Document ID: EPA-HQ-OPP-2007-0589-0007
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-07-25T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, DC 20460

			OFFICE OF  PREVENTION, PESTICIDES,  AND TOXIC SUBSTANCES

 

July 10, 2007

MEMORANDUM:

Subject:	Occupational and Residential Exposure Chapter for Copper and
Zinc Naphthenates in Support of the Reregistration Eligibility Decision
(RED) Document for the Naphthenate Salts (RED Case 3099). 

To:	Rebecca S. Cool, Chemical Review Manager

	Antimicrobials Division (7510P)

			AND

	Timothy McMahon, PhD., Risk Assessor

	Senior Toxicologist

		Antimicrobials Division (7510P)

From: 	Doreen Aviado, Biologist

	Team Two

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Thru:	Nader Elkassabany, Team Leader

	Team Two

	Risk Assessment and Science Support Branch (RASSB)

	Antimicrobials Division (7510P)

	Norm Cook, Branch Chief

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

DP Barcode: 	D337763

					CAS

Chemical Name:	PC Code:	Registry No.:	Common Names:

Copper Naphthenate	023102		1338-02-9	Naphthenic acids, copper salts;
Cuprinol, 

Zinc Naphthenate	088301		12001-85-3	Naphthenic acids, zinc salts

Attached is the revised Occupational and Residential Exposure Chapter
for Copper and Zinc Naphthenates based on error correction comments in
support of the Naphthenate Salts RED (RED Case 3099). 



OCCUPATIONAL AND RESIDENTIAL EXPOSURE CHAPTER FOR

COPPER AND ZINC NAPHTHENATES IN SUPPORT OF 

THE REREGISTRATION ELIGIBILITY DECISION (RED) DOCUMENT 

FOR THE NAPHTHENATE SALTS

REREGISTRATION CASE 3099

July 10, 2007

Antimicrobials Division

Office of Pesticide Programs

U.S. Environmental Protection Agency

1200 Pennsylvania Avenue, NW

Washington, DC 20460

  TOC \h \l "1-4"  TABLE OF CONTENTS

  TOC \h \l "1-4"   HYPERLINK \l "_Toc166035505"  EXECUTIVE SUMMARY	4 

  HYPERLINK \l "_Toc166035506"  1.0	INTRODUCTION	12 

  HYPERLINK \l "_Toc166035507"  1.1	Purpose	12 

  HYPERLINK \l "_Toc166035508"  1.2	Criteria for Conducting Exposure
Assessments	13 

  HYPERLINK \l "_Toc166035509"  1.3	Chemical Identification	 15

  HYPERLINK \l "_Toc166035510"  1.4	Physical/Chemical Properties	16 

  HYPERLINK \l "_Toc166035511"  2.0	USE INFORMATION	  PAGEREF
_Toc166035511 \h  17  

  HYPERLINK \l "_Toc166035512"  2.1	 Formulation Types and Percent
Active Ingredient	  PAGEREF _Toc166035512 \h  17  

  HYPERLINK \l "_Toc166035513"  2.2	Summary of Use Patterns and
Formulations	  PAGEREF _Toc166035513 \h  17  

  HYPERLINK \l "_Toc166035514"  3.0	SUMMARY OF TOXICITY DATA	  PAGEREF
_Toc166035514 \h  20  

  HYPERLINK \l "_Toc166035515"  3.1	Acute Toxicity	   PAGEREF
_Toc166035514 \h  20 

  HYPERLINK \l "_Toc166035516"  3.2	Summary of Toxicity Endpoints	 21

  HYPERLINK \l "_Toc166035516"  3.3	FQPA Considerations	 22	

  HYPERLINK \l "_Toc166035517"  4.0	RESIDENTIAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc166035517 \h  Error! Bookmark not defined.  

  HYPERLINK \l "_Toc166035518"  4.1	Summary of Registered Uses	  PAGEREF
_Toc166035518 \h  Error! Bookmark not defined.  

  HYPERLINK \l "_Toc166035519"  4.2	Dietary Exposure	  PAGEREF
_Toc166035519 \h  24  

  HYPERLINK \l "_Toc166035520"  4.3	Drinking Water Exposure	  PAGEREF
_Toc166035520 \h  24  

  HYPERLINK \l "_Toc166035521"  4.4	Residential Exposures	  PAGEREF
_Toc166035521 \h  24  

  HYPERLINK \l "_Toc166035522"  4.4.1	Residential Handler Exposures	25 

  HYPERLINK \l "_Toc166035523"  4.4.2	Residential Post-application
Exposures	  PAGEREF _Toc166035523 \h  26  

  HYPERLINK \l "_Toc166035524"  4.4.2.1	Treated Outdoor-Use Textiles	 
PAGEREF _Toc166035524 \h  27  

  HYPERLINK \l "_Toc166035525"  4.4.2.2	Treated Lumber	  PAGEREF
_Toc166035525 \h  30  

  HYPERLINK \l "_Toc166035526"  4.4.3	Data Limitations/Uncertainties	 
PAGEREF _Toc166035526 \h  33  

  HYPERLINK \l "_Toc166035527"  5.0	RESIDENTIAL AGGREGATE RISK
ASSESSMENTS AND RISK CHARACTERIZATION	  PAGEREF _Toc166035527 \h  34  

  HYPERLINK \l "_Toc166035528"  5.1	Acute and Chronic Dietary Aggregate
Risk	  PAGEREF _Toc166035528 \h  34  

  HYPERLINK \l "_Toc166035529"  5.2	Short-Term Aggregate Risks	  PAGEREF
_Toc166035529 \h  34  

  HYPERLINK \l "_Toc166035530"  6.0	OCCUPATIONAL EXPOSURE ASSESSMENT	38 

  HYPERLINK \l "_Toc166035531"  6.1	Summary of Registered Uses	38 

  HYPERLINK \l "_Toc166035532"  6.2	Occupational Handler Exposures	40 

  HYPERLINK \l "_Toc166035533"  6.3	Occupational Post-application
Exposures	46 

  HYPERLINK \l "_Toc166035534"  6.4	Wood Preservation	46 

  HYPERLINK \l "_Toc166035535"  6.4.1	Non-Pressure Treatment Scenarios
(Handler and Post-application)	46 

  HYPERLINK \l "_Toc166035536"  6.4.2	Pressure Treatment Scenarios
(Handler and Post-application)	53 

  HYPERLINK \l "_Toc166035537"  6.5	Data Limitations/Uncertainties	57 

  HYPERLINK \l "_Toc166035538"  7.0	REFERENCES	59 

  HYPERLINK \l "_Toc166035538"  APPENDIX A: Summary of CMA and PHED Data
62 

  HYPERLINK \l "_Toc166035538"  APPENDIX B: Calculation of DDAC Exposure
Values	64 

 

 

EXECUTIVE SUMMARY tc \l1 "EXECUTIVE SUMMARY 

		This document is the Occupational and Residential Exposure Chapter for
the active ingredients Copper Naphthenate and Zinc Naphthenate, as part
of the Reregistration Eligibility Decision (RED) document for the
Naphthenate Salts (RED Case 3099).  It addresses the potential risks to
humans that result from the antimicrobial uses of products containing
this chemical in occupational and residential settings. 

		The Office of Pesticide Programs (OPP), Special Review and
Reregistration Division (SRRD) issued a drafted preliminary risk
assessment for a comprehensive RED on Copper compounds which was posted
to the Agency docket January 25, 2006 for public comment (EPA’s
Pesticide Docket EPA-HQ-OPP-2005-0558).  This Coppers RED included a
qualitative human health assessment of copper-containing pesticides from
four copper cases, including: Copper II Compounds (0649), Copper
Sulfates (0636), Copper and Oxides (4025), Copper Salts (4026) and
certain other coppers.  The Copper Salts case (RED Case 4026), included
Copper Naphthenate as an active ingredient.  SRRD had determined that
the cupric ion is the component of toxicological interest, regardless of
the source of Copper.  Since Copper (Cu) is a naturally occurring metal
efficiently regulated in the human system, and due to the lack of
systemic toxicity associated with Copper exposure, no toxicological
endpoints were selected for human health risk assessment purposes;
therefore only a qualitative assessment was conducted (USEPA, 2006).

	The Antimicrobials Division (AD) determined however that a separate RED
document would be developed for the copper salt, Copper Naphthenate, as
a naphthenic acid salt when assessed in conjunction with Zinc
Naphthenate.  Both Copper and Zinc Naphthenates have been assigned to
RED Case 3099, Naphthenate Salts, for joint reregistration review.  At
present, these pesticides are registered as active ingredients in
products solely under the regulatory purview of AD.  Also, they are
considered together for hazard characterization since endpoints of
concern have been identified from the available toxicology database for
both Copper and Zinc Naphthenates, enabling AD to conduct a formal risk
assessment. The presence of a metal ion (zinc or copper) apparently does
not have a significant influence on the mammalian toxicity of naphthenic
acid. (USEPA, 2007).

The Naphthenate Salts (Copper/Zinc) are carboxylates made with
naphthenic acid, a natural component of petroleum.  These organometallic
compounds are registered as antimicrobial fungicides for control of
decay, mold, rot, mildew, stain and as insecticides against certain
wood-boring insects (e.g., termites, powder-post beetles and ants) in
various preservative applications.  

	The Naphthenate Salts are active ingredients used predominantly in
industrial and commercial wood preservation (Use Site Category X -wood
preservatives) for non-pressure (dip/brush/spray) and pressure
treatments (vacuum/full-cell) to protect against fungal rot, decay,
termites and wood-boring insects in unfinished wood and various
fabricated wood products.  These preservatives are also used for
remedial treatments to in-service poles (internal/external surfaces at
ground or below-ground level via brush/trowel, mechanical injection, or
bandage wrap). Treated wood is specified for exterior above-ground,
ground-contact, below-ground and fresh or salt water contact use
applications. The Naphthenate Salts are also used as protective wood
preservative surface treatments when applied to bare seasoned wood.  For
this use, they are readily available to the general public, sold
over-the-counter to consumers as wood protection coatings (and
water-repellents). 

	Copper/Zinc Naphthenates are also used for mainly commercial/industrial
materials preservation (Use Site Category VII - materials preservatives)
of cellulose-based cordage/textiles.   Products are used as fungistats
to control rot and mildew and are registered for impregnation by dip
(primarily), or by spray and brush surface treatment. It is additionally
used for incorporation into industrial textiles meeting military or
government-specified needs.

	Examples of the materials/wood preserved using Naphthenate Salts
include cellulose-based fibers in cordage (ropes, twine, nets) and
non-apparel and industrial textiles (tents, awnings, tarpaulins, canvas
products, burlap, truck and boat covers, and non-rubber fabrics);
outdoor wood building materials, such as particle board; lumber, patio
decking, fence posts, and other wood products; and in-service wood
utility poles and similar members.  The registered Copper and Zinc
Naphthenate wood/materials preservatives are classified as general-use
(not restricted use) products.  Products formulated or repackaged from
these compounds must be labeled for “Exterior Use Only”.  Treated
wood/materials preserved with Naphthenate Salts preservatives are
intended for exterior use-site applications only; indoor
installation/uses are not allowed.  

The Naphthenate Salts have been registered with the Agency for several
decades; Copper Naphthenate since October 29, 1951, and Zinc Naphthenate
since November 26, 1975.  At present there are 38 active registrations
for products containing Copper Naphthenate, and 11 active registrations
for Zinc Naphthenate.   The Copper/Zinc Naphthenate technical chemical
product concentrates are formulation intermediates, all registered to
OMG Americas, Inc.. They are technical sources for use by formulators in
manufacturing wood preservative/materials preservative end-use products
requiring EPA registration.  The percentage of Naphthenate Salts in the
formulator-use technical source products are 58% to 77% (Copper
Naphthenate) and 63% (Zinc Naphthenate).  The various end-use products
can range from 7.5% to 89%.  Products containing Naphthenate Salts are
formulated as soluble concentrates, emulsifiable concentrates and
ready-to-use liquids.

	Based on registered use patterns from product labeling on file with the
Agency for Copper/Zinc Naphthenates, it has been determined that
exposure to handlers can occur in a variety of occupational and
residential environments.  Additionally, post-application exposures are
likely to occur in these settings.  The representative scenarios
selected by AD were evaluated using maximum application rates as stated
on the product labels. 

The durations and routes of exposure evaluated in this assessment
include: residential handler short-term (ST) (1-30 days) dermal and ST
inhalation route exposures; residential post-application adult/child ST
dermal and child ST incidental oral contact exposures from treated wood
and treated textile surfaces.  For occupational scenarios:
intermediate-term (IT) (1 - 6 months) dermal route exposures and, ST/IT
and long-term (LT) (longer than 6 months) inhalation exposures.  

From an oral developmental toxicity study, a maternal NOAEL of 30
mg/kg/day was selected for ST/IT/LT inhalation and ST incidental oral
exposure. A route-specific study was available for selecting dermal
exposure endpoints: the ST dermal endpoint is based on a LOAEL of 100
mg/kg/day leading to dermal irritation (which was converted to a dermal
concentration of 22,222 µg/cm2); and the IT endpoint is the NOAEL of
100 mg/kg/day for dermal exposure leading to systemic effects.  The
level of concern or “target” margin of exposure (MOE) varies by
route and duration of exposure.  For Naphthenate Salts, the target MOE
is 100 for ST incidental oral (residential) and IT dermal exposures
(occupational), 300 for ST dermal irritation exposure (residential), and
1,000 for ST, IT, and LT inhalation exposures (residential/occupational
as appropriate).   The Agency may request a confirmatory inhalation
toxicity study in cases where the inhalation MOEs are below a value of
1,000 since the inhalation endpoint is based on an oral study.

A human dermal absorption factor was not selected since the dermal
endpoint was derived from a route-specific study. An inhalation
absorption factor of 100% was used (default value, assuming oral and
inhalation absorption are equivalent) since an oral endpoint was
selected for determining inhalation exposures (USEPA, 2007).

 

	To assess the handler risks, AD used standard assumptions and surrogate
unit exposure data from the following sources: the Chemical
Manufacturers Association (CMA) antimicrobial exposure study, the
Pesticide Handlers Exposure Database (PHED), and for non-pressure wood
treatments, the proprietary sapstain study (SIG Task Force # 73154) was
used “Measurement and Assessment of Dermal and Inhalation Exposures to
Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the Protection of Cut
Lumber (Phase III)” (Bestari et al., 1999, MRID 455243-04).  Also, the
exposure study sponsored by the American Chemistry Council (2002)
entitled “Assessment of Potential Inhalation and Dermal Exposure
Associated with Pressure Treatment of Wood with Arsenical Wood
Products” (ACC, 2002) was used for occupational pressure treatment
scenarios.  

	Agency standard values and EPA’s Health Effects Division’s (HED)
Standard Operating Procedures (SOPs) for Residential Exposure
Assessments (USEPA, 2000 and 2001), were used to estimate
post-application/bystander exposures. Additionally, without robust
chemical-specific wood leaching data or wood-wipe sampling data on file
with the Agency for Naphthenate Salts, the DDAC study data (Bestari et
al., 1999) was used as a source for estimating maximum surface residue
loads for adult/child post-application exposure to treated wood.

Handler Risk Summary

		For the residential handler inhalation exposure and MOE assessment,
the MOEs for ST inhalation exposure for homeowners applying preservative
were above the target inhalation MOE of 1,000 for both scenarios. 
Dermal irritation exposures for both application scenarios were below
the ST target MOE of 300 as follows:

ST dermal exposure resulting from the application of preservative using
a low-pressure sprayer:  MOE = 4; and

ST dermal exposure resulting from the application of preservative using
brush/roller:  MOE = 6.

		For the occupational handler, calculated MOEs were below the target
MOEs of 100 for IT dermal and 1,000 for ST/IT/LT inhalation for the
following scenarios listed.  For MOEs below 1,000, the Agency may
request a confirmatory inhalation toxicity study to refine the potential
risks since the current inhalation endpoint is based on an oral NOAEL:  

Dermal:

Preservation of textiles, low-pressure sprayer:  MOE = 3 at baseline
dermal;

Preservation of textiles, brush/roller:  MOE = 4 at baseline and 33 with
glove PPE; 

Preservation of textiles, liquid pour:  MOE = < 1 at baseline and 50
with glove PPE;

Preservation of textiles, liquid pump: MOE = 14 at baseline;

General preservation of wood, brush/roller: MOE = 4 at baseline, 25 with
glove PPE; 

General preservation of wood, airless sprayer: MOE = 2 at baseline, 5
for glove PPE;

General preservation of wood, low-pressure sprayer:  MOE = 3 at
baseline;

Application to in-service utility poles, brush: MOE = 5 at baseline, 33
for glove PPE. 

Inhalation:

Preservation of textiles, brush/roller:  MOE = 750 without respirator
PPE;

Preservation of textiles, liquid pour:   MOE = 600 without respirator
PPE;

General preservation of wood, brush/roller:  MOE = 700 without
respirator PPE; 

General preservation of wood, airless sprayer: MOE = 23 without
respirator PPE and 230 with respirator use;

Application to in-service utility poles, brush: MOE = 880 without
respirator PPE.

	Occupational handler and post-application exposures assessed separately
for the industrial wood preservative treatments (non-pressure and
pressure) resulted in the following scenarios of concern:

Dermal:

Blender/Spray Operators (non-pressure mix/load): MOE = 25;

Diptank Operators (non-pressure): MOE = 70 and 90;

Treatment Operator (pressure treatment): MOE = 25;

Post-application Workers (pressure treatment): MOE = 70.

Inhalation:

Blender/Spray Operators (non-pressure mix/load): MOE = 120.

	It should be noted that short-term dermal exposures were not assessed
for occupational handlers because the endpoint is based on dermal
irritation.  Instead, dermal irritation exposures and risks will be
mitigated using default personal protective equipment requirements based
on the toxicity of the end-use product.  To minimize dermal exposures,
the minimum PPE required for mixers, loaders, and others exposed to
end-use products that result in classification of category I, II, or III
for skin irritation potential will be a long-sleeve shirt, long pants,
shoes, socks, chemical-resistant gloves, and a chemical-resistant apron.
 Once diluted, if the concentration in the diluted solution will result
in classification of toxicity category IV for skin irritation potential,
then the chemical-resistant gloves and chemical-resistant apron can be
eliminated for applicators and others exposed to the dilute product.
Note that chemical-resistant eyewear will be required if the end-use
product is classified as category I or II for eye irritation potential. 

Post-application/Bystander Risk Summary

For the residential postapplication risk assessment, MOEs are above the
respective target MOEs (300 for ST dermal irritation exposures, and 100
for ST incidental ingestion exposures) for all scenarios except for the
following:

ST dermal exposure of adults/children to treated textiles:  MOE = 10
(200 if a transfer factor of 5% is used); and  

ST incidental ingestion exposure of children to treated textiles:  MOE =
10.

		Except for the post-application scenarios assessed for wood
preservatives in Section 6.4, occupational post-application exposures
were not assessed and are assumed to be negligible.  The MOEs for
inhalation exposures associated with post-application scenarios assessed
for wood preservatives are all above the target MOE of 1,000.

Aggregate Risk Summary

Non-dietary short- and intermediate-term aggregate exposures and risks
were not assessed for adults and children exposed to residues of
Naphthenate Salts from the use of products in non-occupational
environments.  As described in more detail in Section 5, only the
residential scenarios not identified as concerns are considered for the
aggregate assessment.  These scenarios include: ST inhalation exposure
by adult handlers and ST dermal and incidental oral post-application
exposure by children from contact with treated lumber. Because the
dermal and oral exposure endpoints were based on route-specific studies
resulting in different effects, separate route-specific aggregate
assessment is appropriate.  However, only one exposure scenario was
identified for each route of exposure.  Accordingly, evaluation of
aggregate risk using the Total MOE method outlined in OPP guidance for
aggregate risk assessment is unnecessary.  

		

In addition, the likelihood of co-occurrence is limited since the
majority of registered products are for industrial/commercial-use. 
Representative scenarios for residential exposure are limited to adult
handlers painting with wood preservative/wood protection surface
coatings containing Copper/Zinc Naphthenates.  Potential child
post-application exposure is limited to contact with residues on mainly
in-service treated wood. Textile preservation appears to be limited to
primarily industrial textiles and certain government-issued (military
specified) treatments for cellulose-based cotton, canvas, tentage/tarps,
ropes, cordage and nets.

Data Limitations and Uncertainties:

		There are a number of uncertainties associated with this assessment
and these have been reiterated from Sections 4.4.3 (residential) and 6.5
(occupational) respectively.  The data limitations and uncertainties
associated with the residential handler and post-application exposure
assessments include the following: 

In the absence of chemical-specific exposure data, handler surrogate
dermal and inhalation unit exposure values were taken from the Pesticide
Handlers Exposure Database (PHED)(USEPA, 1998) (See Appendix A for a
summary of this data source). 

The quantities handled/treated and certain exposure factors were
estimated based on information from various sources, including HED’s
Standard Operating Procedures (SOPs) for Residential Exposure
Assessments (USEPA, 2000 and 2001) and AD’s Draft SOPs (unpublished
internal guidance) (USEPA, 2005).  In certain cases, no standard values
were available for some scenarios.  Assumptions for these scenarios were
based on AD estimates and could be further refined from input from
registrants. 

The low pressure spray unit exposure data from PHED were used to assess
outdoor applications of wood preservative coatings (exterior of homes). 
As the PHED low pressure spray data are representative of treating low
to mid-level range targets (shrubs/greenhouse benches) and the scenario
assessed in this document represents treatments that may also occur
above the waist, the unit exposure value may underestimate exposure to
the head and the upper body.  

The methods used to estimate child and adult exposures to treated
textiles are highly conservative and based on approaches from the
Residential SOPs (USEPA 2000, and 2001) for contact with porous treated
surfaces (clothing, mattresses and carpets). Without data on actual
treated textile residues, dissipation or dermal transfer coefficients,
these scenarios have a high degree of uncertainty associated with them.
The registrants’ input will assist in refining the MOEs and confirming
the Naphthenate Salts textile use patterns.    

In this assessment, incidental ingestion and dermal exposures to treated
wood were estimated using surrogate DDAC data (3 (g/cm2).  The degree of
uncertainty (under- or overestimation) associated with using the DDAC
hand residue data for dermal and oral exposure from contacting treated
lumber are unknown.  The amount of residue measured on the test
subjects’ hands is variable and may be influenced by the duration of
exposure, how often wood is contacted, and the degree of contact (i.e.,
do the hand residues from the DDAC study mimic a child’s play activity
on decks and playsets?).  In addition, from the limited data available
to the Agency, it appears that leaching from Naphthenate Salts-treated
wood depends on pH, with the highest leach rates occurring under acidic
conditions (USEPA, 2007a). 

Data are not available to assess the levels of Naphthenate Salts in soil
contaminated from Naphthenate Salts-treated wood (e.g., above
ground/ground contact fabricated components of decks or playsets).
Because of this data gap, EPA was not able to estimate residential
post-application dermal and incidental oral ingestion exposure to soil
contaminated with Naphthenate Salts residues.  It is assumed that any
soil residues attributed to weathering of in-service wood (playsets)
will remain near these structures for potential child exposure (USEPA,
2007a). 

	The data limitations and uncertainties associated with the occupational
handler and post-application exposure assessments include:

Certain surrogate dermal and inhalation unit exposure values were taken
from the proprietary CMA antimicrobial exposure study (US EPA 1999: DP
Barcode D247642) or from the Pesticide Handlers Exposure Database (US
EPA 1998) (See Appendix A for summaries of these data sources). Since
the CMA data are of poor quality, the Agency may request that
confirmatory data be submitted in order to support the values used in
these assessments. 

The quantities handled/treated were estimated using Agency standard
assumptions.  In certain cases where standard values were unavailable,
AD used professional judgment based on Agency understanding of
industrial practices to create estimates.  Assumptions for these
scenarios were could be further refined with input from the registrants.
 

For the preservation of textiles, exposures to handlers during
preparation of dipping solution were assessed assuming a liquid pour or
liquid pump operation associated with automated (large-scale) dipping of
textiles in industrial settings.  However, based on the label use
instructions, it is clear that manual dipping is also used for
preservation of textiles (e.g., via preparation of small-scale dipping
solution by pouring product into a small receptacle and manually dipping
textiles).  Exposures that may occur as part of manual dipping activity
for textiles are not assessed here and may result in possibly higher
exposures than are estimated for the liquid pour/liquid pump scenarios
associated with large-scale dip operations.  However, since the Agency
assessed dip treatment of wood in this document (i.e., diptank
operators), and the use methods are comparable to those for textile
treatment, that assessment can be considered as a high-end
representative estimate of manual textile dip applications.

The type of spray equipment to be used was not specified on most labels
for scenarios involving preservation of outdoor-use textiles and general
preservation of wood use patterns.  Therefore, these scenarios were
assessed using the PHED unit exposures for use of a low-pressure hand
wand (for outdoor-use textiles), and use of an airless sprayer or a
low-pressure hand wand (for the general preservation of wood).  As the
PHED low pressure spray data are representative of treating low to
mid-level range targets (shrubs/greenhouse benches) and the scenarios
assessed in this document represent treatments that may also occur above
the waist, the unit exposure value may underestimate exposure to the
head and the upper body.  Also, it is noted that by assuming use of an
airless sprayer for preservation of wood products, a higher unit
exposure value is selected and the quantity handled is greater;
resulting therefore in increased handler exposure.  In these cases, the
appropriate application equipment could be further refined by the
registrants.  

Remedial treatments with Copper Naphthenate can be made to in-service
wooden poles/piles/posts using brush, trowel, caulking gun (mechanical
pressure pump), or impregnated bandage wraps.  In lieu of
chemical-specific data or surrogate data sources for the remedial
applications, handlers applying remedial-use products to
interior/exterior surfaces of in-service poles were assessed using unit
exposure data for the PHED paintbrush scenario (Scenario 22).  As a
high-end conservative approach, it was assumed that the PHED paintbrush
scenario unit exposure value can be used to represent the remedial
brushing techniques.  Exposures for the other application methods (i.e.,
trowel, caulking gun, or pre-manufactured bandage) were assumed to be
represented by the assessment done using unit exposure data for the
brush use scenario.  This approach may overestimate actual exposures for
workers conducting remedial treatments based on the following
considerations:  

The brush-on application in treating in-service utility poles is
predominantly used for wood preservative pastes.  Brushing  a semi-solid
onto a pole may not present the same exposures as brushing a liquid (as
in PHED painting scenario) due to differences in the viscosity of the
material being brushed;  

The liquid Copper Naphthenate formulations are injected directly into a
pole through a pressure pump to treat the internal areas of a pole. The
exposure to the applicator would be in the mix and load phase of the
application process and not in the actual application to the pole; and

Wrapping a bandage around a pole would not present the same exposures as
brushing a liquid (as in PHED painting scenario).  

For the wood preservative pressure treatment scenarios, CCA exposure
data were used in the absence of exposure data specific to the
Naphthenate Salts.  For the wood preservative non-pressure treatment
scenarios, DDAC exposure data were used in the absence of more specific
exposure data.  Limitations and uncertainties associated with the use of
these data include:

The assumption was made that exposure patterns for workers at treatment
facilities using CCA and DDAC would be similar to exposure patterns for
workers at treatment facilities using Naphthenate Salts, and therefore
the exposures could be used as surrogate data for workers that treat
wood with Copper/Zinc Naphthenate-based formulations. 

For environmental modeling, it was assumed that the leaching process
from the Naphthenate Salts-treated wood would be similar to that of CCA
and DDAC.  However, due to the lack of robust data for wood treated with
Naphthenate Salts, it is not possible to verify this assumption. 

In the occupational assessment, dermal exposures to treated wood were
estimated using surrogate DDAC data (3 (g/cm2).  The degree of
uncertainty (under- or overestimation) associated with using the DDAC
hand residue data for dermal exposure from contacting treated lumber are
unknown.  The amount of residue measured on the test subjects’ hands
is variable and may be influenced by the duration of exposure, how often
wood is contacted, and the degree of contact (i.e., with or without use
of glove PPE). 

1.0	 INTRODUCTION

		1.1	Purpose 

		In this document, the Antimicrobials Division (AD) presents the
results of its review of the potential human health effects of
occupational and residential exposure to the Copper and Zinc Naphthenate
Salts.  This information is for use in EPA's development of the
Reregistration Eligibility Decision (RED) document for the Naphthenate
Salts (RED Case 3099).  

		The Office of Pesticide Programs (OPP), Special Review and
Reregistration Division (SRRD) issued a drafted preliminary risk
assessment for a comprehensive RED on Copper compounds which was posted
to the Agency docket January 25, 2006 for public comment (EPA’s
Pesticide Docket EPA-HQ-OPP-2005-0558).  This Coppers RED included a
qualitative human health assessment of copper-containing pesticides from
four copper cases, including: Copper II Compounds (0649), Copper
Sulfates (0636), Copper and Oxides (4025), Copper Salts (4026) and
certain other coppers.  The Copper Salts case (RED Case 4026), included
Copper Naphthenate as an active ingredient.  SRRD had determined that
the cupric ion is the component of toxicological interest, regardless of
the source of Copper.  Since Copper (Cu) is a naturally occurring metal
efficiently regulated in the human system, and due to the lack of
systemic toxicity associated with Copper exposure, no toxicological
endpoints were selected for human health risk assessment purposes;
therefore only a qualitative assessment was conducted (USEPA, 2006).

	The Antimicrobials Division (AD) determined however that a separate RED
document would be developed for the copper salt, Copper Naphthenate, as
a naphthenic acid salt when assessed in conjunction with Zinc
Naphthenate.  Both Copper and Zinc Naphthenates have been assigned to
RED Case 3099, Naphthenate Salts, for joint reregistration review.  At
present, these pesticides are registered as active ingredients in
products solely under the regulatory purview of AD.  Also, they are
considered together for hazard characterization since endpoints of
concern have been identified from the available toxicology database for
both Copper and Zinc Naphthenates, enabling AD to conduct a formal risk
assessment. The presence of a metal ion (zinc or copper) apparently does
not have a significant influence on the mammalian toxicity of naphthenic
acid. (USEPA, 2007).

		1.2	Criteria for Conducting Exposure Assessments

		An occupational and/or residential exposure assessment is required for
an active ingredient if (1) certain toxicological criteria are triggered
and (2) there is potential exposure to handlers (mixers, loaders,
applicators, etc.) during use or to persons entering treated sites after
application is complete.  For the Copper and Zinc Naphthenates, both
criteria are met.

In this document, scenarios were assessed by using unit exposure data to
estimate occupational and residential handlers’ exposures. Unit
exposures are estimates of the amount of exposure to an active
ingredient a handler receives while performing various handler tasks and
are expressed in terms of micrograms or milligrams (1mg = 1,000 µg) of
active ingredient (a.i.) per pounds of active ingredient handled.  A
series of unit exposures have been developed that are unique for each
scenario typically considered in assessments (i.e., there are different
unit exposures for different types of application equipment, job
functions, and levels of protection).  The unit exposure concept has
been established in the scientific literature and also through various
exposure monitoring guidelines published by the USEPA and international
organizations such as Health Canada and OECD (Organization for Economic
Cooperation and Development).

Using surrogate unit exposure data, maximum application rates from
labels, and EPA estimates of daily amount handled, exposures and risks
to handlers were assessed.  The exposure/risks were calculated using the
following equations:

Daily Exposure: Daily dermal or inhalation handler exposures are
estimated for each applicable handler task with the application rate,
quantity treated/handled in a day, and the applicable dermal or
inhalation unit exposure using the following formula:

Daily Exposure:	E = UE x AR x AT						(Eq. 1)

Where:  

E	=	Amount (mg or (g ai/day) deposited on the surface of the skin that
is available for dermal absorption or amount inhaled that is available
for inhalation absorption;

UE	=	Unit exposure value (mg ai/lb ai) derived from August 1998 PHED
data or from 1992 CMA data;

AR	=	Maximum application rate based on a logical unit treatment, such as
acres (A), square feet (sq. ft.), gallons (gal), or cubic feet (cu. ft).
Maximum values are generally used (lb ai/A, lb ai/sq ft, lb ai/gal, lb
ai/cu ft); and

AT 	=	Normalized application area based on a logical unit treatment such
as acres (A/day), square feet  (sq ft/day), gallons (gal/day), or cubic
feet (cu ft/day).

Daily Dose: The daily dermal (intermediate-term only) or inhalation dose
is calculated by normalizing the daily exposure by body weight and
adjusting, if necessary, with an appropriate absorption factor.  An oral
endpoint was selected for inhalation exposures of all durations;
therefore, an absorption factor of 100% was used (default value,
assuming oral and inhalation absorption are equivalent).  A dermal
absorption factor was not necessary for the intermediate-term dermal
exposures because the endpoints are based on a route-specific dermal
study.  The short-term dermal exposures were not assessed using a daily
dose approach since the endpoint selected is based on irritation
effects, not systemic effects. Daily dose was calculated using the
following formula:

Daily Dose:	ADD = E x ABS							(Eq. 2)

			   BW						

Where:

ADD 		= 	Absorbed dose received from exposure to a chemical in a given
scenario (mg active ingredient/kg body weight/day);

E 		=	Amount (mg ai/day) deposited on the surface of the skin that is
available for dermal absorption or amount inhaled that is available for
inhalation absorption;

ABS 		= 	A measure of the amount of chemical that crosses a biological
boundary such as lungs (% of the total available absorbed); and

BW		= 	Body weight determined to represent the population of interest in
a risk assessment (kg).

Margins of Exposure:  Non-cancer inhalation and dermal risks for each
applicable handler scenario are calculated using a Margin of Exposure
(MOE), which is a ratio of the daily dose to the toxicological endpoint
of concern.

Margins of Exposure:	MOE = NOAEL or LOAEL					(Eq. 3)

					ADD

Where:

MOE 			= 	Margin of exposure, value used to represent risk or how close
a chemical exposure is to being a concern (unitless);

NOAEL or LOAEL	= 	Dose level in a toxicity study, where no observed
adverse effects (NOAEL) or where the lowest observed adverse effects
(LOAEL) occurred in the study; and

ADD 			= 	Average daily dose or the absorbed dose received from exposure
to a chemical in a given scenario (mg ai/kg body weight/day).

	In addition to the target MOEs from Table 3.2 that were used for this
assessment, a series of assumptions and exposure factors served as the
basis for completing the handler risk assessment. Each general
assumption and factor for both residential and occupational assessments
is detailed below.  Assumptions specific to the use site category are
listed in each separate section of this document.  The general
assumptions and factors include:

The Copper and Zinc Naphthenate Salts are broad spectrum fungicides
predominantly used as a wood preservative for pressure and non-pressure
impregnation or remedial treatments, and to a lesser degree as a
materials preservative for treating cellulose-based textiles/cordage. 
They are registered for use in various exterior applications and use
conditions.  As such, AD has patterned this risk assessment on a series
of likely scenarios for use sites believed to be representative of the
majority of use patterns for the Naphthenate Salts.

Based on the adverse effects for the toxicological endpoints, the
average body weight of 70 kg was used for an adult (and 15 kg for
children in the post-application assessment) as appropriate to complete
the non-cancer risk assessment.  

Exposure factors used to calculate daily exposures to handlers were
based on applicable data, if available.  When appropriate data were
lacking, values from a scenario deemed similar were used. 

For a given application method, the maximum use-rates allowed by product
labeling were assumed.  Registrant input is requested for clarification
of use conditions. 

		1.3	Chemical Identification

	The Naphthenates (Copper/Zinc) are organometallic compounds formed as
the reaction products of metal salts (copper/zinc) and petroleum-derived
naphthenic acids.  Naphthenic acids are mixtures of carboxylic acids
derived from certain fractions obtained during the distillation of crude
oil (petroleum).  Table 1.1 shows chemical identification information
for the Copper Naphthenate and Zinc Naphthenate technical grade active
ingredients (TGAIs).

Table 1.1.  Chemical Identification Information for Copper/Zinc
Naphthenates  (TGAIs)

Parameter	Copper Naphthenate	Zinc Naphthenate

Chemical Structure

 

	

O=C(O[Cu])-C12H23

	

R-C=-O=Zn-O-C=O-R

Chemical Name	

Naphthenic acids, copper salts	

Naphthenic acids, zinc salts

Common Name	Copper Naphthenate	Zinc Naphthenate

Chemical Code	023102	088301

CAS Number	1338-02-9	12001-85-3

Molecular Formula	Cu (R-COO)2   

where R= various alkyl and  cycloalkyl groups	

Zn(R-COO)2   

where R= various alkyl and  cycloalkyl groups

		1.4	Physical/Chemical Properties

		Table 1.2 shows physical/chemical characteristics that have been
reported for Copper and Zinc Naphthenates.  The chemicals are stable
under normal conditions and the technical-grade compounds are considered
to be of low volatility. However, due to the nature of the solvent
carriers (e.g., mineral spirits, light and heavy oils, petroleum
distillates) used in formulating registered pesticide end-use products,
and/or in preparing use-dilutions for treatment applications, volatile
organic compounds may be present.  Due to the low solubility properties
of the Naphthenate Salts in water, most pesticide product formulations
are registered as solvent-borne and oil-based soluble concentrates and
liquids.  Certain formulated products contain ingredients which provide
solubilized forms of the Naphthenate Salts allowing for water-based
treatment solutions.  

Table 1.2.  Physical/Chemical Properties of Copper/Zinc Naphthenates
(TGAIs)

Parameter	Copper Naphthenate	Zinc Naphthenate

Molecular Weight	Average ( 550

Variable between 400-750	

Variable between 400-750

Color/Odor	Green-blue /Burnt and hydrocarbon-like odor	Light Brown/
Hydrocarbon-like odor

Physical State	TGAI is a solid amorphous glass at 25 o C;         MUP is
a viscous liquid at 25 o C          	TGAI appears solid;

 MUP appears to be a viscous liquid at 25 o C          

Specific Gravity (Relative Density)	0.99-1.055 g/ml

	0.8-1.02 g/ml

Stability	Stable under normal conditions and elevated temperatures. 
TGAI is non-flammable at 60 o C and non-explosive. 	Stable at ambient
temperatures (22± 2 o C) and elevated temperatures (53-55 o C) for 14
days (based on data from a 14-day study only).  TGAI  is non-flammable
at 60 o C and non-explosive.

Melting Point	Average ( 102 o C 	----

Boiling Point	TGAI is a non-volatile salt (decomposes at around 257 o
C); MUP boiling point 121 o C.	----

Water Solubility	4.6899 mg/L (ppm) at 25 o C 

(practically insoluble in water)         	15-80 ppm (mg/L) at 25 o C

(low solubility in water)        

Solvent Solubility	Highly soluble in organic solvents; more soluble in
non-polar organics than polar organics.	Highly soluble in organic
solvents; more soluble in non-polar organics than polar organics.

Kow	4.1

	1.0 - 1.2

Vapor Pressure (VP)	1.28 x 10-4 mm Hg at  25 o C

 (Assumed to be of low volatility.) 

[Note: Less than 133 mPa  at 100ºC (based on solid form)] a	1.0 x 10-5
mm Hg at  25 o C 

(Assumed to be non-volatile.) 

TGAI = Technical grade active ingredient; MUP = Manufacturing-use
product

Source: Certain data presented in Tables 1.1 and 1.2 were taken from the
following Agency review memoranda from A. Najm Shamim, PhD., Chemist,
AD, prepared in support of the Naphthenate Salts RED: “Data Evaluation
Records (DER) for the Product Chemistry of Copper Naphthenate”, dated
November 8, 2006, and “Data Evaluation Records (DER) for the Product
Chemistry of Zinc Naphthenate”, dated February 9, 2007.  Also, input
provided from the Naphthenate Salts Research Task Force.

a  Data are from the Hazardous Substances Data Bank (HSDB 2007).

2.0	 USE INFORMATION tc \l1 "2.0	USE INFORMATION 

		2.1	 Formulation Types and Percent Active Ingredient tc \l2 "2.1	
Formulation Types and Percent Active Ingredient 

		At present, the forty-nine (49) pesticide products containing Copper
Naphthenate (38 active products) or Zinc Naphthenate (11 active
products) as the active ingredient (a.i.) are registered as either
industrial-use technical chemical source products (5) or formulated
end-use products (44) for industrial/commercial and residential use as
wood/materials preservatives.  Currently, there are three (3) Copper
Naphthenate, and two (2) Zinc Naphthenate, registered manufacturing-use
products (MUPs) as formulation intermediates, used exclusively as
formulator-use technical chemical source product concentrates for
manufacturing pesticide end-use products (EPs).  The forty-four (44)
formulated EPs containing Naphthenate Salts are soluble or emulsifiable
concentrates, and ready-to-use (RTU) solutions.  The percentage of
Naphthenate Salts in the formulator-use technical source MUPs (all
registered to OMG Americas, Inc.) are 58% to 77% (Copper Naphthenate)
and 63% (Zinc Naphthenate).  The concentrations of Naphthenate Salts in
the remaining EPs range from 7.5% to 89% a.i..  

	Commercial Copper/Zinc Naphthenates are typically supplied as 6-8%
copper/zinc (as metal) concentrates which are further diluted with
solvents (e.g., petroleum hydrocarbon), oil carriers or water to yield
1-2% copper/zinc (as metal) use solutions for pressure or certain
non-pressure preservative treatments.  Products used for surface
treatments (e.g., brush/roller applications) may require 10% to 20% or
higher Copper/Zinc Naphthenate solutions to yield a copper/zinc metal
content of 1% to 2% (approximately).

	A pesticide inert use exists for Copper Naphthenate at a limit of 2.5%
in insecticide and nematicide formulations applied to soil and/or
growing crops (prior to formation of edible parts).  An exemption from
the requirement of a tolerance exists for this inert use in accordance
with good agricultural practices (40 CFR 180.920).  Regarding
non-pesticidal inert uses, it is approved by FDA as an indirect food
additive, and for use in veterinary topical treatments to the surface of
horse/pony hooves that have Thrush. (USEPA, 2006a).

		2.2	Summary of Use Patterns and Formulations tc \l2 "2.2	Summary of
Use Pattern and Formulations 

	Copper/Zinc Naphthenates (referred to collectively as Naphthenate
Salts) are broad-spectrum fungicides and insecticides. The Naphthenate
Salts have been registered with the Agency for several decades; Copper
Naphthenate since October 29, 1951, and Zinc Naphthenate since November
26, 1975.  As part of the re-registration process for the Naphthenate
Salts, the Antimicrobials Division (AD) met with the technical source
registrant, OMG Americas, Inc., and members of the Naphthenate Salts
Research Task Force (NSRTF, 2007) to better understand the allowed use
patterns supported under this RED case (USEPA, 2006b). When the MUPs and
formulated EPs for theses chemicals were registered, data to address
human exposure were "reserved" (i.e., not imposed).  Therefore, EPA has
no chemical-specific worker monitoring study data, nor product use and
human activity data, to best characterize use patterns and develop
occupational and residential exposure dose estimates.

	AD determined potential occupational and residential exposure scenarios
by reviewing currently registered labels.  These scenarios are presented
in Table 2.1.  Based on this review of the labels, and
registrant-provided information, it was determined that Naphthenate
Salts products are intended for use predominantly in
industrial/commercial wood preservation (Use Site Category X -wood
preservatives) for non-pressure (dip/brush/spray) and pressure
treatments (vacuum/full-cell) to protect against fungal rot, decay,
termites and wood-boring insects in unfinished wood and various
fabricated wood products.  These preservatives are also used for
remedial treatments to in-service poles (internal/external surfaces at
ground or below-ground level via brush/trowel, mechanical injection, or
bandage wrap). Treated wood is specified for exterior above-ground,
ground-contact, below-ground and fresh or salt water contact use
applications. The Naphthenate Salts are also used as protective wood
preservative surface treatments when applied to bare seasoned wood.  For
this use, they are readily available to the general public, sold
over-the-counter to consumers as wood protection coatings (and
water-repellents). 

	Copper/Zinc Naphthenates are also used for mainly commercial/industrial
materials preservation (Use Site Category VII - materials preservatives)
of cellulose-based cordage/textiles.   Products are used as fungistats
to control rot and mildew and are registered for impregnation by dip
(primarily), or by spray and brush surface treatment. It is additionally
used for incorporation into industrial textiles meeting military or
government-specified needs.  Examples of registered uses for Naphthenate
Salts as a materials preservative include protection of cellulose-based
fibers in cordage (ropes, twine, nets) and non-apparel and industrial
textiles (tents, awnings, tarpaulins, canvas products, burlap, truck and
boat covers, and non-rubber fabrics).

	Use sites for Copper Naphthenate include pressure treatment and
non-pressure treatment of wood for exterior uses (commercial/industrial
and residential use site applications), wood used in contact with fresh
or salt water, and exterior wood exposed to moisture or weather. Copper
Naphthenate is also used in brush, dip, roller, and low pressure spray
applications for the same uses listed above, and in addition is used for
greenhouse and horticultural uses (non-food applications including
wooden seedling trays, plant and flower boxes for ornamental plantings,
trellises, arbors, greenhouse benches, and nursery flats).  Application
by occupational applicators only includes  brush, dip, roller, and low
pressure spray to beverage cases, baskets, tents, awnings, tarpaulins,
canvas products, nets [except fishnets], ropes, cordage, lumber for
ammunition boxes, other boxes, crates, and miscellaneous non-food
contact containers, truck and boat covers, non-rubber fabrics, and
burlap. Copper Naphthenate is also used as a remedial treatment for
standing wood utility poles, mine timbers, bridge timbers, and
cross-ties and stakes.  

Zinc Naphthenate use sites are the same as for Copper Naphthenate but do
not include remedial treatments or to beverage cases, etc. as listed for
Copper Naphthenate. 

	The registered Copper and Zinc Naphthenate wood/materials preservatives
are classified as general-use (not restricted use) products.  Products
formulated or repackaged from these compounds must be labeled for
“Exterior Use Only”.  Treated wood/materials preserved with
Naphthenate Salts preservatives are intended for exterior use-site
applications only; indoor installation/uses are not allowed.  

	Health Canada’s Pest Management Regulatory Agency (PMRA) initiated a
label improvement program in 1990 based on concerns relating to product
misuse and interior applications of naphthenate preservatives.  PMRA
disallowed all “interior uses” for domestic products and cited
required revised label language for product use directions,
precautionary statements, first aid and disposal (PMRA, 1992).  In
1996-1997 the U.S. EPA followed suit at the behest of the California
Environmental Protection Agency, Department of Pesticide Regulation
(DPR) to reevaluate allowed uses of naphthenates due to illnesses
reported to DPR following indoor use of Copper Naphthenate pesticides
where inhalation resulted in nausea, dizziness, headaches and extended
re-entry for building occupants.  Through cooperation with the
Naphthenate Salts Research Task Force a mitigation plan effectively
resulted in required labeling changes; including deleting all indoor
uses, and adding label statements requiring applicators to use
respirators during prolonged or frequent use of products. (DPR, 2000). 

Table 2.1. Potential Use Scenarios Based on Product Labels for
Naphthenate Salts

Use Site Category	

Example Use Sites	

Scenarios

Use Site Category VII

Materials Preservatives	Used to preserve and protect cellulose-based
textiles/cordage intended for exterior-use only; including non-apparel
industrial-use textiles. 

	Application to rope, burlap, canvas, and similar materials in the
production of nets (not including fishing nets), seines, tents, awnings,
tarpaulins, boat and truck covers, and other outdoor-use textiles
(industrial use) and post-production applications to fabricated  textile
articles cited above (commercial and residential use).

Use Site Category X

Wood preservatives	Used in preservation of lumber and wood products for
exterior-use only, via pressure and non-pressure impregnation, and
remedial treatments to outdoor in-service standing poles. 

	Application to lumber and wood processed in treatment facilities
through pressure and non-pressure treatment methods
(industrial/commercial use);

Application to fabricated outdoor-use products, such as fence posts,
patio decking, docks, boats, ladders, millworks, and greenhouse benches
(but not products that come in contact with plants grown for food)
(commercial and residential use);

Application to in-service utility poles and similar members (commercial
use only).

	From Table 2.1, representative exposure scenarios were selected for
assessment in this document.  These scenarios were selected to be
representative of the vast majority of uses and are believed to provide
high-end estimates of dermal, inhalation, or incidental ingestion
exposure.  The representative scenarios assessed in this document are
shown in Table 4.1 (residential) and Table 6.1 (occupational).

3.0	SUMMARY OF TOXICITY DATA tc \l1 "3.0	SUMMARY OF TOXICITY DATA 

3.1	Acute Toxicity

	The acute toxicity database for this compound is considered complete. 
Animal studies conducted with technical grades of the Naphthenate Salts
(Copper/Zinc) active ingredients

show moderate to low acute oral and inhalation toxicity (Toxicity
Categories III- IV) and moderate acute dermal toxicity (Toxicity
Category III).  Irritation studies indicate moderate primary eye
irritation (Toxicity Category III) and moderate to severe primary dermal
irritation (Toxicity Categories III- II).  The irritation study data
indicate that Zinc Naphthenate seems to elicit greater dermal irritation
potential over Copper Naphthenate. The Zinc Naphthenate technical source
compound (( 60% a.i.) may also be a possible sensitizing agent. 
Required dermal PPE precautionary statements appear on registered
product labeling to protect handlers from possible dermatitis or
irritation with prolonged or repeated contact.  The acute toxicity data
for Copper/Zinc Naphthenates TGAIs are summarized below in Table 3.1.

Table 3.1  Acute Toxicity Profile for Copper/Zinc Naphthenates

Guideline Number	Study Type/Test Substance (% a.i.)	MRID Number	Results
Toxicity Category

870.1100

(§81-1)	Acute Oral- Rat

purity 45.4% -copper naphthenate

	00266172	LD50 > 501 mg/kg	III

870.1100

(§81-1)	Acute Oral- Rat

purity 58% -copper naphthenate

	433342402	Not determined	N/A

870.1100

(§81-1)	Acute Oral- Rat

purity 60%- zinc naphthenate

	00244277	LD50 > 2000 mg/kg	IV

870.1200

(§81-2)	Acute Dermal- Rabbit

purity not determined – 

copper naphthenate	41140710	LD50 > 2000 mg/kg	III

870.1200

(§81-2)	Acute Dermal- Rabbit

purity 60%-zinc naphthenate	00244277	LD50 > 2000 mg/kg	III

870.1300

(§81-3)	Acute Inhalation- Rabbit

purity technical- copper naphthenate

	41486301	LC50 > 2.966 mg/L	III

870.1300

(§81-3)	Acute Inhalation- Rabbit

purity 60%- zinc naphthenate

	00244277	LC50 > 11.6 mg/L	IV

870.2400

(§81-4)	Primary Eye Irritation- Rabbit 

purity 80% -copper naphthenate

	00260891	Redness cleared on day 4	III

870.2400

(§81-4)	Primary Eye Irritation- Guinea pig 

purity 60% -zinc naphthenate

	00244277	Redness cleared on day 2	III

870.2500

(§81-5)	Primary Dermal Irritation- Rabbit

purity technical –copper naphthenate

	41140710	Moderate Irritant	III

870.2500

(§81-5)	Primary Dermal Irritation- Rabbit

purity 60% -zinc naphthenate

	00244277	Moderate to severe Irritant	II

870.2600

(§81-6)	Dermal Sensitization - Guinea pig

purity 58 % - copper naphthenate

	41140710	Not a sensitizer.	NA

870.2600

(§81-6)	Dermal Sensitization - Guinea pig

purity 60 % - zinc naphthenate	00244277	Primary skin irritant/possible
sensitizing agent	NA

N/A = Not Assigned; NA = Not Applicable.

Source:  April 16, 2007 Review Memorandum “Naphthenate Salts
(Zinc/Copper) - Endpoint Selection Report” from T.F. McMahon, Ph.D.,
Senior Toxicologist, AD (USEPA, 2007).

3.2	Summary of Toxicity Endpoints

	On April 16, 2007, toxicity endpoints of concern were selected for the
Naphthenate Salts (Copper and Zinc) by Antimicrobials Division
toxicologists’ and members of the former Antimicrobials Division
Toxicity Endpoint Selection Committee (ADTC) based on submitted
dose-response studies conducted with animals.  The Naphthenate Salts
were considered together for hazard characterization.  The ADTC asserted
that the presence of a zinc or copper ion does not have a significant
influence on the mammalian toxicity of naphthenic acid. The
dose-response studies used for endpoint selection were conducted with
the technical grade active ingredients.  Specifically, the dermal
toxicity endpoints were from a rabbit dermal toxicity study using Zinc
Naphthenate, and a rat developmental toxicity study with Copper
Naphthenate was used for selecting incidental oral and inhalation
endpoints. 

	From the oral developmental toxicity study, a maternal NOAEL of 30
mg/kg/day was selected for ST/IT/LT inhalation and ST incidental oral
exposure. The developmental toxicity study revealed an increase in the
mean number of early fetal resorptions only, however the mean litter
size of the treated and control groups was comparable.  Therefore, these
increases were considered to be of no biological significance,
indicating from this study that the Naphthenate Salts did not appear to
elicit developmental effects.  Systemic effects were seen in the form of
decreased body weight and food consumption at 100 mg/kg/day. 

	A route-specific study was available for selecting dermal exposure
endpoints: the ST dermal endpoint is based on a LOAEL of 100 mg/kg/day
leading to dermal irritation (which was converted to a dermal
concentration of 22,222 µg/cm2); and the IT endpoint is the NOAEL of
100 mg/kg/day for dermal exposure leading to systemic effects.  For
dermal route exposures, the short-term (ST) dermal endpoint LOAEL of 100
mg/kg/day was based on moderate to severe dermal irritation observed
during the first 4 weeks of the study.  It was noted that a tolerance
developed to the dermal irritating effects of Zinc Naphthenate during
the final weeks of the study.  Therefore, the use of dermal irritation
for the ST dermal endpoint is supported.  For intermediate-term (IT)
dermal exposure, systemic toxicity was observed in the form of
significantly reduced body weight gain in mid-to-high dose groups. 
Therefore the systemic toxicity endpoint NOAEL of 100 mg/kg/day was
selected. No treatment related clinical signs of systemic toxicity were
noted (hematology, clinical chemistry or histopathology).  

	The level of concern or “target” margin of exposure (MOE) varies by
route and duration of exposure.  For Naphthenate Salts, the target MOE
is 100 for ST incidental oral and IT dermal exposures (an uncertainty
factor of 10x for inter-species extrapolation and 10x for intra-species
variation); the target MOE is 300 for ST dermal irritation exposure (an
extra 3x uncertainty factor for use of a LOAEL), and 1,000 for ST, IT,
and LT inhalation exposures (based on an extra 10x uncertainty factor
for route extrapolation).  The Agency may request a confirmatory
inhalation toxicity study in cases where the inhalation MOEs are below a
value of 1,000 since the inhalation endpoint is based on an oral study.

	A human dermal absorption factor was not selected since the dermal
endpoint was derived from a route-specific study. An inhalation
absorption factor of 100% was used (default value, assuming oral and
inhalation absorption are equivalent) since an oral endpoint was
selected for determining inhalation exposures.  Table 3.2 summarizes the
selected toxicological endpoints which are further detailed in the
toxicology chapter and preliminary risk assessment developed for this
RED (USEPA, 2007). 

	Both Copper and Zinc Naphthenates have demonstrated positive mutagenic
responses in standard mutagenicity assays.  Submitted mutagenicity
studies are considered unacceptable but upgradable if information on
test material purity is provided.  There are no carcinogenicity studies
available for the Naphthenate Salts; therefore they have not been
formally classified as to carcinogenicity.   

	The endpoint selection memorandum (USEPA, 2007) noted a need for a
repeated dose inhalation toxicity study with Naphthenate Salts to
fulfill the current data gap and allow for adequate assessment of risk
from inhalation exposures arising from the preservative use patterns.

3.3	FQPA Considerations  

	Potential enhanced sensitivity of infants and children from exposure to
the Naphthenate Salts was not assessed.  The ADTC concluded that since
there are neither indirect nor direct food uses for Copper/Zinc
Naphthenate Salts, an FQPA analysis is not necessary. 

Table 3.2     SEQ CHAPTER \h \r 1 Summary of Toxicological Doses and
Endpoints for Naphthenate Salts (Copper, Zinc) 

for Use in Human Risk Assessments

  SEQ CHAPTER \h \r 1 Exposure

Scenario	Dose Used in Risk Assessment

(mg/kg/day) 	Target MOE and UF 

for Risk Assessment	Study and Toxicological Effects

Dietary Risk Assessments

Acute Dietary

(general population and females 13-49) 	No direct/indirect food use or
indirect food contact. Therefore, an acute reference dose is not
required.

Chronic Dietary

(all populations)	No direct/indirect food use or indirect food contact.
Therefore, a chronic reference dose is not required. 

Non-Dietary Risk Assessments

Incidental Oral 

Short-Term 

(1-30 days);

Intermediate-term

(30-days – 6 months) 	NOAEL =  30 mg/kg/day

	Target MOE = 100

(UF =10x inter-species extrapolation, 10x intra-species variation) 

	Developmental Toxicity – Rat 

(Copper Naphthenate) MRID 41615101

g/cm2) a

 	

Target MOE = 300 

(UF =10x inter-species extrapolation, 10x intra-species variation, 3x
for use of LOAEL)

 	

90-day Dermal Toxicity- Rabbit 

(Zinc Naphthenate) MRID 41515001

 

LOAEL (dermal)  = 100 mg/kg/day, based on erythema, edema, and
desquamation at 100 mg/kg/day

Intermediate-Term Dermal

 (30 days- 6 months)

(residential and occupational)	

NOAEL= 100 mg/kg/day

 

(Systemic Toxicity)

	Target MOE = 100

(UF =10x inter-species extrapolation, 10x intra-species variation) 

	90-day Dermal Toxicity- Rabbit

(Zinc Naphthenate) MRID 41515001

NOAEL = 100 mg/kg/day, based on reductions in body weight gain observed
at 300 mg/kg/day. 

Dermal

Long-Term ( >6 months)	A long-term dermal endpoint is not required for
the Naphthenate Salts (Copper, Zinc).

Inhalation b                   (all durations)

(residential and occupational)	

NOAEL= 30 mg/kg/day

	Target MOE = 1000  b

(UF = 10x inter-species extrapolation, 10x intra-species variation, 10x
route extrapolation)	Developmental Toxicity – Rat 

(Copper Naphthenate)  MRID 41615101

Maternal NOAEL = 30 mg/kg/day, based on decreased body weight and food
consumption at 100 mg/kg/day.

Cancer	The Naphthenate Salts (Copper, Zinc) have not been formally
classified as to carcinogenicity.  No cancer data available. 

Source:  April 16, 2007 Review Memorandum, “Naphthenate Salts
(Zinc/Copper) - Endpoint Selection Report” from T.F. McMahon, Ph.D.,
Senior Toxicologist, AD (USEPA, 2007).

UF = uncertainty factor, NOAEL = no observed adverse effect level, LOAEL
= lowest observed adverse effect level, and  MOE = margin of exposure. 

a The short-term dermal toxicity endpoint has been converted to an
exposure per area of skin in order to assess the potential for dermal
irritation effects.  The following equation was used for deriving the
short-term dermal endpoint in g/cm2 :  (100 mg[a.i.]/kg[rabbit] x 2.0
kg[body weight of rabbit] x 1000 g/mg ) / 9 cm2 [area of rabbit
exposed] = 22,222 g/cm2.  Assumptions involved in this calculation
include body weight of the rabbit and area of skin exposed.  No systemic
toxicity assessed for  ST dermal exposure. 

b  An additional uncertainty factor of 10x is used for route
extrapolation from an oral endpoint.  The inhalation absorption factor
of 100% (default value, assuming oral and inhalation absorption are
equivalent) should be used since an oral endpoint was selected for the
inhalation exposure scenarios.  If results are below an MOE of 1,000, a
confirmatory inhalation study is warranted.

	4.2	Dietary Exposure tc \l2 "4.2	Dietary Exposure   

Any risks pertinent to dietary exposures are discussed in the
Preliminary Risk Assessment. There is neither direct nor indirect food
uses associated with Copper/Zinc Naphthenate active ingredients.  There
is however, one tolerance exemption for residues of Copper Naphthenate
when used in accordance with good agricultural practices as an inert
ingredient in pesticide formulations applied to growing crops only [(40
CFR 180.920) - No more than 2.5% Copper Naphthenate can be present, and
products containing Copper Naphthenate can only be applied before the
edible portions of plants begin to form.].  

	4.3	Drinking Water Exposure tc \l2 "4.3	Drinking Water Exposure  

Any risks pertinent to drinking water exposures are discussed in the
Preliminary Risk Assessment.  There are no potable water treatment uses
for registered products containing Copper/Zinc Naphthenates, nor are
effluents of this chemical anticipated to impact fresh water
environments through proper product use. 

	4.4	Residential Exposures tc \l2 "4.4	Residential Exposures 

	The exposure scenarios assessed in this document for the representative
uses selected by the Agency are shown in Table 4.1.  The table also
shows the maximum application rates associated with the representative
use and the EPA Registration number for the corresponding representative
product.  For handlers, the representative uses assessed include
application as a wood preservative coating/water repellent (e.g.,
applied via brush, roller, and low-pressure coarse spray to patio
decking).  Exposures evaluated for handlers include ST dermal (leading
to dermal irritation) and inhalation route contact.  Post-application
exposures were assessed for ST dermal irritation (adults/children) and
incidental oral ingestion (children) contact with treated surfaces
including preserved wood and outdoor-use textiles (e.g., treated canvas
tents or tarps). 

	4.4.1	Residential Handler Exposures tc \l3 "4.4.1	Residential Handler
Exposures 

	The residential handler scenarios described in Table 4.1 were assessed
to determine ST dermal and inhalation exposures.  The inhalation dose
calculations were estimated using Equations 1 through 3 in Section 1.2. 
Residential handlers using wood preservative coatings may have
inhalation exposures to aerosol particulates during applications using a
low-pressure sprayer.  Volatile organic compounds are assumed to be
present from carrier solvents (e.g., aliphatic hydrocarbon reducing
solvents) and formulation inert ingredients (e.g., petroleum
distillates), but they are not attributed to the Naphthenate active
ingredient and are therefore not assessed.

	The assumptions and factors used for those scenarios in which surrogate
data were used include the following:

Unit Exposure Values: Unit exposure values were taken from the Pesticide
Handlers Exposure Database (PHED) data presented in HED’s Residential
SOPs (USEPA, 1998).  A summary of the PHED database is presented in
Appendix A.

For the low pressure sprayer (coarse spray) in coating applications
scenario, the PHED dermal and inhalation unit exposure values for a
residential handler pouring a pesticide and applying it via a low
pressure sprayer (handwand) were used (PHED Scenario 32).  These unit
exposure values [102 mg/lb a.i. for dermal (hand only) and 0.030 mg/lb
a.i. for inhalation] represent a handler treating low and mid-level
targets (generally below the waist) while wearing no gloves or
respirator PPE.  

For the paint brush/roller scenario, PHED dermal and inhalation unit
exposure values for a residential handler applying a pesticide using a
paint brush were used (PHED Scenario 22).  These unit exposure values
[175 mg/lb a.i. for dermal (hand only) and 0.284 mg/lb a.i. for
inhalation] represent a handler with no gloves or respirator PPE. 

	As presented in Table 3.2, dermal irritation is a relevant
toxicological endpoint for ST exposures.  To estimate the potential for
dermal irritation, a dermal exposure based on skin surface area was
calculated.  This was accomplished by dividing the unit exposure values 

for the hand surface (i.e., in mg/lb a.i.) from PHED by an assumed total
hand surface area (820 cm2) to obtain a normalized exposure per square
centimeter of skin (i.e., mg/lb a.i./cm2).  Using this approach, the
following dermal unit exposure values were developed:

Low pressure sprayer:  102 mg/lb a.i / 820 cm2  = 0.124 mg/lb a.i./cm2

Paint brush/roller:  175 mg/lb a.i / 820 cm2  = 0.213 mg/lb a.i./cm2		

Quantity Handled/Treated:  The quantities handled/treated were estimated
based on information from various sources and assumptions.  The density
of the ready-to-use product is assumed to be 8.5 lbs/gallon based on a
review of product labels.

For the low pressure sprayer coating applications it is assumed that
42.5 lbs (approximately 5 gallons) of ready-to-use product will be used.

For the brush/roller scenario, it is assumed that 17 lbs (approximately
2 gallons) of ready-to-use products will be used.  This is based on the
90th percentile value of 8 gallons of latex paint used per year divided
by the mean frequency of 4 painting events/year.  	

Duration of Exposure:  The duration of exposure for most homeowner
applications of Naphthenate Salts products is believed to be best
represented by the short-term duration (1 to 30 days).  For example, the
Agency assumes that application to outdoor-use wood materials (e.g.,
fencing, patio decking) are episodic, not daily.  Therefore, exposures
are evaluated for only short-term (ST) durations. 

Results

	The resulting short-term exposures and MOEs for the representative
residential handler scenarios are presented in Tables 4.2 and 4.3.  As
shown in Table 4.2, the calculated MOEs were above the target inhalation
MOE of 1,000 for both scenarios.  Table 4.3 shows that calculated dermal
irritation exposure for both application scenarios. The dermal MOEs (4
and 6) are both below the ST MOE target of 300, denoting potential
dermal irritation concern.  

Table 4.2. Naphthenate Salts Residential Handlers ST Inhalation
Exposures and MOEs

Method of Application	

Unit Exposure

(mg/lb a.i.)a	

Application Rate	

Quantity Handled/ Treated per Day	

Absorbed Daily Dose (mg/kg/day)b	

MOE 

(Target = 1,000)c

Low Pressure Sprayer	0.030	25% a.i. by weight	42.5 lbs/day

(5 gal/day)	0.0045	6,700

Brush/roller	0.284	25% a.i. by weight	17 lbs/day

(2 gal/day)	0.017	1,800

a	No respirator used by exposed individual.

b	Inhalation Daily Dose (mg/kg/day) = [inhalation unit exposure (mg/lb
a.i.) * application rate (0.25) * quantity handled (lbs/day) *
inhalation absorption factor 100% / body weight (70 kg).  

c 	Inhalation MOE = NOAEL (30 mg/kg/day) / Daily Dose.  Target
inhalation MOE is 1,000.

Table 4.3. Naphthenate Salts Residential Handlers ST Dermal Exposures
and MOEs

Method of Application	

Unit Exposure

(mg/lb a.i./cm2)a	

Application Rate	

Quantity Handled/ Treated per day	

ST Absorbed Daily Dose (mg/cm2)b	

MOEc

ST Dermal Irritation

(Target = 300)

Low Pressure Sprayer	

0.124

	25% a.i. by weight	42.5 lbs/day

(5 gal/day)	5.3	4

Brush/roller	0.213	25% a.i. by weight	17 lbs/day

(2 gal/day)	3.6	6

a	All dermal unit exposures represent ungloved replicates.  The low
pressure sprayer and brush/roller unit exposures represent short sleeve
and short pant replicates.

b	Dermal Daily Dose (mg/cm2) = [(PHED hand unit exposure (mg/lb
a.i.)/surface area of adult hand (820 cm2)] * application rate (0.25) *
quantity handled (lbs).

c	Dermal MOE = ST Dermal Irritation concentration (22.222 mg/cm2) /
Daily Dose.  Short-term target dermal MOE is 300.  

	4.4.2	Residential Post-application Exposures tc \l3 "4.4.2	Residential
Post-application Exposures 

	For the purposes of this screening-level assessment, post-application
scenarios have been developed that encompass multiple products, but
still represent high-end exposure scenarios for all products
represented.  As shown in Table 4.1, representative post-application
scenarios assessed include contacting treated textiles (adult/child
dermal and incidental oral exposure to children) and contacting treated
wood (adult/child dermal and incidental oral exposures to children).  It
should be noted that because Naphthenate Salts have a relatively low
vapor pressure, post-application inhalation exposures were not assessed.

	4.4.2.1 Treated Outdoor-Use Textiles tc \l4 "4.4.2.1	Treated
Outdoor-Use Textiles 

	Certain types of textiles are treated with Naphthenate Salts during
industrial manufacturing processes or as a result of registered
residential use applications. These cellulose textiles and cordage
include: canvas tents/tarps, rope, and other products.  Post-application
dermal and incidental oral exposures to treated textiles may occur as
infrequent, episodic events.  Because the textiles impregnated with
Naphthenate Salts are assumed to be used in residential setting, there
is potential for acute exposures to occur.  Therefore, only short-term
exposure durations were assessed.  It was assumed that exposure to a
canvas fabric covering (tent) will represent exposure to all other types
of textiles and similar materials treated with Naphthenate Salts
(including rope).

Dermal Exposure to Adults and Toddlers from Contacting Treated Textiles
(Canvas Tents)

	The Agency assumes that there is the potential for dermal exposure to
adults and children from contact with treated outdoor-use fabrics.  To
evaluate this possibility, the Agency evaluated a scenario in which
adults and children are directly exposed to a treated canvas tent.  This
post-application assessment assumes the tent is new (i.e., not laundered
and not yet exposed to rainfall and outdoor elements) as a conservative
measure (i.e., the effect of dislodgeable residues being diminished over
time is not quantifiable).    

Exposure Calculations	

	There is the potential for short-term dermal exposures leading to
irritation when adults and children contact textiles that have been
treated with Naphthenate Salts.  To determine the dermal exposure to
Naphthenate Salts for this scenario, the following equation was used:

PE = P * WF1 * WF2 * PF

where:

PE 	= 	Potential exposure (mg/cm2)

P 	= 	Fabric density (mg/cm2)

WF1 	= 	Weight fraction of commercial product in textile (mg product
a.i./mg textile)

WF2 	= 	Weight fraction of Naphthenate Salts transferred from textile to
skin (unitless)

PF	= 	Protection factor from single layer of clothing or sheet
(unitless)

	

Assumptions

The canvas tent cloth textile is assumed to be medium weight Army Duck
Canvas (12 oz/yd2) with a density of  408 g/m2 (40.8 mg/cm2)  [This
density estimate is based on a weight specification chart from an
internet source of exported canvas textile (Bharat Textiles, 2007)].  

The product is applied at a rate of 11 % percent a.i. by weight to the
textile (based on a recommended maximum application rate of 1.2% copper
metal by weight).

No data were available from which a transfer factor could be estimated. 
Potential doses were calculated using a conservative percent transfer of
100%, which assumes that all residues are transferable from textile
surfaces to the skin.  Because the calculated MOE was less than the
target MOE for ST exposure, a less conservative estimate of dermal
exposure was also calculated assuming a transfer factor of 5%.  

As a conservative approach it is assumed that adults and children are
sleeping inside a treated tent with no bedding between body and tent
floor surfaces, wearing short pants/tee-shirt or just undergarments. 
The protection factor inhibiting exposure to Naphthenate Salts in the
tent fabric from clothing is 50% based on PHED protection factor for a
single layer of clothing (USEPA 1998).

Results

	Table 4.4 shows the calculation of the short-term dermal exposure and
MOE for children and adults contacting treated textiles.  The MOEs are
below the short-term target of 300 for both scenarios using transfer
factors.  The MOEs are 10 at 100% and 200 at 5%, indicating potential
dermal irritation concerns.  

Table 4.4. Short-term Dermal Exposure and MOE for Children and Adults
Contacting Treated Textiles

Weight Fraction of Product

(% a.i.)	Fabric Density (mg/cm2)	Fraction Transferred to Skin	Protective
Factor	Exposure Dose

(mg/cm2) a	MOEb

	Short Term (Target = 300)

11%	40.8	100%	50%	2.2	10

11%	40.8	5%	50%	0.11	200

a  Potential exposure for ST and IT is expressed as mg a.i. per cm2 of
exposed skin.  Equation used to estimate exposure is presented above.

b  MOE = NOAEL/exposure estimate [Where: ST and IT NOAEL = 22.222
mg/cm2]. 

Incidental Oral Exposure to Toddlers Mouthing Treated Textiles (Canvas
Tents/Tarps)

	Based on the dermal scenario developed above, there is the potential
for ST incidental oral exposure to toddlers from mouthing textiles
(e.g., canvas tents/tarps) treated with Naphthenate Salts. 

    

Exposure Calculations 

Potential doses are calculated as follows:

PDD = C * SE * SA 								

	    BW							

Where: 

PDD	= 	potential daily dose (mg/kg/day);

C 	= 	concentration on textile (mg/cm2);

SE	=	saliva extraction efficiency (%);

SA 	= 	surface area mouthed (cm2/day); and

BW 	= 	body weight (kg).

And

C = WFai * W * CF1 * CF2							

		

Where:

C		=	concentration on textile (mg/cm2);

WFai		= 	weight fraction of a.i. in textile (unitless); 

W 		= 	weight of textile (g/m2);

CF1		=	unit conversion factor (1,000 mg/g); and

CF2		=	unit conversion factor (0.0001 m2/cm2).

Assumptions

The canvas tent cloth textile is assumed to be medium weight Army Duck
Canvas (12 oz/yd2) with a density of  408 g/m2 (40.8 mg/cm2)  [This
density estimate is based on a weight specification chart from an
internet source of exported canvas textile (Bharat Textiles, 2007)].  

The product is applied at a rate of 11% a.i. by weight to the textile
(based on a recommended maximum application rate of 1.2% copper by
weight).

The saliva extraction efficiency was 50% (USEPA, 2000 and 2001).

The surface area of textile mouthed by toddlers is 20 cm2 (professional
judgment).

Toddlers (3 years old) are used to represent the 1 to 6 year old age
group.  For three-year olds, the median body weight is 15 kg (USEPA,
1997a).

Results

    	Table 4.5 shows the calculation of the oral dose and oral MOE for
toddlers mouthing treated textiles.  The ST MOE value is 10, which is
below the ST target MOE of 100, indicating potential risk concern.

Table 4.6. ST Incidental Oral Exposures and MOEs for Toddlers Mouthing
Treated Textiles (Canvas Tent/Tarp)

Weight of Textile (g/m2)	Concentration on Textilea 

(mg/cm2)	Surface Area Mouthed (cm2/day)	

Saliva Extraction Efficiency 	Potential Daily Doseb (mg a.i./kg/day)	ST
Incidental Oral MOE (Target MOE = 100)c

408	4.5	20	50%	3	10

a.	Concentration on textile (mg/cm2) = (Weight fraction a.i. in
clothing) * (weight of textile, g/m2) * (1,000 mg/g) * (0.0001 m2/cm2)

b.	Potential Daily Dose (mg/kg/day) = (concentration on textile, mg/cm2)
* (surface area mouthed, cm2/day) * (saliva extraction efficiency) /
(body weight, 15 kg).

c 	Oral MOE = NOAEL (mg/kg/day) / Potential Daily Dose [Where short-term
incidental oral NOAEL = 30 mg/kg/day].  Target MOE = 100.	

4.4.2.2	Treated Lumber tc \l4 "4.4.2.2	Treated Lumber 

	Certain Naphthenate Salts end-use products are labeled for wood
preservative uses in pressure and non-pressure treatments of wood
products intended for residential applications.  Therefore, the Agency
evaluated potential post-application exposures to individuals exposed to
Naphthenate Salts-treated wood in residential settings (home and farm): 

Dermal contact by children with Naphthenate Salts-treated wood products
for above-ground uses [e.g., residential playground equipment
(playsets), posts, decks, shingles, fencing, outdoor lumber, etc.]; and

Incidental ingestion by children due to hand-to-mouth contact with
Naphthenate Salts-treated wood products.

	Because children are more likely than adults to contact wood surfaces
using playground equipment (playsets), and because children have a
higher surface area to body weight ratio, they represent the maximum
exposed individual.  Incidental ingestion exposure for adults is
expected to be negligible and dermal contact for adults is expected to
be lower than children for crawling on wood decks.  

Surrogate Data 	

	

	No chemical-specific residential post-application studies conforming to
Series 875 guidelines were available; however, data from the proprietary
study, “Measurement and Assessment of Dermal and Inhalation Exposures
to Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the Protection of
Cut Lumber (Phase III)” (Bestari et al., 1999, MRID 455243-04, SIG
Task Force #73154) can be used as surrogate data to estimate
screening-level exposures for the following pathways: outdoor
residential dermal contact with Naphthenate Salts-treated wood products
used in above-ground applications (e.g., residential playsets, posts,
decks, shingles, fencing, outdoor lumber, etc.); and outdoor residential
incidental ingestion due to hand-to-mouth contact with pressure-treated
wood products.  The DDAC study measured dermal and inhalation exposures
for various worker functions/positions for individuals handling
DDAC-containing wood preservatives for non-pressure treatment
application methods and for individuals that could then come into
contact with the preserved wood. 

Outdoor Residential Dermal Contact with Naphthenate Salts-Treated Wood
Products

μg/cm2) of workers handling dry lumber shortly after treatment with an
antisapstain (i.e., surface spray, not pressure treatment) was assumed
to be the dermal skin irritation exposure of children playing on
pressure treated structures.  The results from Table 4.7 indicate that
the dermal MOEs range from 37,000 down to 7, 400 and are well above the
target MOE (i.e., 300) for all test subjects.  Considerable
uncertainties in the assessment (eight-hour work shift, surface spray
applications, and monitored shortly after application) require a
confirmatory surface wipe study on pressure treated wood to refine the
skin concentration/exposure for children playing on treated structures.

End Stacker - Operates an automated stacking system at the end of the
conveyor.  Lumber stacked into loads.  Monitoring was performed over an
eight-hour work shift.  Gloves were worn as indicated on page 196 of the
DDAC study.

Stickman - Places sticks between stacks of wood manually.  At some
mills, this is done automatically by end stacker operator.  Monitoring
was performed over an eight-hour work shift.  Gloves were not worn as
indicated on page 192 of the DDAC study.

Tallyman - Staples information sheet onto wood.  May come in contact
with treated lumber.  (Note: there were two reps available for
tallyman.)  Monitoring was performed over an eight-hour work shift. 
Gloves were not worn as indicated on pages 193 and 207 of the DDAC
study.

Table 4.7.  Hand Residue Data for DDAC for Handling of Dry Wood to
Represent Potential Naphthenate Salts Adult/Child Dermal Exposure and
Risk

Job Description 

Total Hand Residue Data (μg/cm2)

(data page 104 of the DDAC study report)

End Stacker	1.2

Stickman	0.6

Tallyman	0.8

Tallyman 	3.0

(Maximum Value)

Average Hand Residue	1.4

Dermal Skin Irritation Exposurea (μg/cm2)	 Range 0.6 to 3.0

MOEb (Target MOE =300)	Range 37,000 to 7,400 

a	Dermal Skin Irritation Exposure (μg/cm2)= range from 0.6 to 3.0
μg/cm2  (hand residues)

b	MOE  = NOAEL (μg/cm2) / dermal skin irritation exposure (μg/cm2). 
Dermal short-term NOAEL 

is 22,222 μg/cm2.  Target MOE = 300.

  SEQ CHAPTER \h \r 1 Outdoor Residential Hand-to-Mouth Contact with
Naphthenate Salts-treated Wood Products

	The daily hand-to-mouth dose (mg/kg/day) is estimated using the
following equation:

Oral Dose t= Handt * Hand SA * SEF *  Frequency * CF1 *  ET 			
उउ坂圍敨敲ഺऍ慈摮⁴उऽ䑄䍁栠杩敨瑳栠湡⁤敲楳
畤⁥敤整瑣摥⠠⹩⹥錬慔汬浹湡ₔ潷歲湩⁧

				with dry wood) (μg/cm2)

	Hand SA	=	hand surface area (cm2/event),

SEF		=     	saliva extraction efficiency,

Frequency 	= 	frequency of exposure event (events/hr), 

	ET		=	exposure time (hr/day), 

	CF1		=	conversion factor (0.001 mg/µg), and

	BW		=		body weight (kg).

Assumptions

The highest hand residue value from the DDAC study (3.0 µg/cm2) was
used for this assessment.  

The palmar surface area of 3 fingers of a toddler, 20 cm2, was used to
estimate hand-mouthing as opposed to whole hand mouthing (USEPA, 2001).

The saliva extraction factor (SEF), 50%, and was based on the assumption
of 50% removal efficiency of residues from hands by human saliva (USEPA,
2001 and 2005).

The rate of hand-to-mouth activity for outdoor playing is 7 events per
hour based on Freeman et. al (2001) at the 95th percentile.

 The exposure time (ET) is 2 hours and is consistent with the Agency’s
CCA assessment for time playing outdoors.  Although the 2 hour duration
represents “outdoor” time, it is used as a conservative estimate for
playing on decks and playsets.

The mean body weight of a child, age 3, is 15 kg. 

Results

	The results of the hand-to-mouth estimates are presented in Table 4.8. 
The estimated short-term MOE for the hand-to-mouth exposure is above the
target MOE of 100 (as 1,100) and therefore not of concern.  

Table 4.9. Residential Post-application Short-term Incidental Oral
Exposures 

to Naphthenate Salts-treated Wood Products

Hand Residue Concentration

from DDAC Study (µg/cm2)	Finger

 (3 μg/cm2 ) x Hand SA (20 cm2) x SEF (50% as 0.50 ) x Frequency (7
events/hr) x Exposure Time (2 hrs/day) x 0.001 mg/μg] / BW (15 kg)

b	MOE  = NOAEL (mg/kg/day) / daily dose (mg/kg/day).  For incidental
oral exposures, the ST NOAEL is 30 mg/kg/day.  Target MOE = 100.

	4.4.3	Data Limitations/Uncertainties tc \l3 "4.4.3	Data
Limitations/Uncertainties 

	There are several data limitations and uncertainties associated with
the residential handler and post-application exposure assessments. 
These include the following:

In the absence of chemical-specific exposure data, handler surrogate
dermal and inhalation unit exposure values were taken from the Pesticide
Handlers Exposure Database (PHED)(USEPA, 1998) (See Appendix A for a
summary of this data source). 

The quantities handled/treated and certain exposure factors were
estimated based on information from various sources, including HED’s
Standard Operating Procedures (SOPs) for Residential Exposure
Assessments (USEPA, 2000 and 2001) and AD’s Draft SOPs (unpublished
internal guidance) (USEPA, 2005).  In certain cases, no standard values
were available for some scenarios.  Assumptions for these scenarios were
based on AD estimates and could be further refined from input from
registrants. 

The low pressure spray unit exposure data from PHED were used to assess
outdoor applications of wood preservative coatings (exterior of homes). 
As the PHED low pressure spray data are representative of treating low
to mid-level range targets (shrubs/greenhouse benches) and the scenario
assessed in this document represents treatments that may also occur
above the waist, the unit exposure value may underestimate exposure to
the head and the upper body.  

The methods used to estimate child and adult exposures to treated
textiles are highly conservative and based on approaches from the
Residential SOPs (USEPA 2000, and 2001) for contact with porous treated
surfaces (clothing, mattresses and carpets). Without data on actual
treated textile residues, dissipation or dermal transfer coefficients,
these scenarios have a high degree of uncertainty associated with them.
The registrants’ input will assist in refining the MOEs and confirming
the Naphthenate Salts textile use patterns.    

In this assessment, incidental ingestion and dermal exposures to treated
wood were estimated using surrogate DDAC data (3 (g/cm2).  The degree of
uncertainty (under- or overestimation) associated with using the DDAC
hand residue data for dermal and oral exposure from contacting treated
lumber are unknown.  The amount of residue measured on the test
subjects’ hands is variable and may be influenced by the duration of
exposure, how often wood is contacted, and the degree of contact (i.e.,
do the hand residues from the DDAC study mimic a child’s play activity
on decks and playsets?).  In addition, from the limited data available
to the Agency, it appears that leaching from Naphthenate Salts-treated
wood depends on pH, with the highest leach rates occurring under acidic
conditions (USEPA, 2007a). 

Data are not available to assess the levels of Naphthenate Salts in soil
contaminated from Naphthenate Salts-treated wood (e.g., above
ground/ground contact fabricated components of decks or playsets).
Because of this data gap, EPA was not able to estimate residential
post-application dermal and incidental oral ingestion exposure to soil
contaminated with Naphthenate Salts residues.  It is assumed that any
soil residues attributed to weathering of in-service wood (playsets)
will remain near these structures for potential child exposure (USEPA,
2007a).

5.0	RESIDENTIAL AGGREGATE RISK ASSESSMENT AND CHARACTERIZATION tc \l1
"5.0	RESIDENTIAL AGGREGATE RISK ASSESSMENTS AND RISK CHARACTERIZATION 

	

	5.1	Acute and Chronic Dietary Aggregate Risk tc \l2 "5.1	Acute and
Chronic Dietary Aggregate Risk 

	Any potential acute and chronic dietary aggregate risks will be
characterized in the Preliminary Risk Assessment (PRA).

	5.2	Short-Term Aggregate Risks tc \l2 "5.2	Short- and Intermediate-Term
Aggregate Risk 

	In order for a pesticide registration to continue, it must be shown
“that there is reasonable certainty that no harm will result from
aggregate exposure to pesticide chemical residue, including all
anticipated dietary exposures and other exposures for which there are
reliable information.”  Aggregate exposure is the total exposure to a
single chemical (or its residues) that may occur from dietary (i.e.,
food and drinking water), residential, and other non-occupational
sources, and from all known or plausible exposure routes (oral, dermal,
and inhalation).  However, this assessment only addresses non-dietary
residential aggregate exposures and risks.  The PRA of the RED will
address the complete aggregate assessment including both dietary and
non-dietary residential exposures and risks. 

	The Office of Pesticide Programs has published guidance outlining the
necessary steps to perform aggregate exposure and risk assessments
(General Principles for Performing Aggregate Exposure and Risk
Assessments, November 28, 2001; available at
http://www.epa.gov/pesticides/trac/science/aggregate.pdf).  Steps for
deciding whether to perform aggregate exposure and risk assessments are
listed, which include: identification of toxicological endpoints for
each exposure route and duration; identification of potential exposures
for each pathway (food, water, and/or residential);  reconciliation of
durations and pathways of exposure with durations and pathways of health
effects; determination of which possible residential exposure scenarios
are likely to occur together within a given time frame; determination of
magnitude and duration of exposure for all exposure combinations; 
determination of the appropriate technique (deterministic or
probabilistic) for exposure assessment; and determination of the
appropriate risk metric to estimate aggregate risk.

  SEQ CHAPTER \h \r 1 Short-Term Aggregate Exposures and Risks

	Short-term aggregate exposures and risks were not assessed for adults
and children that could be exposed to Naphthenate Salts residues from
the use of products in non-occupational environments.  The following
lists summarize all of the potential non-dietary sources of Naphthenate
Salts exposures for adults and children in residential settings:

Adult Naphthenate Salts exposure sources:

Applying wood preservative/water repellent coatings in residential
settings;

Applying materials preservatives to cellulose-based fibers/textiles in
residential settings;

Post-application exposures to treated outdoor-use wood;

Post-application exposures to treated outdoor-use textiles.

	

Child Naphthenate Salts exposure sources:

Post-application exposure to treated outdoor-use wood; 

Post-application exposures to treated outdoor-use textiles.

	The use patterns of the products and probability of co-occurrence must
be considered when selecting scenarios for incorporation in the
aggregate assessment.  For example, homeowner wood preservative
applications of Naphthenate Salts are considered infrequent, occurring
only once or twice a year (Agency estimate); the same for materials
preservative treatments to certain outdoor-use cellulose-based
fibers/textiles (e.g., rope, burlap, canvas).  Therefore, though
possible, the probability of co-occurrence and the potential for
exposure from these use applications on the same day is low.  Also,
there is limited potential for co-occurrence from post-application
contact with pesticide residues in/on treated wood/textile materials. 
This is based on the premise that children and adults are anticipated to
contact treated wood used in fabricated residential structures (e.g.,
decks, fences and playsets) in far greater frequency than the episodic
contact expected with treated textiles.  Table 5.1 summarizes the
scenarios considered for short-term aggregate assessments.

Table 5.1.  Summary of Exposure Scenarios Considered for Short-Term
Aggregate Assessment

Receptor	Short-Term Aggregate

Adults 	Dermal:

exposure to product during applications with brush/roller;

exposure to product during applications with low pressure sprayer;

exposure to treated outdoor-use wood (e.g., decking, playsets);  

exposure to treated outdoor-use textiles (e.g., canvas tent).  

	Inhalation:

exposure to product during applications with brush/roller;

exposure to product during applications with low pressure sprayer.

Children	Dermal:

exposure to treated outdoor-use wood (e.g., decking, playsets);

exposure to treated outdoor-use textiles (e.g., canvas tent).

	Oral:

hand-to-mouth exposure to treated outdoor-use wood (e.g., decking,
playsets);

mouthing exposure to treated outdoor-use textiles (e.g., canvas tent).

Exposure scenarios identified as concerns to the Agency in Section 4
include short-term handler dermal exposures (both application methods),
short-term post-application dermal exposure to adults and children from
contact with treated textiles, and short-term post-application oral
exposure to children from mouthing treated fabric.    SEQ CHAPTER \h \r
1 Incorporation of these scenarios in the aggregate assessment would
result in risks of concern.  Therefore, only the scenarios not
identified as concerns in Section 4 are considered for the aggregate
assessment.  These scenarios include: short-term inhalation exposure by
adult handlers and short-term dermal and incidental oral
post-application exposure by children from contact with treated lumber. 

Because the endpoints for the ST dermal and incidental oral routes of
exposure were based on route-specific studies resulting in different
effects, separate route-specific aggregate assessment are appropriate. 
However, only one exposure scenario was identified for each route of
exposure.  Accordingly, evaluation of aggregate risk using the Total MOE
method outlined in OPP guidance for aggregate risk assessment (September
1, 2000, Standard Operating Procedure (SOP) for Incorporating Screening
Level Estimates of Drinking Water Exposure into Aggregate Risk
Assessments) is unnecessary.  

6.0	OCCUPATIONAL EXPOSURE ASSESSMENT tc \l1 "6.0	OCCUPATIONAL EXPOSURE
ASSESSMENT 

	6.1	Summary of Registered Uses tc \l2 "6.1	Summary of Registered Uses 

	Potential occupational handler exposure can occur in various use sites,
including both commercial/industrial premises and applications conducted
at residential sites.  The exposure scenarios assessed in this document
for the representative uses selected by AD are presented in Table 6.1. 
The table also shows the maximum application rates associated with the
representative use and the appropriate EPA Registration number for the
product label.  For handlers, the representative uses assessed include
use of products containing Naphthenate Salts as a preservative for
outdoor-use textiles and wood products.  Due to the complexity of the
analysis of exposures that occur in wood treatment facilities, the
results for handlers and post-application exposures are presented
separately in Section 6.4.  

It should be noted that for the dermal route, only intermediate-term
(IT) dermal exposure is assessed for occupational handler scenarios
since the IT toxicity endpoint selected is based on systemic effects. 
Short-term (ST) dermal exposures were not evaluated because the ST
toxicity endpoint is based on dermal irritation.  Dermal irritation
exposures and risks will be mitigated using label-specified personal
protective equipment (PPE) or default PPE requirements based on the
toxicity of the end-use product.  To minimize dermal exposures, the
minimum PPE required for mixers, loaders, and others exposed to end-use
products that result in classification of category I, II, or III for
skin irritation potential will be a long-sleeve shirt, long pants,
shoes, socks, chemical-resistant gloves, and a chemical-resistant apron.
 Once diluted, if the concentration in the diluted solution will result
in classification of toxicity category IV for skin irritation potential,
then the chemical-resistant gloves and chemical-resistant apron can be
eliminated for applicators and others exposed to the dilute product.
Note that chemical-resistant eyewear will be required if the end-use
product is classified as category I or II for eye irritation potential. 

Table 6.1.  Representative Exposure Scenarios Associated with
Occupational Exposures

 to Naphthenate Salts

Representative Use	Method of Application	Exposure Scenario
Representative EPA Reg. No.	Maximum Application Rate

Material Preservatives

Direct application to outdoor-use textiles (e.g., canvas used for tarps
and tents;  ropes, nets)	(Dipping) a

Low-pressure spray

Brush/roller

	Handler:

IT dermal; ST/IT/LT inhalation	1022-409 

(spray)

	25% a.i. by weight, 

ready-to-use (RTU) 

	60061-16; 60061-19

(brush)	22% a.i. by weight, 

ready-to-use (RTU)

Incorporation into textiles during  industrial manufacturing	Liquid pour
(associated with automated dip/spray) b

Liquid pump (associated with automated dip/spray) b

43437-3;

43437-4

	11% a.i. by weight (1.2% copper by weight) deposition in treated canvas
textile.  Incorporation during manufacturing.

Wood Preservatives

Non-pressure treatment of wood and wood products in wood treatment
facilities	Handler Worker Functions

Diptank Operators 

Blender/spray operators

Chemical operators

Post-Application Worker Functions

Graders

Trim saw operators

Clean-up crews

Construction workers 	Handler:

IT dermal; ST/IT/LT inhalation 

Post-application: 

IT dermal; ST/IT/LT  inhalation

	1022-409;

1022-522; 

9630-31.	Blender/spray operators:

25% a.i. in solution used

(RTU product 1022-409); and for wood composite use a 1.4% a.i. solution
(1022-522) 

[i.e., 3% (0.03) w/w * 45.4% a.i. in product = 1.4 % a.i.].  

Diptank operators: 

25% a.i. RTU (1022-409) and

32% a.i. use-solution (9630-31) [i.e., 1:2 v/v use dilution * 63% a.i.
in product = 31.5 (32 % a.i.].  

All other worker functions:

25% a.i. in product 

(RTU product 1022-409)

Pressure treatment of wood and wood products in wood treatment
facilities	Handler Worker Functions

Treatment assistant

Treatment operator

Post-Application Worker Functions

Tram setter, stacker operator, loader operator, supervisor, test borer,
and tallyman	Handler:

IT dermal; ST/IT/LT inhalation 

Post-application: 

IT dermal; ST/IT/LT  inhalation

	43437-4	13% a.i. by weight in treatment solution (89% a.i. in product
diluted with 7 parts solution by volume) c

General preservation of wood/lumber in commercial sites (non-pressure
treatment applications) d,e

	Brush/roller

Airless sprayer d

Low-pressure sprayer	Handler:

IT dermal; ST/IT/LT inhalation 

	7424-1;

1022-409	25% a.i. in solution used 

(RTU products)

Application to in-service utility poles, pilings, posts, and other
standing timbers	Brush, trowel, or caulking/grease gun f

Pre-manufactured  bandage f	Handler:

IT dermal; ST/IT/LT inhalation 

	75341-5

(Highest Use Rate for exterior surface treatments)	20% a.i. by weight in
applied product (RTU).

a	Handler exposures during dipping/immersion operations for textiles are
assumed to be comparable to diptank operations for wood.  Therefore this
scenario is not directly assessed. Refer to the non-pressure treatment
(diptank operator) scenario as representative.

b	Exposures to handlers during preparation of dipping solution were
assessed assuming a liquid pour (open-loading) or operation of a liquid
pump (closed-delivery) associated with automated (large-scale) dipping
of textiles in an industrial setting.  However, based on the label use
instructions, it is possible that manual dipping may also be used for
preservation of textiles (e.g., via preparation of small-scale dipping
solution by pouring product into a small receptacle and manually dipping
textiles).  Exposures that may occur as part of manual dipping activity
are not assessed here.

c	Application rate calculations where concentrated product is diluted
assume that the densities of product and solution are approximately
equivalent; actual densities of product and solution may vary somewhat.

d	The label indicates that applications to existing homes can be made
through brush or spray.  The airless sprayer method was selected because
it is based on applying preservative to the outside of a house in the
same manner as one would use an airless paint sprayer, not an
aerosolized paint sprayer.  It was also assumed that a low-pressure
sprayer could be used for applications involving smaller amounts of
product or area treated.

e	Immersion of wood/lumber is another use application that may occur at
commercial sites outside of wood treatment facilities; however,
exposures for this scenario are assumed to be subsumed by the
non-pressure treatment (diptank operator) scenario.

f	No data were identified on exposures to handlers applying products to
exterior surfaces of in-service poles 	using a trowel, or to interior
surfaces using a caulking gun or mechanical pump injection, (nor data on
other 	remedial-treatment products such as pre-manufactured
bandages/wraps); exposures were assessed using unit 	exposure data for a
brush use scenario as representative of all remedial use patterns.  The
product selected	for this assessment (EPA Reg. No. 75341-5) has the
highest use rate for exterior surface treatments where	commercial
applications can be made by brush (20% ai).  A remedial product for use
only in filling interior	cavities (pre-drilled holes) of poles has a
higher application rate of 28% ai  (EPA Reg. No. 75341-12) but 	unit
exposure data are unavailable to assess this application method
(caulking gun) so the 20% a.i. 	product is used.

	6.2	Occupational Handler Exposures tc \l2 "6.2	Occupational Handler
Exposures 

	Certain occupational handler scenarios included in Table 6.1 were
assessed to determine dermal and inhalation exposures.  The general
assumptions and equations that were used to calculate occupational
handler risks are provided in Section 1.2, Criteria for Conducting the
Risk Assessment.  The scenarios were assessed using either CMA or PHED
data and Equations 1 through 3.  

	

Unit Exposure Values (UE):  Dermal and inhalation unit exposure values
were taken from the proprietary Chemical Manufacturers Association (CMA)
antimicrobial exposure study (USEPA, 1999: DP Barcode D247642) or from
the Pesticide Handlers Exposure Database (PHED; USEPA, 1998).  

For the low pressure spray scenarios (application to outdoor-use
textiles and general preservation of wood), the occupational PHED dermal
and inhalation unit exposure values for a handler pouring a pesticide
and applying it via a low pressure sprayer (handwand) were used (PHED
Scenario 32).  The unit exposure values of 100 mg/lb a.i. for ungloved
dermal, 0.43 mg/lb a.i. for gloved replicates, and 0.030 mg/lb a.i. for
inhalation represent a handler treating low and mid-level targets,
generally below the waist (greenhouse benches and shrubs) while wearing
a single layer of clothing. 

For roller/brush scenarios (application to outdoor-use textiles, general
preservation of wood and application to in-service wood), the
occupational PHED dermal and inhalation unit exposure values for
paintbrush applications (PHED Scenario 22) were used (single layer of
clothing, no respirator). The dermal unit exposures are 180 mg/lb a.i.
for ungloved replicates and 24 mg/lb a.i. for gloved replicates.  The
inhalation exposure value is 0.28 mg/lb a.i.:

  

No data were identified on exposures to handlers applying product to
in-service poles and similar members using a trowel, caulking gun, or
pre-manufactured bandage.  Exposures for these scenarios were assumed to
be represented by the assessment done using unit exposure data for the
brush/roller use scenario.

For the liquid pour scenario (associated with open-loading in
preparation of automated application via dip/spray mechanism for
preservation of textiles and similar materials), the CMA dermal unit
exposure value of 0.135 mg/lb a.i. (gloved data) and inhalation unit
exposure value of 0.00346 mg/lb a.i. for liquid pour of preservative
were used. The values are based on two replicates where the test
subjects were wearing a single layer of clothing and chemical resistant
gloves.  Since no baseline dermal (ungloved) unit exposure data are
available for preservative uses in textiles, the baseline dermal
exposures were evaluated using the cooling tower CMA data (50.3 mg/lb
ai).

For the liquid pump scenario (associated with closed-delivery in
preparation of automated application via dip/spray mechanism for
preservation of textiles and similar materials), the CMA dermal unit
exposure value of 0.00629 mg/lb a.i. (gloved data) and inhalation unit
exposure value of 0.000403 mg/lb a.i. for liquid pump of preservative
were used.  The values are based on two replicates where the test
subjects were wearing a single layer of clothing and chemical resistant
gloves. Since no baseline dermal (ungloved) unit exposure data are
available for preservative uses in textiles, the baseline dermal
exposures were evaluated using the cooling tower CMA data (0.454 mg/lb
ai).

For the airless spray scenario, the occupational PHED dermal and
inhalation unit exposure values for airless sprayer application (PHED
scenario 23) were used (single layer of clothing). The dermal unit
exposures are 38 mg/lb a.i. for ungloved replicates and 14 mg/lb a.i.
for gloved replicates. The inhalation exposure value is 0.83 mg/lb a.i. 

Quantity handled/treated: The quantity handled/treated values were based
primarily on AD assumptions.  The following assumptions were made:

For the scenarios involving low pressure spray, the quantity handled
depends on the material that is being treated.  The following values
were used for the different materials based on AD assumptions:

Textiles:  85 lbs (10 gal of ready-to-use product with a density of
8.5 lb/gal) 

Application of general wood preservative or coating:  425 lbs of fluid
(50 gallons of ready-to-use product with a density of 8.5 lb/gal) 

For the roller/brush application scenarios, it was assumed that 42.5 lbs
of treatment fluid (approximately 5 gallons with a density of 8.5
lb/gal) are used based on AD assumptions.

For the liquid pour scenario, it was assumed that 10,000 lbs of textiles
are treated per day in open-loading systems based on AD assumptions
(USEPA, 2005).

For the liquid pump scenario, it was assumed that 10,000 lbs of textiles
are treated per day in closed-delivery systems based on AD assumptions
(USEPA, 2005).

For the airless spray scenario, it was assumed that 425 lbs of
ready-to-use treatment fluid (approximately 50 gallons of with a density
of 8.5 lb/gal) are used based on AD assumptions.

Duration of Exposure:  It is assumed that occupational handlers will
have exposures of ST, IT, and LT durations in industrial/commercial
settings.  Based on assigned toxicity endpoints, the MOEs were
calculated for ST, IT, and LT inhalation and IT dermal exposures.  Refer
to endpoint selection in Table 3.2.  

Exposure Calculations and Results

	The resulting dermal and inhalation exposures and MOEs for the
representative occupational handler scenarios are presented in Tables
6.2a and 6.2b.  Calculated MOEs were below the target MOEs of 100 for IT
dermal and 1,000 for ST/IT/LT inhalation for the following scenarios
listed.  It should be noted that for MOEs below 1,000, the Agency may
request a confirmatory inhalation toxicity study to refine the potential
risks since the current inhalation endpoint is based on an oral NOAEL.  

Dermal:

Preservation of textiles, low-pressure sprayer:  MOE = 3 at baseline
dermal;

Preservation of textiles, brush/roller:  MOE = 4 at baseline and 33 with
glove PPE; 

Preservation of textiles, liquid pour:  MOE = < 1 at baseline and 50
with glove PPE;

Preservation of textiles, liquid pump: MOE = 14 at baseline;

General preservation of wood, brush/roller: MOE = 4 at baseline, 25 with
glove PPE; 

General preservation of wood, airless sprayer: MOE = 2 at baseline, 5
for glove PPE;

General preservation of wood, low-pressure sprayer:  MOE = 3 at
baseline;

Application to in-service utility poles, brush: MOE = 5 at baseline, 33
for glove PPE. 

Inhalation:

Preservation of textiles, brush/roller:  MOE = 750 without respirator
PPE;

Preservation of textiles, liquid pour:   MOE = 600 without respirator
PPE;

General preservation of wood, brush/roller:  MOE = 700 without
respirator PPE; 

General preservation of wood, airless sprayer: MOE = 23 without
respirator PPE and 230 with respirator use;

Application to in-service utility poles, brush: MOE = 880 without
respirator PPE.

Table 6.2a  Intermediate-Term Dermal Risks Associated with Occupational
Handlers

Exposure Scenario	

Method of Application	Dermal Unit Exposure

 (mg/lb a.i.)

	Application Rate (% a.i. by weight)	Quantity Handled/ Treated per day
Dermal

Absorbed Daily Dose (mg/kg/day)c	IT Dermal

 MOEd

(Target MOE = 100)

Baseline Dermala	PPE-Gloves Dermalb

	Baseline Dermal	Glove PPE	Baseline Dermal	Glove PPE

Material Preservatives

Preservation of  outdoor-use textiles	Low-pressure sprayer	100	0.43	25%
85 lbs	30	0.13	3	770

	Brush/roller	180	24	22%	42.5 lbs	24	3	4	33

	Liquid pour	50.3	0.135	11%	10,000 lbs	790	2	0.13	50

	Liquid pump	0.454	

0.00629	11%	10,000 lbs	7	0.11	14	910

Wood Preservatives

General preservation of wood	Brush/roller	180	24	25%	42.5 lbs	27	4	4	25

	Airless sprayer	

38	

14	25%	425 lbs	58	21	2	5

	Low-pressure sprayer	100	0.43	25%	85 lbs	30	0.13	3	770

Application to

 in-service utility poles	Brush	180	24	20%	42.5 lbs	22	3	5	33

	

	* Note:  Other occupational scenarios for wood preservatives are
assessed separately in Section 6.4.  IT = intermediate-term.

	Unit Exposure (UE) Data are from CMA for Liquid pour/Liquid pump
scenarios, and PHED for Brush and Low pressure/Airless sprayer

	applications.

	a	Baseline Dermal:  Long-sleeve shirt, long pants, and no gloves. It
should be noted that the baseline dermal unit exposures (liquid
pour/liquid pump) for the preservation of textiles were from the cooling
tower CMA data set because baseline (ungloved) dermal unit exposures are
not available for the CMA data set on preservatives. 

	b	PPE Dermal with gloves: baseline dermal plus chemical-resistant
gloves.  

c	Absorbed Daily dose (mg/kg/day) = [unit exposure (mg/lb a.i.) *
absorption factor (NA for dermal) * application rate * quantity treated
/ Body weight (70 kg).

d	MOE = NOAEL  (mg/kg/day) / Absorbed Daily Dose [Where IT dermal NOAEL
= 100 mg/kg/day].

	

Table 6.2b  Short-, Intermediate-, and Long-Term Inhalation Risks
Associated with Occupational Handlers

Exposure Scenario	

Method of Application	Inhalation Unit Exposure (mg/lb a.i.)	Application
Rate (% a.i. by weight)	Quantity Handled/ Treated per day	Inhalation
Absorbed Daily Dose (mg/kg/day)a	Inhalation 

ST/IT/LT MOEb

(Target MOE = 1,000) **

Material Preservatives

Preservation of  outdoor-use textiles	Low-pressure sprayer	0.03	25%	85
lbs	0.009	3,300

	Brush/roller	0.28	22%	42.5 lbs	0.04	750	7,500

(PPE)

	Liquid pour	0.00346	11%	10,000 lbs	0.05	600	6,000

(PPE)

	Liquid pump	0.000403	11%	10,000 lbs	0.0063	4,800

Wood Preservatives

General preservation of wood	Brush/roller	0.28	25%	42.5 lbs	0.043	700
7,000

(PPE)

	Airless sprayer	0.83	25%	425 lbs	1.3	23	230

(PPE)

	Low-pressure sprayer	0.03	25%	85 lbs	0.009	3,300

Application to in-service utility poles	Brush/roller	0.28	20%	42.5 lbs
0.034	880	8,800

(PPE)

	* Note:  Other occupational scenarios for wood preservatives are
assessed separately in Section 6.4.

	ST= Short-term; IT = intermediate-term; and LT = long-term.

	Unit Exposure (UE) Data are from CMA for Liquid pour/Liquid pump
scenarios, and PHED for Brush and Low pressure/Airless sprayer

	applications.

	

	** CMA and PHED Surrogate Inhalation Unit Exposure Data are baseline
values representing no respirator use as PPE.  For scenarios 	assessed
with PHED data, a protection factor of 90% can be applied to UE values
to represent use of organic vapor respirators for any 	inhalation
scenarios with MOEs below the target of 1000 (i.e.,Brush/Roller and
Airless Sprayer).  Protection factors are not applied to 	CMA Datasets.

 

a	Absorbed Daily dose (mg/kg/day) = [unit exposure (mg/lb a.i.) *
absorption factor (100% (1.0) for  inhalation) * application rate *
quantity treated / Body weight (70 kg).

b	MOE = NOAEL  (mg/kg/day) / Absorbed Daily Dose [Where ST/IT/LT
Inhalation NOAEL = 30 mg/kg/day].

	6.3	Occupational Post-application Exposures tc \l2 "6.3	Occupational
Post-application Exposures  

	Except for the post-application scenarios assessed for wood
preservatives in Section 6.4, occupational post-application exposures
are assumed to be negligible. 	

	6.4 	Wood Preservation tc \l2 "6.4	Wood Preservation 

	Copper and Zinc Naphthenates are used industrially as a wood
preservative in treating wood for exterior uses (above-ground,
ground-contact, below-ground, and fresh or salt water).  Copper
Naphthenate imparts a dark-green color to wood which weathers over time
to a light brown.  In contrast, Zinc Naphthenate does not impart color
to treated wood, making it easier to apply paint finishes.  Both
chemicals may leave wood with a noticeable odor, which takes time to
dissipate for Copper Naphthenate, but may linger for Zinc
Naphthenate-treated wood. 

	The formulated EP preservatives are usually supplied as solvent, water
or oil-based solutions having a guaranteed metal content.  Copper
Naphthenate is also used as a remedial surface treatment for fabricated
end-cuts of pressure treated wood and as remedial treatment to
in-service standing wood utility poles, mine timbers, bridge timbers,
and cross-ties and stakes.  Registered uses for Naphthenate Salts
include wood preservative treatments as wood surface coatings [e.g.,
wood protection treatment (including as water repellents) applied via
brush, roller, or spray] and impregnation into wood via non-pressure
(e.g., non-pressure dipping/immersion) and pressure techniques
(vacuum/full-cell).  The products can be used on different types of
wood, including 1) dry, well-seasoned debarked lumber, poles, posts, and
timbers; 2) manufactured wood products such as plywood and particle
board (wood composites); 3) to a minor degree for green, un-seasoned
lumber/timbers; and 4) finished wood products such as millwork,
shingles, shakes, siding, plywood and structural lumber. 

	The exposure scenarios assessed in this document for the representative
wood preservation uses selected by AD are shown in Table 6.1.  The
exposure analysis for scenarios involving general preservation of wood
and application to in-service utility poles and similar items is
presented in Section 6.2.  In Section 6.4.1, the exposure analysis for
the handler and post-application scenarios for non-pressure treatment
scenarios is presented.  The exposure analysis for the handler and
post-application scenarios for pressure treatment scenarios is presented
in Section 6.4.2.

	6.4.1 	Non-Pressure Treatment Scenarios (Handler and Post-application)
tc \l3 "6.4.1	Non-Pressure Treatment Scenarios (Handler and
Post-application) 

	Handler and post-application scenarios for non-pressure treatment of
wood were identified and assessed using surrogate data.  The proprietary
study, “Measurement and Assessment of Dermal and Inhalation Exposures
to Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the Protection of
Cut Lumber (Phase III)” (Bestari et al., 1999, MRID 455243-04)
identified various worker functions/positions for individuals that
handle DDAC-containing wood preservatives for non-pressure treatment
application methods and for individuals that could then come into
contact with the preserved wood. Representative worker
functions/positions identified in the DDAC study are presented below. It
was assumed that the workers at facilities using Naphthenate Salts as a
preservative and handling the treated wood are performing similar tasks
as those monitored in the DDAC study. This study was sponsored by an
industry consortium [Sapstain Industry Group (SIG) Task Force # 73154];
therefore, data compensation issues apply for use of these data as a
surrogate source in assessing exposure.  

Handler:

Blender/spray operators are workers that add the wood preservative into
a blender/sprayer system for composite wood via closed-liquid pumping.

Chemical operators for a spray box system consist of chemical operators,
chemical assistants, chemical supervisors, and chemical captains.  These
individuals maintain a chemical supply balance and are assigned the task
of flushing and cleaning spray nozzles. 

Diptank Operators can be in reference to wood being lowered into the
treating solution through an automated process (i.e., elevator diptank,
forklift diptank).  This scenario can also occur in a small scale
treatment facility in which the worker can manually dip the wood into
the treatment solution.

Post-application: 

Graders are expected to be positioned right after the spray box
sequence, where they grade the dry lumber by hand (i.e. detect faults). 
In the DDAC study, graders graded wet lumber; therefore, the exposures
to graders using Naphthenate Salts are assumed to be the worst-case
scenarios.    

Trim saw operators operate the hula trim saw and consist of operators
and strappers.  In the DDAC study, hula trim saw operators handled dry
lumber. 

Millwrights repair all conveyer chains and are involved in a general
up-keep of the mill.  

Clean-up crews perform general cleaning duties at the mill.

Construction workers install treated plywood, oriented strand board,
medium density fiberboard, and others.  

	In lieu of chemical-specific data available regarding typical exposures
to Naphthenate Salts as a wood preservative, surrogate data were used to
estimate exposure risks. The blender/spray operator position was
assessed using CMA unit exposure data and the remaining handler and
post-application positions were assessed using data from the DDAC study
(Bestari et al., 1999). 

Blender/Spray Operators

	Exposures and risks to the blender/spray operators were assessed using
Equations 1 through 3 in Section 1.2.  The surrogate unit exposures were
taken from the CMA study (USEPA, 1999).  Specifically, the liquid pump
preservative unit exposure for gloved workers was used in this
assessment. (Note that IT dermal exposure was assessed here since a
systemic endpoint is used. The potential for dermal irritation that
might result from ST dermal exposure is assumed to be mitigated through
the use of PPE, including chemical-resistant gloves).  The dermal unit
exposure value used was 0.00629 mg/lb a.i. and the inhalation unit
exposure was 0.000403 mg/lb a.i.. These values are based on two
replicates where the test subjects were wearing a single layer of
clothing and chemical resistant gloves.  The quantity of the wood being
treated was derived from other wood preservative estimates (USEPA, 2004)
for the amount of wood slurry treated because no chemical specific data
were available for Naphthenate Salts.  It was assumed that batches of
wood   SEQ CHAPTER \h \r 1 slurry are treated in 10,000 gallon tanks,
and that eight batches of wood slurry are treated per day (one per hour
for an 8-hr work shift).  Additionally, it was assumed that each batch
requires 3,000 gallons of preservatives and the remaining volume of the
tank consists of wood slurry (7,000 gallons of wood slurry per batch). 
Because wood chips have a density of approximately 380 kg/m3 (SIMetric,
2007), the total amount of wood slurry treated per day is about 177,000
lbs (i.e., 8 batches/day * 7,000 gallons/batch * 0.003785 m3/gallon *
380 kg/m3 * 2.2 lb/kg).    SEQ CHAPTER \h \r 1 The assumptions used for
batch sizes and the quantity of preservative needed are consistent with
an assessment performed previously by the EPA. This assessment was
conducted using two product use-rates to denote: 1) an actual wood
composite labeled use pattern, and 2) a representative product for the
mixer/loader task involved with commercial non-pressure treatments as a
whole.  A Copper Naphthenate product cites a use-application for wood
composite incorporation at a maximum level of 1.4% a.i. during
manufacture of particle board/wood fiber board (i.e., composite wood).  
The product labeling for EPA Reg. No. 1022-522 (45.4% a.i.) cites
maximum incorporation of 3% w/w product based on dry weight of wood
mixed with furnish resin/binding agent (45.4% a.i. * 0.03 = 1.4 % a.i.).
 The other representative product used for non-pressure treatment is a
solvent-based ready-to-use (RTU) solution at 25% a.i. as EPA Reg. No.
1022-409.  Both product labels cite use of eye protection (goggles/face
shield) and rubber gloves as PPE.  Only the 25% a.i. RTU product
includes a respirator-use PPE statement as follows: “Wear a
NIOSH/MHSA-approved mist/vapor respirator when spraying for continued or
prolonged use of this product or for frequent use of the product.” 

  

Table 6.3 provides the short-, intermediate-, and long-term doses and
MOEs for the blender/spray operators adding the preservative to the wood
slurry.  The MOEs for the wood composite use scenario are above the
Agency targets of 100 for IT dermal (as 450) and 1000 for ST/IT/LT
inhalation (as 2,100), denoting no exposure risks of concern.  However,
for the generic non-pressure treatment mixer/loader scenario, both
dermal and inhalation MOEs pose exposure risk concerns.  The dermal IT
MOE was below the target of 100 (as 25) and the inhalation ST/IT/LT MOE
was below the target of 1000 (as 120). Therefore, registrant input is
needed to clarify use rate and quantity treated. Also, a confirmatory
inhalation toxicity study may be warranted based on the results of this
assessment.

Table 6.3. Short-, Intermediate-, and Long-term Exposures and MOEs for
Wood Preservative Blender/Spray Operators

Exposure Scenario

	Dermal Unit Exposurea

(mg/lb ai)	Inhalation Unit Exposureb

(mg/lb ai)	Application Ratec

(% ai by weight)	Wood Slurry Treatedd

(lb/day)	Absorbed Daily Dosee 

(mg/kg/day)	MOEsf

	Dermal	Inhalation	Dermal

IT

Target=100	Inhalation

ST/IT/LT

Target = 1000

Occupational Handler

CMA Liquid Pump	0.00629	0.000403	1.4

(wood composites)	177,000	0.22	0.0143	450	2,100

	25

(non-pressure

mix/load)

4	0.255	25	120

ST =	Short-term duration; IT =Intermediate-term duration; and LT =
long-term.

Dermal unit exposure: Single layer clothing with chemical resistant
gloves.

Inhalation unit exposure: Baseline, with no respirator.	

c.	The maximum application rate is 1.4% a.i. solution for particle board
composite based on product labeling (1022-522); and maximum application
rate is 25% a.i. RTU for representative non-pressure treatment
mixing/loading (1022-409).  

d.	Wood slurry treated = (8 batches/day * 7,000 gallons/batch * 0.003785
m3/gallon * 380 kg/m3 * 2.2 lb/kg)	

e.	Absorbed Daily Dose = unit exposure (mg/lb ai) x App Rate (1.4% or
25% a.i. by weight as 0.014 or 0.25) x Quantity treated (lb/day) x
absorption factor (NA for dermal and 100% for inhalation) / BW (70 kg)

f.	MOE = NOAEL (mg/kg/day) / Daily dose [Where IT NOAEL = 100 mg/kg/day
for dermal and 

	ST/ /IT/LT NOAEL = 30 mg/kg/day for inhalation].  Target MOE is 100 for
dermal exposure and 1000 for inhalation 	exposure.

	

Chemical Operators, Graders, Millwrights, Clean-up Crews, and Trim Saw
Operators

	Exposures to chemical operators, graders, millwrights, trim saw
operators, and clean-up crews were assessed using surrogate data from
the DDAC study (Bestari et al., 1999). This study examined
individuals’ exposure to DDAC while working with anti-sapstains and
performing routine tasks at 11 sawmills/planar mills in Canada.  Dermal
and inhalation exposure monitoring data were gathered for each job
function of interest using dosimeters and personal sampling tubes. 
These sample media were then analyzed for DDAC, and the results were
reported in terms of mg DDAC exposure per person per day.  The study
reported average daily exposures for workers in various categories. 
Exposure data for individuals performing the same job functions were
averaged together to determine job specific averages.  Total exposures
from 2 trim saw workers, 13 grader workers, 11 chemical operators, 3
millwrights, and 6 clean-up staff were used. 

	The individual dermal and inhalation exposures from the DDAC study are
presented in Table B-1 in Appendix B.  The representative maximum
use-application rate is 25% a.i. as a RTU product (EPA Reg. No.
1022-409) for non-pressure treatments via brush/roller/dip/spray. To
determine exposures to Naphthenate Salts, the average DDAC exposures
measured on individuals (in terms of total mg DDAC) were multiplied by a
modification factor of 0.3125 to account for the difference in percent
active ingredient between Naphthenate Salts and DDAC (25% Naphthenate
Salts in the wood preservative product versus 80% DDAC in the
comparative wood preservative product). The pounds of active ingredient
handled by each person or percent active ingredient in the treatment
solution were not provided for these worker functions. 

The following equation was used to calculate daily dose for Naphthenate
Salts: 

Daily Dose = DDAC UE * CR * AB 

           	         BW

Where

DDAC UE	=	DDAC dermal or inhalation unit exposure (mg/day);

CR		=	Conversion ratio (25% Naphthenate Salts / 80% DDAC);

AB	=	Absorption factor (NA for dermal, 100% for inhalation); and

BW		=	Body weight (70 kg).

In using this methodology, the following assumptions were made:

DDAC and Naphthenate Salts end products will be used in similar
quantities. 

The procedures for applying both chemicals are similar. 

The physical-chemical properties that affect the transport of the
chemical are similar. (This assumes similar product densities for the
DDAC and Naphthenate Salts water-borne solutions).

The limits of detections (LOD) for inhalation residues from   SEQ
CHAPTER \h \r 1 chemical operators, graders, mill wrights, and clean-up
staff replicates were not provided in the DDAC report.  For lack of
better data, it was assumed that the inhalation LODs for these worker
positions are equal to the LOD of the diptank operator replicates (5.6
(g).  For all measurements below the air concentration associated with
this detection limit, half the detection limit was used.  The dermal LOD
for all operators is also 5.6 (g.

In the DDAC study, dermal exposures to hands were measured separately
from the rest of the body.  For each replicate, the body dose
measurements and hand dose measurements were summed for a total dermal
dose.

Air concentrations were reported in the DDAC study. To convert air
concentrations ((g/m3) into terms of inhalation unit exposure (mg/day),
the air concentrations were multiplied by an inhalation rate of 1.0
m3/hr for light activity (EPA 1997), sample duration of 8 hrs/day, and a
conversion factor of 1 mg/1000 (g.  Table B-1 in Appendix B presents the
inhalation and dermal DDAC exposures.

Average DDAC dermal and inhalation exposures were multiplied by a
conversion ratio 0.3125 to account for the differences in Naphthenate
Salts and DDAC concentrations [i.e., (25% Naphthenate Salts / 80%
DDAC)].  

Table 6.4 provides the short-, intermediate-, and long-term doses and
MOEs for chemical operators, graders, millwrights, clean-up crews, and
trim saw operators.  For all worker functions the calculated dermal and
inhalation MOEs were not of concern. The inhalation MOEs are above the
target MOE of 1,000 and therefore a confirmatory inhalation toxicity
study is not warranted based on the results of this assessment.  Also,
the dermal MOEs are above the target MOE of 100 for IT durations
assessed.  

Table 6.4. Short-, Intermediate- and Long-Term Exposures and MOEs for
Wood Preservative Chemical Operators, Graders, Millwrights, Trim Saw
Operators, and Clean-Up Crews

Exposure Scenarioa 

(number of volunteers)	Dermal UEb 

(mg/day)	Inhalation UEb 

(mg/day)	Conversion Ratioc 	Absorbed Daily Dosesd 

(mg/kg/day)

	MOEse

Dermal	Inhalation	Dermal

IT

Target = 100	Inhalation

ST/IT/LT

Target = 1000

Occupational Handler

Chemical Operator (n=11)	9.81	0.0281	0.3125	0.044	0.00013	2,300	240,000

Occupational Post-application

Grader (n=13)	3.13	0.0295	0.3125	0.014	0.00013	7,100	230,000

Trim Saw (n=2)	1.38	0.061	0.3125	0.0062	0.00027	16,000	110,000

Millwright (n=3)	12.81	0.057	0.3125	0.057	0.00025	1,800	120,000

Clean-Up (n=6)	55.3	0.60	0.3125	0.25	0.0027	400	11,000

ST = 	Short-term duration; IT = Intermediate-term duration; and LT =
long-term

a.	The exposure scenario represents a worker wearing either long-sleeved
or short-sleeved shirts, cotton work trousers, and cotton glove
dosimeter gloves under chemical resistant gloves. Volunteers were
grouped according to tasks they conducted at the mill.

b.	Dermal and inhalation unit exposures are from Bestari et al (1999). 
Refer to Table B-1 in Appendix B for the calculation of the dermal and
inhalation exposures. Inhalation exposure (mg/day) was calculated using
the following equation: air concentration ((g/m3) x inhalation rate (1.0
m3/hr) x sample duration (8 hr/day) x unit conversion (1 mg/1000 (g). 
The inhalation rate is from USEPA, 1997. 

c.	Conversion Ratio = 25% Naphthenate Salts / 80% DDAC (based on EPA
Reg. No. 1022-409 for 25% a.i. RTU product).

d.	Absorbed Daily dose (mg/kg/day) = exposure (mg/day) * conversion
ratio (0.3125) * absorption factor (NA for dermal and 100% for
inhalation)/body weight (70 kg). 

e.			MOE = NOAEL (mg/kg/day) / Daily dose [Where IT NOAEL = 100
mg/kg/day for dermal and ST/IT/LT NOAEL = 30 mg/kg/day for inhalation ].
Target MOE is 100 for dermal and 1000 for inhalation exposure.

Diptank Operators

	Exposures to diptank operators were also assessed using surrogate data
from the DDAC study (Bestari et al., 1999). The diptank scenario
assessment was conducted differently than for the other job functions
because the concentration of DDAC in the diptank solution was provided. 
Registered product use rates for dip treatments (dipping, diptank,
soaking or immersion) range from levels of 7.5 % a.i. up to 32 % a.i.,
based on the level of protection needed and treatment duration.  Dip
treatments are specified for 1-3 to 30 minutes per inch of wood
thickness, or from 12-48 hours for heavy wooden members. Typical
use-rate levels are closer to 17% - 25% a.i.  As conservative estimates,
the typical high-end and the maximum levels cited on labeling for this
use were assessed as 25% and 32% a.i.. EPA Reg. No.1022-409 is a 25%
a.i. RTU product and EPA Reg. No. 9630-31 is a 63% a.i. concentrate
requiring dilution to yield a 32% a.i. treatment solution prepared by
blending the concentrate with two parts solvent [i.e., 1:2 v/v use
dilution * 63% a.i. in product = 31.5 (32 % a.i.].  Both product labels
cite use of eye protection (goggles/face shield) and
rubber/chemical-resistant gloves as PPE.  Also they include a
respirator-use PPE statement as follows: “Wear a NIOSH/MHSA-approved
mist/vapor respirator when spraying for continued or prolonged use of
this product or for frequent use of the product.” 

	The exposure data for diptank operators wearing gloves were converted
into “unit exposures” in terms of mg a.i. for each 1% of
concentration of the product. The calculation of the inhalation unit
exposure of 0.046 mg/1% solution is presented in Table B-2 in
Appendix B.  The air concentrations presented in the DDAC study were
converted to unit exposures using an inhalation rate of 1.0 m3/hr (light
activity) and a sample duration of 8 hrs/day.

The following equations are used to estimate dermal and inhalation
handler exposure: 

Daily Dose = DDAC UE * AI * AB 

		BW

Where

DDAC UE	=	DDAC dermal or inhalation unit exposure (mg/ 1% in solution);

AI		=	AI (25 % or 32% a.i. in solution/day);

AB	=	Absorption factor (NA for dermal,100% for inhalation); and

BW		=	Body weight (70 kg).

	Table 6.5 provides the short-, intermediate- and long-term doses and
MOEs for diptank operators.  The IT dermal MOEs are below the Agency
target of 100 (ranging from 70-90 for 32% and 25% a.i. products
respectively) and therefore denote potential dermal risk concerns.  The
inhalation ST/IT/LT MOEs are above the Agency target of 1,000, and not
of concern.  Therefore, a confirmatory inhalation toxicity study is not
warranted based on the results of this exposure scenario.

 Table 6.5.  Short-, Intermediate-, and Long-Term Exposures and MOEs
for Diptank Operators 

Exposure Scenarioa

(number of replicates)	Dermal Unit Exposureb 

(mg DDAC/1% solution)	Inhalation Unit Exposureb 

(mg DDAC/1% solution)	App Rate 

(% a.i. in solution/ day)c 	Absorbed Daily Doses d 

(mg/kg/day)	MOEs e

Dermal	Inhalation	Dermal

IT

 

Target MOE = 100	Inhalation

ST/IT/LT 

Target MOE = 1000

Occupational Handler

Dipping, with gloves (n=7)

	2.99	0.046	32 and 25	1.07-1.37	0.016-0.021	70-90	1,400-1,900

ST = 	Short-term duration;  IT =Intermediate-term duration; and LT =
long-term.

a. 	The exposure scenario represents a worker wearing long-sleeved
shirts, cotton work trousers, and gloves. Gloves were worn only when
near the chemical, not when operating the diptank.

b.	Dermal and inhalation unit exposures are from DDAC study (MRID
455243-04). Refer to Table B-2 in Appendix B for the dermal and
inhalation unit exposure calculations. Inhalation exposure (mg) was
calculated using the following equation: Air concentration (mg/m3) x
Inhalation rate (1.0 m3/hr) x Sample Duration (8 hr).  The inhalation
rate is from USEPA, 1997.

c.	The typical high-end and maximum application rates for dip
application method are 25% (1022-409) and 32% a.i. (9630-31) solutions. 

d.	Absorbed Daily dose (mg/kg/day) = unit exposure (mg/1% a.i. solution)
* percent active ingredient in solution (25 or 32) * absorption factor
(NA for dermal and 100% for inhalation) / body weight (70 kg).

e.			MOE = NOAEL (mg/kg/day) / Daily dose [Where IT NOAEL = 100
mg/kg/day for dermal and ST/IT/LT NOAEL = 30 mg/kg/day for inhalation].
Target MOE is 100 for dermal exposure and 1,000 for inhalation exposure.

Construction Workers

	There are insufficient data to estimate the amount of exposure
associated with construction workers who install treated wood.  In
particular, values for the transfer coefficient associated with a
construction worker handling the wood could not be determined. However,
it is believed that the construction worker using a trim saw will have
larger dermal and inhalation exposures than the installer, due to the
amount of sawdust generated and the greater amount of hand contact that
would be necessary to handle the wood when using a saw compared to
installing the wood.

	6.4.2	Pressure Treatment Scenarios (Handler and Post-Application)  tc
\l3 "6.4.2	Pressure Treatment Scenarios (Handler and Post-application) 

	

	Wood preservatives with Naphthenate Salts may be used to treat wood and
wood products using pressurized application methods, specifically
double-vacuum and full-cell pressure impregnation techniques which may
include thermal applications to condition the wood.  Registered product
use-rates for pressure treatment are at levels of 2% to 13% Naphthenate
Salts.  Typical use-rates contain 4 % to 13% a.i. in solvent-, oil- or
water-borne use-dilutions; resulting in 0.5% to 1.5% Copper (as metal),
in the solutions used for treatment.  The highest use rates are with
Copper Naphthenate products.  The ratio of Copper metal to Copper
Naphthenate on most labels where Copper content is specified for
pressure treatment is about 1:8 , although the calculated ratio can
vary.  The maximum rate of application used in this assessment is a 13 %
a.i. solution based on product labeling for EPA Reg. No. 43437-4, which
is an 89% a.i. concentrate for dilution with a hydrocarbon or petroleum
solvent.  The label for this product indicates that pressure treatment
use solutions should be prepared by blending the concentrate with seven
parts solvent [i.e., 1:7 v/v use dilution * 89% a.i. in product = 12.7
(13 % a.i. in solution during application].  In comparison, where water
dilutions are made, the highest use-rate concentration is 10% a.i. for
EPA Reg. No. 1022-568.  

	The Naphthenate Salts are listed in the American Wood-Preservers’
Association (AWPA) Book of Standards for treating major softwood species
used for a variety of wood products (e.g., Douglas-fir and Southern
yellow pine). It is unclear if any hardwood species are pressure-treated
using Copper/Zinc Naphthenates. The minimum Copper Naphthenate
retentions (as elemental copper) range from 0.64 kg/m3 (0.04 lb/ft3) for
wood used above ground, to 0.96 kg/m3 (0.06 lb/ft3) for wood used in
soil (ground) and fresh water contact, 1.2 kg/m3 (0.075 lb/ft3) for wood
used in critical structural applications, 1.60 kg/m3 (0.10 lb/ft3) for
pilings (soil, fresh water and foundation), and up to 2.4 kg/m3 (0.15
lb/ft3) for utility poles.

	Chemical-specific exposure data are not available on Naphthenate Salts
for assessment of pressure treatment exposure.  Therefore, the
assessment relies on surrogate Chromated Copper Arsenate (CCA) data
(ACC, 2002) and was based on the approach used in a previous Agency
exposure assessment (USEPA, 2003).  

Surrogate Unit Exposure Data

	

	Dermal and inhalation exposures for pressure treatment uses are derived
from information in the exposure study sponsored by the American
Chemistry Council (2002) entitled “Assessment of Potential Inhalation
and Dermal Exposure Associated with Pressure Treatment of Wood with
Arsenical Wood Products” (ACC, 2002).  In this study, a treatment
solution of CCA was approximately 0.5 percent active ingredient.  The
CCA exposure monitoring study has been reviewed by the Agency and is
considered a valid surrogate source of data for pressure treatment
applications and is therefore used in estimating exposure to Naphthenate
Salts.  

	The CCA study measured both handlers and post-application activities. 
Although there is overlap in job functions, the handlers are defined as
being either treating operators (TOs) or treating assistants (TAs).  The
TOs were monitored at three sites (A, B, and C) using 5 replicates at
each site.  The TAs were monitored at two sites (Sites A and C) using 5
replicates at each site.  The post-application activities included: tram
setter (TS) at Site A (n=5); stacker operator (SO) at Site A (n=4);
loader operator (LO) at Sites A, B, C (n=15); supervisor (S) at Site B
(n=5); test borer (TB) at Site C (n=5); and the tallyman (TM) at Site C
(n=5).  According to the CCA study, workers wore cotton long-sleeved
shirts and cotton trousers (or one-piece cotton coveralls) over the
whole-body dosimeters (“plus additional shirts or jackets per typical
practice at Site B”) and chemical-resistant or work gloves, when
appropriate.  Therefore, the CCA study provides exposure data associated
with maximum PPE (excluding respirators).  In using the CCA study for
this Naphthenate Salts assessment, the TO and TA handlers are assessed
separately. The post-application job functions, however, have been
combined into one data set to represent post-application activities
because for most activities the sample size is small (5 ≤ n ≤ 15).  

	The measured CCA dermal and inhalation exposure values were normalized
by the treatment solution concentration used at each of the 3 facilities
(i.e., unit exposure reported as µg arsenic/ppm treatment solution). 
Table 6.6 presents the dermal and inhalation unit exposure values
normalized to the treatment solution concentration in ppm for (1) all
sites, (2) treatment operator (TA handler), (3) treatment assistant (TA
handler), and (4) all post-application job functions (TS, SO, LO, S, TB,
TM).  The normalization by treatment solution concentration was
performed to extrapolate the measured exposures in the CCA study
(monitored at ~0.5% a.i. solution) to the maximum Naphthenate Salts
treatment solution concentration from EPA Reg. No. 43437-4 (13 % a.i.
solution) (Shown in Table 6.7).  

Table 6.6.  Dermal and Inhalation Exposure Values from a CCA Pressure
Treatment Study (Exposure Data used as Surrogate Unit Exposures for
Naphthenate Salts Assessment)

Site	Treatment Solution  	Statistic	Dermal Unit Exposure

((g As/ppm)	Air 

Concentrationb

((g As/m3/ppm)	Inhalation Unit Exposurec

((g As/ppm)

	%	ppma

All sites - All Data

(n = 64)	0.438 to 0.595	4,380 to 5,950	Average ± std	0.97 ± Unknown
0.00013 ± 0.00023	0.00104

	Median	0.36	0.00013	0.00104

	90th percentile	2.07	0.00077	0.00617

	Maximum	7.74	0.0011	0.00882

All sites - Handler Treatment Operator

(n = 15)	0.438 to 0.595	4,380 to 5,950	Average ± std	2.04 ± 2.68
0.00032 ± 0.00038	0.00257

	Median	0.37	0.00013	0.00104

	90th percentile	5.39	0.00092	0.00737

	Maximum	7.74	0.0011	0.00882

All sites - Handler Treatment Assistant

(n = 10)	0.438 to 0.595	4,380 to 5,950	Average ± std	0.24 ± 0.14
0.0001 ± 0.00004	0.000802

	Median	0.23	0.00013	0.00104

	90th percentile	0.40	0.00013	0.00104

	Maximum	0.52	0.00014	0.00112

All sites – Post-application: All job functions (TS, SO, LO, S, TB,
TM)

(n = 39)	--	--	Average ± std	0.74 ± 0.73	0.00020 ± 0.00025	0.00160

	Median	0.42	0.00013	0.00104

	90th percentile	1.81	0.00050	0.00401

	Maximum	3.11	0.0011	0.00882

	a.	ppm = (% treatment solution) * (10,000).

	b.	Air concentration was calculated as (g collected per sample per ppm
/ (480 min per day x 2 L/min).

	c.	Inhalation unit exposure = air concentration ((g As/m3/ppm) *
breathing rate for light activities (0.0167 m3/min) * 	sample duration
(480 min).  Values shown in bold are used for the assessment.

Exposure Calculations

The following equation was used to estimate dermal and inhalation
exposure: 

Absorbed Daily Dose = 	UE * AI * AB 

	      	       BW

Where

UE	=	Unit exposure (mg As/ppm);

AI	=	Percent active ingredient (13 % a.i. in solution);

AB	=	Absorption factor (Not applicable [NA] for dermal, 100% for
inhalation); and

BW	=	Body weight (70 kg).

Results

	The estimated dermal and inhalation exposures and MOEs for Naphthenate
Salts pressure treatment uses are presented in Table 6.7.  The
calculated IT dermal MOEs for both the treatment operator handler (MOE =
25) and post-application workers (MOE = 70) were below the Agency target
MOE of 100 and therefore represent potential risks of concern.  The
ST/IT/LT inhalation MOEs for all scenarios are above the target MOE of
1,000 and not of concern.  In addition, because the MOE is greater than
1,000, a confirmatory inhalation toxicity study is not warranted based
on the screening-level results. 

Table 6.7.  Short-, Intermediate-, and Long-Term Exposures and MOEs for
Pressure Treatment Handler and Post-application Scenarios Related to
Naphthenate Salts Use 

Exposure Scenarioa	

Unit Exposurea 

((g As/ppm)

	

Application Rate 

(% ai solution) 	Absorbed Daily Dosesb 

(mg/kg/day)	MOEsc

	Dermal	Inhalation

Dermal	Inhalation	Dermal

IT

Target = 100	Inhalation

ST/IT/LT

Target=1000

Occupational Handler

Treatment Operator (TO)	2.04	0.00257	13	4	0.0048	25	6,300

Treatment Assistant (TA)	0.24	0.000802	13	0.446	0.0015	220	20,000

Occupational Post-application

All Job Functions

(Tram setter, stacker operator, loader operator, supervisor, test borer,
and tallyman) 	0.74	0.00160	13	1.37	0.0030	70	10,000

ST = 	Short-term duration; IT = Intermediate-term duration; and LT =
long-term.

a. 	Unit exposure values taken from CCA study and are shown in Table
6.6.  It is assumed that the dermal and inhalation exposure to As (per
ppm of a.i.) is representative of exposure to Naphthenate Salts.

 (μg As/ppm) x [% Naphthenate Salts in solution (13) x 10,000 (parts
per million conversion)] x (0.001 mg/μg) x absorption factor (NA for
dermal, 100% for inhalation) / Body weight (70 kg).

c.			MOE = NOAEL (mg/kg/day) / Daily dose [Where IT dermal NOAEL = 100
mg/kg/day and ST/IT/LT inhalation NOAEL = 30 mg/kg/day]. Target MOE is
100 for dermal exposure and 1000 for inhalation exposure.

	6.5	Data Limitations/Uncertainties tc \l2 "6.5	Data
Limitations/Uncertainties 

	There are several data limitations and uncertainties associated with
the occupational handler exposure assessments which include the
following:

Certain surrogate dermal and inhalation unit exposure values were taken
from the proprietary CMA antimicrobial exposure study (US EPA 1999: DP
Barcode D247642) or from the Pesticide Handlers Exposure Database (US
EPA 1998) (See Appendix A for summaries of these data sources). Since
the CMA data are of poor quality, the Agency may request that
confirmatory data be submitted in order to support the values used in
these assessments. 

The quantities handled/treated were estimated using Agency standard
assumptions.  In certain cases where standard values were unavailable,
AD used professional judgment based on Agency understanding of
industrial practices to create estimates.  Assumptions for these
scenarios were could be further refined with input from the registrants.
 

For the preservation of textiles, exposures to handlers during
preparation of dipping solution were assessed assuming a liquid pour or
liquid pump operation associated with automated (large-scale) dipping of
textiles in industrial settings.  However, based on the label use
instructions, it is clear that manual dipping is also used for
preservation of textiles (e.g., via preparation of small-scale dipping
solution by pouring product into a small receptacle and manually dipping
textiles).  Exposures that may occur as part of manual dipping activity
for textiles are not assessed here and may result in possibly higher
exposures than are estimated for the liquid pour/liquid pump scenarios
associated with large-scale dip operations.  However, since the Agency
assessed dip treatment of wood in this document (i.e., diptank
operators), and the use methods are comparable to those for textile
treatment, that assessment can be considered as a high-end
representative estimate of manual textile dip applications.

The type of spray equipment to be used was not specified on most labels
for scenarios involving preservation of outdoor-use textiles and general
preservation of wood use patterns.  Therefore, these scenarios were
assessed using the PHED unit exposures for use of a low-pressure hand
wand (for outdoor-use textiles), and use of an airless sprayer or a
low-pressure hand wand (for the general preservation of wood).  In these
cases, the appropriate application equipment could be further refined by
the registrants.  It is noted that by assuming use of an airless sprayer
for preservation of wood products, a higher unit exposure value is
selected and the quantity handled is greater; resulting therefore in
increased handler exposure.

Remedial treatments with Copper Naphthenate can be made to in-service
wooden poles/piles/posts using brush, trowel, caulking gun (mechanical
pressure pump), or impregnated bandage wraps.  In lieu of
chemical-specific data or surrogate data sources for the remedial
applications, handlers applying remedial-use products to
interior/exterior surfaces of in-service poles were assessed using unit
exposure data for the PHED paintbrush scenario (Scenario 22).  As a
high-end conservative approach, it was assumed that the PHED paintbrush
scenario unit exposure value can be used to represent the remedial
brushing techniques.  Exposures for the other application methods (i.e.,
trowel, caulking gun, or pre-manufactured bandage) were assumed to be
represented by the assessment done using unit exposure data for the
brush use scenario.  This approach may overestimate actual exposures for
workers conducting remedial treatments based on the following
considerations:  

The brush-on application in treating in-service utility poles is
predominantly used for wood preservative pastes.  Brushing  a semi-solid
onto a pole may not present the same exposures as brushing a liquid (as
in PHED painting scenario) due to differences in the viscosity of the
material being brushed;  

The liquid Copper Naphthenate formulations are injected directly into a
pole through a pressure pump to treat the internal areas of a pole. The
exposure to the applicator would be in the mix and load phase of the
application process and not in the actual application to the pole; and

Wrapping a bandage around a pole would not present the same exposures as
brushing a liquid (as in PHED painting scenario).  

For the wood preservative pressure treatment scenarios, CCA exposure
data were used in the absence of exposure data specific to the
Naphthenate Salts.  For the wood preservative non-pressure treatment
scenarios, DDAC exposure data were used in the absence of more specific
exposure data.  Limitations and uncertainties associated with the use of
these data include:

The assumption was made that exposure patterns for workers at treatment
facilities using CCA and DDAC would be similar to exposure patterns for
workers at treatment facilities using Naphthenate Salts, and therefore
the exposures could be used as surrogate data for workers that treat
wood with Copper/Zinc Naphthenate-based formulations. 

For environmental modeling, it was assumed that the leaching process
from the Naphthenate Salts-treated wood would be similar to that of CCA
and DDAC.  However, due to the lack of robust data for wood treated with
Naphthenate Salts, it is not possible to verify this assumption. 

In the occupational assessment, dermal exposures to treated wood were
estimated using surrogate DDAC data (3 (g/cm2).  The degree of
uncertainty (under- or overestimation) associated with using the DDAC
hand residue data for dermal exposure from contacting treated lumber are
unknown.  The amount of residue measured on the test subjects’ hands
is variable and may be influenced by the duration of exposure, how often
wood is contacted, and the degree of contact (i.e., with or without use
of glove PPE). 

7.0	REFERENCES tc \l1 "7.0	REFERENCES  

American Chemistry Council (ACC). 2002.  Assessment of Potential
Inhalation and Dermal Exposure Associated With Pressure Treatment of
Wood with Arsenical Wood Products.  MRID 4550211-01.

Bestari et al. 1999.  [Sapstain Industry Group (SIG)-Consortium Task
Force] Measurement and Assessment of Dermal and Inhalation Exposures to
Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the Protection of Cut
Lumber (Phase III). Unpublished Study Prepared by University of Guelph.
309 p. (MRID 455243-04, SIG Task Force #73154).

Bharat Textiles.  2007. Weight/Density Estimate for Army Duck Canvas
taken from a Specification Chart on the internet site   HYPERLINK
"http://www.tentandcanvas.com/product.htm" 
http://www.tentandcanvas.com/product.htm  of this canvas exporter. Last
viewed April 18, 2007.

California Environmental Protection Agency, Department of Pesticide
Regulation (DPR). 2000.

Notice of Final Decision Concerning Reevaluation of Pesticide Products. 
California Notice 2000-5.  Posted Date May 8, 2000.

  SEQ CHAPTER \h \r 1 Freeman, N , Jimenez M, Reed KJ, Gurunathan S,
Edwards RD, Roy A, Adgate JL, Pellizzari ED, Quackenboss J, Sexton K,
Lioy PJ, 2001.  Quantitative analysis of children’s microactivity
patterns:  The Minnesota Children’s Pesticide Exposure Study.  Journal
of Exposure Analysis and Environmental Epidemiology.  11(6): 501-509.

Hazardous Substances Data Bank (HSDB).  2007.    HYPERLINK
"http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB" 
http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB .  Last viewed May
2007.  Data on molecular weight cited in HSDB to:  NIOSH; Information
Profiles on Potential Occupational Hazards: Copper and Compounds.
Contract No 210-79-0030, Rockville, MD: NIOSH, 2nd Draft (1982).  Data
on vapor pressure cited in HSDB to:  Tomlin, C.D.S. (ed.). The Pesticide
Manual - World Compendium, 11th ed., British Crop Protection Council,
Surrey, England 1997, p. 859.

Health Canada. Pesticide Management Regulatory Agency (PMRA).  1992. 
Regulatory Notice. Label Improvement Program.  Mercury In-Can Paint
Preservatives and Copper and Zinc Naphthenate Wood Preservatives. Note
to CAPCO. C92-07. December 22, 1992.

Naphthenate Salts Research Task Force (NSRTF). 2007. Documents submitted
to the Agency outlining NSRTF Registrants supported uses for
Reregistration of Copper Naphthenate and Zinc Naphthenate. NSRTF. Dated
January 29, 2007 and February 24, 2007.

SIMetric.  2007.  Mass, Weight, Density, or Specific Gravity of Bulk
Materials.    HYPERLINK "http://www.simetric.co.uk/si_materials.htm" 
http://www.simetric.co.uk/si_materials.htm , last accessed May 2007.

U.S. Environmental Protection Agency (USEPA).  1997.  Standard Operating
Procedures (SOPs) for Residential Exposure Assessments.  EPA Office of
Pesticide Programs, Human Health Effects Division (HED).  December 18,
1997.

U.S. Environmental Protection Agency (USEPA).  1997a.  Exposure Factors
Handbook. Volume I-II.  Office of Research and Development.  Washington,
D.C.  EPA/600/P-95/002Fa. August 1997.

U.S. Environmental Protection Agency (USEPA).  1998.  PHED Surrogate
Exposure Guide.  Estimates of Worker Exposure from the Pesticide Handler
Exposure Database Version 1.1.   Washington, DC:  U.S. Environmental
Protection Agency.

U.S. Environmental Protection Agency (USEPA).  1999.  Evaluation of
Chemical Manufacturers Association Antimicrobial Exposure Assessment
Study.  Memorandum from Siroos Mostaghimi, Ph.D., USEPA, to Julie
Fairfax, USEPA. Dated November, 4 1999.  DP Barcode D247642.

U.S. Environmental Protection Agency (USEPA).  2000.  Standard Operating
Procedures (SOPs) for Residential Exposure Assessments. Prepared for EPA
Office of Pesticide Programs, Health Effects Division. Dated April 5,
2000.

U.S. Environmental Protection Agency (USEPA).  2001.  HED Science
Advisory Council for Exposure. Policy Update, November 12.  Recommended
Revisions to the Standard Operating Procedures (SOPs) for Residential
Exposure Assessment, February 22, 2001.

U.S. Environmental Protection Agency (USEPA).  2003.  Assessment of the
Proposed Bardac Wood Preservative Pressure Treatment Use.  Memorandum
from Tim Leighton and Siroos Mostaghimi.  February 11, 2003.

U.S. Environmental Protection Agency (USEPA). 2004.  Occupational and
Residential Exposure Assessment for Carboquat WP-50.  Memorandum from
Siroos Mostaghimi, USEPA to Velma Noble, USEPA.   Dated November 4,
2004. DP Barcodes D303714 and D303938.

U.S. Environmental Protection Agency (USEPA).  2005.  Antimicrobials
Division’s Draft Standard Operating Procedures for Occupational and
Residential Exposure Assessments.  July, 2005. (Unpublished Internal
Guidance).

U.S. Environmental Protection Agency (USEPA).  2006. Coppers: Second
Revised Human Health Chapter of the Reregistration Eligibility Decision
Document (RED). Reregistration Case Numbers 0636, 0649, 4025 and 4026.
DP Barcode 319683. Dated January 17, 2006. Document ID:
EPA-HQ-OPP-2005-0558-0006. (EPA Docket: EPA-HQ-OPP-2005-0558; Copper
Cases; Coppers Reregistration Eligibility Decision, Notice of
Availability, January 25, 2006.).

U.S. Environmental Protection Agency (USEPA). 2006a. Registration
Division (RD) Action Memorandum. Reassessment of the One Exemption from
the Requirement of a Tolerance for Copper Naphthenate (CAS Reg. No.
1338-02-9).  Memorandum from Pauline Wagner, Chief, Inert Ingredient
Assessment Branch, RD. June 27, 2006.

U.S. Environmental Protection Agency (USEPA). 2006b. Meeting Minutes of
SMART Meeting for Naphthenate Salts. Reregistration Case 3099. November
6, 2006.  Transmittal from K. Avivah Jakob, Chemical Review Manager,
USEPA to Copper/Zinc Naphthenate RED Team Members, USEPA. Dated December
11, 2006.

U.S. Environmental Protection Agency (USEPA). 2007.   Review Memorandum:
Naphthenate Salts (Zinc/Copper) – Endpoint Selection Report from T.F.
McMahon, Ph.D., Senior Toxicologist, AD. April 16, 2007.

  

U.S. Environmental Protection Agency (USEPA).  2007a. Review Memoranda:
Environmental Fate Transport Assessments for Zinc Naphthenate and Copper
Naphthenate for Reregistration Eligibility Decision (RED). Two documents
from A. Najm Shamim, Ph.D., Chemist, AD. Dated February 20, 2007 and May
9, 2007 respectively.



APPENDIX A:

Summary of CMA and PHED Data

Chemical Manufacturers Association (CMA) Data:

In response to an EPA Data Call-In Notice, a study was undertaken by the
Institute of Agricultural Medicine and Occupational Health of The
University of Iowa under contract to the Chemical Manufacturers
Association.  In order to meet the requirements of Subdivision U of the
Pesticide Assessment Guidelines (superseded by Series 875.1000-875.1600
of the Pesticide Assessment Guidelines), handler exposure data are
required from the chemical manufacturer specifically registering the
antimicrobial pesticide.   The applicator exposure study must comply
with the assessment guidelines for “Applicator Exposure Monitoring”
in Subdivision U and the “Occupational and Residential Exposure Test
Guidelines” in Series 875.  For this purpose, CMA submitted a study on
February 28, 1990, entitled "Antimicrobial Exposure Assessment Study
(amended on December 8, 1992)" which was conducted by William Popendorf,
et al..  It was evaluated and accepted by the Occupational and
Residential Exposure Branch (OREB) of Health Effect Division (HED),
Office of Pesticide Programs (OPP) of EPA in 1990.  The purpose of this
CMA study was to characterize exposure to antimicrobial chemicals in
order to support pesticide reregistrations (CMA, 1992).  The unit
exposures presented in the most recent EPA evaluation of the CMA
database (USEPA, 1999) were used in this assessment.

The Agency determined that the CMA study had fulfilled the basic
requirements of Subdivision U - Applicator Exposure Monitoring.  The
advantages of CMA data over other “surrogate data sets” is that the
chemicals and the job functions of mixer/loader/applicator were defined
based on common application methods used for antimicrobial pesticides. 
A few of the deficiencies in the CMA data are noted below:

The inhalation concentrations were typically below the detection limits,
so the unit exposures for the inhalation exposure route could not be
accurately calculated. 

QA/QC problems including lack of either/or field fortification,
laboratory recoveries, and storage stability information.

Data have an insufficient amount of replicates.

The Pesticide Handlers Exposure Database (PHED):

The Pesticide Handlers Exposure Database (PHED) has been developed by a
Task Force consisting of representatives from Health Canada, the U.S.
Environmental Protection Agency (EPA), and the American Crop Protection
Association (ACPA).  PHED provides generic pesticide worker (i.e.,
mixer/loader and applicator) exposure estimates.  The dermal and
inhalation exposure estimates generated by PHED are based on actual
field monitoring data, which are reported generically (i.e., chemical
specific names not reported) in PHED.  It has been the Agency’s policy
to use “surrogate” or “generic” exposure data for pesticide
applicators in certain circumstances because it is believed that the
physical parameters (e.g., packaging type) or application technique
(e.g., aerosol can), not the chemical properties of the pesticide,
attribute to exposure levels. [Note: Vapor pressures for the chemicals
in PHED are in the range of E-5 to E-7 mm Hg.]  Chemical specific
properties are accounted for by correcting the exposure data for study
specific field and laboratory recovery values as specified by the PHED
grading criteria.

PHED handler exposure data are generally provided on a normalized basis
for use in exposure assessments.  The most common method for normalizing
exposure is by pounds of active ingredient (ai) handled per replicate
(i.e., exposure in mg per replicate is divided by the amount of ai
handled in that particular replicate).  These unit exposures are
expressed as mg/lb ai handled.  This normalization method presumes that
dermal and inhalation exposures are linear based on the amount of active
ingredient handled.	



APPENDIX B:

Calculation of DDAC Unit Exposure Values

Table B-1:  DDAC Dermal and Inhalation Exposure Values for Chemical
Operators, Graders, Millwrights, Clean-up Crews, and Trim Saw Operators
a

Replicate Number	Chemical Operator	Grader	Trim Saw Operator	Millwright
Cleanup Crew

	Dermal	Inhalation	Dermal	Inhalation	Dermal	Inhalation	Dermal	Inhalation
Dermal	Inhalation

	Potential exposure (mg)	Air Concentration ((g/m3) b, c	Potential
exposured (mg)	Potential exposure (mg)	Air Concentration

((g/m3) b, c	Potential exposure d (mg)	Potential exposure (mg)	Air
Concentration ((g/m3) b, c	Potential exposured (mg)	Potential exposure
(mg)	Air Concentra-tion ((g/m3) b, c	Potential exposured (mg)	Potential
exposure (mg)	Air Concentration ((g/m3) b, c	Potential exposured (mg)

1	3.5	10.1	0.0808	3.05	2.90	0.0232	0.78	2.83	0.0227	1.31	2.92	0.0233
68.3	2.99145	0.0239

2	6.11	2.80	0.0224	7.47	2.93	0.0234	1.98	12.3	0.0984	29.08	2.83	0.0226
0.720	2.78840	0.0223

3	6.07	2.79	0.0223	1.09	2.91	0.0233

8.03	15.6	0.1248	166	30.3	0.2424

4	46.37	2.82	0.0226	10.51	3.00	0.0240

	95.2	412	3.2960

5	0.94	2.93	0.0235	0.61	2.82	0.0226

	1.20	2.83585	0.0227

6	22.15	2.83	0.0227	0.98	2.85	0.0228

	0.260	2.80989	0.0225

7	21.45	2.77	0.0222	2.63	2.91	0.0233

	8	0.22	2.73	0.0218	5.23	2.85	0.0228

	9	0.44	2.77	0.0222	0.19	13.20	0.1056

	10	0.33	3.14	0.0251	1.47	2.89	0.0231

	11	0.29	2.88	0.0230	2.38	2.85	0.0228

	12

4.09	2.81	0.0225

	13

1.03	2.94	0.0235

	Arithmetic Mean	9.81	3.51	0.0281	3.13	3.68	0.0295	1.38	7.57	0.061	12.8
7.12	0.057	55.3	75.6	0.60

Minimum	0.22	2.73	0.0218	0.19	2.81	0.0225	0.78	2.83	0.0227	1.31	2.83
0.0226	0.260	2.79	0.0223

Maximum	46.4	10.1	0.081	10.51	13.2	0.106	1.98	12.3	0.098	29.1	15.6	0.125
166	412	3.30

a.	“Measurement and Assessment of Dermal and Inhalation Exposures to
Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the Protection of Cut
Lumber (Phase III)” is the proprietary Sapstain Industry Group (SIG)
study that values were obtained from for this table (Bestari et al.,
1999, MRID 455243-04, SIG Task Force #73154 ).

b.	The inhalation LOD was not provided for chemical operators, graders,
trim saw operators, millwrights, or the clean-up crew.  Therefore, the
LOD provided for the diptank operator (5.6 (g) was used for these
positions.  Residues less than the LOD were adjusted to 1/2 LOD.

c.	The inhalation limit of detection was converted to (g/m3 using the
following equation: Air concentration ((g /m3) = 5.6 (g / [average flow
rate (L/min) * sampling duration (480 min) * 1000 L/m3.  Data was
obtained from Bestari et al (1999).  

d.	DDAC air concentrations were converted to inhalation exposure using
the following equation: Air concentration ((g /m3) x inhalation rate
(1.0 m3/hr) x Conversion factor (1mg/1000(g) x sample duration (8
hours/day).

Note: Arithmetic Mean values shown in bold typeface by job function are
recommended for use in dermal and inhalation exposure assessments for
non-pressure wood preservative treatments, where appropriate.

Table B-2:  Normalization of DDAC Dermal and Inhalation Exposure Values
for Diptank Operators a

Worker ID	Mill number	Sample Time (min)	DDAC

Conc. in

Diptank

(%)	Gloves	Dermal Body Exposure b (mg)	Hand Exposure b (mg)	Total Dermal
Exposure (mg)	Normalized Total Dermal Unit Exposure c

(mg/ 1 % solution)	Air Conc.d 

(mg/m3)	Inhalation Exposure e (mg)	Normalized Inhalation Unit Exposure c

(mg /1% solution)

M7P1A	7	480	0.64	Rubber	0.5	3.44	3.94	6.16	0.003	0.024	0.0375

M7P1B	7	480	0.64	Rubber	0.32	2.02	2.34	3.66	0.003	0.024	0.0375

M8P4A	8	408	0.42	Rubber	0.04 f	1.34	1.38	3.29	0.003	0.024	0.057

M8P4B	8	480	0.42	Rubber	0.04 f	0.5	0.54	1.29	0.003	0.024	0.057

M8P7	8	480	0.42	Cotton	0.03	0.04	0.07	0.17	0.003	0.024	0.057

M11P9A	11	395	0.63	Leather	0.15	3.33	3.48	5.52	0.003	0.024	0.0381

M11P9B	11	480	0.63	Leather	0.1	0.45	0.55	0.87	0.003	0.024	0.0381

Arithmetic Mean	0.17	1.59	1.76	2.99	0.0030	0.0240	0.046

Standard Deviation	0.18	1.39	1.53	2.32	0.0000	0.0000	0.0103

Median	0.10	1.34	1.38	3.29	0.0030	0.0240	0.0381

Geometric Mean	0.10	0.83	0.99	1.86	0.0030	0.0240	0.045

90%tile	0.39	3.37	3.66	5.78	0.0030	0.0240	0.057

Maximum	0.50	3.44	3.94	6.16	0.0030	0.0240	0.057

 

a.	“Measurement and Assessment of Dermal and Inhalation Exposures to
Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the Protection of Cut
Lumber (Phase III)” is the proprietary Sapstain Industry Group (SIG)
study that values were obtained from for this table (Bestari et al.,
1999, MRID 455243-04, SIG Task Force #73154).

b.	DDAC concentration that was detected in the monitoring study (MRID
#455243-04).

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萏ː萑ﴰ葞ː葠ﴰ摧㘎ఀed Unit Exposure (mg/1% ai solution) =
Exposure (mg DDAC) / concentration in diptank solution (% DDAC)

d.	All inhalation residues were <LOD (5.6 (g or 0.0056 mg/m3). 1/2 LOD
was used in all calculations (0.003 mg/m3). Air Concentration (mg/m3) =
5.6 (g / (~2 L/min flow rate x ~480 min) x 1000 L/m3 conversion x 0.001
(g /mg = 0.003 mg/m3

e.	Inhalation exposure (mg) = air concentration (mg/m3) x inhalation
rate (1.0 m3/hr) x sample duration (8 hours/day).

f.	Residues were <LOD for dermal samples M8P4A, M8P4B.  Sample size of
~11,231 cm2 x <0.007 ug/cm2 = LOD of 0.079 mg.  1/2 LOD reported (i.e.,
0.04 mg)

Note: Arithmetic Mean values shown in bold typeface are the recommended
Normalized Dermal and Inhalation Unit Exposure values for use in
exposure assessments for non-pressure wood

 	There is one tolerance exemption for residues of Copper Naphthenate
when used in accordance with good agricultural practice as an inert
ingredient in pesticide formulations applied to growing crops only (40
CFR 180.920).  No more than 2.5% Copper Naphthenate can be present, and
products containing Copper Naphthenate can only be applied before the
edible portions of plants begin to form.  This existing inert use has
been separately assessed within OPP (USEPA, 2006a).

 	Based on an Agency query of the Office of Pesticide Programs
Information Network (OPPIN), there are several cancelled registrations
for Copper and/or Zinc Naphthenate products which represent use patterns
no longer supported for these pesticides. These include: agricultural
fungicide uses as foliar treatments against mildew on ornamental
flowering plants (e.g., asters, dahlias, delphiniums, hydrangeas,
lilacs, roses and zinnias), dormant applications to apricots and
cherries, and surface treatments against mold, rot and mildew on seed
bag covers, sand bags, clay pots, tool handles and log homes. 

 Because the ST dermal toxicological endpoint is based on skin
irritation and provided in terms of body surface area, the exposure must
be calculated in terms of body surface area (i.e., mg a.i. per cm2
exposed skin surface area).

 To convert from volume to weight of ready-to-use product, the density
of the product is required.  Product density was provided on some, but
not all, labels.  A density of 8.5 lb/gal was assumed for all products
based on the typical label values that were present.  Where dilution of
product was included in the use instructions, it was assumed that the
product was diluted with water at a density of 8.34 lb/gal (although it
is noted that some product labels instruct the user to dilute with an
organic solvent such as mineral spirits for some uses).

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