investigation methods, compared test
procedures to those specified in the quality assurance test plan, and reviewed data acquisition
and handling procedures. The QA Officer did not identify any findings that required corrective
action.
4.4 Performance Evaluation Audit
Performance evaluation (PE) audits, provided in Table 40 with results, addressed those reference
measurements that factored into the data used in quantitative analysis during the evaluation,
including volume and time measurements and GC/MS calibration and performance. The volume
of VX or HD dispensed correlated directly to the mass of each CWA on the coupons. The
measured times that CWA and the decontamination technologies were allowed to remain in
contact with the coupons directly influenced efficacy of the decontaminants. Calibration of the
GC/MS and IS recovery provided confidence that the analysis system was providing accurate
data.
Temperature and RH were monitored and recorded on each day of testing, but not controlled.
Therefore, no PE audit of these parameters was performed.
57
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Table 40. Performance Evaluation Audit Results
Parameter
Audit Procedure
Required Tolerance
Results
Volume
(mL, (iL)
Syringes/pipettes were checked
for accuracy and repeatability
one time before use by
determining the mass of water
delivered.
The syringe/pipette
will be acceptable if
the range of observed
masses for five
droplets is ±10% of
expected.
100 |iL syringe verification -
Percent difference across five
measurements ranged from
0.24% to 5.25%.
Pipette verification - Percent
difference across five
measurements ranged from
0.57% to 1.07%.
Time (sec)
Compared to time provided at
NIST.time.gov once before
testing.
±2 sec/hour
No difference was observed
between the timer and
NIST.time.gov after one hour.
CWA in Spike Control
Extracts
((ig/mL)
Used GC/MS to determine mass
of CWA delivered as 2 |iL
droplet into 25 mL of extraction
solvent and compared to target
application level.
>80% of spike target
< 120% of spike
target
< 30% CoV
Spike control means throughout
testing were within specification
except for two instances (refer to
Table 37).
GC/MS VX and HD
Calibration Standards
(%)
Verified all standards and CCVs
used to calibrate and confirm
calibration of the GC/MS system
used for analysis during the
project fell within the
requirements provided in Section
4.2.2.
Refer to Table 39
All standards and CCVs were
within specification for all
reported data.
Naphthalcnc-dx IS
Recovery
Used GC/MS to measure from a
secondary source and compare
to the primary source one time.
±10% relative percent
difference
0.6% relative percent difference
4.5 Data Quality Audit
The QA Manager audited at least 10% of the investigation data and traced the data from initial
acquisition, through reduction and statistical comparisons, to final reporting. All data analysis
calculations were checked. The QA Officer did not identify any findings that required corrective
action.
58
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5. SUMMARY
The primary objective of this project was to quantitatively evaluate efficacy of three candidate
decontamination technologies to decontaminate CWAs from select SE-related materials and to
concurrently evaluate qualitatively the effects of the decontaminants on the integrity of the
materials to which they were applied. Bench scale decontamination efficacy tests using neat VX
and HD and the SE-related materials ABS molded plastic, acrylic, and aluminum were
performed. The decontaminants evaluated were Dahlgren Decon from First Line Technology,
EasyDECON DF200 from Intelagard®, and the TDA HDA eClCh decontaminant. During the
decontamination efficacy evaluation, compatibility of the decontamination technologies with the
SE-related materials was evaluated through visual assessment of the decontaminated materials
and documentation of any visible deterioration or damage caused to the materials by application
of the decontamination technologies.
Prior to evaluation of decontamination efficacy, method demonstration testing was conducted to
evaluate the effectiveness of the coupon surface wipe-sampling and coupon solvent extraction
methods planned for use during testing. Using hexane as the wipe-wetting and wipe and coupon
extraction solvent, the requirement that recovery of each CWA from the three SE-related
materials fall within the range of 70% to 120% with < 30% RSD was achieved. VX recoveries
from ABS plastic, acrylic, and aluminum measured 107%), 120%, and 119%, respectively.
Recoveries of 75% from ABS plastic, 97% from acrylic, and 97% from aluminum were
measured for HD. To improve analytical sensitivity, a VX stabilizer, N,N'-
diisopropylcarbodiimide, was added to the wipe and coupon extraction solvent. Naphthalene-dx
was used as the IS.
Additionally, methods for halting the decontamination reactions after a predefined interval
(quenching) were evaluated. The quench methods tested included: (1) solvent extraction in
hexane alone and (2) extraction in hexane with a 3M solution of STS added. The quench
methods selected for each CWA/decontaminant combination for use during decontamination
efficacy testing were:
• HD by EasyDECON DF200: Extraction in hexane alone (78% recovery of post-spiked
HD in wipe extracts, 98% in coupon extracts)
• HD by Dahlgren Decon: 3M STS added to extraction solvent (100% recovery of post-
spiked HD in wipe extracts, 100% in coupon extracts)
• HD by TDA eClCh: Extraction in hexane alone (97% recovery of post-spiked HD in wipe
extracts, 100% in coupon extracts)
• VX by EasyDECON DF200: 3M STS added to extraction solvent (89% recovery of post-
spiked HD in wipe extracts, 91% in coupon extracts)
• VX by Dahlgren Decon: 3M STS added to extraction solvent (101% recovery of post-
spiked HD in wipe extracts, 101% in coupon extracts)
59
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• VX by TDA eClCh: Extraction in hexane alone (101% recovery of post-spiked HD in
wipe extracts, 97% in coupon extracts).
Coupons of each of the SE-related materials measuring 4.0 cm by 2.5 cm (10 cm2 surface area)
were each spiked with 2 |iL of VX or HD. After a 60-minute CWA dwell period, 100 |iL of one
of the three test decontaminants was applied to the coupon surface, on top of the CWA
contamination. The decontaminant was then allowed to react with CWA on the coupon surfaces
for 60 minutes. Following the decontamination period, coupons were wipe-sampled and
subsequently extracted in solvent. Wipe and coupon extracts were then analyzed by GC/MS to
quantify residual CWA on the coupon surface following decontamination. Associated
quantitation limits were 0.25 |ig/cm2 (2.5 |ig residual CWA mass per coupon). Positive controls
were included that consisted of SE-related material coupons that were spiked with CWA using
the same equipment and procedures as the test coupons, but to which no decontaminants were
applied.
Percent efficacy of each decontaminant was calculated as:
(Co7itpespos ContneSTeSf\
Efficacy = Resrest x 1000/o
V C07lt^espos J
where: ContResTest = Residual test coupon contamination (|ig/cm2)
ContResPos = Residual positive control coupon contamination (|ig/cm2)
Average residual CWA contamination results are provided in Table 41 and average percent
decontamination efficacies are summarized in Figure 14.
Table 41. Average Residual Contamination Summary
Avg Residual Contamination
Decontaminant
Material
Sample
Description
Avg.
VX
St. Dev.
RSD
Avg.
HD
St. Dev.
RSD
(jig/cm2)
(jig/cm2)
(%)
(jig/cm2)
(jig/cm2)
(%)
ABS Plastic
Positive Controls
179
7.6
4.2%
157
3.7
2.3%
Test Coupons
30
19
62%
111
31
28%
EasyDECON
Acrylic
Positive Controls
183
5.6
3.1%
217
11
5.2%
DF200
Test Coupons
3.3
2.5
75%
177
15
8.7%
Aluminum
Positive Controls
187
12
6.6%
231
4.8
2.1%
Test Coupons
5.3
7.3
138%
210
7.0
3.3%
ABS Plastic
Positive Controls
186
11
5.9%
153
26
17%
Test Coupons
1.5
2.3
148%
94
13
14%
Dahlgren
Acrylic
Positive Controls
198
7.0
3.5%
238
12
5.1%
Decon
Test Coupons
2.4
1.9
78%
111
25
23%
Aluminum
Positive Controls
201
15
7.7%
220
46
21%
Test Coupons
3.2
4.5
140%
102
25
25%
ABS Plastic
Positive Controls
199
17
8.6%
152
24
16%
Test Coupons
191
14
7.4%
97
12
12%
TDA eC102
Acrylic
Positive Controls
196
4.4
2.3%
239
4.6
1.9%
Test Coupons
139
9.4
6.7%
92
17
19%
Aluminum
Positive Controls
198
5.8
2.9%
223
13
5.6%
Test Coupons
139
21
15%
137
18
13%
60
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100% -
CT 80%
CO
o
it
LU
c 60%
<
20% -
0%
r
ABS Plastic
1
Acrylic
Aluminum
\©v-
<8
.G\0^
CP
\<8~
V
&
vx
HD
CWA
I
©'
,0\0i
Figure 14. Average Percent Decontamination Efficacy by CWA/Decontaminant/Material
Numerically, Dahlgren Decon demonstrated the highest efficacy for decontamination of VX
from all three SE-related material types, achieving 99% efficacy on ABS plastic and acrylic and
98% on aluminum. DF200 demonstrated similarly high efficacy in decontaminating VX from
acrylic (98%) and aluminum (97%), though DF200 decontamination of VX from ABS plastic
was slightly lower at 83%. A statistical comparison showed that the recovered amounts for
Dahlgren Decon and DF200 for the ABS Plastic and aluminum were not significantly different
(p<0.05). The TDA eClCh decontaminant demonstrated the lowest VX decontamination
efficacies, measuring 30% from aluminum, 29% from acrylic, and only 4.4% from ABS plastic.
Conversely, eClCh demonstrated generally higher efficacies for decontamination of HD in
comparison to the other two decontaminants. Efficacy of eClCh against HD was 37% from ABS
plastic, 39% from aluminum, and 61% from acrylic (which was the highest HD decontamination
efficacy measured during this work). Dahlgren Decon measured 54% HD decontamination
efficacy from aluminum, 53% from acrylic, and 38% from ABS plastic. A statistical comparison
showed that recovered amounts on ABS plastic and acrylic were not significantly different
among all three decontaminants.
61
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In contrast to its VX decontamination efficacy, DF200 demonstrated only 29% efficacy against
HD on ABS plastic, 19% on acrylic, and 9.4% on aluminum. In summary, all three
decontaminants evaluated demonstrated some degree of efficacy for decontamination of both VX
and HD from all three SE-related materials. Generally, Dahlgren Decon and DF200 were much
more efficacious in decontamination of VX than of HD. Conversely, eClCh demonstrated greater
efficacy in decontamination of HD than in decontamination of VX. Considering the measurable
amount of VX and HD remaining on the surface following any of the decontamination solution
applications, additional efforts may be required to further degrade the residual agent. Such may
be accomplished through an extended dwell time beyond 1 h or a reapplication of the
decontaminant. Neither approach was part of the test matrix and was not investigated as part of
this study.
With regard to VX and HD degradation/decontamination byproducts, neither EMPA-associated
VX degradant (diethyl methanephosphonate or diethyl dimethylpyrophosphonate) was detected
in any sample. No TDG was detected in any sample. However, mustard sulfone was detected in
several samples, including four of five wipe sample extracts taken from HD-contaminated
aluminum coupons decontaminated with Dahlgren Decon, and all wipe extracts taken from all
three SE-related materials decontaminated with the eClCh decontaminant. Mustard sulfone was
also detected in extracts of HD-contaminated ABS plastic and acrylic coupons decontaminated
with the eC102 decontaminant. Detection of mustard sulfone was minor, ranging only from
0.12%) to 14%o of the peak area response of the mustard sulfone standard included in the
analytical runs (see Section 2.4.3). The toxic byproduct of VX degradation, EA-2192, cannot be
identified by GC/MS. Analysis for EA-2192 requires the use of LC/MS, which was outside the
scope of this testing. Thus, degradation of VX into EA-2192 was not evaluated during this work.
Generally, Dahlgren Decon appeared to demonstrate the highest degree of compatibility with the
three SE-related materials included in this evaluation. Residual decontaminant was easily wiped
from the surface of all three material types, leaving no lasting observable effects on acrylic and
only very slight discoloration of ABS plastic and aluminum. In contrast, DF200 and eClCh
discolored ABS plastic to a greater degree and left residues on aluminum that were not easily
removed and/or actual physical damage to/deterioration of the aluminum coupon surface
(eC102).
62
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6. REFERENCES
[1] EPA, 2016. Fate and Transport of Chemical Warfare Agents VX and HD Across a
Permeable Layer into Porous Subsurfaces. EPA/600/R-16/173. U.S. Environmental
Protection Agency (EPA), Office of Research and Development, National Homeland
Security Research Center.
[2] Stone, H.; See, D.; Smiley, A.; Ellingson, A.; Schimmoeller, J.; Oudejans, L. Surface
decontamination for blister agents Lewisite, sulfur mustard and agent yellow, a Lewisite
and sulfur mustard mixture. Journal of Hazardous Materials. 2016, 314, pp 59-66.
[3] Munro, N.B.; Talmage, S.S.; Griffin, G.D.; Waters, L.C.; Watson, A.P.; King, J.F.;
Hauschild, V. The sources, fate, and toxicity of chemical warfare agent degradation
products. Environmental Health Perspectives. 1999, 107(12), pp 933-974.
63
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Attachment A - Environmental Data
Figures T015-MDEM-HD-1:
Temperature and RH during HD method development
Figures T015-MDEM-VX-1:
Temperature and RH during VX method development
Figures TO 15-QUENCH-1:
Temperature and RH during 1st quenching study
Figures T015-QUENCH-2:
Temperature and RH during 2nd quenching study
Figures ABS, ACRY DF200 VX:
Temperature and RH during DF200 decon test with VX on ABS and acrylic
Figures ALUM DF200, ABS DD VX:
Temperature and RH during DF200 decon test with VX on aluminum and DD decon test
with VX on ABS
Figures ACRY, ALUM DD VX:
Temperature and RH during DD decon test with VX on acrylic and aluminum
Figures ABS, ACRY eC102 VX:
Temperature and RH during eC102 decon test with VX on ABS and acrylic
Figures ALU eC102 VX:
Temperature and RH during eC102 decon test with VX on aluminum
Figures ABS DF200 HD:
Temperature and RH during DF200 decon test with HD on ABS
Figures ACRY, ALUM DF200 HD:
Temperature and RH during DF200 decon test with HD acrylic and aluminum
Figures ABS DD HD:
Temperature and RH during DD decon test with HD on ABS
Figures ACRY, ALUM DD HD:
Temperature and RH during DD decon test with HD on acrylic and aluminum
Figures ABS, ACRY eC102 HD:
Temperature and RH during eC102 decon test with HD on ABS and acrylic
Figures ALUM eC102 HD:
Temperature and RH during eC102 decon test with HD on aluminum
64
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T015-MDEM-HD-1 Laboratory Temperature
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24.5
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21.5
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Date, Time
T015-MDEM-HD-1 Laboratory Relative Humidity
£
i§ 40
20
15
10
Date, Time
65
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T015-MDEM-VX-1 Laboratory Temperature
25.0
24.5
24.0
23.5
23.0
22.5
22.0
21.5
„ 21.0
P
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T015-MDEM-VX-1 Laboratory Relative Humidity
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T015-QUENCH-1 Laboratory Temperature
Date, Time
T015-QUENCH-1 Laboratory Relative Humidity
Date, Time
67
-------
T015-QUENCH-2 Laboratory Temperature
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68
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ABS, ACRY DF200 VX Laboratory Temperature
25.0
24.5
24.0
23.5
23.0
22.5
22.0
21.5
„ 21.0
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; 20 5
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ABS, ACRY DF200 VX Laboratory RH
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69
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ALUM DF200, ABS DD VX Laboratory Temperature
25.0
24.5
24.0
23.5
20.0
19.5
19.0
18.5
18.0
17.5
17.0
16.5
16.0
15.5
15.0
Date, Time
ALUM DF200, ABS DD VX Laboratory RH
Date, Time
-------
ACRY, ALUM DD VX Laboratory Temperature
25.0
24.5
24.0
23.5
23.0
22.5
22.0
21.5
_ 21.0
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ACRY, ALUM DD VX Laboratory RH
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71
-------
ABS, ACRY eCl02 VX Laboratory Temperature
25.0
24.5
24.0
23.5
23.0
22.5
22.0
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ALUM eCl02 VX Laboratory Temperature
Date, Time
ALUM eCl02 VX Laboratoy RH
70
65
60
55
50
Date, Time
73
-------
ABS DF200 HD Laboratory Temperature
Date, Time
ABS DF200 HD Laboratory RH
Date, Time
74
-------
75
-------
ABS DD HD Laboratory Temperature
-------
ACRY, ALUM DD HD Laboratory Temperature
25.0
24.5
24.0
23.5
23.0
22.5
22.0
21.5
„ 21.0
V 20.5
| 20.0
| 19.5
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18.5
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16.5
16.0
15.5
15.0
Date, Time
ACRY, ALUM DD HD Laboratory RH
Date, Time
77
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ABS, ACRY eCl02 HD Laboratory Temperature
25.0
24.5
24.0
23.5
23.0
22.5
22.0
21.5
_ 21.0
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| 20.0
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ALUM eCl02 HD Laboratory Temperature
Date, Time
ALUM eCl02 HD Laboratory RH
Date, Time
79
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vvEPA
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
Office of Research and Development (8101R)
Washington, DC 20460
Official Business
Penalty for Private Use
$300
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