EPA/600/R-20/157 | November 2020
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
&EPA
Water Rinses and Their Impact on
Decontamination Efficacies of
Surfaces Contaminated with
Chemical Warfare Agent Simulants
Office of Research and Development
Homeland Security Research Program

-------
EPA/600/R-20/157
November 2020
Water Rinses and Their Impact on
Decontamination Efficacies of Surfaces
Contaminated with Chemical Warfare Agent
Simulants
Lukas Oudejans,
Barbara Wyrzykowska-Ceradini,
Eric Morris and
Alexander Korff
Homeland Security and Materials Management Division (HSMMD)
Center for Environmental Solutions and Emergency Response (CESER)
Office of Research and Development
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711

-------
Disclaimer
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development
Center for Environmental Solutions and Emergency Response's Homeland Security and Materials
Management Division (ORD CESER HSMMD), funded and managed this investigation through Contract
No. EP-C-15-008, work assignments 1-078, 2-078 and 3-078 with Jacobs Technology, Inc. (Jacobs). This
report has been peer and administratively reviewed and has been approved for publication as an
Environmental Protection Agency document. It does not necessarily reflect the views of the
Environmental Protection Agency. No official endorsement should be inferred. This report includes
photographs of commercially available products. The photographs are included for purposes of illustration
only and are not intended to imply that EPA approves or endorses the product or its manufacturer. EPA
does not endorse the purchase or sale of any commercial products or services.
Questions concerning this document, or its application should be addressed to the principal investigator:
Lukas Oudejans, Ph.D.
Wide Area Infrastructure Decontamination Branch
Homeland Security and Material Management Division
Center for Environmental Solutions and Emergency Response
Office of Research and Development
U.S. Environmental Protection Agency
Mail Code E343-06
109 T.W. Alexander Drive
Research Triangle Park, NC 27711
Telephone No.: (919) 541-2973
E-mail Address: Oudejans.Lukas@epa.gov

-------
Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the Agency
strives to formulate and implement actions leading to a compatible balance between human activities and
the ability of natural systems to support and nurture life. To meet this mandate, EPA's research program
is providing data and technical support for solving environmental problems today and building a science
knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect
our health, and prevent or reduce environmental risks in the future.
The Center for Environmental Solutions and Emergency Response (CESER) within the Office of
Research and Development (ORD) conducts applied, stakeholder-driven research and provides
responsive technical support to help solve the Nation's environmental challenges. The Center's research
focuses on innovative approaches to address environmental challenges associated with the built
environment. We develop technologies and decision-support tools to help safeguard public water systems
and groundwater, guide sustainable materials management, remediate sites from traditional
contamination sources and emerging environmental stressors, and address potential threats from
terrorism and natural disasters. CESER collaborates with both public and private sector partners to foster
technologies that improve the effectiveness and reduce the cost of compliance, while anticipating
emerging problems. We provide technical support to EPA regions and programs, states, tribal nations,
and federal partners, and serve as the interagency liaison for EPA in homeland security research and
technology. The Center is a leader in providing scientific solutions to protect human health and the
environment.
This report assesses the impact of pre- and post decontamination water rinses on the overall
decontamination efficacy of a hydrogen peroxide-based decontamination product for the cleaning of clean
or grimed surfaces that are contaminated with chemical warfare agent simulants. The study also
investigates the presence of these simulants in the liquid runoff from these materials.
Gregory Sales, Director
Center for Environmental Solutions and Emergency Response
11

-------
Acknowledgments
This research effort is part of the U.S. Environmental Protection Agency's (EPA's) Homeland
Security Research Program (HSRP) to evaluate surface-applied liquid-based decontamination
methodologies for decontamination of a persistent chemical agent that has (partially) absorbed into a
permeable building material. The results of this work would inform responders, governments, and health
departments in their guidance development for decontamination technology recommendations of building
materials contaminated with toxic chemicals.
This effort was directed by the principal investigator from the Office of Research and
Development's (ORD's) Homeland Security and Materials Management Division (HSMMD) within
Center for Environmental Solutions and Emergency Response (CESER). The contributions of the
individuals have been a valued asset throughout this effort.
EPA Project Team
Lukas Oudejans, ORD/CESER/HSMMD (PI)
Matthew Magnuson, ORD/CESER/HSMMD
Jacobs Technology Inc. Team
Barbara Wyrzykowska-Ceradini
Abderrahmane Touati
Science Systems Applications, Inc. Team
Eric Morris
Alexander Korff
U.S. EPA Technical Reviewers of Report
Kiara Lech, ORD/CESER/HSMMD
Jennifer Gundersen, Office of Emergency Management, Consequence Management Advisory
Division (OEM/CMAD)
U.S. EPA Quality Assurance
Eletha Brady-Roberts, ORD/CESER
Ramona Sherman, ORD/CESER/HSMMD
Jacobs Technology Inc. Quality Assurance
Wendy Plessinger
U.S. EPA Editorial Review
Joan Bursey
the
following

-------
Executive Summary
Under Emergency Support Function (ESF) #10, the U.S. Environmental Protection Agency (EPA)
coordinates, integrates, and manages the Federal effort to decontaminate and clean up infrastructure
following releases of hazardous materials. Those hazardous materials include chemical, biological,
radiological, and nuclear (CBRN) substances, whether accidentally or intentionally released. EPA's
Homeland Security Research Program (HSRP) advances EPA's ability to carry out its homeland security
responsibilities to respond to wide-area contamination. The HSRP has directed multiple research efforts that
focused on liquid-based surface decontamination options using commercially available products that are
expected to degrade various highly toxic chemical agents from various types of surfaces. These
decontamination studies are typically limited to the measurement of efficacy of the decontamination product
itself after a fixed contact time. This document reports on a study that was conducted to investigate a three-
step pre-cleaning, decontamination, and post-rinse procedure that more realistically mimics possible field
treatments of building surfaces contaminated with chemical warfare agents. This study also assessed
whether this approach is advantageous in the presence of grime on a surface in improving overall efficacy.
A multistep decontamination procedure - consisting of detergent-water spray, followed by a spray
application of a commercially available specialized decontaminant (EasyDECON DF200) and a post-
decontamination water rinse - was performed on selected nonporous, semi-porous, and porous building
materials. Test materials were decontaminated in a horizontal and/or vertical surface orientation, depending
on their most common use. The pre-decontamination treatment of dirty or grimed surfaces is a
recommendation found in quick references guides and other remediation guidance documents as dirt and
grime may interfere with the action of the decontaminant. In cases where the presence of residual
decontaminant is undesirable, post-decontamination rinses are also recommended to remove residual
decontaminant from the surface.
Materials were contaminated separately with malathion, an organophosphate pesticide, and a
simulant for the VX nerve agent as well as 2-chloroethyl phenylsulfide (2-CEPS), a simulant for sulfur
mustard (HD) blister agent. VX and HD are considered to be the most toxic and persistent chemical warfare
agents (CWAs). Post-decontamination surface sampling of test surfaces was performed using dry cotton
gauze to absorb residual rinse and decontaminant liquid and/or cotton twill wipes semi-saturated with
acetone as the wetting agent. Liquid waste runoffs from each procedural step were collected as a composite
sample (one per three test coupons). A mechanical removal of residual decontamination liquid using a
squeegee was performed for selected surfaces tested in horizontal orientation. Decontamination efficacies
for chemical-material-test orientation combinations were calculated using the means of chemical mass
recovered from the surface of replicate test (decontaminated) coupons and the associated set of positive
control (nondecontaminated) coupons through surface wipe sampling. Figures ES-1 and ES-2 show the
measured decontamination efficacies.
Decontamination Results- Galvanized Metal
The decontamination efficiencies of the multistep decontamination procedure demonstrated that the
tested procedure was suitable for decontamination of malathion and 2-CEPS from galvanized metal tested
in horizontal and vertical orientations, with average decontamination efficacies ranging from a low of 49 
14% to >99.9% depending on chemical target and orientation of the material (Figure ES-1). The presence of
surface grime reduced the average efficacy for malathion from galvanized metal tested in horizontal
orientation to approximately 50% but increased efficacy to >99% in the vertical position (Figure ES-2).
iv

-------
Changes in test procedure by switching from detergent-water to DF200 in the first step (H1 and V1 data in
Figure ES-2) did not change efficacies appreciably. The addition of a mechanical removal of the rinse and
Malathion
Efficacy
2-CEPS
Efficacy
100-
100-
60-
60-
40-
40-
20-
20-
GM-H GM-V
Material and Orientation
PC-H PC-V
GM-H GM-V VF-H PC-H PC-V
Figure ES-1. Average percent decontamination efficacies [% DE  standard deviation (SD)] of malathion and
2-CEPS from different test materials/test surface orientations, without presence of surface grime. GM-H, VF-
H, PC-H-galvanized metal, vinyl tile, and painted concrete (tested in horizontal (H) orientation); GM-V, PC-V-
galvanized metal and painted concrete (tested in vertical (V) orientation).
decontamination liquid from horizontal grimed (applied manufactured grime) surfaces (H2) prior to wipe
sampling rendered the residual surface concentration of malathion to below the limit of detection (LOD). The
100-
100-
60-
50-
40-
20-
2-CEPS
Efficacy
Malathion
Efficacy
rS^ r&
Material and Orientation
Figure ES-2. Average percent decontamination efficacies [% DE  SD] of malathion and 2-CEPS from
different test materials/test surface orientations, with a presence of surface grime. GGM-H, GGM-V-
galvanized metal in horizontal (H) or vertical (V) orientation.
additional change in pre-rinse from detergent-water to DF200 (H2A) did not change efficacy.
Direct comparisons of efficacies for the cleaning of galvanized metal contaminated with malathion
or 2-CEPS are convoluted by differences in solubility of these two chemicals, different affinity to adhere to
the nonporous surface or grime, and actual degradation rate of the chemical by the decontaminant.
v

-------
Decontamination Results- Porous/Permeable Materials
The reduced decontamination efficiency (DE) observed for semi-porous and porous building
materials (Figure ES-1), with a maximum DE of 45% (malathion on painted concrete in vertical position) was
linked to the permeation of the chemical into the test material, resulting in a limited availability of the
chemical for perhydrolysis/oxidation by the DF200 decontaminant on the surface. Malathion and 2-CEPS
recoveries from positive controls were also significantly impacted by the permeation into the materials,
leaving less chemical (< 47% for malathion and < 20% for 2-CEPS) on the surface that is accessible during
the wipe sampling.
Results - Liquid Wastes
Runoff collected and analyzed for residual chemical from vertically oriented materials showed a
significant physical transfer/distribution of the applied chemical from the surfaces. Figure ES-3 illustrates the
distribution of malathion across liquid wastes generated by each of the three steps in the decontamination
procedure for a grimed galvanized metal surface. In (A), no runoff was collected, and all liquid remained on
the surface until the wipe sampling of the surface. In (B), each fraction was collected by a skimming of the
liquid off the surface. In (C), liquid waste for each fraction was collected as runoff due to the vertical position
of the coupon. The slice that represents the degradation is derived from the difference between the positive
control amount and the malathion that was otherwise unaccounted for in liquid wastes (as applicable). The
liquid that remained on the horizontal surface contributed to the high recovery of malathion in the wipe
sample (Figure ES-3A), whereas the wipe sample (Figure ES-3B) collected only residual malathion (less
than 1%) from the surface with minimal residual liquid on it. This finding is consistent with what was
observed for the vertically oriented coupon (Figure ES-3C). Absorption of the residual liquid on the surface
Malathion Distribution Horizontal
Galvanized Metal Coupon
 Degradation
Residual on Surface
Malathion Distribution Horizontal
Galvanized Metal Coupon
Pre-rinse waste
I Degradation
I Decon waste
Post-rinse waste
Residual on Surface
B
Malathion Distribution Vertical
Galvanized Metal Coupon

Pre-rinse waste
Wnr
a Degradation

 Decon waste
E3 j
I Post-rinse waste
^ J
| Residual on Surface
c
Figure ES-3. Relative mass distribution of malathion (normalized to positive control recovery) in liquid
waste fractions associated with the three-step decontamination process using detergent-water in Step 1.
vi

-------
by the surface wipe may lead to the conclusion that the surface was not clean. However, the surface wipe
facilitated in the physical transfer of unreacted chemical on the surface leaving much less on the surface. It
is possible, as shown here, that unreacted chemical resides in the liquid on the surface, even in the
presence of the decontamination solution, especially under more challenging conditions such as the
presence of grime, higher initial contamination levels, or short contact time that lead to incomplete
degradation. An investigation of potential toxic by-product formation would also be important but was not
part of this study. The liquid waste generated was initially found to be contaminated with target chemicals at
levels up to grams per liter [g/L]. However, residual decontaminant in the liquid waste resulted in a
statistically significant degradation. Any treatment methods for contaminated waste were, however, not
addressed in the present study.
Main findings
The main findings of this study are:
	Decontamination of permeable or porous materials remains problematic due to the fast permeation
of some chemical agents into the surface. The presence of grime on the surface did not alter this
observation.
	If a spray-based decontamination method is used but the residual liquid from the surface is not
removed prior to wipe sampling, the calculated decontamination efficacy may be lower than
expected because samples for such surfaces include unreacted chemicals present in the liquid on
the surface.
	Tested decontamination methods resulted in physical transfer/distribution of chemical agent on the
surface, yielding highly contaminated liquid waste which may degrade to lower concentrations due
to the presence of residual decontaminant. Removing grime by pre-cleaning may result in physical
transfer of the agent without degrading it.
	The addition of a mechanical removal of the remaining decontaminant on the surface after a
specific dwell time may prove to be a promising aspect of surface decontamination.

-------
Table of Contents
Disclaimer	i
Foreword	ii
Acknowledgments	iii
Executive Summary	iv
Acronyms and Abbreviations	xiii
1.	Introduction	1
1.0.	Project Objectives	1
2.	Experimental Approach	2
2.1.	Test Facility	2
2.2.	Experimental Design	2
3.	Materials and Methods	3
3.1.	Preparation of Test Coupons	3
3.2.	Preparation of Standard Grime	4
3.3.	Application of Grime to Test Coupons	4
3.4.	Chemical Agents and Contamination Procedure for Coupons	5
3.5.	Decontamination of Building Materials	9
3.5.1.	Preparation of decontamination solution	9
3.5.2.	Preparation of detergent-water solution and water-only rinses	9
3.5.3.	Decontamination procedure	9
3.5.4.	Decontamination test matrix	11
3.6.	Sampling and Analysis Method Development	13
3.6.1.	Sampling methods	13
3.6.1.1.	Surface wipe sampling and extraction of surface wipe samples	13
3.6.1.2.	Sampling and extraction of decontamination samples	16
3.6.1.2.1.	Liquid-liquid extraction of aqueous waste	19
3.6.1.2.2.	Verification of quenching of decontamination reaction in wipe extracts	22
3.6.1.2.3.	Verification of quenching of decontamination reaction in liquid waste	24
3.6.2.	Decontamination process design for horizontal and vertical coupon testing	25
3.6.2.1.	Surface sampling and extraction methods	28
3.6.2.2.	Liquid waste sampling and extraction procedures	30
3.6.3.	Preparation of extracts for analysis	31
3.6.4.	Instrumental analysis	31
3.7.	Data Reduction Procedures	36
3.7.1.	Chemical concentration in extract calculations	36
3.7.2.	Decontamination cleanup efficacy calculations	36
4.	Results	37
4.1.	Surface Decontamination Tests	37
4.1.1.	Nongrimed coupons	37
4.1.2.	Grimed coupons	41
4.2.	Transfer to Liquid Waste - Vertical Coupons	44
4.3.	Transfer to Liquid Waste - Horizontal Coupons	47
4.3.1 Direct extraction	47
4.3.1. Delayed extraction	49
5.	Quality Assurance/Quality Control	50
viii

-------
5.1.	Test Equipment Calibration	50
5.2.	Data Quality Results for Critical Measurements	50
6. Summary	52
References	53
Appendices	55
Appendix A: Grime Application Procedure	55
Appendix B: Experimental parameters	57
Appendix C: Wipe sampling procedure	60
IX

-------
Figures
Figure ES-2. Average percent decontamination efficacies [% DE  SD] of malathion and 2-CEPS from
different test materials/test surface orientations, with a presence of surface grime. GGM-H, GGM-
V- galvanized metal in horizontal (H) or vertical (V) orientation	v
Figure ES-1. Average percent decontamination efficacies [% DE  standard deviation (SD)] of malathion
and 2-CEPS from different test materials/test surface orientations, without presence of surface
grime. GM-H, VF-H, PC-H- galvanized metal, vinyl tile, and painted concrete (tested in horizontal
(H) orientation); GM-V, PC-V- galvanized metal and painted concrete (tested in vertical (V)
orientation)	v
Figure ES-3. Relative mass distribution of malathion (normalized to positive control recovery) in liquid
waste fractions associated with the three-step decontamination process using detergent-water in
Step 1	vi
Figure 2-1. Decontamination procedure	2
Figure 3-1. HVLP sprayer components: reservoir (a), reservoir cap (b), trigger (c) and hose connector (d).
	5
Figure 3-2. Pattern for discrete droplet application of chemicals onto the 12-in x 12-in (a) and 8-in x 16-in
test surfaces (b)	7
Figure 3-3. Application of chemical solution (a) and dried out (or post-weathering) chemical droplet
pattern (b); the example shown is malathion on nongrimed galvanized metal	7
Figure 3-4. Chemical contamination pattern on nongrimed test materials immediately after spiking onto
vinyl (a), galvanized metal (b), painted concrete flooring (c), and painted concrete block (d)	8
Figure 3-5. Post-weathering chemical contamination pattern of malathion (a) and 2-CEPS (b) on grimed
galvanized metal coupons	8
Figure 3-6. Application of rinses or decontamination solution onto various coupon materials: pre-rinse
detergent-water applications onto painted concrete (a), grimed galvanized metal (b) and
nongrimed galvanized metal in a vertical position (c) and decontaminant application onto vinyl
flooring (d), galvanized metal (e) and painted concrete block in a vertical position (f)	10
Figure 3-7. Mechanical removal of DF200 (A - at start; B - at end) and post-decontamination water rinse
(C) from the grimed galvanized metal surface	10
Figure 3-8. Malathion surface recovery from surface sampling and extraction method tests Round 1
(patterned bars) and results for Round 2 (solid bars) for nongrimed materials	14
Figure 3-9. 2-CEPS surface recovery from surface sampling and extraction method optimization tests
(patterned bars) and results for optimized method (solid bars) for nongrimed coupons	14
Figure 3-10. Malathion surface recovery from surface sampling and extraction method tests Round 1
(isopropanol (IPA)) and results for Round 2 (acetone (ACE)) for grimed surfaces	15
Figure 3-11. 2-CEPS surface recovery from surface sampling and extraction method tests using acetone
as the wiping solvent for grimed surfaces; ACE - acetone	16
Figure 3-12. Runoff of pre-decontamination rinse (left), decontaminant (middle) and post-decontamination
rinse (right)	17
Figure 3-13. Experimental scheme for liquid waste extraction tests	20
Figure 3-14. Extraction of liquid waste containing detergent collected from nongrimed surfaces. *: % ratio
of recovery of malathion and 2-CEPS in nonpreserved versus preserved samples collected from
nongrimed surfaces	21
Figure 3-15. Optimization of extraction of liquid waste containing detergent collected from grimed
surfaces. *: %ratio of recovery of malathion and 2-CEPS in nonpreserved samples collected from
grimed surfaces	22
Figure 3-16. Effect of decontamination solution in wipe extracts tests	23
Figure 3-17. Recovery of malathion and 2-CEPS from sampling wipe containing residual DF200	23
x

-------
Figure 3-18. Effect of decontamination solution in liquid waste tests	24
Figure 3-19. Recovery of malathion and 2-CEPS from DF200 runoff using extraction solvent only (ESN)
and extraction solvent with sodium thiosulfate (STS)	25
Figure 3-20. Sample process design for horizontal coupon decontamination testing	26
Figure 3-21. Sample process design for vertical coupon decontamination testing	27
Figure 3-22. Sample process design for positive control testing	28
Figure 3-23. Example of surface wipe sampling in horizontal orientation (left - cotton gauze sampling of
galvanized metal; right - the follow-on cotton twill wipe sampling of galvanized metal)	30
Figure 3-24. Example of surface wipe sampling in vertical orientation (left - cotton twill wipe sampling of
galvanized metal; right - cotton twill wipe sampling of painted concrete block)	30
Figure 4-1. Recovered mass of (A) malathion and (B) 2-CEPS from test coupons and positive controls on
nongrimed surfaces: GM-H, VF-H, PC-H: galvanized metal, vinyl tile, and painted concrete paver
(tested in horizontal orientation); GM-V, PC-V: galvanized metal, and painted concrete block
(tested in vertical orientation)	38
Figure 4-2. Galvanized metal coupon contaminated with 2-CEPS after application of the Step 1 water-
detergent rinse	40
Figure 4-3. 2-CEPS droplets on horizontal coupons and runoff of chemical contamination after turning
galvanized metal in vertical orientation (30 minutes post-spiking)	40
Figure 4-4. Recovered mass of (A) malathion and (B) 2-CEPS from test coupons and positive controls on
grimed surfaces: GGM-H, H1, H2: galvanized metal (tested in horizontal orientation); GGM-V:
galvanized metal (tested in vertical orientation)	41
Figure 4-5. 2-CEPS spiking pattern on grimed galvanized coupons immediately after spiking, after
weathering and readied for the vertical orientation testing	44
Figure 4-6. Transfer of malathion contamination from galvanized metal (GM) in vertical position to
different types of liquid waste from decontamination process. Grime* refers to the use of DF200 in
the pre-rinse step	45
Figure 4-7. Transfer of 2-CEPS contamination from galvanized metal (GM) in vertical position to different
types of liquid waste from decontamination process	45
Figure 4-8. Transfer of malathion contamination from galvanized metal (GM) in horizontal position to
different types of liquid waste by physical removal from decontamination process. Grime* refers
to the modified method that uses DF200 in the pre-rinse step	48
Figure C-1. Folding wipe for sampling the first wiping pathway (horizontal)	60
Figure C-2. Horizontal wiping pathway	61
Figure C-3. Folding wipe for sampling the second wiping pathway (vertical)	61
Figure C-4. Vertical wiping pathway	61
Figure C-5. Folding wipe for sampling the third wiping pathway (diagonal)	62
Figure C-6. Diagonal wiping pathway	62
Figure C-7. Folding wipe for sampling the fourth pathway (perimeter)	63
Figure C-8. Perimeter wiping pathway	63
Tables
Table 3-1. Specifications of Building Materials	3
Table 3-2. Specifications of Grime Components	4
Table 3-3. Physical and Chemical Properties of Malathion and 2-CEPS	6
Table 3-4. Test Matrix for Decontamination Testing	12
Table 3-5. Characterization of Liquid Effluents from Step 1 of Simulated Decontamination
Procedure	18
XI

-------
Table 3-6. Characterization of Liquid Effluents from Step 2 of Simulated Decontamination
Procedure	18
Table 3-7. Characterization of Liquid Effluents from Step 3 of Simulated Decontamination
Procedure	18
Table 3-8. Surface Sampling Parameters for Malathion and 2-CEPS	29
Table 3-9. Instrumental Parameters and Conditions for GC/MS Analyses of Malathion by EMSL
Analytical, Inc	32
Table 3-10. Instrumental Parameters and Conditions for GC/MS Analyses of 2-CEPS by EMSL
Analytical, Inc	32
Table 3-11. GC/MS Parameters for Analysis of Malathion by OSL	33
df: film thickness	33
Table 3-12. GC/MS Parameters for Analysis of 2-CEPS by OSL	33
df: film thickness	33
Table 3-13. QC Checks for Instrumental Analyses	34
*re-calibrate when continuous calibration fails acceptance criteria and or after system
maintenance; RPD - relative percent difference	34
Table 3-14. Laboratory Proficiency Results	35
Table 4-1. Material- and -Orientation-Specific Decontamination Test Results of Nongrimed
Materials for Malathion and 2-CEPS	39
Table 4-2. Material- and Orientation- Specific Decontamination Test Results of Grimed
Materials for Malathion and 2-CEPS	43
Table 4-3. Recovered Mass and Concentration of Malathion and 2-CEPS in Liquid Waste from
Decontamination Procedures	46
Table 4-4. Recovered Mass and Concentration of Target Chemicals in Liquid Waste from
Decontamination Procedures for Horizontal Grimed Galvanized Metal	48
Table 5-1. Instrument Calibration Frequency	50
Table 5-2. Acceptance Criteria for Critical Measurements	51
Table B-l. Characterization of DF200 Decontamination Solution	57
Table B-2. Characterization of Pre-decontamination Detergent-water Rinse Solution Application
	57
Table B-3. Characterization of DF200 Decontamination Solution Application	58
Table B-4. Characterization of Post-decontamination Water Rinse Application	59
xii

-------
Acronyms and Abbreviations
2-CEPS	2-chloroethyl phenyl sulfide
CBRN	chemical, biological, radiological, and nuclear
CC	continuous calibration
CESER	Center for Environmental Solutions and Emergency Response (US EPA)
cm	centimeters)
cm3	cubic centimeter(s)
COC	chain of custody
CS	control spike
CT	contact time
CWA	chemical warfare agent
DE	decontamination efficacy
Dl	deionized (water)
DQI	data quality indicator
DT	dwell time
DUP	duplicate
EC	end check (of calibration)
EMSL	Environmental Molecular Sciences Laboratory
EPA	U.S. Environmental Protection Agency
ESF	Emergency Response Function
ft	foot/feet
g	gram(s)
GC/MS	gas chromatography/mass spectrometry
GGM	grimed galvanized metal
GM	galvanized metal
GVF	grimed vinyl flooring (-material)
H2O2	hydrogen peroxide
HD	sulfur mustard
HPLC	High Performance Liquid Chromatography
h	hour(s)
HSMMD	Homeland Security and Material Management Division (US EPA)
HSRP	Homeland Security Research Program (US EPA)
HVAC	heating, ventilation, and air conditioning
HVLP	High Volume Low Pressure

-------
HWCL	hazardous waste control limits
ICAL	initial calibration
ICV	initial calibration verification
ID	identification
in	inch(es)
IPA	isopropanol (2-propanol)
IS	internal standard
ISO	International Organization for Standardization
L	liter
LB	laboratory blank
LCS	laboratory control sample
LCSD	laboratory control sample duplicate
LOQ	limit of quantitation
LSB	laboratory solvent blank
LW	liquid waste
LWD	liquid waste (from) decontaminant
m	meter(s)
mg	milligram(s)
min	minute(s)
mL	milliliters)
mm	millimeter(s)
ND	nondetect
NIOSH	National Institute for Occupational Safety and Health
NIST	National Institute of Standards and Technology
NRT	National Response Team
ORD	Office of Research and Development
OSL	Organic Support Laboratory (US EPA)
oz	(liquid) ounce(s)
PB	procedural blank
PC	positive control
PTFE	polytetrafluoroethylene
OA	quality assurance
QAPP	quality assurance project plan
QC	quality control
xiv

-------
QRG
Quick Reference Guide
R2
coefficient of determination
RH
relative humidity
RLV
reporting limit verification
RPD
relative percent difference
RSD
relative standard deviation
RTP
Research Triangle Park
SB
solvent blank
SC
spike control
SD
standard deviation
sec
second(s)
STS
sodium thiosulfate
TC
test coupon
|JL
microliter(s)
vx
Ethyl ({2-[bis(propan-2-yl)amino]ethyl}sulfanyl)(methyl)phosphinate

-------
1. Introduction
A vital characteristic of any decontamination strategy is its ability to degrade a wide array of different
chemicals using either specialized chemical decontamination treatments or commercial off-the-shelf
products that would be widely available following a wide-area chemical (or biological) release. EPA's
Homeland Security Research Program (HSRP) has directed multiple research efforts that focused on liquid-
based surface decontamination options using commercially available products that are expected to degrade
various highly toxic chemical agents from various types of surfaces [1-6], These decontamination studies
are typically limited to the measurement of efficacy of the decontamination product itself after a fixed contact
time. Decontamination procedures using concentrated liquid formulations of hydrogen peroxide, and
especially activated hydrogen peroxide are suggested to be effective decontaminants for various chemical
agents, including chemical warfare agents (CWAs) and organophosphorus pesticides [3, 6-8],
Hydrogen peroxide-based (and other degradative) treatments can cause severe material
incompatibilities, including permanent damage of the decontaminated material due to excessive corrosion or
erosion post-treatment [6-7], Some treatments also have well-known limitations for decontamination of
chemical agents from semi-porous and porous materials due to permeation of target chemicals into inner
layers of materials [9], To address this problem, field decontamination procedures typically include a post-
decontamination water rinse step to remove residual decontaminant and allow for better overall material
compatibility. Another common problem that can limit decontamination efficacy is a high organic burden on
the material surface. The presence of surface grime and dirt can lead to increased material-demand for the
decontaminant, especially in comparison to materials with otherwise lower demand [10], To mitigate the
effect of organic burden, field decontamination procedures often suggest pre-decontamination detergent-
based water rinses prior to deployment of core-decontaminant as indicated in, for example, the National
Response Team's (NRT's) Quick Reference Guides (QRG) for CWAs [11], The pre-treatment step is
intended to remove (some of) the dirt/grime layer - that would otherwise be competing for decontaminant -
and/or mobilize the chemicals that may be absorbed into the dirt/grime layer and therefore less accessible
to the decontaminant.
This report discusses the investigation of a three-step cleaning and procedure for decontamination
of surfaces contaminated with organophosphate pesticides and/or simulant CWAs and contributes to the
understanding of the impact of water-based rinses on cumulative decontamination efficacy.
1.0. Project Objectives
The primary objective of this project is to provide responding agencies and field remediation
specialists with more information on effectiveness of adding the pre- and post-decontamination water-based
rinses for cleaning of various types of indoor surfaces contaminated with pesticides and/or CWAs
(simulants). The secondary objective is to provide initial information on the contamination of liquid waste
(runoff) generated, including determination of material-dependent chemical transfer rates to liquid waste.
Results from this project contribute to formation of guidelines for selection of the best standardized
approaches for remediation of permeable, semipermeable, and nonpermeable surfaces contaminated with
pesticides and CWAs, with and without presence of surface grime.
1

-------
2. Experimental Approach
2.1.	Test Facility
The experimental work was performed at the EPA's facilities in Research Triangle Park (RTP), NC.
Instrumental analyses of the residual amounts of chemicals remaining on the coupons were performed
initially by an external chemical analysis laboratory (Environmental Molecular Sciences Laboratory (EMSL)
Analytical Inc., Cinnaminson, NJ, USA) and later by an on-site EPA laboratory.
2.2.	Experimental Design
This study evaluated the cumulative decontamination efficacy of multistep cleaning procedures for
degradation of selected organophosphate pesticides and/or simulant CWAs. After completion of a series of
method demonstration tests (Section 3.6), a three-step decontamination procedure was tested on four types
of surfaces (galvanized metal, painted concrete flooring, painted concrete blocks, and vinyl floor tile) in
horizontal and/or vertical orientations (Section 3.1). Neat chemical (malathion or2-CEPS) solutions in
ethanol were applied using a discrete droplet application method (Section 3.4). After a contact time (CT) of
30 minutes (min) (i.e., a simulated weathering of the chemical on the surface) under room temperature
conditions, the decontamination sequence was applied, which consisted of: (Step 1) pre-rinse of the surface
with detergent in water solution; (Step 2) application of the decontaminant; and (Step 3) post-rinse of the
surface with water to remove the residual decontaminant. At the conclusion of the decontamination
sequence, a surface sampling was performed using a wipe-based surface sampling approach, followed by
extraction of sampling media (wipes) and analysis of extracts via gas chromatography/mass spectrometry
(GC/MS) (Sections 3.6.2.1, 3.6.3 and 3.6.4). The analysis of liquid effluents (volumes and chemical
concentrations) for each step was performed as well (Sections 3.6.2.2, 3.6.3 and 3.6.4). The cleanup
efficacy for each material was then determined using the total mass recovered of the contaminant from the
test coupon and from the associated positive control (Section 3.7.2). The scheme and general timeline for
each decontamination test are shown in Figure 2-1 with experimental details in Chapter 3.
Step 3: Apply post-
decon rinse
Contamination
of coupons
Step 1: Apply
pre-decon rinse
Step 2: Apply
decontaminant
V.
Application of
decontaminant
DF200
Collection of
decontaminant
runoff; DT2 = 60
min**
Extraction of liquid
and preparation of
samples for
analysis
Application of post-
decon rinse [water
spray]
Surface sampling
including sampling
of procedural
blanks, PBs at DT3
= 30 min**
Collection of post-
decon runoff ***
Extraction and
preparation of
samples for
analysis
Discrete droplet
application (20
droplets [10 pl-
each] per coupon)
Contact time CT*
=30 min sampling
of positive controls,
PCs
Extraction and
preparation of
samples for
analysis
Application of pre-
decon rinse
[detergent and water
spray or DF200]
Collection of pre-
decon runoff; DT1 =
30 min**
Extraction of liquid
waste and
preparation of
samples for analysis
* Contact time (CT) is the time the chemical (maiathion/2-CEPS) is in contact with the material surface; ** Dwell time (DT) is the time
the pre-rinse (DT1) or decontaminant (DT2) or post-decon rinse (DT3) is in contact with the contaminated material surface; *** for
selected tests, a mechanical removal ('skimming') of liquid waste was performed for grimed surfaces tested in horizontal orientation.
Figure 2-1. Decontamination procedure.
2

-------
3. Materials and Methods
3.1. Preparation of Test Coupons
Four building materials (galvanized metal, painted concrete flooring pavers, painted concrete
blocks, and vinyl floor tile) were used for evaluation of cleanup procedures. Galvanized metal was a
representative material for nonpermeable building surfaces and is used in heating, ventilation, and air
conditioning (HVAC) systems. Vinyl flooring and concrete were selected as representative of a
semipermeable and permeable building material, respectively. Selected sealers and paints for concrete
paver and concrete blocks were based on their purpose to seal the open porous concrete and can be found
in indoor environments as apposed to nonsealed or painted concrete in the outdoors. The building material
specifications are given in Table 3-1.
Table 3-1. Specifications of Building Materials
Material
Description
Manufacturer/
Supplier Name/Location
Coupon
Size,
LxW
(in) or
DxHx
W (in)
Material Preparation
Galvanized
metal
24-in x 3-ft
sheet
galvanized
metal, 30 gauge
Imperial 24-in x 3-ft sheet metal,
Lowe's Item #50186, Model #GVL01087 Lowe's,
Morresville, NC, USA
12x 12
Remove any
lubricant/grease from
shearing with acetone
and wipe dry.
Remove particles and
dust by wiping clean
with acetone and water
and then wipe dry.
Vinyl flooring
3/32-in x 12-in x
12-in
commercial
vinyl tile
Tarkett 12-in x 12-in Cloudburst speckle pattern
commercial vinyl tile, Lowe's Item #378985 Model
#L0786-2/ Lowe's, Morresville, NC, USA
12x 12
Remove particles by
wiping clean with
acetone and water and
the wipe dry.
Concrete
flooring
(sealed)
12-in x 12-in
Concrete paver
and sealant
12 in x 12 in Pewter Concrete Step Stone. Home
Depot Item # 556211 Model # 71200; Home
Depot, Atlanta, GA, USA
Valspar Solid Color Concrete Sealer Concrete
Gray; The Valspar Corporation, Minneapolis, MN,
USA; Lowes Item # 293575 Model #
024.0082020.007/ Lowe's, Morresville, NC, USA
12x 12
Remove particles by
wiping clean with
acetone and water and
then wipe dry.
Concrete
blocks
(painted)
8-in x 8-in x 16-
in concrete
block and
sealant
Normal Weight/Standard Cored Concrete Block
(8-x 8-x 16-in; actual: 7.625-in D x 7.625-in H x
15.625-in W); Lowe's Item # 10383 Model #
8008/ Lowe's, Morresville, NC, USA
Loxon Concrete & Masonry Primer; Sherwin
Williams, P/N 6501-32646; Sherwin-Williams
Company, Cleveland, OH, USA, and Cashmere
Interior Acrylic Latex in Ultra White; Sherwin
Williams, USA; P/N 6504-06713; Sherwin-
Williams Company, Cleveland, OH, USA
8 x 8 x
16
Remove particles by
wiping clean with
acetone and water and
then wipe dry.
3

-------
Galvanized metal coupons were prepared using heavy-duty powered hydraulic shears. The
commercially available vinyl tiles and concrete blocks (concrete blocks) and concrete pavers did not require
mechanical processing. Sealants and paints were applied onto concrete surfaces per manufacturer's
instructions.
3.2. Preparation of Standard Grime
A standard grime formulation was prepared to simulate dirty surfaces in an urban indoor
environment. The standard grime consisted of three classes of functional components: general dust, soot,
and biological components (Table 3-2).
Table 3-2. Specifications of Grime Components
Grime Component
Weight %*
Manufacturer/Product number
General dust component
Arizona fine dust
94%
Powder Technology Inc. Arden Hills, MN USA; P/N PP2G4 A2 fine
Soot-related components
Black carbon
2.5%
Powder Technology Inc. Arden Hills, MN USA; P/N Raven 410
Diesel particulate matter
0.25%
National Institute of Standards and Technology (NIST)
Gaithersburg, MD USA; P/N SRM 2975
10W30 motor oil
0.125%
O'Reilly Auto Parts Springfield, MO; P/N10-30
Biological components
Alpha-pinene (neat)
0.125%
Fisher Scientific Waltham, MA USA; P/N AC1646-0050
Lycopodium powder
1%
Fisher Scientific Waltham, MA USA; P/N S25396
Ragweed pollen
1%
Polysciences Warrington, PA USA; P/N 7673
Paper mulberry mixture
1%
Polysciences Warrington, PA USA; P/N7670
*in the finished grime mixture
It is expected that the dust in the grime may absorb some of the decontaminant leading to a lower
mobility for the decontaminant to reach the contaminant. The soot related components in the grime may
degrade the decontaminant (an increased "material demand" by the grime) while the biological
components are likely not of critical importance here considering their small weight percentage in the
grime.
The grime mixture was prepared by mixing of standard components using the recipe in Table 3-2.
The components were weighed and added to a 500-milliliter (mL) polypropylene bottle, and the bottle was
capped and placed in a laboratory tumbler overnight (18 hours [h]) to mix the grime components. After
tumbling the mixture, the standard grime was stored at room temperature in a capped 500-mL plastic bottle
until use.
3.3. Application of Grime to Test Coupons
Coupon surfaces were grimed with standard grime dissolved in analytical grade ethanol (Fisher
Scientific, Fair Lawn, NJ, USA) and applied to the surface with a high-volume low pressure (HVLP) sprayer
(Transtar Autobody Technologies Inc., Brighton, Ml, USA; P/N 6618) connected to the pressurized house
4

-------
air supply via an air hose connector. The main structural components of the HVLP sprayer are shown in
Figure 3-1. The method for applying grime to the test coupon surface is detailed in Appendix A.
Figure 3-1. HVLP sprayer components: reservoir (a), reservoir cap (b), trigger (c) and hose connector (d).
3.4. Chemical Agents and Contamination Procedure for Coupons
The relevant physical and chemical properties of the target chemicals are summarized in Table 3-3.
Malathion is an organophosphate insecticide widely used in applications such as agriculture, outdoor pest
control, and residential landscaping. It is also considered a simulant for the CWA nerve agent VX [12], The
second chemical is 2-chloroethyl phenyl sulfide (2-CEPS). Based on chemical similarity, 2-CEPS is
considered a valid simulant for sulfur mustard (HD) CWA [12], The malathion analytical standard was
purchased from Chem Service (Chem Service, Inc., West Chester, PA, USA; P/N N-12346-1OOMG; purity:
99,5%). The 2-CEPS analytical standard was purchased from Sigma-Aldrich (Sigma-Aldrich Co. LLC, St.
Louis, MO, USA; P/N 417602-25ML; purity 98%).
5

-------
Table 3-3. Physical and Chemical Properties of Malathion and 2-CEPS
Property
Malathion*
2-CEPS**
CAS
121-75-5
5535-49-9
Molecular weight
330.4
172.67
Formula
C10H19O6PS2
CsHgCIS
Density (g/cm3) at 20 C
1.23
1.17
Physical form at 20 C
Liquid
Liquid
Vapor pressure
3.3E-6 mm Hg at 25 C
1.86E-2 mm Hg at 25 C
Solubility in water
0.143 g/L
0.084 g/L
Log Kow
2.36-2.89
3.58
*: See https://pubchem.ncbi.nlm.nih.gov/compound/Malathion
**: See https://pubchem.ncbi.nlm.nih.aov/compound/2-Chloroethvl-phenvl-sulfide
The target surface chemical concentrations in this study were approximately 1 gram/square meter
(g/m2). The test area of each 12-in * 12-in coupon (total surface area of 929 centimeter2 [cm2]) were
contaminated with twenty 10 jjL-droplets of 500 milligrams (mg) per mL (mg/mL) solutions of the target
chemical agents, yielding contamination levels of 100 mg/coupon, equivalent to 1.1 g/m2.
Solutions were prepared using procedures developed in previous research efforts [5] by dissolution
of neat chemicals in organic solvents. Briefly, neat chemicals were dissolved in High Performance Liquid
Chromatography (HPLC) grade ethanol to produce a 500 mg/mL concentration, then mixed using a vortex
mixer and then via sonication for approximately 30 seconds (sec). The accuracy and precision of
preparation of spiking solution was tested along with each experimental batch, by analysis of control spike
(CS) samples (see Section 5.2 for results of analysis of control spikes).
Chemical solutions were applied onto test coupons using a discrete droplet micro-application of
chemicals. Priorto application, each 12-in * 12-in test coupon was placed in an individual, pre-cleaned test
box (sliding storage box, IRIS USA, Inc., Surprise, AZ USA; P/N 491530). Chemical solutions were then
applied to the coupons under ambient room temperature conditions in a chemical safety hood using a
separate tip-programmable electronic repeatable pipette (Eppendorf Repeater Plus Single Channel
Repeater Pipette, Eppendorf AG, Hamburg, Germany; P/N 22260201) and pre-cleaned stainless steel
spiking template standing over the coupon surface. The 20 discrete droplets were applied following the
pattern shown in Figure 3-2.
6

-------

2"



c
5 o
o
o
o
o
o
o
o
o
2"



2"
o o
o
o
o
o o
o
o
o



4


2"


-2"
2"
3"
0 o	o o
~o o	o o
o o	o o
o o	o o
o o o o
3"
-1"
Figure 3-2. Pattern for discrete droplet application of chemicals onto the 12-in x 12-in (a) and 8-in x 16-in test
surfaces (b).
After application of chemical, the boxes were closed to allow a 30-miri long simulated weathering to
ensure that the ethanol had evaporated. This weathering was performed under ambient laboratory
conditions of 22 C and 25% relative humidity (RH) (uncontrolled; averages typical for indoor laboratory in
early winter/spring months when testing was performed). Figure 3-3 shows an example of the sampling
template placed over a coupon and the weathered/dried out (CT=30 min) chemical droplet pattern.
Figure 3-3. Application of chemical solution (a) and dried out (or post-weathering) chemical droplet pattern
(b); the example shown is malathion on nongrimed galvanized metal.
7

-------
The chemical contamination pattern for other nongrimed materials is shown in Figure 3-4.
Weathering was always performed with materials in the horizontal position. A subset of galvanized metal
and all concrete block coupons were positioned in the vertical orientation immediately after contamination.
Figure 3-4. Chemical contamination pattern on nongrimed test materials immediately after spiking onto vinyl
(a), galvanized metal (b), painted concrete flooring (c), and painted concrete block (d).
Figure 3-5 shows examples of post-weathering malathion and 2-CEPS chemical contamination pattern
as visible on the grimed galvanized metal surface.
Figure 3-5. Post-weathering chemical contamination pattern of malathion (a) and 2-CEPS (b) on grimed
galvanized metal coupons.
8

-------
3.5. Decontamination of Building Materials
3.5.1.	Preparation of decontamination solution
The decontamination product that was used in this study was EasyDECON DF200 (hereafter,
DF200) manufactured by Envirofoam Technologies/lntelagard (Lafayette, CO, USA). The manufacturer
markets the DF200 formulation as 100% effective for decontamination of HD (1-hour dwell time, challenge
ratio 1:200) [13], The active ingredient of DF200 is hydrogen peroxide (H2O2), and its pH range is 9.6-9.7.
The liquid-based results for malathion suggest full decontamination (nondetectable in test samples) at 1-
hour dwell time (challenge ratio not provided) [14],
Fresh batches of DF200 solution were prepared daily through proportional mixing as per the
manufacturer's instructions. After mixing, the manufacturer recommends the use of the EasyDECON
Fortifier Test Kit to test the stability of the DF200 final blend. This test (a "Go/No Go" test) measures the
percentage of active ingredient and instills confidence that the decontamination solution is effective and
ready to use. The ongoing evaluations that occurred prior to use also included pH and temperature
measurements of the finished blend. Results are shown in Appendix B (Table B-1).
3.5.2.	Preparation of detergent-water solution and water-only rinses
The pre-rinse detergent-water solution was prepared by adding 1 part of Dawn Ultra Dishwashing
Liquid Original Scent (Procter & Gamble, Cincinnati, OH, USA) to 50 parts of deionized (Dl) water followed
by thorough mixing. The solution was mixed by hand shaking for 10 sec prior to application of this
decontamination solution to the coupon. No evaluation of the detergent solution was performed. Dl water
was used for post-decontamination rinses.
3.5.3.	Decontamination procedure
Pre- and post-decontamination rinses and decontamination solution DF200 were applied using
commercially available cleaning-grade spray bottles. A durable industrial sprayer bottle was used (32-ounce
(oz) plastic spray bottle, Lowe's Item #366843, Model #LOAPS30; as shown in use on Figure 3-6). This type
of bottle is equipped with a trigger sprayer with no adjustable spray pattern and is recommended by the
manufacturer of the sprayer bottle for general household cleaning purposes, including application of
concentrated formulas. Bottles were rinsed with Dl water prior to use.
DF200 was sprayed onto each coupon using a pre-filled bottle. The pre- and post-decontamination
water rinses were applied using separate spray bottles. The surface of the coupon was always sprayed
using horizontal (left to right) overlapping strokes, that were applied from top to bottom of each coupon. Fill
volumes - measured by use of a graduated cylinder - were 20 mL  1 mL. The actual volumes of
decontaminant and water rinses sprayed onto each coupon were 20 mL  4 mL (20% of surface target)
across all testing and were determined gravimetrically by weighing each test box before and after
application. Accuracy of the scale was sufficient to measure an absolute mass change of 1 g (an equivalent
of approximately 1 mL of liquid decontaminant). Test-specific results are given in Tables B-2 and B-3
(Appendix B). Figure 3-6 shows application of rinses or decontamination solution onto various coupon
materials.
9

-------
Figure 3-6. Application of rinses or decontamination solution onto various coupon materials: pre-rinse
detergent-water applications onto painted concrete (a), grimed galvanized metal (b) and nongrimed
galvanized metal in a vertical position (c) and decontaminant application onto vinyl flooring (d), galvanized
metal (e) and painted concrete block in a vertical position (f).
For selected tests on grimed surfaces (Table 3-4), the pre-rinse, decontaminant and post-rinse
fractions were mechanically removed using a small hand-held cleaning device equipped with a rubber blade
(Polypropylene-Thermoplastic Rubber Home Squeegee, Walmart, Inc., Bentonville, AR, USA; P/N
564493773). The mechanical removal step was not intended to scrub the chemical contamination of the
horizontal surface, but rather to gently skim the pre-rinse liquid, processed decontaminant liquid, or water
rinse fraction of the test coupon surface. Figure 3-7 shows the mechanical removal of the DF200 and post-
decontamination water rinse from a horizontal grimed galvanized metal surface. The recovered liquid waste
was split equally, and the two aiiquots were extracted at 0 and 24 h to assess whether the liquid waste
contained residual decontaminant that would reduce the malathion concentration.
Figure 3-7. Mechanical removal of DF200 (A - at start; B - at end) and post-decontamination water rinse (C)
from the grimed galvanized metal surface.
10

-------
3.5.4. Decontamination test matrix
The complete decontamination test matrix is shown in Table 3-4. Results from the nongrimed
coupon decontamination tests (Test ID 1M - 5M for malathion; 1C - 5C for 2-CEPS) were used to determine
the test conditions and materials for the grimed coupon testing (Test ID 6M - 11M for malathion; 6C - 7C for
2-CEPS). For example, low recoveries of both malathion and 2-CEPS from permeable materials resulted in
excluding these types of materials in further testing to focus on the facets of the three-step decontamination
procedure. Test ID 1M - 7M and 1C - 7C were conducted with malathion (M-series) and 2-CEPS (C-series)
as the contaminants. Test ID 8M - 9M were related to modifications of the default decontamination
procedure (Modi) by replacing the initial detergent and water rinse with an initial application of the DF200
decontaminant. The purpose was to assess whether any demand of the grime on the surface could be
overcome with a pre-decon application of the actual decontaminant (instead of the detergent-water pre-
rinse). These tests were executed only in the presence of malathion. The last two tests (Test ID 10M-11M)
included the use of a physical removal of excess liquid from the horizontal surface using a squeegee; one
with detergent-water as the first step (Mod2) and one test with the DF200 as the first step (Mod2A).
Each test consisted of three decontaminated test coupons for each chemical in horizontal and/or
vertical orientation (depending on material tested), three positive controls per test day per material (coupons
contaminated with chemical that did not undergo decontamination), and one procedural blank (coupon not
spiked with chemical but did undergo decontamination in the horizontal orientation). Additionally, one
composite sample of liquid waste (LW) per set of three test coupons - pre-decontamination composite rinse,
decontamination composite rinse, and post-decontamination composite rinse runoffs were collected for
vertical orientation testing. The horizontal orientation testing did not result in appreciable liquid waste
volumes. One control spike sample was prepared per test day to check for nominal concentration of spiking
solution as well as for ongoing laboratory proficiency testing. The sample was prepared as a direct spike of
chemical solution into hexane at a level corresponding to 100% of the target surface concentration of the
chemical expected in the final extract. Types of samples resulting from decontamination testing are
summarized in Table 3-4. The decontamination test results are provided in Section 4.1.
11

-------
Table 3-4. Test Matrix for Decontamination Testing
Test ID
Test Material
Material
Orientation
Pre-rinse
Decontaminant
Post-
rinse
Mechanical
Removal
Method ID
Types
of Samples
Target chemical:
Malathion

1M
Galvanized
Metal
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
2M
Galvanized
Metal
Vertical
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS, LW
3M
Vinyl
Tile
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
4M
Painted [sealed]
concrete flooring
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
5M
Painted [sealed]
concrete block
Vertical
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS, LW
6M
Grimed
galvanized
Metal
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
7M
Grimed
galvanized
Metal
Vertical
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS, LW,
LWD
8M
Grimed
galvanized
metal
Horizontal
DF200
DF200
Water
No
Modi
PC, TC, PB,
LB, CS
9M
Grimed
galvanized
metal
Vertical
DF200
DF200
Water
No
Modi
PC, TC, PB,
LB, CS, LW,
LWD
10M
Grimed
galvanized
metal
Horizontal
Soapy
water
DF200
Water
Yes
Mod2
PC, TC, PB,
LB, CS, LW,
LWD
11M
Grimed
galvanized
metal
Horizontal
DF200
DF200
Water
Yes
Mod2A
PC, TC, PB,
LB, CS, LW,
LWD
Target chemical:
2-CEPS

1C
Galvanized
metal
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
2C
Galvanized
metal
Vertical
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS, LW
3C
Vinyl
tile
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
4C
Painted [sealed]
concrete flooring
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
5C
Painted [sealed]
concrete block
Vertical
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS, LW
6C
Grimed
galvanized
metal
Horizontal
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS
7C
Grimed
galvanized
metal
Vertical
Soapy
water
DF200
Water
No
UM
PC, TC, PB,
LB, CS, LW
UM - unmodified (default) method, Modi- Modified method 1; Mod2 - Modified method 2; Mod2A - Modified method
2A; PC -positive control, TC -test coupon, PB -procedural blank, LB -laboratory blank, CS - control spike, LW-
liquid waste, LWD - liquid waste of decontaminant
12

-------
3.6. Sampling and Analysis Method Development
Method development was required to: (1) demonstrate that the surface wipe sampling and
subsequent extraction ofthewipe(s) met the minimal requirements (higher than 70% recovery); (2) assess
whether the presence of grime was impacting the data quality; (3) establish acceptable methods to extract
malathion or 2-CEPS from the liquid waste extracts through liquid-liquid extraction; (4) verify that residual
decontaminant in the wipe extract or liquid waste extract was adequately quenched to assure that the
sample itself was inactive; and (5) determine whether samples were preserved adequately. The method
development established the final protocol for the decontamination tests including the sampling and analysis
of all generated extracts. This section addresses these elements and was executed prior to the
decontamination testing.
3.6.1. Sampling methods
3.6.1.1. Surface wipe sampling and extraction of surface wipe samples
For surface sampling and wipe extraction efficacy tests, all test surfaces were spiked with target
chemicals using the procedure described in Section 3-4 and placed in the same type of pre-cleaned test
boxes that were used during the decontamination testing. After weathering of the chemical (CT = 30 min),
gauze-wipe (Dukal Honeywell North, 2" x2" 12-ply sterile cotton gauze pads; Fisher Scientific
Waltham, MA USA; P/N 17986468) samples were collected and extracted using procedures described in
Section 3.6.2.1. The initial wetting solvent used for the first round of sampling method development (Round
1) was isopropanol (IPA), and the volume used was 3 mL per wipe, resulting in the semi-saturation of the
wipe material. IPA was selected as a solvent as it would be compatible with painted surfaces. Post-sample
collection wipes were extracted in n-hexane and prepared for analysis as per Section 3.6.4. Each test set
consisted of three TCs complemented by one PB; there was one solvent blank (SB) and one control spike
(CS) sample per test day per chemical. Initial optimization of surface sampling was performed for materials
in the horizontal orientation only.
After the first round of surface wipe sampling tests, malathion and 2-CEPS extraction efficacy from
the galvanized metal was within project-specific acceptance criteria of 60-140% of theoretical surface target
(average recovery of 68% and 86%, as shown on Figures 3-8 and 3-9 below, for malathion and 2-CEPS,
respectively). The average recoveries of malathion from other materials ranged from nondetect (ND; <2.4%)
for painted concrete block to 46% (Figure 3-8) for painted concrete paver, and from below 1% (painted
concrete block) to less than 5% (painted concrete paver) for 2-CEPS (Figure 3-9).
13

-------
Method Development: Malathion Surface Sampling Recoveries

o
o
0)
	
V
o
03
M
k_
3
to
c
o
id
Q
100%
80%
60%
40%
20%
0%
~	Vinyl (Round 1)
~	Vinyl (Round 2)
~	Painted concrete block (Round 1)
~	Painted concrete block (Round 2)
~	Painted paver (Round 1)
~	Painted paver (Round 2)
~	Galvanized metal (Round 1)
~	Galvanized metal (Round 2)
28%
45%
>2.4%
4.7%
28%
78%
Material/Round of method development
Figure 3-8. Malathion surface recovery from surface sampling and extraction method tests Round 1
(patterned bars) and results for Round 2 (solid bars) for nongrimed materials.
Method Development: 2-CEPS Surface Sampling Recoveries
100%
80%
60%
40%
20%
0%
~	Vinyl (Round 1)
~Vinyl (Round 2)
~	Painted concrete block (Round 1)
~	Painted concrete block (Round 2)
~	Painted paver (Round 1)
~	Painted paver (Round 2)
~	Galvanized metal (Round 1)
~	Galvanized metal (Round 2)
2.6%
1.6%
0.5%
0.6%
1.9%
71%
Material/Round of method development
Figure 3-9. 2-CEPS surface recovery from surface sampling and extraction method optimization tests
(patterned bars) and results for optimized method (solid bars) for nongrimed coupons.
Based on these initial results, the sampling method was repeated by introduction of an additional
wiping medium (Cotton twill wipe, 4x4 in., MG Chemicals; Surrey, BC, Canada; P/N 829-4X4) for sampling
of all surfaces and the use of acetone instead of IRA as wetting solvent (Round 2). Cotton Twill wipes
14

-------
resulting from each coupon underwent composite extraction (i.e., placed in the same sample extraction jar
as the wipe and co-extracted together). The multiwipe method offered improved recovery of malathion from
challenging porous surfaces (5-45% across painted concrete materials), but no major improvement of 2-
CEPS recovery (less than 5% across vinyl and painted concrete surfaces). The 2-CEPS sampling method
could not be further optimized likely due to high permeation rates of 2-CEPS into these permeable
materials, even after only a 30-min contact time.
A similar improvement in changing from IPA to acetone as the wetting solvent was observed when
grimed surfaces were sampled. Figure 3-10 shows the wipe sampling recoveries for malathion from grimed
galvanized metal and vinyl.
100%
Method Development: Surface Sampling and Extraction:
Grimed galvanized metal (GGM) and grimed vinyl flooring (GVF)
80%
60%

o
CD 40%
01
20%
0%
73%
86%
11%
16%
GGM-IPA
GGM-ACE	GVF-IPA
Material/Solvent
GVF-ACE
Figure 3-10. Malathion surface recovery from surface sampling and extraction method tests Round 1
(isopropanol (IPA)) and results for Round 2 (acetone (ACE)) for grimed surfaces.
High recovery (>80%) of malathion from the grimed galvanized metal material was observed when
acetone was used as the wipe-wetting solvent. These results were comparable to the results for the
nongrimed galvanized metal, indicating that the presence of surface grime does not negatively affect the
performance of the sampling and analytical methods. However, wipe-sampling efficacies for the grimed vinyl
were noticeably lower (11-16%) than for nongrimed surfaces (28-45%). Based on the repeated
improvement for acetone, only acetone was verified as the wetting solvent for the wipe sampling of 2-CEPS
from grimed surfaces. Figure 3-11 shows that the average 2-CEPS recoveries were high (80%) for grimed
galvanized metal and below 5% (2.1 %) for grimed vinyl. Further surface sampling method development for
the grimed vinyl or other semi-porous and porous materials was beyond the scope of this study and was not
performed. Similarly, for nongrimed materials, low recoveries from these types of surfaces were attributed to
the permeation-related transport of chemicals into subsurface layers [9] despite the presence of a layer of
grime that could have made the surface effectively less permeable.
15

-------
Method Development: Surface Sampling and Extraction:
Grimed galvanized metal (GGM) and grimed vinyl flooring (GVF)

o
0
CD
01
100%
80%
60%
40%
20%
0%
80%
2.1%

GGM-ACE
GFV-ACE
Material/Solvent
Figure 3-11. 2-CEPS surface recovery from surface sampling and extraction method
tests using acetone as the wiping solvent for grimed surfaces; ACE - acetone.
3.6.1.2. Sampling and extraction of decontamination samples
Liquid sample characterization tests were designed to determine the volumes of effluents collected
for each of the three decontamination procedure steps (Step 1 pre-rinse; Step 2 decontamination; and Step
3 post-rinse). Concentration of the residual active ingredient (H2O2) was determined in liquid waste samples
from Step 2 and 3 of a simulated decontamination process (i.e., in the DF200 runoff and in the post-
decontamination water rinse runoff, respectively). This information was needed to determine the need for a
quenching of H2O2 and/or preservation of post-decontamination liquid waste (see Section 3.6.1.2.1 and
3.6.1.2.3 for details). H2O2 concentration in the liquid waste samples was measured via permanganate
(potassium permanganate, KMnCM) titration. The H2O2 concentrations were recorded only for the liquid
samples associated with the grimed surfaces. In addition, surface wipes were collected and extracted to
confirm that the extraction into a nonpolar solvent (hexane) is a satisfactory approach to halt further reaction
of residual decontaminant in the extract which may occur if most of the active ingredient, H2O2, remained in
the aqueous layer and not in the hexane layer containing the extracted chemical (see Section 3.6.1.2.2).
The method development test procedure started with the preparation and assessments of DF200
decontaminant and detergent-water solution (using procedures described in Section 3.5.1 and 3.5.2). Four
clean galvanized metal coupons (labeled A through D) were placed in vertical coupon holders and
positioned in clean test boxes used to secure test surfaces in the vertical orientation. Each box was
weighed, and the mass was recorded in the laboratory notebook. Spray bottles were filled with detergent-
water and DF200 solutions and pre-weighed. A pre-decontamination detergent solution rinse was first
applied to all four coupons (target application rate of 20  4 mL per coupon), and the post-application mass
of the spray bottle was recorded. After DT1 =30 min, each test box was weighed, and the results were
recorded in the laboratory notebook. The detergent-water rinse runoffs were then composited into clean
16

-------
beakers for pH and temperature measurements. After conclusion of Step 1, the decontamination solution
was applied to all four coupons (target application rate of 20  4 mL per coupon), and gravimetric
measurements were recorded. After DT2 = 60 min, each box was weighed, and the results were recorded.
Any changes in weight between the start and end of the decontamination application period (60 min) can be
attributed to decontamination solution evaporation losses. Coupon D was sampled using the wipe
procedure described in Section 3.6.1, and the wipe used was placed into hexane for immediate extraction.
The individual post-decontamination runoffs were composited into clean beakers for pH, temperature and
H2O2 concentration measurements. Lastly, the spraying procedure was repeated for the application of the
post-decontamination water rinse to coupons A through C, followed by 30 minutes of processing (DT3 = 30
min), and a final determination of pH, temperature and hydrogen peroxide concentration in the water rinse
composite sample. After completion of the entire effluent characterization procedure, liquid samples were
refrigerated for liquid-liquid extraction and decontamination efficacy of aqueous waste tests.
Figure 3-12 shows Steps 1 through 3 processing with the visible runoff of pre-decontamination
rinse, decontaminant, and post-decontamination rinse, respectively.
3-12. Runoff of pre-decontamination rinse (left), decontaminant (middle) and post-
decontamination rinse (right).
chemicals were applied during these method development tests. The results from this
of simulated liquid effluents from nongrimed surface testing are given in Tables 3-5 through
3-7.
Figure
No contaminant
characterization
17

-------
Table 3-5. Characterization of Liquid Effluents from Step 1 of Simulated Decontamination
Procedure
Coupon
Spray bottle
initial mass
Test box
initial
Spray bottle
final mass
Test box
final
Step 1
rinse
Mass of
runoff from
Composite sample
Measurements*
[g]
mass
[g]
[g]
mass
[g]
applied
[g]
Step 1
[g]
Mass
[g]
Volume
[mL]
T
[C]
PH
A
368.2
785
348.5
793
19.7
7




B
348.5
814
321.9
824
26.6
8.5
23.6
23.6
22.3
8.41
C
321.9
802
301.7
807
20.2
3.7
D
301.7
800
281.6
806
20.1
4.4




*composite sample collected from four coupons
Table 3-6. Characterization of Liquid Effluents from Step 2 of Simulated Decontamination
Procedure
Coupon
Spray
bottle
initial
mass
[g]
Test
box
initial
mass
[g]
Spray
bottle
final
mass
[g]
Test
box
final
mass
[g]
Step 2
decontaminant
applied
[g]
Mass
of
runoff
from
Step 2
[g]
A
254.7
799
234.5
807
20.2
3.9
B
234.3
810
214.6
820
19.7
7.2
C
214.5
784
194.3
791
20.2
4.7
D
194.2
799
173.2
808
21
6.8
Composite sample
Measurements*
Mass
[g]
Volume
[mL]
T
[C]
PH
H2O2
[%]
19.1
23.6
22.4
9.8
3.2
*composite sample collected from four coupons
Table 3-7. Characterization of Liquid Effluents from Step 3 of Simulated Decontamination
Procedure

Spray
bottle
Test
box
Spray
bottle
final mass
[g]
Test
box
Step 3
Mass of
runoff from
Step 1
[g]
Composite sample
Measurements*
Coupon
initial
mass
[g]
initial
mass
[g]
final
mass
[g]
applied
[g]
Mass
[g]
Volume
[mL]
T
[C]
PH
H2O2
[%]
A
439.2
784
418.9
791
20.3
5.1





B
418.9
785
398.8
792
20.1
5.7
15.5
15.5
21.7
9.9
0.20
C
398.8
806
379.8
813
19
4.7





*composite sample collected from three coupons
Measured weight gains in test boxes for each of the three steps are noticeably lower than the
weight of the applied spray volume. This difference can be explained by evaporative losses of the applied
liquid in any of the three steps and some spray volume that does not reach the surface. The relative weight
of the recovered liquids was 81 %, 66%, and 74% of the weight gain of the test boxes for Step 1, Step 2, and
Step 3, respectively. The H2O2 concentration in the Step 2 effluent (3.2%) is only slightly lower than the 4%
(or higher) concentration based on the Go/No-Go test that was conducted for this solution. The H2O2
concentration in the Step 3 effluent (0.2%) is significantly lower due to the dilution of decontaminant runoff
with the post-rinse water.
18

-------
3.6.1.2.1. Liquid-liquid extraction of aqueous waste
Liquid waste in this study was extracted using the modified extraction procedure described in EPA
SW-846 Method 3571 (Extraction of Solid and Aqueous Samples for Chemical Agents) [15], The method
recommends an extraction solvent of 10% IPA/dichloromethane that was replaced with 100% n-hexane.
Method performance with n-hexane was demonstrated to be equivalent to or better than the recommended
solvent using the simulated liquid waste samples collected in tests to characterize liquid effluents as described
in Section 3.6.1.2. The 0.5- to 0.6-mL aliquots of simulated liquid waste samples from Step 1 (pre-
decontamination detergent solution rinse) were spiked with malathion or 2-CEPS solutions prepared per
Section 3.4. The Step 1 effluents were chosen for the liquid-liquid extraction tests as they are representative
of the matrix but do not contain any decontaminant (i.e., they will not require quenching) but do contain
surfactants (detergent).
Two target concentrations were tested in these matrix spike samples (1% and 100% of the
maximum concentration) that could be expected in a composite sample of liquid waste, i.e., target
concentrations of 0.05 mg/mL and 5 mg/mL, respectively. There were six samples for each target chemical
and concentration combination, three with preservative added and three without preservative, accompanied
by one procedural blank (Step 1 liquid effluent aliquot that was not spiked). There was one solvent blank
sample (n-hexane) per test per chemical. The preservation of samples varied depending on the analyte:
1.	Six samples, three at 1 % and three at 100% for analysis of 2-CEPS, were preserved through
addition of 0.5 mL of glacial acetic acid/NaCI for each 0.5 mL of aqueous sample containing 2-
CEPS immediately after spiking. Acidic conditions (pH within a range of 3.5 to 5) are expected to
slow the decomposition rate of 2-CEPS like that of HD (hydrolysis to thiodiglycol and other
compounds). The presence of chloride ion would reduce the effects of metal cations. Six samples,
three at 1% concentration and three at 100% concentration, were prepared without preservatives.
In this study, preserved and unpreserved liquid samples were extracted with 5 mL of hexane
immediately after collection to avoid losses of target chemicals.
2.	Six samples, three at 1 % and three at 100% for analysis of malathion, were preserved with L-
ascorbic acid, ethylenediaminetetraacetic acid, and pH-adjusted with trisodium salt potassium
dihydrogen citrate to pH 3.8 to slow alkaline hydrolysis of malathion [16], Preserved samples were
each spiked with 30 |jL of concentrated L-ascorbic acid, ethylenediaminetetraacetic acid, and pH-
adjusted with trisodium salt potassium dihydrogen citrate solutions. Six samples, three at 1%
concentration and three at 100% concentration, were prepared without preservatives. In this study,
preserved and unpreserved liquid samples were extracted with 5 mL of hexane immediately after
collection to avoid losses of target chemicals.
Samples were prepared for analysis per Section 3.6.3. In addition, CS samples were prepared by direct
spiking of the chemical solution into hexane. Figure 3-13 shows the experimental scheme for the liquid
waste extraction optimization tests.
19

-------
Composite liquid waste
from Step 1
5 mL for <
blank
Split the remaining liquid
into 6 equal vials
m
Procedural
Blank
Split the remaining liquid into 4
equal vials
/M m
1 2 3 4 5 6 1 2 3 4
1 L
' *|jl
Malathion Malathion Malathion Malathion 2-CEPS 2-CEPS 2-CEPS 2-CEPS
Preserved* unpreserved Preserved* unpreserved preserved** unpreserved preserved** unpreserved
' L-Ascorbic acid+ethylenediaminetetraacetic acid+trisodium salt potassium dihydrogen citrate
' Glacial acetic acid+NaCI
(1)	V1 spiked with 100% malathion
to a target concentration of 5 mg/mL
(2)	V2 spiked with 1% malathion
to a target concentration of 0.05 mg/mL
(3)	V3 spiked with 100% 2-CEPS
to a target concentration of 5 mg/mL
(4)	V4 spiked with 1 % 2-CEPs
to a target concentration of 0.05 mg/mL
Each sample extracted
with 5 mL of hexane
Figure 3-13. Experimental scheme for liquid waste extraction tests.
20

-------
Results for the extraction of nonpreserved as compared to preserved liquid waste matrix spike
samples for malathion and 2-CEPS are shown in Figure 3-14.
CD
O
c
0
I
s
120%
100%
80%
60%
40%
15 20%
tt:
o%
~	100% concentration target - malathion (MA)
~	1% concentration target - malathion (MA)
~	100% concentration target - 2-CEPS
~	1% concentration target - 2-CEPS
MA _100%	MA_1%	2-CEPS _100% 2-CEPS _1%
Chemical/Target Concentration
Figure 3-14. Extraction of liquid waste containing detergent collected from nongrimed surfaces.
*: % ratio of recovery of malathion and 2-CEPS in nonpreserved versus preserved samples
collected from nongrimed surfaces.
The relative percent difference in recoveries of malathion and 2-CEPS between preserved and
nonpreserved liquid waste was less than 20%, while at least 80% of the amount of chemical (with a
coefficient of variance less than 30%) was recovered from all samples processed using the reference versus
modified method [15], Based on the relatively small (within experimental error) differences between
nonpreserved and preserved liquid waste samples, the modified method that did not include the
preservation step was deployed in the follow-on testing, including testing of grimed surfaces. Results from
the extraction efficacy testing of liquid samples collected from the grimed surfaces are shown in Figure 3-15.
21

-------
140%
~	100% concentration target - malathion (MA)
~	1% concentration target - malathion (MA)
~	100% concentration target - 2-CEPS
~	1% concentration target - 2-CEPS
100%
9- 80%
119%
114%
g>
2 40%
20%
MA _100%	MA_1%	2-CEPS _100% 2-CEPS_1%
Chemical / Target Concentration
Figure 3-15. Optimization of extraction of liquid waste containing detergent collected from
grimed surfaces. *: %ratio of recovery of malathion and 2-CEPS in nonpreserved samples
collected from grimed surfaces.
Recoveries from the spiked liquid waste from a grimed surface using the modified extraction
procedure without preservation step were found to be better than 80%, which indicated that any grime that
was present in the extract did not impact the analysis of the liquid waste. This procedure was therefore
deployed in the actual decontamination testing of nongrimed and grimed surfaces.
3.6.1.2.2. Verification of quenching of decontamination reaction in wipe extracts
Verification tests were performed to verify whether the use of a nonpolar wipe extraction solvent
(here, hexane) is a satisfactory approach to halt degradation of the contaminant in the wipe extract in the
presence of residual decontamination solution. This approach is based on the affinity of both malathion and
2-CEPS to move from an aqueous decontamination layer to the nonpolar solvent layer based on their high
log Kow values (see Table 3.3). These verification tests were solution-based tests (i.e., no coupon material
or wipe was present). For wipes, extracts were used from the Step 2 wipe sampling performed during waste
characterization tests described in Section 3.6.1.2. Six samples were generated (for each chemical-material
combination); three test vials (Vials 1 - 3) received 5 mL of wipe extract, three vials (Vials 4 - 6) received
solvent only (hexane). Wipe extracts were then spiked with chemical solutions corresponding to 100% of the
target chemical concentration on the coupon surface (Figure 3-16).
22

-------
5 mL of hexane
wipe extract
Wipe Extract from Step 2
5 mL of hexane
3
4 5 6	1 2 3 1 2
5 mL of hexane
\\\ ///\\\
4 5 6
\\\ /// \\\ ///
Spike with 200 uL of
2-CEPS solution
Spike with 200 uL of
malathion solution
Figure 3-16. Effect of decontamination solution in wipe extracts tests.
Samples were prepared for analysis per Section 3.6.3. In addition, CS samples were prepared by
direct spiking of chemical solution into hexane. Results from avoiding oxidant reaction in the
wipes through use of the nonpolar extraction solvent are summarized in Figure 3-17.
140%
120%
100%
S2
o
o
0
o:
40%
~	Spiked wipe extract - malathion
~	Solvent spike (no wipe extract) - malathion
~	Spiked wipe extract - 2-CEPS
~	Solvent spike (no wipe extract) - 2-CEPS
119%
108%
MA _WS	MA _SS 2-CEPS _WS 2-CEPS _SS
Chemical/Sample Type
Figure 3-17. Recovery of malathion and 2-CEPS from sampling wipe
containing residual DF200.
23

-------
Recovery of malathion and 2-CEPS in wipe extract matrix spikes (108  10%; relative standard
deviation (RSD) = 9% and 119  28%; RSD = 24%, respectively) was within QAPP acceptance criteria of 60
- 140% with an RSD less than 30%. Hence, the extraction-solvent-based avoidance of further reaction in a
sample by residual H2O2 present in the sampling wipes was considered sufficient. No additional chemical
quenching (e.g., through the addition of sodium thiosulfate [STS]) to the extract was required for these wipe
extracts.
3.6.1.2.3. Verification of quenching of decontamination reaction in liquid waste
The solution-based test approach used for the verification of quenching of decontamination solution
in liquid waste was similar to one described in Section 3.6.1.2.2 for wipes. The quenched and nonquenched
Step 2 liquid waste extracts were extracted using the procedure described in Section 3.6.3. Since the
amount of residual decontaminant was expected to be higher than in a wipe extract, the quenching tests
included samples that were extracted with and without an additional quenching chemical (here, STS). Six
test samples (for each chemical) were generated: three test vials (Vials 1 - 3) received extracts that were not
treated with STS, three vials (Vials 4 - 6) received extracts that were quenched with STS. All extracts were
then spiked with chemical solutions corresponding to 10% of the target chemical concentration on the
coupon surface, or the equivalent of 10% transfer to liquid waste (Figure 3-18). After spiking, all samples
were sonicated for 5 minutes and allowed to stand for 15 minutes, then prepared for analysis as per Section
3.6.3.
Composite liquid waste
from Step 2
For nonquenched
subset
5 mL of non-
quenched
sample
Spike with 10 uL
of 2-CEPS solution
For subset quenched
with STS
5 mL of sample
quenched with STS
/II \\\
4 5 6
4 5 6
/// \\\
Spike with 10 uL
of malathion solution
Spike with 10 uL
of 2-CEPS solution
Spike with 10 uL
of malathion solution
Figure 3-18. Effect of decontamination solution in liquid waste tests.
24

-------
In addition, CS samples were prepared by direct spiking of chemical solution into hexane. Results from
these experiments of the liquid waste are shown in Figure 3-19.
140% t
120%
100%
>
o
o
0
01
80%
60%
40%
20%
0%
~	Extraction solvent quench - malathion
~	STS quench - malathion
~	Extraction solvent quench - 2-CEPS
~	STS quench - 2-CEPS
102%
115%
129%
MA_ESN	MA _STS 2-CEPS _ESN 2-CEPS _STS
Chemical/Quench Type
Figure 3-19. Recovery of malathion and 2-CEPS from DF200 runoff using extraction solvent only
(ESN) and extraction solvent with sodium thiosulfate (STS).
Recoveries of malathion and 2-CEPS in the Step 2 liquid waste (or DF200 runoff) without STS (i.e.,
extraction solvent only) were 86  12% (RSD = 14%) and 115  17% (RSD = 15%), respectively. The
relative % difference between the two types of sample preparation processes was less than 20% and met
the quality assurance (QA) criteria of at least 80% of the amount of chemical (with RSD less than 30%)
recovered in solvent-only extracted liquid waste samples, versus the same liquid waste samples that
underwent quenching with the STS addition step. The addition of STS did improve the recoveries
somewhat. However, the objective to recover at least 80% of the spiked solution was met without the use of
STS as an additional quenching agent. Therefore, the STS quenching agent was not included in the final
procedure of the waste extraction. All waste samples were immediately extracted, followed by sonication
and separation of organic extracts from post-extraction aqueous layer of the final sample.
3.6.2. Decontamination process design for horizontal and vertical coupon testing
After completion of the method development tests, a multiple group material- and orientation-
specific decontamination process/experimental design was used for each test. This process for horizontal
and vertical surface decontamination testing is shown in Figures 3-20 and 3-21, respectively. Each
decontamination test was accompanied by the collection of reference (nondecontaminated) positive
controls. The process design that was used for testing of PC coupons is shown in Figure 3-22. The
implemented sampling and extraction methods for surface wipes and liquid waste are summarized in
Section 3.6.2.1 and 3.6.2.2.
25

-------
TC-1
Horizontal Coupon
Decontamination
Testing
Apply 20 mL of pre-
decontamination water-detergent
rinse, allow processing; DT= 30min
Apply 20 mL of decontamination
solution, EasyDECON DF200;
allow processing; DT= 60min
Apply 20 mL of post-
decontamination rinse, Dl water,
DT= 30min
Surface wipe sampling with
cotton gauze wipe (twice), followed by
cotton twill wipe for each coupon
Add 50 mL of
hexane to
extraction jars
	H
	I
w
IT"
|
W
PB11^1
T
 I
~
E53

I
I


~

m
~

I
I
t
~

m
m

m

&
&

&

0
Q

o
x
Q
x
~
s
~
0
~
0
~

I
I
Step 1. Spike coupon
with 20-10 uL of chemical solution (500
mg/mLmalathionor 2-CEPS in ethanol
Step 2. Application of pre-
decontamination rinse step (detergent-
water solution).
Step 3. Application of decontamination
solution
I
I
I
Step 4. Application of post-
decontamination rinse step.
Step 5. Wipe dry TCs with 2 cotton
gauze wipes (to remove excess
decontaminant).
Then sample the surface with 1 cotton
twill wipe wetted with 3 mL of solvent
Step 6. Place all three wipes in 60 mL
jar. Add 50mL of hexane and sonicate
for 15 min. Transfer sample to storage
vial.
Figure 3-20. Sample process design for horizontal coupon decontamination testing.
26

-------
TC-1
Vertical Coupon
Decontamination
Testing
Apply 20 mL of pre-
decontamination water-detergent
rinse, allow processing; DT=
30min; collect liquid run-off
Apply 20 mL of decontamination
solution, EasyDECON DF200;
allow processing; DT= 60min;
collect liquid run-off
Apply 20 mLof post-
decontamination rinse, Dl water,
DT= 30min; collect run-off
Surface wipe sampling with
cotton twill wipe (twice) for each coupon
Add 50 mL of
hexanes to
extraction jars

1 1

1

~

P P
p
w
m it
it
m
B



M

&
&
O D
x x
Q
x
1 0
x
~ t
 0 0
t
0
t
0
I
I
I
I
I
Step 1. Spike coupon
with 20- 10 uL of chemical solution (500
mg/mL malathion or 2-CEPS in ethanol
Step 2. Application of pre-
decontamination rinse step (detergent-
water solution). Collection of liquid run-off
from Step 2 (composite)
Step 3. Applicationof decontamination
solution. Collection of liquid run-off from
Step 3 (composite)
Step 4. Applicationof post-
decontamination rinse step. Collection of
liquid run-off from Step 4 (composite)
Step 5. Wipe dry TCs with 2 cotton
gauze wipes (to remove excess
decontaminant).
Then sample the surface with 1 cotton
twill wipe wetted with 3 mL of solvent
Step 6. Place all three wipes in 60 mL
jar. Add 50mL of hexane and sonicate
for 15 min. Transfer sample to storage
vial.
Figure 3-21. Sample process design for vertical coupon decontamination testing.
27

-------
Positive Controls
PC-1
* *
I I
Cotton twill wipe
(twice) per coupon
Add 50 mL of hexane
to extraction jars
itit Jtit Itlt
I
Step 1. Spike coupon
with 20-10 uL of chemical solution (500 mg/mL
malathion or2-CEPS in ethanol
Step 2. Wipe PCs with cotton twill wipes
wetted with 3 mL of solvent (2 wipes)
Step 3. Place twill wipes in 60mL jars. Add
50mL of hexane and sonicate for 15 min.
Transfer sample to storage vial
Figure 3-22. Sample process design for positive control testing.
28

-------
3.6.2.1. Surface sampling and extraction methods
Table 3-8 summarizes test parameters for wipe sampling and extraction methods for all material-
test-orientation combinations. Test parameters were identical for tests with malathion- or 2-CEPS-
contaminated materials. Table 3-8 includes types of wiping media, wetting solvents, and amount of wetting
solvents for all material-orientation combinations that were used for collection of pre- and post-
decontamination surface wipe samples. Wipe sampling methods were optimized prior to testing as
described in Section 3.6.1.1. The surface wipe sampling of each coupon was a multistep process involving
two to three wipes per coupon:
for horizontal-test-orientation materials, two cotton gauze wipes were used first to remove
excess liquid decontaminant that did not run off or dry out. After collection of two cotton gauze
samples, a final cotton twill wipe was deployed across the same material;
for vertical materials and all positive controls, two twill wipes were deployed on each coupon.
Table 3-8. Surface Sampling Parameters for Malathion and 2-CEPS
Material
Wipe
Number of
wipes per
coupon
Wetting
Solvent
Wetting
Solvent
Volume per
Wipe
Extraction
Solvent
Galvanized metal [horizontal,
decontaminated]
Cotton
gauze/Cotton twill
wipe
2/1
None/Acetone
0/3 mL
Hexane
Galvanized metal [horizontal,
nondecontaminated]
Cotton twill wipe
2
Acetone
3 mL
Hexane
Galvanized metal [vertical,
decontaminated]
Cotton twill wipe
2
Acetone
3 mL
Hexane
Painted [sealed] concrete flooring
[horizontal, decontaminated]
Cotton
gauze/Cotton twill
wipe
2/1
None/Acetone
0/3 mL
Hexane
Painted [sealed] concrete flooring
[horizontal, nondecontaminated]
Cotton twill wipe
2
Acetone
3 mL
Hexane
Painted [sealed] concrete block
[vertical, contaminated and
nondecontaminated]
Cotton twill wipe
2
Acetone
3 mL
Hexane
Vinyl [horizontal, decontaminated]
Cotton
gauze/Cotton twill
wipe
2/1
None/Acetone
0/3 mL
Hexane
Vinyl [horizontal,
nondecontaminated]
Cotton twill wipe
2
Acetone
3 mL
Hexane
29

-------
Each surface wipe sampling used a four-step process consisting of a series of horizontal, vertical,
diagonal and perimeter wiping strokes, in which the wipe was folded over after each step (with contaminated
side always inward). A detailed procedure is shown in Appendix C. Figures 3-23 and 3-24 show examples
of the wipe sampling of horizontal and vertical materials, respectively .
Figure 3-23. Example of surface wipe sampling in horizontal orientation (left - cotton gauze sampling of
galvanized metal; right - the follow-on cotton twill wipe sampling of galvanized metal)
Figure 3-24. Example of surface wipe sampling in vertical orientation (left - cotton twill wipe sampling of
galvanized metal; right - cotton twill wipe sampling of painted concrete block)
After completion of sampling, wipes resulting from each coupon were placed in pre-cleaned 60- or
120-mL wide-mouth extraction jars with polytetrafluoroethylene (PTFE)-lined lids (Thermo Fisher Scientific
Inc., Waltham, MA; P/N 240-0060 and P/N 240-0120, respectively). Each jar received 50 mL of n-hexane,
capped, and transferred to a sonicator. Wipe samples were extracted via sonication for 15 minutes. After
extraction was completed, a 15-mL aliquot of extract was transferred to a 20-mL glass vial and refrigerated
at 4  2C for further processing. The remainder of the sample extracts was discarded. Sample preparation
for instrumental analysis is described in Section 3.6.3.
3.6.2.2. Liquid waste sampling and extraction procedures
Liquid waste (runoff) extraction, preservation, and quenching methods for dealing with residual
oxidant were optimized prior to testing as described in Section 3.6.1.2. Malathion and 2-CEPS were
extracted from liquid waste samples using a simplified liquid-liquid extraction procedure that did not include
preservation or quenching of the decontaminant active ingredient (hydrogen peroxide), as solvent extraction
(with no preservation of sample) was proven efficacious during method development tests. After the
determination of the waste volume for each type of collected runoff, liquid waste samples were transferred
to clean extraction vials and an equal volume of hexane was added to each sample (1:1 v/v liquid
waste:hexane). Additionally, 25 grams of sodium chloride was added to the detergent-water runoff samples
from Step 1 to salt-out the soap from the solution. Each sample was manually shaken for one minute. After
30

-------
the aqueous and hexane layer separated, the entire hexane layer was carefully collected using a Pasteur
pipette (KIMBLE Disposable Borosilicate Pasteur Pipet Unplugged, 9 in; DWK Life Sciences, LLC,
Rockwood, TN; P/N 63B92) into a 15-mL graduated test tube, and the total extract volume was recorded.
One (1) mL of hexane extract was then transferred into a 1,8-mL amber glass screw top GC vial (Thermo
Scientific GC vial, PTFE/Silicone/PTFE septum, Thermo Fisher Scientific Inc., Waltham, MA; P/N
C5000188W). Samples were then refrigerated prior to shipment to the subcontracting laboratory or transfer
to onsite analytical laboratory for analysis. In addition, a 10-mL aliquot of the remaining extract was
transferred to a 12-mL vial and archived at 4  2C. Sample preparation for instrumental analysis is
described in Section 3.6.3.
3.6.3.	Preparation of extracts for analysis
Extracts generated from the extraction of wipes and liquid waste were prepared for analysis in 1,8-
mL amber glass autosampler vials. The concentration of chemicals in the raw extract was expected to be
approximately 2,000 jjg/mL. The detection limit for GC/MS analysis of these two compounds was expected
to be 1 jjg/mL with a dynamic calibration range of 1 - 100 jjg/mL. Based on surface sampling recovery
established in method development tests, PC extracts from galvanized metal tests underwent a 20-fold
dilution - a 50-|jL aliquot of raw extract was drawn using an appropriate size micropipette (Eppendorf AG,
Hamburg, Germany) and added to a GC vial filled with 950 |jL of hexane. The control spike samples were
also diluted 20-fold. Other extracts (PCs from nonreference material, all decontaminated TCs, blanks, and
liquid waste extracts) were submitted to the subcontracting laboratory as is - a 1000-|jL aliquot of sample
was drawn from each extract using an electronic pipette and added to the GC vial. If analytical results were
outside the calibration range, the laboratory performed necessary dilutions and reported dilution factors
along with QC data packages. The samples were refrigerated at 4  2C or below prior to shipment. All
shipments were accompanied by the chain of custody (COC) form and were inspected by the analytical
laboratory upon receipt.
3.6.4.	Instrumental analysis
Instrumental analyses were performed by the subcontracted analytical laboratory (EMSL Analytical,
Inc.; Cinnaminson, NJ, USA) using modified National Institute for Occupational Safety and Health (NIOSH)
Method 5600 [17] or by the EPA Organic Support Laboratory (OSL). EMSL analyzed samples that were
generated with nongrimed coupons while OSL analyzed samples related to the grimed surface studies.
These tests were completed in chronological order with no overlap in analyses by both laboratories on the
same extract.
Sample extracts were analyzed by means of GC/MS. Malathion was detected with ions 93,125 and
173 (quantitation with ion m/z 173). 2-CEPS was detected with ions m/z 123 and m/z 172 (quantitation with
ion m/z 123). The instrumental parameters and conditions for GC/MS analyses for both analytes are given
in Tables 3-9 through 3-12.
31

-------
Table 3-9. Instrumental Parameters and Conditions for GC/MS Analyses of Malathion by EMSL
Analytical, Inc.
Parameter
Description/Conditions
Instrument
Agilent 6890 Gas Chromatograph equipped with Agilent 5973 Mass Selective
Detector (Agilent Technologies, Santa Clara, CA, USA)
Autosampler
Agilent 7683 Automatic Sampler (Agilent Technologies, Santa Clara, CA, USA)
Column
Rtx-5Sil MS w/5 m Integra-Guard column, 30 m* 0.25 mm I.D., 0.25 |jm df; part
no. 13623-124 (Restek Corporation, Bellefonte, PA, USA)
GC column program
100C initial temperature, hold 0 min, 15C/min to 250C, hold 5 min
Carrier gas flow rate
1.0 mL/min (helium)
Injection volume/type
1.0 [jL/splitless
Inlet temperature
250C
MS quad temperature
150C
MS source temperature
230C
MS transfer line
270C
Solvent delay
4 min
df: film thickness
Table 3-10. Instrumental Parameters and Conditions for GC/MS Analyses of 2-CEPS by EMSL
Analytical, Inc.
Parameter
Description/Conditions
Instrument
Agilent 6890 Gas Chromatograph equipped with Agilent 5973 Mass Selective
Detector (Agilent Technologies, Santa Clara, CA, USA)
Autosampler
Agilent 7683 Automatic Sampler (Agilent Technologies, Santa Clara, CA, USA)
Column
Rtx-MS5 column, 30 m* 0.32 mm I.D., 0.50 |jm df; part no. 13439 (Restek
Corporation, Bellefonte, PA, USA)
GC column program
100C initial temperature, hold 0 min, 15C/min to 25 C, hold 5 min
Carrier gas flow rate
1.0 mL/min (helium)
Injection volume/type
1.0 [jL/splitless
Inlet temperature
225C
MS quad temperature
150C
MS source temperature
230C
MS transfer line
270C
Solvent delay
4 min
df: film thickness
32

-------
Table 3-11. GC/MS Parameters for Analysis of Malathion by OSL
Parameter
Description/Conditions
Instrument
Thermo Trace 1300 Gas Chromatograph GC ISQ Mass Spectrometer (Thermo
Fisher Scientific, Inc., Waltham, MA)
Autosampler
AS/AI 1310 Autosampler (Thermo Fisher Scientific, Inc., Waltham, MA)
Column
DB-5, 20 m x 0.25 mm ID, 0.25 |jm df (Agilent, Santa Clara, CA)
GC column program
60 C initial temperature, hold 0 min, 8 C/min to 260 C, hold 8 min
Carrier gas flow rate
1.3 mL/min (helium)
Injection volume/type
1.0 [jL/splitless
Inlet temperature
250 C
MS source temperature
250 C
MS transfer line
250 C
df: film thickness
Table 3-12. GC/MS Parameters for Analysis of 2-CEPS by OSL
Parameter
Description/Conditions
Instrument
Thermo Trace 1300 Gas Chromatograph GC ISQ Mass Spectrometer (Thermo
Fisher Scientific, Inc., Waltham, MA)
Autosampler
AS/AI 1310 Autosampler (Thermo Fisher Scientific, Inc., Waltham, MA)
Column
DB-5, 20 m x 0.25 mm ID, 0.25 |jm df (Agilent, Santa Clara, CA)
GC column program
60 C initial temperature, hold 0 min, 8 C/min to 260 C, hold 8 min
Carrier gas flow rate
1.3 mL/min (helium)
Injection volume/type
1.0 [jL/splitless
Inlet temperature
250 C
MS source temperature
250 C
MS transfer line
250 C
df: film thickness
33

-------
The calibration range for EMSL was 1-100 jjg/mL for both analytes; a 7-point nonlinear (no
weighting) calibration curve (1-10-20-40-60-80-100 jjg/mL) was used for initial calibration, with reporting limit
verification (RLV) and initial calibration verification (ICV) analyses performed at lowest and mid-calibration
level, respectively, prior to each analytical run. ESML restricted the concentration range of the calibration
curve to less than 7 points, when applicable, to obtain a linear response. Additionally, analysis of laboratory
control sample (LCS) and laboratory control sample duplicate (LCSD) was performed prior to each
analytical run. A continuous calibration standard at mid-concentration level was analyzed every ten
samples, with calibration end check performed at the end of each analytical run. Additional QC samples
included duplicate injections of test samples and analysis of laboratory blanks. Samples with results below
the lowest calibration point (i.e., 1 jjg/mL) were reported as less than the quantitation limit (0.995). The continuous calibration verification was performed using a mid-
concentration calibration standard, that is, approximately every 10 test samples and at the end of the
analytical run, with an acceptance control limit of 80-120% of the ICAL concentration. If QC criteria were not
met, the instrument was recalibrated, and any affected samples were reanalyzed. Additional QC samples
included duplicates of test samples (one duplicate per analytical run; acceptance criteria: relative percent
difference (RPD) <20%) and analysis of blanks (PB, laboratory blank [LB], and laboratory solvent blank
[LSB]).
34

-------
Prior to testing, an initial laboratory proficiency evaluation was performed by both analytical
laboratories. Accuracy and precision were determined by analysis of multiple measurements of control spike
solutions at concentrations corresponding to 100% and 10% of chemical amount applied to test materials (n
= 3 to 5 for each concentration level; single analytical run).
Two sets of control spike samples were generated by spiking the same amount of chemical solution
(200 |jl_) as used during the decontamination testing directly into the extraction solvent. All control spikes
were sonicated for 10 minutes and then diluted as needed per Section 3.6.3 for one set and with an
additional ten-fold dilution to create a 10% level control spike as the second set. Each control spike set was
accompanied by one solvent blank sample (1 mL of n-hexane used for extraction and preparation of
samples for analysis). These control spike experiments were used as independent verifications of the
results obtained from the outside chemical analysis laboratory. The laboratory proficiency results are listed
in Table 3-14.
Table 3-14. Laboratory Proficiency Results


Spike Control A
Spike Control B

Target Chemical
Laboratory
100% Target
Concentration,
*
No Coupon ;n=3 to 5
10% Target
Concentration,
No Coupon*; n=3 to 5
Solvent
Blank


Accuracy and precision

Malathion (initial)
EMSL
95  2.5%; RSD = 3%
80  3.1% SD; RSD = 4%

-------
analytical measurement and good results of analysis of control samples prepared by the subcontracting
laboratory (accuracy for LCS/LCSD at mid-point concentration was 95% and 96% of true value,
respectively; RSD <1%; data not shown); the follow-on analyses of continuing QC checks of CS samples
prepared along with 2-CEPS decontamination samples from this study have shown both high accuracy and
precision of analytical measurement by both laboratories.
3.7. Data Reduction Procedures
3.7.1.	Chemical concentration in extract calculations
The GC/MS concentration results (|jg/mL) were converted to total mass of chemical per sample (mg
per sample) by multiplying by the extraction solvent volume and dilution factor (if applicable):
Ms = Cs x Ve x DfxIOOO
where:
Ms: mass of chemical in sample (mg)
Cs: concentration (|jg/mL) from an individual replicate sample
Ve: extraction solvent volume (mL)
Df: sample dilution factor prior to analysis (if any)
The percent recovery of chemical from QC samples (e.g., control spikes) was calculated against
theoretical chemical amount spiked into solution:
%Rqc = Cqc/(Vsp x Sc/Vt/Df) x 100%
where:
%Rqc: percent recovery for an individual QC sample (versus theoretical)
Cqc: concentration (|jg/mL) from an individual replicate QC sample
Vsp: volume of spike (mL)
Sc: concentration of chemical in spiking solution (500 mg/mL or 50 mg/mL)
Vt: total sample volume (mL)
Df: sample dilution factor prior to analysis (if any)
The sample concentration (Ms) results used for decontamination efficacy calculations (as described
in Section 3.5.2.) were not adjusted for QC sample recovery (%Rqc).
3.7.2.	Decontamination cleanup efficacy calculations
36

-------
The decontamination cleanup efficacy was calculated using the mean of chemical mass recovered
from the replicate test coupons (TCs) and the mean chemical mass recovered from the associated set of
positive control (PC) coupons.
DE = (1-xTCn/xPCn)*100
where:
DE - mean decontamination efficacy (%)
xTCn - mean of chemical amount remaining on replicate TC (decontaminated) coupons (mg)
xPCn- mean of chemical amount remaining on replicate PC (nondecontaminated) coupons (mg)
The mean decontamination efficacy along with the standard deviation was a cumulative
decontamination efficacy (or resulting from application of all three procedural steps for each test). The
standard deviation of the efficacy was calculated by propagation of error using the standard deviation of the
average mass of agent remaining on the test coupons and on the positive control coupons. If the average
mass of remaining agent on the test coupon was found to be below the LOQ, the efficacy was calculated
using the LOQ value and reported as "greater than" this calculated value.
4. Results
4.1. Surface Decontamination Tests
4.1.1. Nongrimed coupons
37

-------
Residual malathion and 2-CEPS surface contamination on different materials before and after
treatment with the multi-step decontamination procedure is shown in Figure 4-1 for nongrimed surfaces.
Test-specific results including overall decontamination efficacy (DE) are given in Table 4-1.
120-
100-
80-
o> 60'
E 40-
w
w
ro
20-
0-
113
30.8
33.4
113
Malathion
Test Coupon
Positive Control
35.8
s

r-
1
45.7

41.7
47.3
TD
CD
!	
0
> 80'
o
 60-
40-
20-
0-
GM-H
B
72.7
37.2
GM-V
VF-H
PC-H
PC-V
72.7
2-CEPS

Test Coupon

Positive Control
GM-H	GM-V	VF-H	PC-H
Material/Coupon Orientation
PC-V
Figure 4-1. Recovered mass of (A) malathion and (B) 2-CEPS from test coupons and positive
controls on nongrimed surfaces: GM-H, VF-H, PC-H: galvanized metal, vinyl tile, and painted
concrete paver (tested in horizontal orientation); GM-V, PC-V: galvanized metal, and painted
concrete block (tested in vertical orientation).
For malathion, the theoretical mass spiked was 100 mg per coupon (Section 3.4). Recoveries for
positive controls (not decontaminated coupons) exceeded the minimum requirement of 70% recovery for
galvanized metal only. After a 120-min contact time between malathion and vinyl and painted concrete, a
significant amount of malathion appears to permeate into the vinyl/paint layer. This permeation may have
been enhanced using ethanol in the application of malathion. The surface wipe sampling does not efficiently
collect malathion that has permeated into these sublayers, leading to lower recoveries. The same
observation can be made for 2-CEPS, namely, only the surface wipe sampling of galvanized metal resulted
in high (>70%) recoveries. As for malathion, the theoretical 2-CEPS mass spiked was 100 mg per coupon
(Section 3.4). Recoveries for positive controls from vinyl and painted concrete are even lower than observed
for malathion.
38

-------
Table 4-1. Material- and -Orientation-Specific Decontamination Test Results of Nongrimed Materials for Malathion and 2-CEPS
Material-
Type
Material
Orientation

Decontaminated
Coupons
Positive Controls
Procedural
Blank
Decontamination
Efficacy, DE
ID
Mean
SD
RSD
Mean
SD
RSD





mg/coupon

mg/coupon

mg/coupon
%
SD
Malathion
Galvanized metal
Horizontal
1M
31
11
34%
113
5.8
5.1%
<0.05
73
25
Galvanized metal
Vertical
2M
33
8.5
25%
113
5.8
5.1%
<0.05
70
18
Vinyl flooring
Horizontal
3M
36
10
29%
46
2.9
6.4%
<0.05
22
6.4
Sealed concrete [paver]
Horizontal
4M
42
6.8
16%
47
11
24%
<0.05
12
3.4
Sealed concrete [cinder
block]
Vertical
5M
2.6
0.18
7%
4.7
0.46
10%
<0.05
45
5.4
2-CEPS
Galvanized metal
Horizontal
1C
37
12
31%
73
2.1
2.9%
<0.05
49
15
Galvanized metal
Vertical
2C
<0.05 (UJ-)
NA
NA
73
2.1
2.9%
<0.05
>99.9 (J+)*
2.9
Vinyl flooring
Horizontal
3C
2.1
0.25
12%
1.6
0.33
20%
<0.05
no decon
NA
Sealed concrete [paver]
Horizontal
4C
4.0
0.07
2%
4.2
0.13
3%
<0.05
6.3
0.2
Sealed concrete [concrete
block]
Horizontal
5C
0.63
0.21
33%
0.75
0.0
0%
<0.05
16
5.2
(UJ-) samples were reported at 
-------
The most effective decontamination for both chemicals was observed on the nonporous galvanized
metal surfaces (Table 4-1). Figure 4-2 shows an example of a galvanized metal coupon contaminated with
2-CEPS after application of the Step 1 water-detergent rinse, with a distinct (oily droplet) contamination
pattern of 2-CEPS still visible.
Figure 4-2. Galvanized metal coupon contaminated with 2-CEPS after application of the Step 1 water-
detergent rinse.
The material orientation was not a statistically significant factor in the decontamination (at
confidence level of 95%; Student's t-test) of malathion-contaminated galvanized metal (no grime present).
For painted concrete, efficacy values for the vertical orientation were higher than for the horizontally
positioned painted concrete. However, recoveries from painted surfaces were poor (both for horizontal and
vertical orientation painted concrete), leading to some ambiguity of the efficacy value.
For 2-CEPS, the vertically positioned galvanized metal had surface DE >99.9% compared to an
average of 49% DE for galvanized metal tested in horizontal position, possibly due to the characteristic of 2-
CEPS post-weathering that appears as oily small droplets on galvanized metal material surface (Figure 4-3),
as opposed to completely dried-out malathion (Figure 3-3 in Section 3.2). After turning the coupon to the
vertical orientation, a partial runoff of spiking solution/chemical contamination was observed (Figure 4-3),
leading to a larger localized contaminated area at lower localized surface concentrations.
Figure 4-3. 2-CEPS droplets on horizontal coupons and runoff of chemical contamination after turning
galvanized metal in vertical orientation (30 minutes post-spiking).
The distribution of discrete droplets into a chemical film could have been more prone to chemical reaction
during decontamination. Analytical data and decontamination efficacy results for tests in which the residual
agent was below the limit of quantification are flagged as appropriate in Table 4-1.
40

-------
For semi-porous and porous materials, the maximum DE was 45  5.4%, observed for the
malathion test on the painted concrete block (Table 4-1). For tests using materials other than nongalvanized
metal, the computed DE was <16%, and differences between the chemical loading before- and post-
decontamination were not statistically significant (at the 95% confidence level; Student's t-test), most likely
due to inherent permeability of vinyl and painted concrete materials causing migration of chemicals [spiked
as ethanol solutions] into deeper layers of those materials. Such a migration could deter both
decontamination and surface (wipe-based) sampling effectiveness. A recent study [9] suggests that CWAs
permeate into painted/sealed porous materials at significant rates, e.g., sulfur mustard (HD) can quickly
migrate through latex semigloss paints, with less than 20% of initial concentration detected by wipe-based
surface sampling within 3 hours after spiking, and 70% confirmed to be retained in the paint layer and
another 10% retained in the underlying porous material simulant, SPE disk. Authors have also suggested
that different types of paint layer and/or underlying porous material can serve as a potential chemical
reservoir, creating potential for diffusive transport of chemicals back to the surface. This observation is in
line with the lower surface recovery of target chemicals observed in this study for positive controls of vinyl
and painted concrete materials (as compared to galvanized metal). A similar study was recently performed
for malathion [19], with surface concentration of neat chemical reduced by approximately 20% after 3 hours
(post spiking), due to transfer to paint and underlying porous material simulant. It is then plausible that a
small fraction of chemicals, especially 2-CEPS, was potentially inaccessible to decontamination on vinyl and
painted/sealed concrete coupons, due to into-the-material transfer ("in-transfer").
4.1.2. Grimed coupons
Decontamination testing of grimed materials was limited to galvanized metal only. Figure 4.4 shows
the recovered amounts of malathion (A) and 2-CEPS (B) after the three-step decontamination process.
T3

o
o
a)
Q1
120-
100-
80-
60-
40-
20-
0-
120-j
100-
80-
60-
40-
20-
0-
B
77
Malathion
I | Test Coupon
I I Positive Control
0.36
84
48
82
0.049
82
60
GGM-H GGM-V
GGM-H1
GGM-V1
GGM-H2

i

E

98

98
0.32

0.05

2-CEPS
I | Test Coupon
I I Positive Control
H1, V1, H2: No tests conducted
i	1	1	1	1
GGM-H GGM-V
Material/Coupon Orientation
Figure 4-4. Recovered mass of (A) malathion and (B) 2-CEPS from test coupons and positive
controls on grimed surfaces: GGM-H, H1, H2: galvanized metal (tested in horizontal orientation);
GGM-V: galvanized metal (tested in vertical orientation).
41

-------
Test-specific results including overall DE are provided in Table 4-2. For malathion, the decontamination
tests included two modifications to the decontamination procedure. The first modification was to use the
decontaminant solution DF200 as the first "pre-rinse" step instead of the detergent and water solution. The
second modification was an approach to collect liquid waste residing on the horizontal surface by skimming
of the excessive liquid from the surface as described in Section 3.5.3. Recoveries from grimed positive
controls were, in general, high (>70% of the theoretical 100 mg applied) for malathion. Note that one set of
positive controls was shared for both horizontal and vertical test conditions for the first modified testing and
appears therefore twice in Figure 4-4. Recoveries from positive controls were not expected to have been
different based on orientation of the nonporous galvanized metal coupon. The recovery for the positive
control associated with the second decontamination procedure modification was only 60%. No evidence
was found for any deviation from normal procedures that would explain this lower recovery.
42

-------
Table 4-2. Material- and Orientation- Specific Decontamination Test Results of Grimed Materials for Malathion and 2-CEPS
Material-
Material
ID
Decon
Decontaminated Coupons
Positive Controls
Procedural
Blank
Decontc
r
Efficai
minatio
5V, DE
Type
Orientation
method
Mean
SD
RSD
Mean
SD
RSD






mg/coupon
mg/coupon

mg/coupon
%
SD
Malathion
Grimed galvanized
metal
Horizontal
6M
UM
39
10
26%
77
2.0
2.6%
<0.05
50
13
Grimed galvanized
metal
Vertical
7M
UM
0.36 (J)
0.15
36%
84
3.0
3.6%
<0.05
>99.5
0.4
Grimed galvanized
metal
Horizontal
8M
Modi
48
1.8
3.7%
82
1.6
2.0
<0.05
41
1.7
Grimed galvanized
metal
Vertical
9M
Modi
0.049 (J)
0.0012
2.1%
<0.05
>99.94
0.002
Grimed galvanized
metal
Horizontal
10M
Mod2
0.80 (J)
0.66
8.3%
60
5.0
8.3
<0.05
>98.7
1.1
Grimed galvanized
metal
Horizontal
11M
Mod2A
0.085 (J)
0.074
85%
<0.05
>99.2
0.007
2-CEPS


Grimed galvanized
metal
Horizontal
6C
UM
0.32
0.076
24%
98
2.7
2.7%
<0.05
99.7
0.078
Grimed galvanized
metal
Vertical
7C
UM
<0.05
NA
NA
<0.05
>99.94
NA
UM
unmodified method, Modi- modified method 1; Mod2 - modified method 2; Mod2A - modified method 2A
(J) estimated results reported below LOQ
Legend:
Statistically significant reduction of chemical surface loading for decontaminated versus nondecontaminated coupons (p<0.05; Student's t-test)
43

-------
The calculated DE for malathion from the grimed galvanized metal appeared to be strongly
dependent on the orientation of the coupon. Whereas minimal malathion was found on the vertically
positioned coupon after the three-step decontamination procedure, a significant amount (39 mg) was found
in the wipe of the horizontal surface. One significant difference is that the vertically oriented surface had
minimal liquid remaining on the surface when wiped due to the gravitational pull on the liquid. The horizontal
coupons still had a significant amount of liquid on the surface, which became part of the wipe sample.
Hence, residual malathion that is dissolved in the liquid on the surface is included in the recovered amount
of malathion from a horizontal surface. The pre-rinse step of the coupon in the vertical position also reduced
the chemical loading somewhat based on the presence of malathion in the liquid waste of this first step
(approximately 8% of applied amount; see Section 4.2).
The modification in the three-step procedure to replace the detergent-water solution with the actual
decontaminant DF200 did not make a significant difference in overall decontamination efficacy; recoveries in
the horizontal orientation remained moderately high leading (39 mg recovered when using a detergent-
water pre-rinse vs 48 mg when using a DF2000 pre-rinse). With the galvanized metal in the vertical position,
residual malathion on the vertical coupon was significantly less and just slightly above or at the limit of
quantification for malathion. The second modification (Tests 10M and 11M) to the three-step
decontamination procedure which included a skimming of the liquid from the surface prior to wipe sampling
did make a significant change in the amounts recovered from the horizontally oriented test coupons. In
these two tests, the residual malathion was significantly lower and similar to the low amounts (less than 1
mg) recovered from vertical coupons. This result can be explained by the introduced physical removal of
excessive liquid on the surface prior to the wipe sampling. Indeed, a significant amount of malathion was
detected in the liquid waste as discussed in detail in Section 4.2.
DEs for 2-CEPS from the grimed galvanized metal were greater than 99.7% for both horizontal and
vertical orientations (Table 4-2), which is noticeably different from what was observed for malathion. Spiking
of the 2-CEPS in ethanol solution leaves a visible pattern leading to an enlarged area of actual
contamination in comparison to the initial discrete droplets. No runoff of 2-CEPS solution was observed from
the grimed PCs, suggesting that the grime coating may act like a sink for the surface-delivered liquid spike
(Figure 4-5).
Figure 4-5. 2-CEPS spiking pattern on grimed galvanized coupons immediately after spiking, after weathering
and readied for the vertical orientation testing.
4.2. Transfer to Liquid Waste - Vertical Coupons
The overall effectiveness of a decontamination approach is a measure of its ability to remove the
target chemical from material surfaces (i.e., represented by coupons in this study; decontamination results
are discussed in Section 4.1), while taking into account residual chemical that might be transferred to liquid
44

-------
and sometimes solid waste fractions. Such waste streams necessitate additional remediation and disposal
strategies. Those strategies were not studied in this work. Instead, this study provides initial estimates of the
transfer of the contaminant/chemical to liquid waste as collected for materials where runoffs are present due
to their orientation.
Composite samples of the liquid waste (or runoff) of the three replicate test coupons were collected
during each step of the decontamination procedure. The results expressed as the average (n=3) mass of
the contaminant recovered and as in the actual concentration of the liquid waste are shown in Figure 4-6
and Figure 4-7 for malathion and 2-CEPS, respectively, and summarized in Table 4-3.
35
 30
03
E
o 20
'jZ
03
E
15
0 10
0
C
5-
] Post-rinse
] Decontaminant
l Pre-rinse
0.30'
0.25 
0.20'
0.15'
0.10'
0.05'
0.00'
GM non-grimed GM grimed GM grimed*
Material and grime status
Painted Concrete non-grimed
Figure 4-6. Transfer of malathion contamination from galvanized metal (GM) in vertical position to different
types of liquid waste from decontamination process. Grime* refers to the use of DF200 in the pre-rinse step.
15-
03
E
10-
Q_
LU
O
0
>
O
O
0
C
5 -
GM non-grimed
I	
] Post-rinse
] Decontaminant
I Pre-rinse
0.09'
0.08'
0.07'
0.06'
0.05'
0.04'
0.03'
0.02'
0.01 
0.00'
GM grimed
Material and grime status
Paint Concrete non grimed
Figure 4-7. Transfer of 2-CEPS contamination from galvanized metal (GM) in vertical position to different
types of liquid waste from decontamination process.
45

-------
Table 4-3. Recovered Mass and Concentration of Malathion and 2-CEPS in Liquid Waste from
Decontamination Procedures
Material
Material orientation
ID
Type of waste
Recovered mass in
runoff (mg/coupon)*
Concentration in
waste
[g/L]*



Malathion




Pre-rinse detergent-
water runoff (Step 1)
19
2.1
Galvanized metal
Vertical
2M
Decontaminant runoff
(Step 2)
5.7
0.86



Post-decon water rinse
runoff (Step 3)
2.5
0.19



Pre-rinse detergent-
water runoff (Step 1)
0.11
0.016
Painted concrete block
Vertical
4M
Decontaminant runoff
(Step 2)
0.0087
0.0013



Post-decon water rinse
runoff (Step 3)
0.16
0.024



Pre-rinse detergent-
water runoff (Step 1)
6.8
0.59
Galvanized metal
Vertical and grimed
7M
Decontaminant runoff
(Step 2)
25
2.48



Post-decon water rinse
runoff (Step 3)
0.25
0.023



Pre-rinse DF200 runoff
(Step 1)
2.1
0.25
Galvanized metal
Vertical and grimed
9M
Decontaminant runoff
(Step 2)
21
1.9



Post-decon water rinse
runoff (Step 3)
0.89
0.084

2-CEPS



Pre-rinse detergent-
water runoff (Step 1)
11
1.1
Galvanized metal
Vertical
2C
Decontaminant runoff
(Step 2)
2.8
0.56



Post-decon water rinse
runoff (Step 3)
1.1
0.097



Pre-rinse detergent-
water runoff (Step 1)
0.031
0.0044
Painted concrete block
Vertical
4C
Decontaminant runoff
(Step 2)
0.0078
0.0039



Post-decon water rinse
runoff (Step 3)
0.048
0.0063



Pre-rinse detergent-
water runoff (Step 1)
4.6
0.49
Galvanized metal
Vertical and grimed
7C
Decontaminant runoff
(Step 2)
0.0055
0.00083



Post-decon water rinse
runoff (Step 3)
0.015
0.0023
*composite sample of waste runoffs collected from three test coupons.
The average amount of malathion and 2-CEPS transferred from nongrimed galvanized metal in a
vertical orientation was estimated at 27 and 15 mg per coupon, respectively (Figure 4-6 and 4-7),
corresponding to 24% and 21% of the initial chemical loading of the coupon (using the average PC
recovered amount of 113 and 73 mg for malathion and 2-CEPS, respectively [Table 1]). For the grimed
coupons, a total of 32 mg of malathion was recovered in the liquid waste (38% of applied amount based on
46

-------
positive control recovery) while for2-CEPS, 4.6 mg was recovered (5% of applied amount based on positive
control recovery). The largest mass transfer of malathion from the galvanized metal material was in the Step
1 detergent-water waste followed by Step 2 decontaminant runoff and Step 3 post-decontamination water
rinse, implying that the actual contamination at the start of the decontamination step was noticeably lower.
For the grimed coupons contaminated with malathion, the largest amount recovered was for Step 2 followed
by Stepl and Step 3. For the grimed material, it is plausible that the initial detergent and water rinse did not
remove an appreciable amount of grime with malathion from the surface while the DF200 runoff (Step 2)
contained significant amounts of malathion (25 mg or 30%). Similarly, most of the 2-CEPS was recovered in
the Step 1 liquid waste followed by Step 2 and Step 3. For 2-CEPS, this order did not change when
assessing the liquid waste from the grimed material with Step 1 holding more 2-CEPS than Step 2 or 3.
The average amount of chemical transferred to liquid waste from the decontamination process for
the more permeable painted concrete block tested in the vertical orientation was a fraction (< 1%) of the
chemical mass that transferred into liquid waste from the nonpermeable galvanized metal as estimated at
0.28 mg (malathion) and 0.087 mg (2-CEPS) per coupon (Figures 4-6 and 4-7), corresponding to 6% and
12% of the recovered chemical loading of the coupon (using the average PC recovered amount of 4.7 mg
and 0.75 mg for malathion and 2-CEPS, respectively, as a reference). Considering that the spiked malathion
and 2-CEPS amounts were 100 mg per coupon, these liquid waste amounts add up to less than 0.3% of the
spiked amount. As discussed previously in Section 4.1.1, both malathion and 2-CEPS are either strongly
bound or permeated into the paint layer leading to low recoveries in the pre-rinse liquid waste similar to the
low recovery of the positive control wipe samples. The ratio of chemical mass transfer between liquid waste
fractions was different when comparing painted concrete (permeable) against galvanized metal
(nonpermeable) with the majority of malathion and 2-CEPS found in Step 3 water rinse followed by Step 1
pre-rinse waste. The amount of chemicals corresponding to the decontaminant application step (Step 2)
was less than 5% of total chemical mass transferred to liquid waste from each coupon.
The malathion and 2-CEPS concentrations that were detected in the liquid waste fractions in this
study (Table 4-3) are up to three orders of magnitude higher than hazardous waste control limits (HWCL) for
HD- and VX- containing liquid waste derived from the chemical agent toxicity and exposure values for
workers with possible occasional exposure at hazardous waste facilities (0.7 mg/L and 0.08 mg/L,
respectively) [20], If 2-CEPS and malathion were to simulate HD and VX, respectively, the generated liquid
wastes in this study would require further treatment. The reaction of chemical agents in the liquid waste was
not addressed in this study. See Section 4.3.1 for an assessment of the liquid waste concentration one day
after the decontamination when the waste was created.
4.3. Transfer to Liquid Waste - Horizontal Coupons
4.3.1 Direct extraction
Liquid waste from horizontal grimed galvanized material was collected via physical removal using a
squeegee (Section 3.5.3) as a composite sample of replicate test coupons and collected for each step of the
decontamination procedure. The results expressed as the average (n=3) mass of the contaminant
recovered per coupon and as in the actual concentration of the liquid waste are shown in Figure 4-8 and
summarized in Table 4-4.
47

-------
Figure 4-8. Transfer of malathion contamination from galvanized metal (GM) in horizontal position to different
types of liquid waste by physical removal from decontamination process. Grime* refers to the modified
method that uses DF200 in the pre-rinse step.
40-
O)
E
35-
(/) 30 .
03 OU
E
=
O
25 -
03
03
E
"O
(D
(D
>
O
o
CD
C
20-
15-
10-
5 -

Post-rinse

Decontaminant

Pre-rinse
GM grimed horizontal	GM grimed* horizontal
Material and grime status
Table 4-4. Recovered Mass and Concentration of Target Chemicals in Liquid Waste from
Decontamination Procedures for Horizontal Grimed Galvanized Metal
Material
Material
Orientation
ID
Type of waste
Recovered
mass in runoff
(mg/coupon)*
Concentration
in waste
fa/Ll*

Malathion
Galvanized
metal
Horizontal
10M
Pre-rinse detergent-water runoff
(Step 1)
7.6
0.79



Decontaminant runoff (Step 2)
17
1.5



Post-decon water rinse runoff (Step
3)
3.4
0.24
Galvanized
metal
Horizontal
11M
Pre-rinse DF200 runoff (Step 1)
28
2.6


Decontaminant runoff (Step 2)
8.9
0.94



Post-decon water rinse runoff (Step
3)
0.62
0.049
Composite sample of waste runoffs collected from three test coupons.
The average amount of malathion that was physically removed from the horizontal galvanized metal
coupon was estimated at 28 mg when Stepl was a detergent and water rinse while 38 mg of malathion was
physically removed when Stepl was a DF200 application (Figure 4-8). This result corresponds to 46% and
62% of the initial chemical loading of the coupon (using the average PC recovered amount of 60 mg for
malathion [Table 1]). These recovered amounts are like those measured in the runoff from the vertically
placed grimed galvanized metal coupons (32 mg for test with detergent and water as pre-rinse and 25 mg
for test with DF200 as the first pre-rinse step). The presence of the unreacted malathion in the liquid on the
horizontal coupon is also like the amount that was recovered on the coupon via wiping (39 mg, see Table 4-
2), suggesting that a large fraction of the residual malathion as collected via wipe sampling of the grimed
surface in the presence of the remaining liquids is found in the liquid and would not be an indication of
48

-------
unreacted malathion remaining on the coupon surface itself. This hypothesis is supported by the minimal
amount recovered on the horizontal surface (0.80 mg) when most of the liquid has been physically removed
from the surface. Hence, reported efficacy values for horizontal surfaces based on surface wipe samples
that contain all remaining pre-rinse, decontaminant, and post-rinse liquids are biased low.
4.3.1. Delayed extraction
A split sample of the generated combined liquid waste was extracted (and hereby the reactivity
halted) forTest ID 10M and 11M (Table 4-4) after24 h. Based on collected volumes for each of the three
steps, the malathion concentration in the liquid waste immediately after the decontamination was calculated
to be 0.81 and 1.1 g/L for Tests 10M and 11M, respectively. The malathion concentrations recovered after
24 h were reduced to 0.0028 and 0.0013 g/L, respectively, accounting for a more than 99% reduction in
malathion concentration due to the presence of residual decontaminant in the combined liquid waste. A
further degradation may occur after 24 h but was not investigated. This high reduction shows that the waste
stream is reactive and may become less hazardous overtime.
49

-------
5. Quality Assurance/Quality Control
5.1. Test Equipment Calibration
All equipment was verified as calibrated at the time of use. Calibration of instruments was done at
the frequency shown in Table 5-1. In case of any deficiencies, instruments were adjusted to meet calibration
tolerances and/or were recalibrated prior to testing.
Table 5-1. Instrument Calibration Frequency
Equipment
Calibration/Certification
Expected Tolerance
Thermometer
Compare to independent NIST thermometer (a thermometer
that is recertified annually by either NIST or an ISO-17025
facility) value once per quarter.
 1C
Stopwatch
Compare to official U.S. time @ time.qov everv 30 davs.
 1 min/30 days
Micropipettes
Certified as calibrated at time of use. Recalibrated by
gravimetric evaluation of performance to manufacturer's
specifications every year.
 5%
Scale
Compare reading to Class S weights every day.
 1%
pH meter
Two-point calibration using NIST-traceable buffer solutions
immediately prior to testing.
0.1 pH units
Graduated cylinder
Certified by manufacturer at the time of use (class A cylinder)
 1 mL
NIST = National Institute of Standards and Technology; ISO = International Organization for Standardization
5.2. Data Quality Results for Critical Measurements
The following measurements were deemed critical to accomplishing a part of or all the project
objectives:
Initial and post-decontamination surface concentrations of malathion and 2-CEPS, both in
the surface wipe samples and in liquid waste extracts as determined by GC/MS.
Contact time and dwell times.
Hydrogen peroxide concentration and pH of DF200 decontamination solution prior to each
test.
Volume of decontaminant (DF200) and rinse water applied.
Mass of liquid waste (pre- and post-decontamination water rinse and decontaminant
runoffs).
Volume of extraction solvent.
The data quality indicators (DQIs) for the test measurements are provided in Table 5-2. The limited
number of results/tests that were not within acceptance criteria as determined in the project QAPP were not
indicative of any systematic error introduced into the experimental results and do not change the general
findings of this study. The lower surface delivery rate of DF200 was due to significant foaming but this
foaming allowed for complete coverage of test areas. Test coupons were still wet after 60 minutes of contact
time. The excess decontaminant was removed with dry wipes prior to surface sampling with solvent (wipe
samples were extracted as a composite sample).
50

-------
Table 5-2. Acceptance Criteria for Critical Measurements
Critical Measurement
Target Value and
Acceptance criteria
Results
Contact/weathering time
30  1 min
All contact times (CTs) within 30  1 min
from spiking
Dwell/rinse and decontamination interaction
time
30 - 60 min  5 min
All dwell times (DTs) within 30 - 60 min  5
min from application of rinse/decontaminant
Delivery of target surface concentration of
chemical*
80-120% of target
The mean spike controls for
decontamination tests were 88  12 % for
malathion and 95  25% for 2-CEPS
Recovery of chemical from positive control
coupon
60 to 140% with less than
a 30 % coefficient of
variation for identical test
set
Recovery of malathion and 2-CEPS from
ungrimed galvanized metal PC was 78 
2% and 71  2%. For grimed galvanized
metal PC was 81  3.1% and 98  2.7%.
Coefficients of variation were 25% between
replicates (both chemicals)**
Recovery of chemical from positive test
coupon
30 % coefficient of
variation for identical test
set
5 out of 18 tests had >30 % coefficient of
variation forTCs resulting from identical
test set**
Test specific results in Tables 4-1 and 4-2.
Procedural blank
< 5 % of the analyte
amount recovered from
the positive control.
All PB samples within acceptance criteria
Solvent blank

-------
6. Summary
After comparing the decontamination efficiencies of the multistep decontamination procedure
method deployed onto several building materials, the data indicate the following:
(a)	The tested pre-rinse - decontaminant - post-rinse three step procedure has shown potential for
decontamination of nonporous materials tested in horizontal and vertical orientation and in the presence of
grime; decontamination efficacy against malathion (organophosphate pesticide and simulant for VX nerve
agent) and 2-CEPS (simulant for sulfur mustard (HD) CWA) varied from 49  14% to more than 99.9%
depending on the chemical, orientation, and presence of grime. Lower efficacy values for materials in a
horizontal position can be partially attributed to the potential presence of a significant amount of nonreacted
chemical that can be readily skimmed/physically removed from the surface (and collected as liquid waste)
prior to the surface wipe sample to determine the full cleanup efficacy.
(b)	A reduced surface decontamination efficiency was observed for semi-porous and porous
building materials, with maximum DE of 32  14%, for which a fast (within 120 min) chemical permeation
into test material was observed. A possible degradation reaction mechanism of the chemical with the paint
layer cannot be excluded. However previous efforts with HD [9], even though with a different coating, has
indicated a more complete mass balance that suggest that permeation is more prevalent mechanism for
forming a reservoir that resists decontamination.
(c)	Added surface grime reduced the average DEs for malathion from galvanized metal tested in
horizontal orientation to approximately 50%. However, an addition of mechanical removal of the processed
rinse or decontamination liquid rendered the final surface concentration of malathion to below LOQ.
(c) The procedure generated liquid wastes that were significantly contaminated with the applied
chemicals [g/L range]. The combined liquid waste contains enough decontaminant runoff to expect a further
degradation of the chemical in the waste.
The main finding of this study is that spray-based decontamination methods with no mechanical
removal of residual liquid from the surface step combined with a relatively short processing time of
decontaminant (dwell times of one hour) shows minimal potential for decontamination of permeable
materials contaminated with CWA [simulants]. However, when combined with a mechanical removal
technique, the overall efficacy shows promise for some surface materials.
These results indicate that further studies are needed for optimization of decontamination
procedures for decontamination of chemical agents absorbed into permeable building materials, including
modification of decontamination solution, longer processing times, and/or addition of various mechanical
treatment/cleaning steps (e.g. wiping or scrubbing). In addition to relatively poor surface decontamination
efficacy, especially for porous materials, the tested methods yielded highly contaminated (liquid) waste
materials. The treatment methods for contaminated wastes were not addressed in the present study.
52

-------
References
1.	U.S. EPA (2008) Decontamination of Toxic Industrial Chemicals and Chemical Warfare Agents
on Building Materials Using Chlorine Dioxide Fumigantand Liquid Oxidant Technologies.
EPA/600/R-08/125
2.	U.S. EPA (2008) Enzymatic Decontamination of Chemical Warfare Agents. EPA 600/R-12/033
3.	U.S. EPA (2011) Evaluation of Household or Industrial Cleaning Products for Remediation of
Chemical Agents. EPA/600/R-11/055
4.	Oudejans L, Wyrzykowska-Ceradini B, Wlliams C, Tabor D, Martinez J. (2013) Impact of
Environmental Conditions on the Enzymatic Decontamination of a Material Surface
Contaminated with Chemical Warfare Agent Simulants. Ind. Eng. Chem. Res. 52 (30), 10072-
10079
5.	Oudejans L, O'Kelly J, Evans AH, Wyrzykowska-Ceradini B, Touati A, Tabor D, Gibb-Snyder E.
(2016) Decontamination of Personal Protective Equipment and Related Materials
Contaminated with Toxic Industrial Chemicals and Chemical Warfare Agent Surrogates. J.
Environ. Chem. Engineering 4(3), 2745-2753
6.	Stone H, See D, Smiley A, Ellingson A, Schimmoeller J, Oudejans L. (2016) Surface
Decontamination for Blister Agents Lewisite, Sulfur Mustard and Agent Yellow, a Lewisite and
Sulfur Mustard Mixture, Journal of Hazardous Materials 314, 59-66
7.	Singh B, Prasad GK, Pandey KS, Danikhel RK, Vijayaraghavan R. (2010) Decontamination of
Chemical Warfare Agents. Def. Science J., 60, 428-441
8.	Wagner GW. (2011) Decontamination of Chemical Warfare Agents Using Household
Chemicals. Ind. Eng. Chem. Res., 2011, 50 (21), 12285-12287
9.	U.S. EPA (2016) Fate and Transport of Chemical Warfare Agents VX and HD across a
Permeable Layer of Paint or Sealant into Porous Subsurfaces. EPA/600/R-16/173
10.	U.S. EPA (2012) Assessment of Liquid and Physical Decontamination Methods for
Environmental Surfaces Contaminated with Bacterial Spores: Evaluation of Spray Method
Parameters and Impact of Surface Grime EPA/600/R-12/591
11.	Chemical Hazards: Quick Reference Guides (QRGs), U.S. National Response Team
https://www.nrt.org/Main/Resources.aspx?ResourceTvpe=Hazards&ResourceSection=2. Last
accessed April 19, 2020
12.	Bartelt-Hunt SL, Knappe DRU, Barlaz MA. (2008) A Review of Chemical Warfare Agent
Simulants for the Study of Environmental Behavior, Crit. Rev. Environ. Sci. Technol. 38(2),
112-136
13.	Environfoam Technologies EasyDecon DF200 Technical Technology and Performance Data,
https://intelaqard.com/portfolio/easvdecon-df200/. Last accessed April 19, 2020
14.	Sandia National Laboratory (SNL). (2013) Sandia Decon Formulation for Mitigation and
Decontamination of Chemical and Biological Warfare Agents, Chemical Toxins, and Biological
53

-------
Pathogens. http://intelaqard.com/wp-content/uploads/2015/03/Sandia-Decon-Formulation-Test-
Results2.pdf Last accessed April 19, 2020
15.	U.S. EPA. (2007) Method 3571 (SW-846): Extraction of Solid and Aqueous Samples for
Chemical Agents. Revision 0. https://www.epa.gov/sites/production/files/2015-
12/documents/3571 .pdf (last accessed May 09, 2020)
16.	U.S. EPA 2005 Method 527: Determination of selected pesticides and flame retardants in
drinking water by solid phase extraction and capillary column gas chromatography/mass
spectrometry (GC/MS) Revision 1.0. https://well-labs.com/docs/epa method 527 2005.pdf.
Last accessed April 19, 2020
17.	NIOSH. 1994. "Method 5600: Organophosphorus Pesticides," Issue 1. NIOSH Manual of
Analytical Methods, Fourth Edition. DHHS (NIOSH) Publication No. 94-113. Washington, DC.
https://www.cdc.oov/niosh/docs/2003-154/pdfs/5600.pdf. Last accessed April 19, 2020
18.	U.S. EPA. 2014. "Method 8270E (SW-846): Semivolatile Organic Compounds by Gas
Chromatography/ Mass Spectrometry (GC/MS)," Washington, DC.
https://www.epa.gov/sites/production/files/2017-
04/documents/method 8260d update vi final 03-13-2017 O.pdf. Last accessed April 19,
2020
19.	Oudejans L, Wyrzykowska-Ceradini B, Morris E, Korff A. Assessment of Decontamination
Solution Application Methods for Decontamination of Surfaces Contaminated with Pesticides.
U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-17/394, 2018.
20.	OSHA Summary of Multimedia Chemical Agent Toxicity and Exposure Values Table 2. OSHA,
(2004, August 3).
https://www.osha.qov/SLTC/emerqencypreparedness/quides/nerve cwa othermedia table 08
032004.pdf. Last accessed April 19, 2020
54

-------
Appendices
Appendix A: Grime Application Procedure
The multistep grime application procedure that was used in this study is detailed below. The procedure
was optimized for grime application onto a 10 in * 10 in coupon.
Step 1
|- Set up the sprayer
~	Verify the house air supply is off.
~	Connect the air hose to the screw fitting on the sprayer handle and hand-tighten. Turn on house air and
check the air pressure and the hose connection for leaks. The air pressure is read on the regulator gauge
and should be 20 psi. If the pressure is not 20 psi, use the black knob on the regulator to adjust the
pressure to 20 psi. If the hose connection is leaking, turn the house air off, retighten the connection hose
connection and recheck.
~	When there are no leaks and the air pressure is set, turn the house air off and bleed the air pressure by
pulling spray trigger. Verify the line pressure is zero on the regulator gauge.
Step 2
j- Prepare the grime and ethanol solution
~	Weigh out four grams of standard grime and add to a 400-mL beaker.
~	Add 84 mL of ethanol to the 400-mL beaker. Add a magnetic stir bar, cover the beaker with aluminum
foil and slowly stir the grime solution on a stir plate until the grime is in suspension.
Step 3
- Prepare three test coupons for spray application of grime suspension
~	Cover hood floor with clean white paper. Tape the paper down to avoid movement during the
application process.
~	Pre-weigh three clean test coupons using the designated laboratory balance (Sartorius BL1500 Basic
Lite Portable Balance [P/N # BL1500 Sartorius AG, Gottingen, Germany]).
~	Place three pre-weighed test coupons touching side by side in the bottom of the chemical fume hood.
~~] - Spray application of grime to test coupons
Step 4
~	Add 84 mL grime/ethanol suspension to reservoir of the spray gun. Remove the gray reservoir cap and
pour in the standard grime/ethanol solution. Replace cap when finished with the grime/ethanol addition.
~	Turn the house air on, prime the sprayer by spraying a few test sprays into a waste beaker.
~	Set a timer for 45 seconds.
~	Start time and then begin spraying the coupons in an "S" pattern. Start at the top left and move to the
right covering all three coupons. When the end of the third coupon is reached, move the sprayer down the
coupon surface and go from right to left slightly overlapping the previous pass. Continue this pattern until
the bottom edges of the three coupons are reached. Then, work from the bottom to top using the same
pattern. Continue until 45 seconds has elapsed and stop spraying. Turn the house air off and pour
remaining grime/ethanol back into the 400-mL beaker from step 2. Re-cover beaker with aluminum foil
and stir until needed for the next application.
~	Allow the ethanol to evaporate off the coupon surface (about 10 minutes).
55

-------
~	After the ethanol evaporates from the coupon surfaces, rotate the coupons 90 degrees and repeat the
complete sequence of Step 4 until all test coupons are covered with standard grime.
~	After the ethanol evaporates, weigh each coupon and calculate mass of grime delivered onto each
coupon. Each test coupon should contain 1  0.2g of grime applied.
56

-------
Appendix B: Experimental parameters
Table B-1. Characterization of DF200 Decontamination Solution
Preparation
Date
Decontamination
Test
Go/No Go pH of
Test Results Solution
[Pass or [pH
Fail] units]
Temperature of
Solution
[C]
3/1/2017
Malathion on galvanized metal horizontal/vertical
pass
9.78
21.6
3/6/2017
Malathion on vinyl flooring
pass
9.79
24.9
3/8/2017
Malathion on sealed concrete [paver and block]
pass
9.87
23.7
3/2/2017
2-CEPS on galvanized metal horizontal/vertical
pass
9.77
22.3
3/6/2017
2-CEPS on vinyl flooring
pass
9.79
24.9
3/9/2017
2-CEPS on sealed concrete [paver and block]
pass
9.75
22.7
8/20/2018
Malathion and 2-CEPS on grimed galvanized
metal horizontal
pass
9.67
22.9
8/23/2018
Malathion on grimed galvanized metal vertical
pass
9.68
22.8
8/28/2018
2-CEPS grimed galvanized metal vertical
pass
9.68
23.3
9/26/2018
Malathion on grimed galvanized metal horizontal
pass
9.76
22.7
9/26/2018
Malathion on grimed galvanized metal vertical
pass
9.65
23.2
12/6/2018
Malathion on grimed galvanized metal horizontal
pass
9.73
22.8
12/6/2018
Malathion on grimed galvanized metal horizontal
pass
9.77
23.1
Table B-2. Characterization of Pre-decontamination Detergent-water Rinse Solution Application
Test
Date
Decontamination
Test
Detergent-
water
Spray Mass*
[g  SD]
Detergent-water
Spray Volume
[mL  SD]
3/1/2017
Malathion on galvanized metal horizontal
18.72.4
18.72.4
3/1/2017
Malathion on galvanized metal vertical
15.81.9
15.71.9
3/6/2017
Malathion on vinyl flooring
16.30.8
16.30.8
3/8/2017
Malathion on sealed concrete [paver] horizontal
18.30.8
18.30.8
3/8/2017
Malathion on sealed concrete block vertical
16.40.9
16.40.9
8/20/2018
Malathion on grimed galvanized metal horizontal
20.71.0
20.71.0
8/23/2018
Malathion on grimed galvanized metal vertical
19.90.3
19.90.3
12/6/2018
Malathion on grimed galvanized metal horizontal
squeegee
18.70.6
18.70.6
3/2/2017
2-CEPS on galvanized metal horizontal
19.20.5
19.20.5
3/2/2017
2-CEPS on galvanized metal vertical
19.02.1
18.92.0
3/6/2017
2-CEPS on vinyl flooring
18.20.1
18.20.1
3/9/2017
2-CEPS on sealed concrete [paver] horizontal
16.20.3
16.20.3
3/9/2017
2-CEPS on sealed concrete block vertical
17.90.8
17.90.8
8/20/2018
2-CEPS on grimed galvanized metal horizontal
19.80.2
19.80.2
8/24/2018
2-CEPS on grimed galvanized metal vertical
20.00.3
20.00.3
*calculated based on cumulative specific gravity d=1.0006 g/mL
57

-------
Table B-3. Characterization of DF200 Decontamination Solution Application
Test
Date
Decontamination
Test
DF200 Spray
Mass* [g]
Average  SD
(n=3)
DF200
Spray Volume
[mL]
(n=3)
3/1/2017
Malathion on galvanized metal horizontal
14.91.8
12.61.5
3/1/2017
Malathion on galvanized metal vertical
14.1 0.1
11.90.1
3/6/2017
Malathion on vinyl flooring
16.81.4
14.31.2
3/8/2017
Malathion on sealed concrete [paver] horizontal
13.72.3
11.62.0
3/8/2017
Malathion on sealed concrete block vertical
14.40.5
12.20.4
8/20/2018
Malathion on grimed galvanized metal horizontal
20.20.6
17.1 0.5
8/23/2018
Malathion on grimed galvanized metal vertical
20.30.2
17.20.2
9/26/2018
Malathion on grimed galvanized metal horizontal 1st application
19.1 2.1
16.21.8
9/26/2018
Malathion on grimed galvanized metal horizontal 2nd application
19.50.7
16.50.6
9/26/2018
Malathion on grimed galvanized metal vertical 1st application
20.40.7
17.30.6
9/26/2018
Malathion on grimed galvanized metal vertical 2nd application
20.01.0
16.90.9
12/6/2018
Malathion on grimed galvanized metal squeegee
18.71.1
16.70.9
12/6/2018
Malathion on grimed galvanized metal horizontal 1st application
squeegee
19.71.2
16.71.0
12/6/2018
Malathion on grimed galvanized metal horizontal 2nd application
squeegee
19.50.6
16.50.5
3/2/2017
2-CEPS on galvanized metal horizontal
11,33.8
9.53.2
3/2/2017
2-CEPS on galvanized metal vertical
13.1 1.1
11.00.9
3/6/2017
2-CEPS on vinyl flooring
9.70.70
8.20.60
3/9/2017
2-CEPS on sealed concrete [paver] horizontal
15.2 1.4
12.91.2
3/9/2017
2-CEPS on sealed concrete block vertical
11,51.8
9.81.5
8/20/2018
2-CEPS on grimed galvanized metal horizontal
21,00.8
17.80.7
8/24/2018
2-CEPS on grimed galvanized metal vertical
20.00.5
16.90.4
*based on cumulative specific gravity d=1.18 g/mL
58

-------
Table B-4. Characterization of Post-decontamination Water Rinse Application
Test
Date
Decontamination
test
Detergent-water
spray mass* [g]
(n=3)
Detergent-water
spray volume
[mL]
(n=3)
3/1/2017
Malathion on galvanized metal horizontal
19.21.1
19.21.1
3/1/2017
Malathion on galvanized metal vertical
20.60.20
20.60.20
3/6/2017
Malathion on vinyl flooring
21.1 0.11
21.1 0.11
3/8/2017
Malathion on sealed concrete [paver] horizontal
21.40.10
21.40.10
3/8/2017
Malathion on sealed concrete block vertical
20.90.10
20.90.10
8/20/2018
Malathion on grimed galvanized metal horizontal
20.40.2
20.50.2
8/23/2018
Malathion on grimed galvanized metal vertical
20.50.5
20.60.5
9/26/2018
Malathion on grimed galvanized metal horizontal
20.10.9
20.20.9
9/26/2018
Malathion on grimed galvanized metal vertical
20.80.9
20.80.9
12/26/2018
Malathion on grimed galvanized metal horizontal
squeegee
19.50.5
19.50.5
12/26/2018
Malathion on grimed galvanized metal horizontal
squeegee
19.30.7
19.40.7
3/2/2017
2-CEPS on galvanized metal horizontal
20.30.40
20.30.40
3/2/2017
2-CEPS on galvanized metal vertical
21.1 0.10
21.1 0.10
3/6/2017
2-CEPS on vinyl flooring
21 91.5
21 91.5
3/9/2017
2-CEPS on sealed concrete [paver] horizontal
20.31.2
20.31.2
3/9/2017
2-CEPS on sealed concrete block vertical
20.80.70
20.90.70
8/20/2018
2-CEPS on grimed galvanized metal horizontal
19.90.6
20.00.6
8/24/2018
2-ECPS on grimed galvanized metal vertical
20.40.2
20.40.2
*calculated based on specific gravity at 22C d=0.998 g/mL
59

-------
Appendix C: Wipe sampling procedure
The details on the wipe sampling procedure below are for a 10 in x 10 in material coupon. This
multistep sampling procedure is summarized below:
1.	Prepare sampling wipes:
	Don disposable nitrile gloves.
	Using forceps, remove one clean wipe from the storage container and place it on a clean
Petri dish.
	Pipette 3 mL of wetting solvent (IPA, hexane, acetone etc.) onto the center of the wipe, cover
the dish, and allow the solvent to disperse into the wipe material.
	Proceed to wipe sampling immediately.
2.	Don a fresh pair of nitrile gloves.
3.	Grasp the wetted decontamination wipe with one hand and use the other hand to gently fold the
wipe (Figure C-1). Do not squeeze the wipe to avoid loss of the wetting solvent.
Note: Photographs show hexane-based wipe sampling; for acetone sampling used in the
optimized method in this study, latex gloves were worn over nitrile gloves.

Figure C-1. Folding wipe for sampling the first wiping pathway (horizontal).
4. Starting in the top left corner, wipe the surface horizontally, working downward, to completely
cover the surface. The horizontal wipe sampling pathway is shown in Figure C-2.
60

-------









Q-



n
H


n
n
r* ^

Figure C-2. Horizontal wiping pathway.
5.	Using both hands, gently refold the wipe so that that the surface used for the horizontal wipe
sampling is now on the inside (Figure C-3).
Figure C-3. Folding wipe for sampling the second wiping pathway (vertical).
6.	Starting in the bottom left corner, wipe the surface vertically, working toward the right, to
completely cover the surface. The vertical wipe sampling pathway is shown in Figure C-4.
,r
O C
i
i C
1
) 1
1 1
0 {
1 c
l 1
1 c
O (
i 3
5 C
i i
C5 1
1
1 A
1 c
1
> <
Figure C-4. Vertical wiping pathway.
7. Using both hands, gently refold the wipe diagonally, so that that surface used for the vertical wipe
sampling is now on the inside (Figure C-5).
61

-------
Figure C-5. Folding wipe for sampling the third wiping pathway (diagonal).
8. Starting in the top left corner, wipe the surface diagonally, working toward the bottom right corner,
to completely cover the surface. The diagonal wipe sampling pathway is shown in Figure C-6.
Figure C-6. Diagonal wiping pathway.
9. Using both hands, gently refold the wipe so that that surface used for the diagonal wipe
sampling is now on the inside (Figure C-7).
62

-------
Figure C-7. Folding wipe for sampling the fourth pathway (perimeter).
10. Starting in any corner, wipe the perimeter of the coupon. The perimeter wipe sampling pathway
is shown in Figure C-8.
k
o
o
o
o
o
0
0
o
o
0
0
0
o
o
0
o
o
o
o
o
1
Figure C-8. Perimeter wiping pathway.
63

-------
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

-------