Document ID: EPA-HQ-OPP-2006-0693-0011
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-10-20T04:00Z

Evaluation of the Effectiveness of Coatings in Reducing Dislodgeable
Arsenic, Chromium, and Copper from CCA Treated Wood

Wipe Comparison Report

Category III/Sampling and Analysis

Prepared for:

U.S. Environmental Protection Agency

Air Pollution Prevention and Control Division

Research Triangle Park, 

North Carolina 27711

Contract Number:

68-C99-201

Work Assignment Number 1-05

Our Ref.:

RN990231.0021

Date:

9 May 2005

  TOC \o "1-3" \t "Heading 4,4,Heading 5,5,Heading 6,6,Heading
7,7,Headline,1,Heading 1 no numbering,1"  Tables	  PAGEREF _Toc142801627
\h  ii 

Figures	  PAGEREF _Toc142801628 \h  iii 

Appendices	  PAGEREF _Toc142801629 \h  iii 

Acronym List	  PAGEREF _Toc142801630 \h  iv 

1.	Project Description and Organization	  PAGEREF _Toc142801631 \h  1 

1.1	Overall Project Objectives	  PAGEREF _Toc142801632 \h  1 

1.2	Background	  PAGEREF _Toc142801633 \h  1 

1.3	Data Quality Objectives	  PAGEREF _Toc142801634 \h  2 

1.4	Project Organization and Responsibilities	  PAGEREF _Toc142801635 \h
 2 

2.	Test Methods	  PAGEREF _Toc142801636 \h  4 

2.1	Terminology	  PAGEREF _Toc142801637 \h  4 

2.2	Sources of Wood	  PAGEREF _Toc142801638 \h  5 

2.3	Study Design	  PAGEREF _Toc142801639 \h  8 

2.3.1	Randomized Block Design	  PAGEREF _Toc142801640 \h  10 

2.3.1.1	August 2003 Study	  PAGEREF _Toc142801641 \h  10 

2.3.1.2	January 2004 Study	  PAGEREF _Toc142801642 \h  12 

2.4	Characterization of Wood Sources	  PAGEREF _Toc142801643 \h  14 

2.5	Wipe Sampling	  PAGEREF _Toc142801644 \h  15 

2.5.1	EPA Wipe Method (Adaptation of Referenced CPSC Staff Method)	 
PAGEREF _Toc142801645 \h  15 

2.5.2	EPA Acid-Wash, Rinse, and Saturate with DI Water Wipe Preparation
Technique (A2 Method)	  PAGEREF _Toc142801646 \h  16 

2.5.3	EPA 2X DI Water Wipe Preparation Technique (2X Method)	  PAGEREF
_Toc142801647 \h  17 

2.5.4	CPSC Staff 1X 0.9% Saline Wipe Preparation Technique (CPSC Method)
  PAGEREF _Toc142801648 \h  17 

2.5.5	EPA Laboratory Wipe Extraction and Analysis Techniques	  PAGEREF
_Toc142801649 \h  18 

2.5.6	CPSC Staff Technique Laboratory Wipe Extraction and Analysis
Techniques	  PAGEREF _Toc142801650 \h  20 

2.5.7	Differences between EPA and CPSC Staff Wipe and Sample Preparation
Procedures	  PAGEREF _Toc142801651 \h  21 

2.5.8	Wipe Sampling Method Limitations and Recommendations for
Improvements	  PAGEREF _Toc142801652 \h  21 

2.6	Quality Control Samples	  PAGEREF _Toc142801653 \h  22 

3.	Data Reduction	  PAGEREF _Toc142801654 \h  24 

3.1	Calculation of DCCA from Extraction and Digestion Fluid
Concentrations	  PAGEREF _Toc142801655 \h  24 

4.	Results and Discussion	  PAGEREF _Toc142801656 \h  25 

4.1	Wipe Comparison Data	  PAGEREF _Toc142801657 \h  25 

4.1.1	Converting A2 DCCA Measurements to 2X DCCA Measurements	  PAGEREF
_Toc142801658 \h  25 

4.1.2	Converting CPSC Measurements to 2X DCCA Measurements	  PAGEREF
_Toc142801659 \h  27 

5.	References	  PAGEREF _Toc142801660 \h  29 

 

Tables

  TOC \t "Table Caption,1" \a "Figure"  Table 1-1. Data Quality
Indicator Goals for Critical Measurements	  PAGEREF _Toc102545248 \h  2 

Table 1-2. Contact Information for Key Project Staff	  PAGEREF
_Toc102545249 \h  5 

Table 2-1. Summary of Test Blocks (note each block equals six samples)
for August 2003 Tests	  PAGEREF _Toc102545250 \h  13 

Table 2-2. Summary of Test Blocks (note each block equals three samples)
for January 2004 Tests	  PAGEREF _Toc102545251 \h  15 

 

Figures

  TOC \t "Figure Caption" \c  Figure 1-2. Organizational Chart for
Weathering Testing	  PAGEREF _Toc102545252 \h  4 

Figure 2 1. Wood Board Nomenclature	  PAGEREF _Toc102545253 \h  6 

Figure 2-2. ERC Deck Map	  PAGEREF _Toc102545254 \h  8 

Figure 2-3. Views of ERC Deck (note that moisture stains were temporary
and that boards under benches were not used to construct minidecks)	 
PAGEREF _Toc102545255 \h  9 

Figure 2-4. New Hill Deck Map	  PAGEREF _Toc102545256 \h  9 

Figure 2-5. Views of New Hill Deck	  PAGEREF _Toc102545257 \h  10 

Figure 2-6. Randomized Block Design: August 2003 tests – top sketch is
a typical board, bottom sketch is same board showing example block
(dashed line) and example locations of wipe areas (shaded)	  PAGEREF
_Toc102545258 \h  13 

Figure 2-7. Randomized Block Design: January 2004 Tests – Top Sketch
is a Typical Board, Bottom Sketch is Same Board Showing Example Blocks
(Dashed Lines) and Example Locations of Wipe Areas (Shaded)	  PAGEREF
_Toc102545259 \h  15 

Figure 4-1. As-2X versus As-A2 for Rinsed and Unrinsed Wood Specimens	 
PAGEREF _Toc102545260 \h  28 

 

Appendices 

APPENDIX A. WIPE COMPARISON DATA

Acronym List

As	Arsenic

CCA	Chromated Copper Arsenate

CLP	Contract Laboratory Program

CPSC	Consumer Product Safety Commission

DCCA	Dislodgeable CCA Wood Analytes

DAs	Dislodgeable Arsenic

DCr	Dislodgeable Chromium

DCu	Dislodgeable Copper

DI	Deionized Water

DQI	Data Quality Indicator

EPA	United States Environmental Protection Agency

ERC	Environmental Research Center

H&S	Health and Safety

ICP	Inductively Coupled Plasma

ICP-MS	Inductively Coupled Plasma-Mass Spectrometry

ID	Identification

MS	Matrix Spikes

MS/MSD	Matrix Spikes and Matrix Spike Duplicates

MSD	Matrix Spike Duplicates

OLS	On-Site Laboratory Support

OPP	Office of Pesticide Programs

PFA	Perfluoroalkoxy

PM	Project Manager

PTFE	Polytetrafluoroethylene

QA/QC	Quality Assurance and Quality Control

QAPP	Quality Assurance Project Plan

RPD	Relative Percent Difference

RSD	Relative Standard Deviation

STL	Severn Trent Laboratory

SYP	Southern Yellow Pine

TFE	Tetrafluoroethylene

U.S.	United States

WA	Work Assignment

Project Description and Organization

Overall Project Objectives

This study was undertaken in support of existing CCA-treated wood
mitigation studies being conducted by the United States Environmental
Protection Agency (EPA) and Consumer Products Safety Commission (CPSC)
staff, including the study described in EPA’s publicly-available
outdoor testing protocol established in the QAPP entitled, “Evaluation
of the Effectiveness of Coatings in Reducing Dislodgeable Arsenic,
Chromium, and Copper from CCA Treated Wood” (U.S. EPA, 2003).
Additional background information on the on-going efforts to mitigate
potential exposure to CCA chemicals from the surfaces of CCA treated
wood can be found in the referenced test plan.

Two series of tests were conducted to determine the relationship between
dislodgeable arsenic, chromium, and copper measurements obtained using
several related, but different, wipe sampling methods on the surfaces of
chromated copper arsenate (CCA) treated wood. Several wipe sampling
methods have been employed in mitigation studies being conducted by EPA
and CPSC, collaboratively under interagency agreement CPSC-I-03-1235, to
determine the efficacy of coatings in reducing dislodgeable arsenic
(DAs), chromium (DCr), and copper (DCu), collectively called “DCCA”,
from the surfaces of CCA treated wood. The primary objective of this
wipe comparison study was to determine factors to correlate the wipe
methods that have been employed for mitigation and field screening
studies. 

Background

A is expressed in units of mass per surface area wiped (μg/cm2). 

The data obtained will be used by EPA and CPSC staff in support of
efforts to inform the public regarding the use and maintenance of
existing CCA-treated wood products, such as decks and playground
equipment. A supplemental objective of this study is to evaluate and
demonstrate the use of the test protocol and to begin to understand its
utility and realism, and to identify future research needs. This second
objective is relevant because there are currently no standardized
protocols for determining the efficacy of coatings to reduce DCCA from
CCA-treated wood. In this regard, the test is a pilot study that may set
the stage for systematic development of standardized test methods that
will promote development, evaluation, and demonstration of products that
mitigate the potential for dermal contact with DCCA from CCA-treated
wood.

Data Quality Objectives

The critical measurements for the natural weathering tests are total
arsenic, total chromium, and total copper concentrations, which are
subsequently converted to dislodgeable arsenic, chromium, and copper,
which are reported on a mass per unit area basis. Data quality indicator
(DQI) goals for concentration in terms of accuracy, precision, and
completeness, as established in the QAPP for this project, are shown in
Table 1-1. 

Table 1-1. Data Quality Indicator Goals for Critical Measurements

Analyte	Method	Accuracy (%Recovery)	Precision (%RSD/RPD)	Completeness
(%)

Arsenic (total)	SW-846 Method 6020 (modified)	90-110	10	90

Chromium (total)	SW-846 Method 6020 (modified)	90-110	10	90

Copper (total)	SW-846 Method 6020 (modified)	90-110	10	90

Project Organization and Responsibilities

The EPA Work Assignment Manager for this project is Mark Mason, who
coordinates involvement by other EPA staff and CPSC staff via an
interagency agreement (CPSC-I-03-1235) between EPA and CPSC staff, as
appropriate. Paul Groff, EPA’s QA Officer for this project reviews
project QAPPs and reports, audits sampling methodology, and has
stop-work authority on the project. Key CPSC staff includes Jacque
Ferrante, Dave Cobb, and Joel Recht. Key EPA-Office of Pesticide
Programs (OPP) staff includes Jack Housenger, Norm Cook, Nader
Elkassabany, Timothy Leighton, and Jonathan Chen. The contractor Work
Assignment Leader is Victor D’Amato, who is intimately involved with
most facets of the project including test plan development, data
analysis, data reporting, project and fiscal management, and regular
reporting tasks. The contractor QA Officer, serves EPA by providing
quality assurance and quality control (QA/QC) management services, while
contractor Safety Officers serve EPA by providing health and safety
management services.

Test Methods

The methodologies used during these tests are described below, but more
detailed testing procedures are included in the approved QAPP entitled,
CCA Wood Wipe Method Comparison Testing, Revision 3, dated January 19,
2004 (EPA 2004).

Terminology

Before proceeding further, it is essential to review the terminology for
this project as applied in this report. Wood nomenclature used in this
report is defined in Figure 2-1. Note that a “board” is defined as
the unit of wood purchased or removed from an existing structure, while
“sampling area” refers to the segments of each board that were wipe
sampled using the three methods to be tested. Reiterating, a “block”
consists of three adjacent wipe areas on one single board, where each of
the three wipe techniques were matched with one of the three wipe areas
within each block. Two blocks per board were sampled for the January
2004 study, but for the earlier study, wipe sampling techniques were
randomized across each entire board (single block design).

Figure 2 1. Wood Board Nomenclature

Note that all sampling was done on the top faces of the boards; that is,
the face of the board that was originally exposed, facing up, on the
source deck. Furthermore, note that a “grain-up” or “bark side
up” board is defined as one where the tree rings, evident on the cut
end of the board, form a convex pattern (a “hill”) when observed
with the face of the board that was exposed on the source deck facing
up. Likewise, a “grain-down” or “bark side down” board is
defined as one where these rings form a concave (a “valley”) pattern
when the exposed face is facing up. Since wood tends to deform along
these ring lines, grain orientation may be an important variable in the
measurement and mitigation of DCCA on surfaces of CCA-treated wood.
Grain-down boards tend to deform in a manner which “cups” and holds
water or moisture, while grain-up boards tend to deform in a manner
which sheds water from the surface of the board. For this reason, it is
typically recommended to build outdoor structures, like decks, with
boards oriented grain-up, though it appears that many contractors do not
control this particular variable and grain-up and grain-down boards are
commonly found randomly located within a single deck.

Sources of Wood

The wood used was aged southern yellow pine (SYP) that had been
originally CCA-C treated to 0.40 pcf, in nominal 5/4” x 6”
cross-sectional dimensions. 

Two excellent sources of aged wood which were selected and are being
used in the aforementioned mini-deck study were utilized for these
experiments. The two structures have the following characteristics:

“Environmental Research Center (ERC) Deck” - This structure was
located outside of the cafeteria of EPA’s old (leased) Research
Triangle Park facility. It was a stand-alone deck with generally full
exposure (except for several boards – which were not used – located
under attached benches), with only moderate shading by adjacent
buildings during low sun positions. Given its open, stand-alone nature,
abrasion patterns appeared very consistent and the boards were visually
similar to one another. Additional information on this source was
gathered as it was being dismantled under the supervision of ARCADIS.
The deck was constructed of SYP, treated to 0.40 pound per cubic foot
(pcf) with Ground Contact CCA-C. This source was approximately 7 years
old and was believed to have received one application of a standard deck
sealant near the beginning of its use (over 5 years ago). The overall
condition of the wood was considered fair: the coloration was gray and
there was slight-to-moderate splintering. Specific locations and
orientations of individual boards were documented during dismantling of
the source structure; a map of the structure showing the location of
each specimen tested was prepared. This map is shown in Figure 2-2.
Photos are provided in Figure 2-3. This deck is referenced as the
“A” source.

“New Hill Deck” - This source, donated for use during this project,
was taken from an outdoor deck on a private residence. It represents an
ideal source of relatively new, good-condition, aged CCA-treated wood.
The coloration of the wood was light brown and relatively bright and
there was minimal splintering. The New Hill Deck was an exposed,
attached structure. There was no noticeable biological growth or other
dampness-related defects. The deck was constructed of SYP, treated to
0.40 pcf with Ground Contact CCA-C, had been in service for just over
one year, and had never been cleaned or treated. Specific locations and
orientations of individual boards were documented during dismantling of
the source structure; a map of the structure showing the location of
each specimen tested was prepared. This map is shown in Figure 2-4.
Photos are provided in Figure 2-5. This deck is referenced as the
“C” source.

 

Figure 2-2. ERC Deck Map

Figure 2-3. Views of ERC Deck (note that moisture stains were temporary
and that boards under benches were not used to construct minidecks)

 

Figure 2-4. New Hill Deck Map



Figure 2-5. Views of New Hill Deck

Boards from these two sources are identified as shown in Figures 2-2 and
2-4, with the first letter corresponding to the source (either “A”
for the ERC Deck or “C” for the New Hill Deck), followed by a dash
(“-“), followed by a letter, or letter sequence, to identify the
specific board from that source. 

Study Design

Two series of tests were conducted to determine the relationship between
dislodgeable arsenic, chromium, and copper measurements obtained using
several related, but different, wipe sampling methods on the surfaces of
CCA-treated wood. Several wipe sampling methods have been employed in
mitigation studies being conducted by the United States Environmental
Protection Agency (EPA) and the Consumer Products Safety Council (CPSC),
collaboratively under interagency agreement CPSC-I-03-1235, to determine
the efficacy of coatings in reducing dislodgeable arsenic, chromium, and
copper (collectively, “DCCA”) from the surfaces of CCA-treated wood.
The primary objective of this wipe comparison study was to determine
factors to correlate the wipe methods that have been employed for
mitigation and field screening studies. 

All of the wipe sampling methods tested employ the use of a moistened
polyester wipe applied using a wiping apparatus developed and built by
CPSC staff. However, the methods differ in the preparation of the
polyester wipes before sampling and in sample preparation and analysis.
EPA, through its contractor ARCADIS, used acid-washed wipes for baseline
sampling in an on-going study to determine whether
commercially-available coatings can mitigate exposure to dislodgeable
arsenic, chromium, and copper from the surfaces of CCA-treated wood.
Wipes were acid-washed to ensure their cleanliness for trace metals
analysis, rinsed, and then wetted with deionized (DI) water to a
saturated condition, which was subsequently measured to be approximately
three times the dry weight of the wipe (i.e., wetted with about 2x the
dry wipe weight of DI water). However, it was later determined that
rinsing efforts were insufficient at removing all of the nitric acid
used to wash the wipes. Thus, subsequent sampling for this project was
conducted using out-of-the-bag wipes (unwashed) wetted with DI water to
a weight three times the dry weight of the wipe. CPSC staff wets wipes
with a 0.9% saline solution to two times the dry weight of the wipe
(i.e., wetted with 1x dry wipe weight of 0.9% saline). These wipe
preparation procedures are detailed in Section 2.5.

In August 2003, a series of tests was conducted to compare the use of
EPA’s acid washed wetted wipe method (hereinafter, called “A2”)
and EPA’s non-acid washed wetted wipe method (hereinafter, called
“2X”). An additional “1X” wipe method was also tested, but the
results are of no consequence to the objectives of this report are thus
are not presented herein. 

After informally reviewing the data from the August experiments, it was
concluded that a more exhaustive series of tests be conducted in January
2004, comparing the three wipe methods that have actually been used by
researchers on this project (A2, 2X and CPSC staff’s 1X, saline-wetted
wipe method, hereinafter called “CPSC”). These three methods were
tested by sampling adjacent areas of a common board in the same manner
and by the same personnel as typically done, in a randomized block
design, where blocks were defined as three adjacent wipe areas on a
common board, and the locations of the areas wiped using the three wipe
techniques were randomized within each block. Additionally, since EPA
and CPSC staff utilize different (but similar) extraction and analysis
procedures, half of the samples taken during this study were prepared
and analyzed by EPA and half by CPSC staff to ascertain whether the
sample preparation and analysis methods produce different results.
Furthermore, a subset of the samples taken for this study was simply
split between the two labs to directly compare analytical results.
Additional control samples were conducted to further assess
comparability of analytical results between laboratories, in addition to
determining analytical precision and accuracy for each laboratory. 

Other important variables were controlled and tested during these
studies including wood source (the two sources, A and C were tested),
grain orientation (grain-up versus grain-down), and board preparation
(rinsed versus unrinsed).

In addition to the wipe samples discussed, a series of quality control
samples were also tested. These are discussed in Section 2.6. 

Randomized Block Design 

Because it was believed that intraboard (within board) DCCA variability
would be considerably less than interboard (board-to-board) variability,
the design of this experiment was such that the three wipe techniques
(including preparation and sampling) tested in each study were each
tested on adjacent surface areas on a single board (considered a
“block” for this study) for direct comparison. As such, the boards
had to be of suitable, consistent quality, and sufficient length to
accommodate adjacent (end-to-end) wipe techniques (wipe areas were
selected randomly within each block). 

August 2003 Study

For the August 2003 experiments, two sets of the two wipe methods were
randomly assigned to four wipe areas on each board. So, four discrete
wipe areas would be randomly assigned the following wipe methods: 2X,
2X, A2, A2. In other words, each board was considered a single block.

In addition to comparing wipe techniques, other variables were
secondarily explored in this testing, including:

Wood source (both sets of experiments)

Grain-up versus grain-down board orientation (both sets of experiments)

Five A source boards (two grain up and three grain down) and six C
source boards (three grain up and three grain down) were tested. All of
the boards were used “as is”; that is, none were pre-rinsed prior to
sampling. Again, for this study, each board (six sampling areas) was
considered a block and two sets of the three wipe methods were
randomized within each block. Each wipe method utilized EPA’s
“between nailhole” wipe length of 38 cm. All wipes were prepared,
sampled, and extracted by EPA. All EPA wipe sample extracts are analyzed
by STL-Savannah for total As, Cr, and Cu. 

A summary of the test blocks is provided in Table 2-1. Figure 2-6
provides clarification on the random block test design for the two sets
of tests conducted. 

Table 2-1. Summary of Test Blocks (note each block equals six samples)
for August 2003 Tests

Wood Source	Grain-up orientation	Grain-down orientation

“A”	2	3

“C”	3	3

Figure   STYLEREF 1 \s  2 -6. Randomized Block Design: August 2003 tests
– top sketch is a typical board, bottom sketch is same board showing
example block (dashed line) and example locations of wipe areas (shaded)

January 2004 Study

For the January 2004 experiments, one set of the three wipe methods
tested was randomly assigned to three areas on one-half of each board,
while another set of the three wipe methods was randomly assigned to the
three wipe areas on the other half of the board. In other words, each
board was split into two blocks. 

The three wipe techniques that were compared are described in detail
later in this section and are designated as follows:

EPA acid-wash, rinse, wetted to saturation (approx. 2x dry wipe weight)
with DI water = “A2”

EPA out-of-bag wipe, wetted with 2x weight of DI water = “2X”

CPSC staff out-of-bag wipe, wetted with 1x weight of 0.9% saline =
“CPSC”

In addition to comparing wipe techniques, other variables were
secondarily explored in this testing, including:

Wood source 

Grain-up versus grain-down board orientation 

Pre-rinsed versus as-is boards 

EPA versus CPSC staff preparation techniques 

EPA versus CPSC staff analytical techniques 

Five boards or ten blocks were tested for each of the two sources of
wood (10 boards or 20 blocks, total). Boards selected for this study had
at least nine sets of nail holes spaced on approximately 16-inch
centers. This allowed for a total of at least eight, 16-inch spaces on
each board. Because the two EPA wipe methods (both having a 38 cm wipe
length) utilize the area between nail holes for sampling, while CPSC
staff’s method (having a 50 cm wipe length) crosses over one set of
nail holes, four 16-inch spaces were required for each block
(replicate). Since 10 blocks were tested for each of the two sources of
wood, five boards per wood source were required. Two of these boards
were tested as-is, while three were rinsed with tap water using a light
pressure wash (or relatively hard garden hose nozzle) setting, then
allowed to dry, undisturbed, for at least 48 hours before testing.
Additionally, for each source of wood, both grain-up and grain-down
oriented boards were tested and half of the samples were prepared and
analyzed per EPA’s method, while half were prepared and analyzed using
CPSC staff’s method. Finally, 20% of the sample extracts generated by
this project were split for testing by both laboratories, in order to
directly compare analytical results. 

A summary of the test blocks is provided in Table 2-2. Figures 2-7
provides clarification on the random block test design for the two sets
of tests conducted. 

Table 2-2. Summary of Test Blocks (note each block equals three samples)
for January 2004 Tests

	Unrinsed Boards	Rinsed Boards

	Grain-up orientation	Grain-down orientation	Grain-up orientation
Grain-down orientation

Wood Source	EPA Lab	CPSC Lab	EPA Lab	CPSC Lab	EPA Lab	CPSC Lab	EPA Lab
CPSC Lab

“A”	2	2	1	1	1	1	1	1

“C”	2	2	1	1	1	1	1	1

Figure 2-7. Randomized Block Design: January 2004 Tests – Top Sketch
is a Typical Board, Bottom Sketch is Same Board Showing Example Blocks
(Dashed Lines) and Example Locations of Wipe Areas (Shaded)

Characterization of Wood Sources

For the January 2004 tests, digital photos were taken of each board at
the beginning of the test (i.e., prior to wipe sampling) and archived.
All boards were qualitatively and semi-quantitatively characterized for
visually-observable wood condition characteristics, with data recorded
on a standardized wood characterization data sheet. The characteristics
recorded included knotting (number of knots for that specimen was
recorded), splintering, cracking, and rotting (for these last three, a
rating of 1 to 5, with 5 being like new wood and 1 being complete
failure, was assigned).

For each aged CCA-treated board, visually-observable source wood
characteristics were recorded, including predominant grain orientation
(up versus down), predominant grain type (percent flat versus percent
edge grain), predominant ring spacing (tight, medium, wide), predominant
wood season (percent early versus percent late wood), and predominant
wood type (percent  heartwood versus percent  sapwood). The percentages
of the various grain characteristics, where reported, were gross visual
observations and should only be considered estimates.

Grain orientation was assessed by viewing the end of a board and noting
the shape of the grain pattern. A concave or “U” shape would be
considered “grain down”, while a convex or “hill” shape would be
considered “grain up”. The significance is that boards will tend to
deform or warp over time in the direction of their grain. That is, a
grain down board will tend to “cup” and may hold water, while a
grain up board will tend to shed water.

Grain type was assessed by noting whether the board was cut across the
grain (flat grain) or perpendicular through it (edge grain).

Ring spacing was determined by viewing the spacing of the tree’s rings
and recording whether they were spaced tightly, widely, or in-between
(medium).

Wood season was determined based on the prevalence of large cells, or
small dense cells within a growth ring. If a majority of each concentric
growth ring were light in color, a high percentage of early wood
(springwood) would be indicated. If, on the other hand, the dark and
light-colored portions of the growth ring were of equal thickness, 50%
of the wood would be late wood (summerwood).

The wood type was determined by noting the relative color of the wood
grain, with darker colors reflecting heartwood (from the center of the
tree) and lighter colors reflecting sapwood (from the outer rings of the
tree).

Wipe Sampling

Wipe sampling techniques utilized are based on the method developed and
documented by CPSC staff, using the wipe sampling device designed and
constructed by CPSC staff. The CPSC staff wipe sampling device utilizes
a 1.1 kg disc that is approximately 8.65 cm in diameter as the wiping
block (note that the actual width of 5/4” x 6” decking is
approximately 5.5” or 14 cm). With the 38-cm wipe length utilized, the
sampling area is approximately 314 cm2. The referenced CPSC staff method
has been described previously (CPSC staff 2003b). There are several
differences between the procedures employed by EPA and those employed by
CPSC staff. The EPA wipe technique is described in detail below, along
with wipe preparation and sample extraction and analysis procedures for
both researchers, while the differences between techniques are
enumerated in Section 2.5.7.

EPA Wipe Method (Adaptation of Referenced CPSC Staff Method)

The wipe method employed by EPA for the referenced minideck study is as
follows:

Prior to starting a new wipe sample, the sampler puts on a new pair of
disposable nitrile or latex gloves. Then, the rubber-coated side of the
steel rubbing disk is covered with plastic wrap (SaranWrap or similar).
The wetted wipe is then removed from the PTFE tube, folded in half, and
placed over the plastic wrap and secured with a plastic tie-wrap strap. 

The disk is lowered so that it is in contact with the wood. 

The sampler slides the disc along the tracks forward and backward for
five 5 38-cm (15-inch) strokes between nail holes while another person
holds the end of the wiping device in place. A stroke consists of one
forward and back movement. The speed of sampling is variable depending
on the quality of the area being wipes, with rougher wipe areas
requiring longer sampling times (slower speeds). Smooth wipe areas may
take one second to wipe in each direction, while rough areas may take up
to 30 seconds.

The wipe is rotated 90° on the rubbing disk, which is then slid forward
and back for five more strokes, for a total of 10 front-and-back
strokes. 

The sampler then removes the wipe from the disk and places it back into
its PTFE extraction vessel. Wood splinters larger than a grain of rice
are removed prior to placing the wipe in the extraction vessel. 

After the sample is taken, the plastic wrap is discarded and the wiping
apparatus is decontaminated by wiping the rails which were in contact
with the wood surfaces with lint-free wipes wetted with DI water. Then
the apparatus is checked for structural integrity and any loose bolts
are tightened. Finally, the sampler removes and discards their gloves
and, for the next sample, items 1 through 6 are repeated.

EPA Acid-Wash, Rinse, and Saturate with DI Water Wipe Preparation
Technique (A2 Method)

For the baseline samples, the following acid-wash wipe preparation
procedure was employed:

Wipes (TexWipes TX1009 cleanroom wipes, 100% continuous filament
polyester) are cut in half using a new razor blade that had been cleaned
using acetone and a lint-free wiper (i.e., Kimwipe) on a lab bench which
has also been cleaned with acetone. 

After cutting, the half-wipes are placed in a wide mouth glass bottle
and soaked in a 10% solution of Trace Metals Grade Nitric Acid. 

The bottle is placed in an oven at 85 ºC overnight. 

The bottle is removed from the oven, nitric acid solution is decanted,
and wipes are rinsed in the bottle five times with deionized H2O.

After the final rinse, each wipe is then removed and squeezed by hand so
that they are damp but no more water could be removed. This technique
was subsequently determined to yield moisture contents of 2.1 ( 0.1 (1
standard deviation) times the dry wipe weight. 

The damp wipes are individually placed into individual Digitubes until
they are used for wipe sampling.

Note that nitrile gloves are worn during all handling of wipes. 

EPA 2X DI Water Wipe Preparation Technique (2X Method)

The EPA wipe preparation procedure for subsequent sampling events (taken
at 1, 3, 7, 11 months after coating) for the referenced minideck study
was as follows:

Wipes (TexWipe TX1009 cleanroom wipes, 100% continuous filament
polyester) are cut in half using a new razor blade or scissors cleaned
using acetone and a lint-free wipe (i.e., Kimwipe) on a lab bench which
has also been cleaned with acetone. 

After cutting, the half-wipes are inserted into PTFE tubes, into which
two times the wipe weight in DI water is added to be soaked up by the
wipe. Therefore the wet wipe, as used, is three times its dry weight. 

Wetted wipes are stored in their sealed PTFE tubes until use. Sampling
staff cutting, transferring, and wetting the wipes wear nitrile or latex
gloves. 

CPSC Staff 1X 0.9% Saline Wipe Preparation Technique (CPSC Method)

The wipe method employed by CPSC staff for their related minideck study
was as follows:

Wipes (TexWipes TX1009 cleanroom wipes, 100% continuous filament
polyester) are cut into quarters using scissors cleaned with acetone and
a lint-free wiper (e.g., Kimwipe).

After cutting, the wipes are weighed and then soaked in 0.9% saline
solution. The wipes are squeezed and shaken until the wipe has absorbed
an equal weight (1X) of saline solution.

Wetted wipes are stored in sealed glass test tubes until use. The
sampler cutting, transferring, wetting and sampling the wipes wears
nitrile or latex gloves.

The rubber-coated side of the steel rubbing disk is covered with a clean
piece of Parafilm for each sample wipe. The wetted wipe is removed from
the test tube and placed over the Parafilm. The wipe is secured to the
disk with a rubber band and hose clamp. The wipe should be smoothly
stretched over the disk.

The wipe-covered disk is attached to the lower arm of the sampler.

The wipe covered rubbing disk is placed at one end of the wiper. Then
the wiper is placed over the area of the board to be sampled. The
rubbing disk is then slid along the tracks of the wiper forward and back
for five 50-cm strokes. The rubbing disk is lifted from the board,
rotated 90°, and slid forward and back five more strokes for a total of
10 strokes. As for the EPA method, the speed of sampling is variable
depending on the quality of the area being sampled.

The wipe is removed from the disk. Any wood splinters larger than a
grain of rice are removed. The edges of the wipe that did not contact
the board during sampling are cut and the wipe is placed back in the
glass test tube, and covered. Any splinters are noted.

After the sample is taken, the Parafilm strip is discarded and the
wiping apparatus is decontaminated by wiping the rails that are in
contact with the wood surfaces with lint-free wipes wetted with DI
water. Then the apparatus is checked for structural integrity and any
loose bolts are tightened. Finally, the sampler removes and discards
their gloves and for the next sample, items 4 through 7 are repeated.

EPA Laboratory Wipe Extraction and Analysis Techniques

Wipe samples were prepared for analysis using techniques similar to
those employed by other researchers including CPSC staff (2003) and
Stilwell, et al. (2003), adapted for use with laboratory equipment
available for this project. As such, a microwave- or heat-assisted
extraction procedure comparable to that used in prior studies, and
similar to SW-846 Methods 3051 and 3052, was employed. Steps involved in
the extraction procedure are outlined following:

Pre-cleaned disposable digestion vessels are used for sample collection
and digestion. All volumetric glassware is prepared by acid cleaning.
Volumetric glassware is cleaned by leaching with hot 1:1 nitric acid for
a minimum of two hours, then rinsed with deionized water and dried in a
clean environment.

30 ± 0.1 mL 10% nitric acid (trace metal grade HNO3, DI H2O) is added
slowly to the digestion vessel containing the wipe sample to allow for
pre-extraction. Once any initial reaction has ceased, the sample is
capped and introduced into the HotBlock. Using the Environmental Express
HotBlock System, 54 samples may be digested in a single batch.

Using temperature and pressure curves developed under other research
programs for EPA as a guide, the vessels are placed into the HotBlock
and heated for 1 hour at 95 °C. 

After HotBlock extraction, sample vessels are allowed to cool for a
minimum of 5 min. prior to removing them from the system. Then the
liquid is poured off into a 100 mL volumetric flask. As much extraction
liquid as possible is squeezed by hand from each wipe; the funnels and
flask necks are rinsed with DI H2O. 

The extracted wipe is then placed back into the extraction flask with an
additional 30 mL of 10% HNO3. 

Again, the vessels are placed into the HotBlock and heated for 1 hour at
95 °C. 

After extraction, the liquid is poured off into the aforementioned 100
mL volumetric flask. As much extraction liquid as possible is squeezed
by hand from each wipe and the funnels and flask necks are rinsed with
DI H2O. 

The wipe is placed back into the extraction vessel and 20 mL of 10% HNO3
is added to each extraction vessel before the HotBlock cycle is
repeated.

The extract is then poured into the 100 mL volumetric flask. Deionized
water is used to rinse the extraction vessel; rinsate is added to the
100mL volumetric flask. If necessary, deionized water is added to take
the contents to the 100 mL level.

Samples are stored in plastic tubes with plastic caps as manufactured by
SCP Science. These tubes are certified contaminant-free. Duplicate tubes
(split samples) for each sample are stored. One is sent to a contract
laboratory for analysis, while the other is archived. 

Note that nitrile or latex gloves are worn during all handling of wipes.

Per the specified analytical method, the hold time for all metals other
than mercury is 6 months, and samples are stored at 4 °C until
analysis. Sample containers are of tetrafluoroethylene (TFE) or
perfluoroalkoxy (PFA) in accordance with the analytical method
recommendations.

Analyses for total arsenic, chromium, and copper are conducted by STL in
Savannah, Georgia, using a modification of SW-846 Method 6020 (ICP-MS).
STL utilizes ICP-MS for arsenic analysis, modifying the technique to
utilize hydrogen plasma, rather than argon as classically performed.
This modification eliminates concerns over the formation of Ar40Cl35,
which can create a positive bias when measuring As. STL-Savannah’s
analytical method has reporting limits of 0.10 µg/L for all three CCA
analytes (this corresponds to a DCCA of 0.000032 µg/cm2)

STL is an accredited laboratory, participating in the Contract
Laboratory Program (CLP), as well as numerous state programs. In
addition to prequalifying the laboratory for use in the minideck study,
each set of samples submitted includes blind blanks and spiked samples,
allowing for continued monitoring of laboratory performance.

CPSC Staff Technique Laboratory Wipe Extraction and Analysis Techniques

The extraction and analysis procedures used by CPSC staff are outlined
as follows:

After sampling, the wipes are carefully rolled up and placed back in the
glass test tube in which the wipe was stored prior to sampling.

20 ( 0.1 mL of 10% nitric acid (trace metal grade HNO3, DI H2O) is added
to each test tube containing a sample wipe. The test tubes are covered.

The test tubes are placed in a hot water bath at 60 °C overnight
(approximately 15-24 hours). The test tubes are removed from the water
bath and allowed to cool to room temperature. 

The test tubes are vortexed prior to analysis to ensure mixing. The wipe
remains in the test tube throughout the extraction and analysis process.

Analysis for total arsenic, chromium, and copper are conducted at the
CPSC laboratory in Gaithersburg, Maryland using a modification of EPA
Method 200.7. CPSC staff utilizes ICP for analysis.

Differences between EPA and CPSC Staff Wipe and Sample Preparation
Procedures

Differences between the CPSC staff and EPA 2X methods for collection and
analysis of surrogate wipes on CCA-treated wood are as follows:

ARCADIS uses plastic wrap to cover the rubber-coated side of the rubbing
disk rather than Parafilm.

C-clamps are not used by EPA to secure the horizontal wiper (because the
boards being wiped are part of a deck structure). An assistant holds the
wiper in place.

In the EPA method, poly wipes are immediately placed directly into the
vessels in which extraction will take place. 

A three-step extraction and digestion procedure, as detailed above, is
used by EPA rather than CPSC staff’s one-step water bath extraction
and digestion.

EPA uses a 2x DI water spike (wetted wipe weight is three times the dry
wipe weight) to pre-wet the wipes while CPSC staff uses a 1x 0.9% saline
solution spike (wetted wipe weight is two times the dry wipe weight).

EPA uses a 38-cm (15-in) wipe length (nominal 314 cm2 sampling area) and
samples between nail holes of boards supported 16 inches on-center,
while CPSC staff uses a 50-cm (19.7-in) wipe length (nominal 386 cm2
sampling area). 

Wipe Sampling Method Limitations and Recommendations for Improvements

Wipe sampling is typically a relatively imprecise method of sampling.
During this study, several notable observations have been made regarding
the wipe sampling procedure. Most notably, the apparatus does not always
appear to apply even wipe sampling pressure during sampling,
particularly if the wood member is even slightly deformed, warped, or
cupped. It appears that the rigid structure of the weighted disc to
which the wipe is affixed does not allow for much in the way of
“form-fitting” the wood member being sampled. The use of a less
rigid face for the weight (perhaps something like a beanbag or
gel-filled pad) may allow the wipe to fit better to the areas being
sampled. 

Quality Control Samples

In addition to the wipe samples discussed, a series of quality control
samples were also tested. These include samples to assess blank
contamination and laboratory quality control. Note that two analytical
techniques and laboratories were involved in the January 2004
experiments as mentioned. EPA subcontract analyses to STL-Savannah,
while CPSC staff conducts their analyses in-house. 

Blank contamination was assessed by testing one blind field blank
(extracted unused wet wipe) per wipe preparation procedure per
laboratory, and one blind blank (extraction fluid only) per laboratory.
For these samples, EPA provided CPSC staff with two or more unused wet
wipes for each of the two EPA wipe methods being tested. Likewise, CPSC
staff provided EPA with two or more unused wet wipes prepared using the
CPSC staff method.

Laboratory quality control was assessed by testing one set of
four-concentration spiked samples per laboratory:

1.0 µg/l As, Cr, and Cu in digestion fluid,

50 µg/l As, Cr, and Cu in digestion fluid,

1,000 µg/l As, Cr, and Cu in digestion fluid,

10,000 µg/l As, Cr, and Cu in digestion fluid.

These spiked standards were prepared by EPA and provided to CPSC staff
so that both labs could verify analytical results to the same standard. 

Wood dust spike samples were also prepared and analyzed by each lab. The
CCA wood dust was provided by CPSC staff and used to spike unused,
wetted wipes which were then extracted and analyzed by each lab. Spiking
was done in accordance with standard CPSC staff procedures. Extraction
and analysis was done consistent with the methods described earlier in
this section. At least one wood dust spike was conducted for each of the
three wipe preparation methods. 

Approximately 20% of the EPA prepared samples (three for each wood
source) were randomly selected for analysis by both laboratories and,
likewise, 20% of the CPSC staff prepared samples were randomly selected
for analysis by both laboratories.

Precision (relative standard deviation) was assessed by analyzing
duplicates (split samples) for approximately 5% (three per lab) of the
wipe sample digestates analyzed. 

In addition to the external quality control samples listed, the
analytical laboratories will conduct standard internal control samples
including matrix spikes and matrix spike duplicates (MS/MSD) for each
analyte, and equipment blanks run on each batch of samples analyzed for
this project.

Data Reduction

Calculation of DCCA from Extraction and Digestion Fluid Concentrations

Raw data from the subcontract analytical laboratory is reported in units
of µg/L and represents the mass of analyte per unit volume of
extraction and digestion solution sent to the laboratory. For standard
wipe sample results, data is reduced in order to characterize the mass
of analyte per unit surface area wipe sampled, in units of µg/cm2,
using the following equation:

 	(Equation 3.1)

Where:	CDCCA = DCCA of a sample (µg/cm2)

	CDF = Concentration of analyte in extraction fluid (µg/L)

	V = Total volume of extraction fluid (mL)

	A = Area of wiped surface (cm2)

Results and Discussion

Wipe Comparison Data

The complete data set is provided at the end of this appendix. Since the
primary objective of this wipe comparison study was to generate
equations to correlate the various wipe sampling methods utilized, only
the results of the associated statistical analyses are presented here.

Converting A2 DCCA Measurements to 2X DCCA Measurements

Statistical model selection was used to identify calibration equations
for predicting method 2X DCCA measurements from method A2 DCCA
measurements and the other factors, including grain orientation (up,
down), source deck (A, C), sample date (1 month, 3 months, 7 months, 11
months), rinse (rinsed, unrinsed), and prep lab (EPA, CPSC). Based on
these analyses, separate calibration equations are suggested for rinsed
and unrinsed boards, but not for any of the other factors. In other
words, when models for predicting DCCA using 2X wipes from DCCA using A2
wipes, grain, source deck, sample date, rinse, and prep lab are
considered, the identified prediction model depends only on DCCA using
A2 wipes and rinse.

The wipe method correction factors are simple, no-intercept linear
calibrations, and are summarized as follows:

For arsenic:

Rinsed Specimens: DAs-2X = 1.42 (DAs-A2), 95% Confidence Interval:
(1.18, 1.66)

Unrinsed Specimens: DAs-2X = 0.80 (DAs-A2), 95% Confidence Interval:
(0.72, 0.88)

The R-square value for the combined models is 0.78

For chromium:

Rinsed Specimens: DCr-2X = 1.31 (DCr-A2), 95% Confidence Interval:
(1.05, 1.57)

Unrinsed Specimens: DCr-2X = 0.81 (DCr-A2), 95% Confidence Interval:
(0.73, 0.89)

The R2 value for the combined models is 0.62.

For copper:

Rinsed Specimens: DCu-2X = 1.18 (DCu-A2), 95% Confidence Interval:
(0.94, 1.42)

Unrinsed Specimens: DCu-2X = 0.83 (DCu-A2), 95% Confidence Interval:
(0.75, 0.91)

The R2 value for the combined models is 0.81

The need for the different equations is evident in Figure 4-1, which is
a plot of DAs-2X vs. DAs-A2 using different symbols for rinsed and
unrinsed boards.

Figure 4-1. As-2X versus As-A2 for Rinsed and Unrinsed Wood Specimens

Converting CPSC Measurements to 2X DCCA Measurements 

The same approach used to identify the DAs-A2 to DAs-2X calibration
equation was used to identify a DAs-CPSC to DAs-2X calibration equation.
Compared to the former calibration relation, the latter relationship is
not as strong. Rinse does not manifest itself as a significant
predictor, but there is statistical evidence that source deck does.
However, statistical evidence suggesting the relevance of source deck
should be discounted because of the tendency for the C-deck values to be
lower than the A-deck values. This has the effect of confounding source
deck with DAs-CPSC. Combined with the lack of theoretical support for a
source-deck effect, the suggested calibration equation is: 

DAs-2X = 3.18 DAs-CPSC

For this model, R2 = 0.25

The data set contains one possibly outlying DAs-2X value (2.895). If
this value is removed from the data, the calibration equation changes to

DAs-2X = 2.96 DAs-CPSC

with R2 = 0.47

Of course, the latter equation should only be considered if there is
some external supporting evidence explaining the outlying 2X value,
which there isn’t.

For DCr, the correlation equation is:

DCr-2X = 3.24 (DCr-CPSC)

with R2 = 0.08 (Note this is very low).

For DCu, the correlation equation is:

DCu-2X = 2.56 (DCu-CPSC)

For this model R2 = 0.17.

With the one possible outlier removed, the equation changes to:

DCu-2X = 2.43 (DCu-CPSC)

For this model R2 = 0.55.

In summary, the DCCA-CPSC and DCCA-2X measurements are on very different
scales (the regression coefficient is not close to 1), and the
correlation between the methods is not all that strong (low R2 values).

References

U.S. CPSC staff. 2003. Memorandum from David Cobb to Patricia Bittner,
“CCA-Pressure Treated Wood Analysis – Exploratory Studies Phase I
and Laboratory Studies Phase II,” in the Briefing Package, “Petition
to Ban Chromated Copper Arsenate (CCA)-Treated Wood in Playground
Equipment (Petition HP 01-3), U.S. Consumer Product Safety Commission,
Washington, D.C., February 4, 2003. pp 229.   HYPERLINK
"http://www.cpsc.gov/LIBRARY/FOIA/FOIA03/brief/briefing.html. April 27" 
http://www.cpsc.gov/LIBRARY/FOIA/FOIA03/brief/briefing.html. April 27 ,
2005.

U.S. EPA. 2003. “Evaluation of the Effectiveness of Coatings in
Reducing Dislodgeable Arsenic, Chromium, and Copper from CCA Treated
Wood. Revision 6.” U.S. EPA, Research Triangle Park, NC, September 24,
2003.

U.S. EPA. 2004. “CCA Wood Wipe Method Comparison Testing, Revision
3.” U.S. EPA, Research Triangle Park, NC, January 19, 2004.

APPENDIX A. WIPE COMPARISON DATA

ID	Sample Date	Wipe Method	Grain	Rinse	Prep Lab	As (ug/cm2)	Cr (ug/cm2)
Cu (ug/cm2)

C-AF	8/20/2003	1X	Up	Unrinsed	EPA	0.59	0.67	0.23

C-AF	8/20/2003	2X	Up	Unrinsed	EPA	0.71	0.83	0.32

C-AF	8/20/2003	2X	Up	Unrinsed	EPA	1.74	1.82	0.63

C-AF	8/20/2003	A2	Up	Unrinsed	EPA	1.90	2.10	0.67

C-AF	8/20/2003	A2	Up	Unrinsed	EPA	2.38	2.69	0.91

C-AF	8/20/2003	1X	Up	Unrinsed	EPA	1.11	1.35	0.51

C-BB	8/20/2003	A2	Down	Unrinsed	EPA	1.11	1.74	1.15

C-BB	8/20/2003	1X	Down	Unrinsed	EPA	0.87	1.35	0.83

C-BB	8/20/2003	2X	Down	Unrinsed	EPA	1.74	2.22	0.99

C-BB	8/20/2003	1X	Down	Unrinsed	EPA	1.70	1.86	2.22

C-BB	8/20/2003	A2	Down	Unrinsed	EPA	2.65	3.37	3.01

C-BB	8/20/2003	2X	Down	Unrinsed	EPA	2.22	3.41	2.89

C-G	8/20/2003	2X	Up	Unrinsed	EPA	0.40	0.51	0.21

C-G	8/20/2003	1X	Up	Unrinsed	EPA	0.32	0.48	0.21

C-G	8/20/2003	A2	Up	Unrinsed	EPA	0.87	1.19	0.40

C-G	8/20/2003	A2	Up	Unrinsed	EPA	0.22	0.27	0.09

C-G	8/20/2003	1X	Up	Unrinsed	EPA	0.30	0.38	0.13

C-G	8/20/2003	2X	Up	Unrinsed	EPA	1.78	2.22	0.55

C-K	8/20/2003	2X	Down	Unrinsed	EPA	1.11	1.54	0.79

C-K	8/20/2003	A2	Down	Unrinsed	EPA	1.78	2.30	0.99

C-K	8/20/2003	1X	Down	Unrinsed	EPA	1.19	1.54	0.67

C-K	8/20/2003	A2	Down	Unrinsed	EPA	2.89	3.45	1.43

C-K	8/20/2003	2X	Down	Unrinsed	EPA	1.78	2.14	0.91

C-K	8/20/2003	1X	Down	Unrinsed	EPA	1.35	1.62	0.55

C-P	8/20/2003	2X	Down	Unrinsed	EPA	1.86	2.34	1.03

C-P	8/20/2003	A2	Down	Unrinsed	EPA	3.41	3.68	1.70

C-P	8/20/2003	2X	Down	Unrinsed	EPA	1.78	2.06	0.75

C-P	8/20/2003	1X	Down	Unrinsed	EPA	1.19	1.51	0.55

C-P	8/20/2003	A2	Down	Unrinsed	EPA	2.06	2.46	0.87

C-P	8/20/2003	1X	Down	Unrinsed	EPA	1.15	1.54	0.55

A-AM	8/29/2003	2X	Down	Unrinsed	EPA	2.42	2.10	1.23

A-AM	8/29/2003	A2	Down	Unrinsed	EPA	4.75	3.68	2.06

A-AM	8/29/2003	1X	Down	Unrinsed	EPA	2.38	1.19	0.71

A-AM	8/29/2003	A2	Down	Unrinsed	EPA	3.13	1.58	0.99

A-AM	8/29/2003	1X	Down	Unrinsed	EPA	1.54	1.23	0.83

A-AM	8/29/2003	2X	Down	Unrinsed	EPA	3.76	2.22	1.31

A-BA	8/29/2003	A2	Up	Unrinsed	EPA	1.58	1.66	0.63

A-BA	8/29/2003	1X	Up	Unrinsed	EPA	0.71	0.83	0.40

A-BA	8/29/2003	2X	Up	Unrinsed	EPA	1.19	1.35	0.51

A-BA	8/29/2003	1X	Up	Unrinsed	EPA	0.79	0.87	0.36

A-BA	8/29/2003	2X	Up	Unrinsed	EPA	1.15	1.15	0.59

A-BA	8/29/2003	A2	Up	Unrinsed	EPA	1.62	2.02	0.67

A-BJ	8/29/2003	A2	Down	Unrinsed	EPA	2.53	2.38	1.27

A-BJ	8/29/2003	A2	Down	Unrinsed	EPA	1.90	1.82	1.19

A-BJ	8/29/2003	1X	Down	Unrinsed	EPA	1.47	1.31	0.91

A-BJ	8/29/2003	2X	Down	Unrinsed	EPA	2.93	2.85	1.90

A-BJ	8/29/2003	2X	Down	Unrinsed	EPA	1.62	1.19	0.91

A-BJ	8/29/2003	1X	Down	Unrinsed	EPA	1.94	1.58	1.11

A-H	8/29/2003	1X	Up	Unrinsed	EPA	0.99	1.23	0.63

A-H	8/29/2003	A2	Up	Unrinsed	EPA	1.94	2.46	1.54

A-H	8/29/2003	2X	Up	Unrinsed	EPA	1.35	1.58	1.11

A-H	8/29/2003	2X	Up	Unrinsed	EPA	1.47	1.94	1.27

A-H	8/29/2003	A2	Up	Unrinsed	EPA	1.98	2.22	1.15

A-H	8/29/2003	1X	Up	Unrinsed	EPA	1.35	1.58	0.87

A-K	8/29/2003	2X	Down	Unrinsed	EPA	2.14	2.02	1.07

A-K	8/29/2003	A2	Down	Unrinsed	EPA	2.50	2.65	1.43

A-K	8/29/2003	A2	Down	Unrinsed	EPA	2.34	2.34	1.43

A-K	8/29/2003	2X	Down	Unrinsed	EPA	2.26	2.26	1.35

A-K	8/29/2003	1X	Down	Unrinsed	EPA	1.07	1.11	0.71

A-K	8/29/2003	1X	Down	Unrinsed	EPA	1.03	1.19	0.63

C-BF	8/29/2003	2X	Up	Unrinsed	EPA	0.48	0.63	0.26

C-BF	8/29/2003	1X	Up	Unrinsed	EPA	0.48	0.48	0.27

C-BF	8/29/2003	2X	Up	Unrinsed	EPA	0.87	1.03	0.71

C-BF	8/29/2003	A2	Up	Unrinsed	EPA	1.35	1.70	1.11

C-BF	8/29/2003	A2	Up	Unrinsed	EPA	1.19	1.62	0.91

C-BF	8/29/2003	1X	Up	Unrinsed	EPA	0.55	0.71	0.63

A-AI	1/21/2004	2X	up	rinsed	CPSC	1.20	0.94	0.45

A-AI	1/21/2004	A2	up	rinsed	CPSC	1.04	0.81	0.38

A-AI	1/21/2004	CPSC	up	rinsed	CPSC	0.31	0.26	0.15

A-AI	1/21/2004	CPSC	Up	rinsed	EPA	0.52	0.44	0.22

A-AI	1/21/2004	2X	Up	rinsed	EPA	1.34	1.02	0.51

A-AI	1/21/2004	A2	Up	rinsed	EPA	1.08	0.95	0.48

A-AQ	1/21/2004	2X	up	unrinsed	CPSC	1.98	1.95	0.77

A-AQ	1/21/2004	A2	up	unrinsed	CPSC	1.71	1.76	0.80

A-AQ	1/21/2004	CPSC	up	unrinsed	CPSC	0.55	0.38	0.28

A-AQ	1/21/2004	CPSC	Up	unrinsed	EPA	0.47	0.42	0.30

A-AQ	1/21/2004	2X	Up	unrinsed	EPA	1.72	1.65	0.73

A-AQ	1/21/2004	A2	Up	unrinsed	EPA	2.13	1.75	1.02

A-BJ	1/21/2004	2X	down	unrinsed	CPSC	0.40	0.43	0.26

A-BJ	1/21/2004	A2	down	unrinsed	CPSC	0.45	0.44	0.30

A-BJ	1/21/2004	CPSC	down	unrinsed	CPSC	0.26	0.26	0.16

A-BJ	1/21/2004	CPSC	Down	unrinsed	EPA	0.35	0.30	0.30

A-BJ	1/21/2004	2X	Down	unrinsed	EPA	0.45	0.57	0.27

A-BJ	1/21/2004	A2	Down	unrinsed	EPA	0.83	0.83	0.54

A-BR	1/21/2004	2X	down	rinsed	CPSC	3.01	2.40	1.22

A-BR	1/21/2004	2X	down	rinsed	CPSC	2.78	2.21	1.08

A-BR	1/21/2004	A2	down	rinsed	CPSC	1.66	1.42	0.86

A-BR	1/21/2004	CPSC	down	rinsed	CPSC	0.31	0.23	0.14

A-BR	1/21/2004	CPSC	Down	rinsed	EPA	0.44	0.42	0.20

A-BR	1/21/2004	2X	Down	rinsed	EPA	2.29	1.94	0.83

A-BR	1/21/2004	A2	Down	rinsed	EPA	1.78	1.65	0.70

A-BZ	1/21/2004	2X	up	unrinsed	CPSC	0.80	0.87	0.49

A-BZ	1/21/2004	A2	up	unrinsed	CPSC	1.53	1.56	0.98

A-BZ	1/21/2004	CPSC	up	unrinsed	CPSC	0.52	0.45	0.27

A-BZ	1/21/2004	CPSC	Up	unrinsed	EPA	0.49	0.52	0.35

A-BZ	1/21/2004	2X	Up	unrinsed	EPA	1.94	1.91	1.08

A-BZ	1/21/2004	A2	Up	unrinsed	EPA	1.65	1.75	0.89

C-AB	1/21/2004	2X	down	rinsed	CPSC	1.43	1.85	0.83

C-AB	1/21/2004	A2	down	rinsed	CPSC	0.72	1.03	0.50

C-AB	1/21/2004	CPSC	down	rinsed	CPSC	0.61	0.71	0.35

C-AB	1/21/2004	CPSC	Down	rinsed	EPA	0.25	0.32	0.16

C-AB	1/21/2004	2X	Down	rinsed	EPA	0.70	0.95	0.45

C-AB	1/21/2004	A2	Down	rinsed	EPA	0.70	0.99	0.48

C-AL	1/21/2004	2X	up	unrinsed	CPSC	0.63	0.83	0.36

C-AL	1/21/2004	A2	up	unrinsed	CPSC	0.80	0.96	0.55

C-AL	1/21/2004	CPSC	up	unrinsed	CPSC	0.32	0.37	0.27

C-AL	1/21/2004	CPSC	Up	unrinsed	EPA	0.37	0.40	0.22

C-AL	1/21/2004	2X	Up	unrinsed	EPA	0.80	1.02	0.51

C-AL	1/21/2004	A2	Up	unrinsed	EPA	1.05	1.30	0.70

C-AO	1/21/2004	2X	down	unrinsed	CPSC	0.45	0.51	0.25

C-AO	1/21/2004	A2	down	unrinsed	CPSC	0.87	0.93	0.46

C-AO	1/21/2004	CPSC	down	unrinsed	CPSC	0.35	0.29	0.16

C-AO	1/21/2004	CPSC	Down	unrinsed	EPA	0.32	0.35	0.20

C-AO	1/21/2004	2X	Down	unrinsed	EPA	0.70	0.76	0.31

C-AO	1/21/2004	A2	Down	unrinsed	EPA	0.92	1.08	0.38

C-BG	1/21/2004	2X	up	rinsed	CPSC	0.65	0.86	0.44

C-BG	1/21/2004	A2	up	rinsed	CPSC	0.49	0.66	0.50

C-BG	1/21/2004	CPSC	up	rinsed	CPSC	0.13	0.19	0.14

C-BG	1/21/2004	CPSC	Up	rinsed	EPA	0.08	0.13	0.09

C-BG	1/21/2004	2X	Up	rinsed	EPA	0.35	0.41	0.23

C-BG	1/21/2004	A2	Up	rinsed	EPA	0.38	0.51	0.38

C-BQ	1/21/2004	2X	up	unrinsed	CPSC	0.76	1.05	0.37

C-BQ	1/21/2004	A2	up	unrinsed	CPSC	0.72	1.02	0.37

C-BQ	1/21/2004	CPSC	up	unrinsed	CPSC	0.20	0.20	0.09

C-BQ	1/21/2004	CPSC	Up	unrinsed	EPA	0.27	0.32	0.20

C-BQ	1/21/2004	2X	Up	unrinsed	EPA	0.89	1.11	0.38

C-BQ	1/21/2004	A2	Up	unrinsed	EPA	0.89	0.92	0.38

Note: A-BJ results from 1/21/2004 not used in data analysis as it had
already been wipe sampled during the 8/29/2003 test

Confidentiality Statement (optional)

  FILENAME \* Lower \p \* MERGEFORMAT  g:\technical publications\ols
documents\reports\2005\cca report & wipe comparison study - april
2005\appendix a - wipe comparison study report final v3.doc 	  PAGE  31 

Table of Contents

	  PAGE  i 

Acronym List

Evaluation of the Effectiveness of Coatings in Reducing Dislodgeable
Arsenic, Chromium, and Copper from CCA Treated Wood

Wipe Comparison Study Report

9 May 2005

(Section-Page)   PAGE  31  of 13

Revision 1

October 2004

Evaluation of the 

Effectiveness of Coatings 

in Reducing Dislodgeable Arsenic, Chromium, and 

Copper from CCA Treated 

Wood

Interim Data Report

9 May 2005

	  PAGE  28 

Evaluation of the 

Effectiveness of Coatings 

in Reducing Dislodgeable Arsenic, Chromium, and 

Copper from CCA Treated 

Wood

Interim Data Report

9 May 2005

	  PAGE  29 

	



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Evaluation of the Effectiveness of Coatings in Reducing Dislodgeable
Arsenic, Chromium, and Copper from CCA Treated Wood

Wipe Comparison Report

Category III/Sampling and Analysis