Document ID: EPA-HQ-OPP-2007-1151-0006
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-01-16T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, DC 20460

OFFICE OF  PREVENTION, PESTICIDES,  AND TOXIC SUBSTANCES

 

January 9, 2008

MEMORANDUM:

Subject:	Occupational and Residential Exposure Chapter for
Diiodomethyl-p-tolylsulfone  

To:		Kathryn Jakob, Chemical Review Manager, Reregistration Team 36

		Regulatory Management Branch II

Antimicrobials Division (7510P)

			AND

		William Hazel, Ph.D., Risk Assessor

Risk Assessment and Science Support Branch (RASSB)

		Antimicrobials Division (7510P)

From: 		Nathan Mottl, Biologist 

		Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Thru:		Norm Cook, Branch Chief

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

DP Barcode: 	344853

Chemical Name:		Case#	  PC Codes:	CAS Registry No.     Abbreviation

Diiodomethyl-p-tolylsulfone  	4009	  101002	20018-09-1		noneTABLE OF
CONTENTS

  TOC \o "1-3" \h \z \u    HYPERLINK \l "_Toc182797130"  EXECUTIVE
SUMMARY	  PAGEREF _Toc182797130 \h  3  

  HYPERLINK \l "_Toc182797131"  1.0	 INTRODUCTION	  PAGEREF
_Toc182797131 \h  7  

  HYPERLINK \l "_Toc182797132"  1.1	Purpose	  PAGEREF _Toc182797132 \h 
7  

  HYPERLINK \l "_Toc182797133"  1.2	Criteria for Conducting Exposure
Assessments	  PAGEREF _Toc182797133 \h  7  

  HYPERLINK \l "_Toc182797134"  1.3	Chemical Identification	  PAGEREF
_Toc182797134 \h  9  

  HYPERLINK \l "_Toc182797135"  1.4	Physical/Chemical Properties	 
PAGEREF _Toc182797135 \h  9  

  HYPERLINK \l "_Toc182797136"  2.0	 USE INFORMATION	  PAGEREF
_Toc182797136 \h  10  

  HYPERLINK \l "_Toc182797137"  2.1	 Formulation Types and Percent
Active Ingredient	  PAGEREF _Toc182797137 \h  10  

  HYPERLINK \l "_Toc182797138"  2.2	 Summary of Use Pattern and
Formulations	  PAGEREF _Toc182797138 \h  10  

  HYPERLINK \l "_Toc182797139"  3.0	SUMMARY OF TOXICITY DATA	  PAGEREF
_Toc182797139 \h  11  

  HYPERLINK \l "_Toc182797140"  3.1	Acute Toxicity	  PAGEREF
_Toc182797140 \h  11  

  HYPERLINK \l "_Toc182797141"  3.2	Summary of Toxicity Endpoints	 
PAGEREF _Toc182797141 \h  12  

  HYPERLINK \l "_Toc182797142"  3.3	FQPA	  PAGEREF _Toc182797142 \h  13 

  HYPERLINK \l "_Toc182797143"  4.0	RESIDENTIAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc182797143 \h  13  

  HYPERLINK \l "_Toc182797144"  4.1	Summary of Registered Uses	  PAGEREF
_Toc182797144 \h  13  

  HYPERLINK \l "_Toc182797145"  4.2	Dietary Exposure	  PAGEREF
_Toc182797145 \h  14  

  HYPERLINK \l "_Toc182797146"  4.3	Drinking Water Exposure	  PAGEREF
_Toc182797146 \h  14  

  HYPERLINK \l "_Toc182797147"  4.4	Residential Exposure	  PAGEREF
_Toc182797147 \h  14  

  HYPERLINK \l "_Toc182797148"  4.4.1	Residential Handler Exposures	 
PAGEREF _Toc182797148 \h  15  

  HYPERLINK \l "_Toc182797149"  4.4.2	Residential Post-application
Exposures	  PAGEREF _Toc182797149 \h  18  

  HYPERLINK \l "_Toc182797150"  4.4.3	Data Limitations/Uncertainties	 
PAGEREF _Toc182797150 \h  27  

  HYPERLINK \l "_Toc182797151"  5.0	RESIDENTIAL AGGREGATE RISK
ASSESSMENT AND CHARACTERIZATION	  PAGEREF _Toc182797151 \h  27  

  HYPERLINK \l "_Toc182797152"  5.1	Acute and Chronic Dietary Aggregate
Risk	  PAGEREF _Toc182797152 \h  27  

  HYPERLINK \l "_Toc182797153"  5.2	Short and Intermediate Term
Aggregate Risk	  PAGEREF _Toc182797153 \h  28  

  HYPERLINK \l "_Toc182797154"  6.0	OCCUPATIONAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc182797154 \h  30  

  HYPERLINK \l "_Toc182797155"  6.1 	Occupational Handler Exposures	 
PAGEREF _Toc182797155 \h  32  

  HYPERLINK \l "_Toc182797156"  6.2  	Occupational Post-application
Exposures	  PAGEREF _Toc182797156 \h  37  

  HYPERLINK \l "_Toc182797157"  6.3 	Wood Preservation	  PAGEREF
_Toc182797157 \h  37  

  HYPERLINK \l "_Toc182797158"  6.4	Data Limitations/Uncertainties	 
PAGEREF _Toc182797158 \h  45  

  HYPERLINK \l "_Toc182797159"  7.0	REFERENCES	  PAGEREF _Toc182797159
\h  47  

  HYPERLINK \l "_Toc182797160"  APPENDIX A:	  PAGEREF _Toc182797160 \h 
49  

  HYPERLINK \l "_Toc182797161"  APPENDIX B:	  PAGEREF _Toc182797161 \h 
51  

  HYPERLINK \l "_Toc182797162"  APPENDIX C:	  PAGEREF _Toc182797162 \h 
62  

 EXECUTIVE SUMMARY  TC "EXECUTIVE SUMMARY" \f C \l "1"   

		This document is the Occupational and Residential Exposure Chapter of
the Reregistration Eligibility Decision Document (RED) for
Diiodomethyl-p-tolylsulfone.  It addresses the potential risks to humans
that result from the use of these chemicals in occupational and
residential settings. 

	At this time the active ingredient diiodomethyl-p-tolylsulfone is used
in products as a fungicide, algaecide, bacteriostat, insecticide,
miticide and disinfectant used in food handling/storage establishments,
material preservatives, industrial processes and water systems, and wood
preservatives (Use Site Categories  II, VII, VIII and X respectively). 
Examples of registered uses for Diiodomethyl-p-tolylsulfone include
incorporation as a preservative paints, paper, metal working fluids,
textiles (non-clothing), building materials, and leather, and is used in
wood preservation (sapstain non-pressure, and pressure treatment). The
percentage of active ingredient in various products can range from 15%
to 95%.  Products containing diiodomethyl-p-tolylsulfone and its actives
are formulated as flowable dispersions, wettable powder, and powders.

	It should be noted that the Dow Chemical Company has proposed to cancel
the following uses: (1) Metal working fluids; (2) Nitrocellulose; (3)
and Preservation of drains, grease traps and septic systems. These uses
have not officially been cancelled; however, the Agency is working with
the technical registrant to ensure that the necessary steps are taken to
cancel these uses. As a result, these uses will not be assessed in the
risk assessment at this time.   

The routes of exposure evaluated in this assessment include: short-term
(ST) [1-30 days], intermediate-term (IT) [1-6 months], and long-term
(LT) [>6 months] dermal, inhalation and incidental oral exposures.  For
the dermal exposure routes, the doses used in risk assessment for ST is
an oral NOAEL of 4 mg/kg/day and for IT/LT an oral LOAEL of 2 mg/kg/day.
 A human dermal absorption factor of 12% was used because the dermal MOE
calculations were based on oral endpoints.  An inhalation absorption
factor of 100% was used (default value, assuming oral and inhalation
absorption are equivalent) in all inhalation exposure since the
inhalation MOE calculations were based on an oral endpoint.  For
short-tem incidental oral exposures an oral maternal NOEAL of 4
mg/kg/day was used and for intermediate-term oral (1-6 months) an oral
LOAEL of 2 mg/kg/day was used.   

	The uncertainty factor or “target” margin of exposure (MOE) for the
ST dermal exposure scenario is 100 [10X for interspecies and 10X for
intraspecies] and 300 [10X for interspecies, 10X for intraspecies and 3X
for database uncertainty factor] for IT.  For inhalation exposure
scenario the MOE is 300 [10X for interspecies, 10X for intraspecies, and
3X for using a LOAEL] for all durations.  It should be noted that if a
MOE of 3000 is not achieved a route-specific inhalation toxicity study
will be needed (hence the extra 10x). For short-term incidental oral
exposure scenario the MOE is 100 [10X for interspecies, 10X] and for the
intermediate-term incidental oral exposure scenario the MOE is 300 [10X
for interspecies, 10X for intraspecies, and 3X for using a LOAEL].    

		Based on examination of product labels, it has been determined that
exposure to handlers can occur in a variety of occupational and
residential environments.  Additionally, postapplication exposures are
likely to occur in these settings.  The representative scenarios
selected by the Antimicrobials Division (AD) for this assessment were
evaluated using maximum application rates as stated on the product
labels. 

	To assess the handler risks, AD used surrogate unit exposure data from
the following proprietary resources: Chemical Manufacturers Association
(CMA) antimicrobial exposure study, the Pesticide Handlers Exposure
Database (PHED), and the proprietary sapstain study (task force #
73154), 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). 
Additionally, the EPA’s Health Effects Division’s (HED) Standard
Operating Procedures (SOPs) for Residential Exposure Assessments, was
used when estimating postapplication/bystander exposures.

Handler Risk Summary

		For the residential handler short-term dermal risk assessment, the
calculated short-term (ST) dermal MOEs are above the target MOE of 100
and below the Agency’s level of concern (except for painting with an
airless sprayer MOE 40). However, the calculated intermediate-term (IT)
dermal MOEs for applying paint and wood preservative  are all below the
target MOE of 300. The inhalation MOE for painting with an airless
sprayer (MOE 230) is the only scenario that is below the Agency’s
target MOE of 300. However, all the inhalation MOEs did not exceeded
3,000; therefore, a confirmatory inhalation toxicity study is warranted
based on the results of these exposure scenarios. 

	For occupational handlers at baseline (without gloves) dermal all of
the dermal IT MOEs are below the target MOE of 300 and exceed the level
of concern except:

Preservation of Slurries (liquid pump).

Preservation of Paper (liquid pump).

Diptank Operator.

Treatment Operator.

Treatment Assistant.

Application of Wood Preservative (airless sprayer)

	For baseline (without gloves) dermal all of the dermal ST MOEs are
below the target MOE of 100 and exceed the level of concern except:

Preservation of Adhesives and Caulks (liquid pump)

Preservation of Slurries (liquid pump).

Preservation of Emulsions (liquid pump).

Preservation of Paper (liquid pump).

Application of Wood Preservative by professionals (brush and airless
sprayer).

Chemical Operator (Wood Preservative).

Blender/spray Operator

Diptank Operator.

Treatment Operator.

Treatment Assistant

For PPE (gloves) dermal, all of the dermal IT MOEs are above the target
MOE of 300 and are below the level of concerns except. 

Preservation of Paint for liquid pump (MOE 188) and liquid pour (MOE
88).

Application of Paint by professionals for brush (MOE 197) and airless
sprayer (MOE 34).

Preservation of Adhesives and Caulks by liquid pour (MOE 288).

Preservation of Rubber and Plastic for pour liquid (MOE 56) and pump
liquid (MOE 120).

Preservation of Leather for pour liquid for raceway (MOE 34), mixers
(MOE 168), and tanning drum (MOE 84).

Preservation of Textiles for pour liquid (MOE 182). 

For PPE (gloves) dermal all of the dermal ST MOEs are above the target
MOE of 100 and are less than the level of concern except:

Application of Paint by professionals for airless sprayer (MOE 67).

Preservation of Leather for pour liquid for raceway (MOE 67).

For baseline (without respirator) inhalation the following scenarios are
below the target MOE of 300 (at all exposure levels) and do exceed the
level of concern except:

Application of Paint (airless sprayer) with MOE 68.

Preservation of Rubber and Plastic for pour liquid (MOE 261) and pump
liquid (MOE 224).

Preservation of Leather for pour liquid for raceway (MOE 157)

For PPE (respirators) inhalation all the scenarios were above the target
MOE of 300. However even with PPE some of the calculated inhalation MOEs
(e.g., painting with an airless sprayer MOE 341) were less than the
target MOE of 3,000. Therefore, a confirmatory inhalation toxicity study
is warranted based on the results of this assessment of paint.

 

Post-application/Bystander Risk Summary

For the residential postapplication risk assessment, MOEs are below the
respective target MOEs (ST dermal  = 100, inhalation = 3,000, and
incidental ingestion = 300) for the following scenarios and therefore a
concern:

Dermal contact of children contact treated carpet (ST MOE 9 and IT MOE
4).

Dermal contact to treated wood products (IT MOE 99).

Incidental oral exposures with treated carpet (ST MOE 49 and IT MOE 51).

	For occupational postapplication, the inhalation MOEs for treated HVAC
systems and for cleanup activities at lumber mills exceeded the target
MOE of 300.  However, they did not exceed the target MOE of 3,000
therefore, a confirmatory inhalation toxicity study is warranted based
on the results of this assessment.

For the occupational postapplication risk assessment, dermal ST MOEs are
above the respective target MOEs ((ST dermal  = 100) for all scenarios
except for the following:

Cleanup activities at a lumber mill (MOE 70).

For the occupational postapplication risk assessment, dermal IT MOEs are
above the respective target MOEs ((IT dermal  = 300) for all scenarios
except for the following:

Millwright at lumber mill (MOE 152).

Cleanup activities at a lumber mill (MOE 35).

Chemical operator (MOE 198)

Aggregate exposure risk summary

	Short- and intermediate-term aggregate exposures and risks were
assessed for adults and children that could be exposed to
diiodomethyl-p-tolylsulfone residues from the use of products in
non-occupational environments. The adult scenarios were not aggregated
based on the use patterns.  Because the calculated residential
short-term and intermediate dermal MOEs to children were unacceptable
for both short-term (painting with an airless sprayer, postapplication
exposure to carpet) and intermediate-term (applying paint and wood
preservative, postapplication exposure to deck (IT) and carpet), the
aggregate MOEs were not calculated.

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 6.3
(occupational) respectively.

The data limitations and uncertainties associated with the residential
handler and postapplication exposure assessments include the following:

Surrogate 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
Handler Exposure Database (USEPA, 1998) (See Appendix A for summaries of
these data sources). Most of the CMA data are of poor quality therefore,
AD requests that confirmatory monitoring data be generated to support
the values used in these assessments.  

The quantities handled/treated were estimated based on information from
various sources, including HED’s Standard Operating Procedures (SOPs)
for Residential Exposure Assessments (USEPA 2000, and 2001) and standard
AD assumptions that can be further refined from input from registrants. 

The low pressure spray unit exposure data from PHED were used to assess
outdoor applications to hard surfaces (exterior of homes).  As the low
pressure spray data are representative of treating low to mid level
shrubs and the scenario assessed in this document represents treatments
above the waist, the unit exposure value may underestimate exposure to
the head and the upper body.

The data limitations and uncertainties associated with the occupational
handler and postapplication exposure assessments include:

Surrogate 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
Handler Exposure Database (USEPA, 1998) (See Appendix A for summaries of
these data sources).   Since the CMA data are of poor quality, the
Agency requests that confirmatory data be submitted to support the
occupational scenarios assessed in this document.

1.0	 INTRODUCTION  TC "1.0	 INTRODUCTION" \f C \l "1"   tc \l1 "1.0	
INTRODUCTION 

		1.1	Purpose  TC "1.1	Purpose" \f C \l "2"    tc \l2 "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 exposures to diiodomethyl-p-tolylsulfone.
This information is for use in EPA's development of the
Diiodomethyl-p-tolylsulfone Reregistration Eligibility Decision Document
(RED). 

		1.2	Criteria for Conducting Exposure Assessments tc \l2 "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 diiodomethyl-p-tolylsulfone, 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 per pounds of product 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:  

μg 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 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
used for dermal exposures of short-, intermediate- and long-term
duration and inhalation exposures of all durations, therefore, an
absorption factor of 12% was necessary for the short-, intermediate-and
long-term dermal exposures and an absorption factor of 100% was
necessary for all inhalation exposures.  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 the
analysis, 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:

Diiodomethyl-p-tolylsulfone products are widely used material
preservatives and have a large number of use patterns that are difficult
to completely capture in this document.  As such, AD has patterned this
risk assessment on a series of likely representative scenarios for each
use site that are believed by AD to represent the vast majority of
diiodomethyl-p-tolylsulfone uses.

Based on the adverse effects for the endpoints, the average body weight
of an adult handler of 70 kg was used 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.

The maximum application rates allowed by labels were assumed. 	

		1.3	Chemical Identification tc \l2 "1.3	Chemical Identification 

	Table 1.1 shows chemical identification information for
diiodomethyl-p-tolylsulfone . 

Table 1.1 Chemical Identification

Chemical Code	101002

CAS Number	20018-09-1

Molecular Formula	C8H8SO2I2

		1.4	Physical/Chemical Properties tc \l2 "1.4	Physical/Chemical
Properties 

		Table 1.2 shows physical/chemical characteristics that have been
reported for diiodomethyl-p-tolylsulfone.

Table 1.2.  Physical/Chemical Properties of Diiodomethyl-p-tolylsulfone

Molecular Weight	422

Color	Tan

Physical State	Solid  powder at room temperature 

Density	1.08 mg/L

Dissociation Constant	NA

pH	4.3

Stability	Stable at room temperature and stable at 52°C

Melting Point	136°C, 149-152°C

Boiling Point	Decomposition before boiling

Water Solubility	10 mg/L

Kow	462±5

Vapor Pressure	NA

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 

		The products containing diiodomethyl-p-tolylsulfone as the active
ingredient (a.i) are formulated as liquids, wettable powders, and
ready-to-use solutions. Concentrations of diiodomethyl-p-tolylsulfone in
these products range from 15% to 95%.

		

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

	Diiodomethyl-p-tolylsulfone is an active ingredient used as a
fungicide, algaecide, bacteriostat, insecticide, and miticide used in
materials preservatives, and wood preservatives.  The majority of the
products are virucidal, fungicidal, tuberculocidal, bactericidal,
pseudomonacidal, or staphylocidal. The Agency determines potential
exposures to handlers of the product by identifying exposure scenarios
from the various application methods that are plausible, given the label
uses. These scenarios are identified in Table 2.1.  Based on a review of
product labels, products containing diiodomethyl-p-tolylsulfone are
intended for use as a materials preservative for a variety of products
(Use Site Category VII) and as a wood preservative (Use Site Category
X).  Examples of registered uses for diiodomethyl-p-tolylsulfone
products as material preservatives include application to paints
(in-can), HVACs, coatings, fire retardant, adhesives, caulks, sealants,
slurries, dispersions/emulsions/solutions/suspensions, metalworking
fluids, rubber products, plastic/pvc/vinyl products,
hides/leathers/leather products, textiles, papermaking, and paper and
paperboard, drains, grease traps and septic tanks and  wood preservative
uses. 

In the October 29, 2007 Use Closure Memorandum, the technical registrant
has indicated that they will be cancelling the following uses: metal
working fluid, nitrocellulose, and preservation of drains, grease traps
and septic systems. Therefore, these uses will not be assessed in the
preliminary risk assessment for diiodomethyl-p-tolylsulfone.  In
addition, the technical registrant of diiodomethyl-p-tolylsulfone has
proposed to cancel product registration number 464-671 (AMICAL 50). The
Agency is working with the technical registrant to ensure that the
necessary steps are taken to cancel this product registration and the
Agency did not asses this product in the preliminary risk assessment for
diiodomethyl-p-tolylsulfone

Table 2.1. Potential Use Scenarios Based on Product Labels for
Diiodomethyl-p-tolylsulfone

Use Site Category	

Example Use Sites	

Scenarios

Use Site Category VII

Material Preservatives	

Used in the production of various household, institutional and
industrial items	

glues and adhesives

gaskets

concrete admixes

slurries (clay, calcium carbonate, kaolin, and other filler suspensions)

leather (shoe liners, hat bands, gloves)

stains and paints

textiles (non-clothing)

dyes, pigments and filler suspensions

wax emulsions and polishes

paper slurries and paperboard

plastics/pvc/vinyl products

other construction applications (concrete, plaster, caulk)

Use Site Category X

Wood Preservatives	

Used in preservation of wood products	

pressure, non-pressure, dip, and spray treatment methods

	From Table 2.1, AD selected representative exposure scenarios to assess
in this document.  These scenarios were selected to be representative of
the vast majority of uses and are believed to provide high-end degrees
of dermal and inhalation 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 CONCERNS
RELATING TO EXPOSURE 

	3.1	Acute Toxicity

 tc \l2 "3.1	Acute Toxicity 

Adequacy of database for Acute Toxicity:  The acute toxicity database
for diiodomethyl-p-tolylsulfone is considered complete. 
Diiodomethyl-p-tolylsulfone has a low order of acute toxicity via the
oral route of exposure (Toxicity Category IV); low to moderate  dermal
toxicity (Toxicity Category III); low to moderate inhalation toxicity
(Toxicity Category III).   Diiodomethyl-p-tolylsulfone is not a dermal
sensitizer. The acute toxicity decisions for diiodomethyl-p-tolylsulfone
are summarized in Table 3.1.

Table 3.1.  Acute Toxicity Decisions for Diiodomethyl-p-tolylsulfone

Guideline

 No.	

Study Type	

MRID #(S).	

Results	

Toxicity

 Category

870.1100

(81-1)	

Acute Oral	

41765401, 43008702, and 42586801	LD50  > 5000 mg/kg 

( for both male and female)

	

III

870.1200

(81-2)	

Acute Dermal

(Rats)	

00141066	LD50 (Combined) = 3.67 mL/kg

LD50 (Males) = 2.83 mL/kg

LD50 (Females) = 4.76 mL/kg	

III

870.1300

(81-3)	

Acute Inhalation	43660901	LC50 (combined)= 0.96 mg/L

LC50 (male) = 1.15 mg/L 

LC50 (female) = 0.77 mg/L	

III

870.2400

(81-4)	

Primary Eye Irritation	41765402 and 43008703

	

Severe irritant to ocular tissue of Rabbit	

I

870.2500

(81-5)	

Primary Skin Irritation	41765403, 43008704, and 00141066	

Minimum irritant to skin of Rabbit	

IV

870.2600

(81-6)	Dermal Sensitization	00230726, and 00141067	Not a Dermal
Sensitizer

	3.2	Summary of Toxicity Endpoints tc \l2 "3.2	Summary of Toxicity
Concerns Relating to Exposures 

	Table 3.2 summarizes the toxicological endpoints for
diiodomethyl-p-tolylsulfone and has been extracted from the
toxicological chapter of this RED (USEPA, 2007).

Table 3.2 Summary of Toxicological Dose and Endpoints for
Diiodomethyl-p-tolylsulfone

Exposure

Scenario	

Dose Used in Risk Assessment, UF 	

Special FQPA SF* and Level of Concern for Risk Assessment	

Study and Toxicological Effects

Acute Dietary

 (All populations)	No appropriate end-point can be selected for Acute
RfD.

Chronic Dietary

(All populations)	Oral LOAEL =2 mg/kg/day

UF = 1000 

[10x for interspecies, 10x for intraspecies, 3X for database uncertainty
(missing chronic/cancer  and reproductive studies) and 3 for using
LOAEL]	

NA	90-day Oral  (Dog)

MRID 42054403 and 43246402

based on decreased body weight gain, decreased activity, dehydration,
mucoid ocular discharge, weakened appearance, abnormal feces, and
degeneration of the thyroid.

 

Short-Term Incidental Oral (1-30 days)

	

Oral Maternal NOAEL =4 mg/kg/day 

UF = 100

(10x for interspecies, 10x for intraspecies)

	

N/A	

Rabbit Developmental Toxicity – 

(MRID  41161801)

based on clinical signs, reduced body weight gain and food consumption.

 

Intermediate-Term Oral (1- 6 months)

	

Oral LOAEL =2 mg/kg/day

MOE = 300 

[10x for interspecies, 10x for intraspecies, and 3X for using LOAEL]	

N/A	

90-day Oral  (Dog)

MRID 42054403 and 43246402

based on decreased body weight gain, decreased activity, dehydration,
mucoid ocular discharge, weakened appearance, abnormal feces, and
degeneration of the thyroid.

Dermal Abs. Factor

	

12% [based on the Rat Pharmacokinetics and Metabolism (MRID 47076641]

Dermal (System, Short-Term)	Oral Maternal NOAEL =4 mg/kg/day 

MOE = 100

(10x for interspecies, 10x for intraspecies)

	NA	Rabbit Developmental Toxicity – 

(MRID  41161801)

based on clinical signs, reduced body weight gain and food consumption.

Dermal (Inter-term)	

Oral LOAEL =2 mg/kg/day

MOE = 300 

[10x for interspecies, 10x for intraspecies, 3X for using LOAEL]	

N/A	90-day Oral  (Dog)

MRID 42054403 and 43246402

based on decreased body weight gain, decreased activity, dehydration,
mucoid ocular discharge, weakened appearance, abnormal feces, and
degeneration of the thyroid.

Dermal (long-term)	

Oral LOAEL =2 mg/kg/day

MOE= 1000 

[10x for interspecies, 10x for intraspecies, 3X for database uncertainty
(missing chronic/cancer  and reproductive studies) and 3X for using
LOAEL]	

NA

	

 90-day Oral  (Dog)

MRID 42054403 and 43246402

based on decreased body weight gain, decreased activity, dehydration,
mucoid ocular discharge, weakened appearance, abnormal feces, and
degeneration of the thyroid.based on lymphocytic infiltration in females
and erosion of gastric mucosa and prominence of limiting ridge of the
stomach in males

Inhalation (All Exposure Terms)	

Oral LOAEL =2 mg/kg/day

MOE = 300 (see note)* 

[10x for interspecies, 10x for intraspecies,   10X for route-to-route
extrapolation and 3X for using LOAEL]*

	

NA

	

 90-day Oral  (Dog)

MRID 42054403 and 43246402

based on decreased body weight gain, decreased activity, dehydration,
mucoid ocular discharge, weakened appearance, abnormal feces, and
degeneration of the thyroid.based on lymphocytic infiltration in females
and erosion of gastric mucosa and prominence of limiting ridge of the
stomach in males

Cancer (oral, dermal, inhalation)	

	

	

no cancer data available

UF = uncertainty factor, FQPA SF = Special FQPA safety factor, NOAEL =
no observed adverse effect level, LOAEL = lowest observed adverse effect
level, PAD = population adjusted dose (a = acute, c = chronic) RfD =
reference dose, MOE = margin of exposure, LOC = level of concern, NA =
Not Applicable

*Note: if a target MOE of 3000 is not achieved a route-specific
inhalation tox study will be needed (hence the extra 10x). A MOE of 300
is selected for all  inhalation risk assessments.

3.3	FQPA

	No food use was involved in this registration, therefore, no FQPA
concern.

4.0	RESIDENTIAL EXPOSURE ASSESSMENT  tc \l1 "4.0	RESIDENTIAL EXPOSURE
ASSESSMENT 

	4.1	Summary of Registered Uses tc \l2 "4.1	Summary of Registered Uses 

	Some products containing diiodomethyl-p-tolylsulfone that are labeled
for residential uses include paints, wood preservatives, and carpets. 
The residential scenarios in this assessment represent worst case
exposure. Postapplication is expected to be negligible since the vapor
pressure is expected to be less than 1E-6 torr since the technical
product is a solid. Table 2.1 presents a summary of all exposure
scenarios that may occur from the residential use site category based on
examination of product labels.  Table 4.1 identifies the representative
exposure scenarios assessed in this document.

	4.2	Dietary Exposure tc \l2 "4.2	Dietary Exposure/Risk Pathway  

Any risks pertinent to dietary exposures are discussed in the
Preliminary Risk Assessment

	4.3	Drinking Water Exposure tc \l2 "4.3	Drinking Water Exposure/Risk
Pathway  

Any risks pertinent to dietary exposures are discussed in the
Preliminary Risk Assessment

	4.4	Residential Exposure tc \l2 "4.4	Residential Exposure/Risk Pathway 

	The exposure scenarios assessed in this document for the representative
uses selected by AD are shown in Table 4.1. The table also shows the
maximum application rate associated with the representative use and the
EPA Registration number for the corresponding product label.  For
handlers, the representative uses assessed include the application of
paints and wood preservatives (brush, roller, and airless sprayer) and
post-application dermal and oral exposure to toddlers that contact
preservative incorporated in carpet felt.   It should be noted, for the
calculation of application rates in which 8.34 lb a.i./gal is noted, the
product was assumed to have the density of water.  

Table 4.1. Representative Uses Associated with Residential Exposure 

Representative Use	

Exposure Scenario	

Application Method	

Registration #	

Application Rate

HVAC Air Duct Coatings	ST Bystander: Inhalation	Sprayer	464-672	0.05 lb
ai/gal (10.2 lb ai/100 gal x 48.45%)

Wood Preservatives on Decks	

ST/IT Handler: Dermal and Inhalation 

ST/IT Post-app: child dermal, incidental ingestion	

Paint brush,

rollers,

airless sprayer	

60061-9	

0.00021 lb ai/sq ft

(8.34 lb/gal x 0.38% ai x

1 gal /150 sq. ft)

Textiles (i.e. carpets)

	

ST/IT Post-app: child dermal, incidental ingestion 	

none

	

464-670

	

0.00475 lb ai/lb dry fabric (5 lb per 1000 lb dry fabric x 95%)

Inks 	ST/IT child fingerpainting	fingerpainting	464-673	0.15 % ai
(0.375% product x 40 % ai) 

Paint

	

ST/IT Handler: Dermal and Inhalation 

ST Post-app: child dermal 	

Paint brush,

rollers,

airless sprayer	

464-672	

 0.050 lb ai/gal

 (10.2 lb/100 gal x 48.45%)

ST = Short-term exposure, IT = Intermediate-term exposure

	

	4.4.1	Residential Handler Exposures  TC "4.4.1	Residential Handler
Exposures" \f C \l "3"  

	The residential handler scenarios described in Table 4.1 were assessed
to determine dermal and inhalation exposures.  The majority of the
scenarios were assessed using PHED data and Equations 1-3 in Section
1.2, “Criteria for Conducting Risk Assessment.” 

   

The assumptions and factors used for those scenarios in which PHED data
were used include:

Unit Exposure Values: Unit exposure values were taken from the PHED data
presented in HED’s Residential SOPs (USEPA, 1997). See Appendix A for
a summary.  

For the airless sprayer scenario, PHED dermal and inhalation unit
exposure values for a residential handler applying a pesticide using an
airless sprayer were used.  These unit ungloved exposure values (79
mg/lb a.i. for dermal and 0.83 mg/lb a.i. for inhalation) represent a
handler painting indoors wearing short pants and a short sleeve shirt,
with no gloves. 

For the brush/roller scenario, PHED dermal and inhalation unit exposure
values for a residential handler applying a pesticide using a paint
brush were used.  These unit exposure values (230 mg/lb a.i. for dermal
and 0.28 mg/lb a.i. for inhalation) represent a handler wearing short
pants and a short sleeve shirt, with no gloves.

Quantity handled/treated: The quantities handled/treated were estimated
based on information from various sources and assumptions. 

For the airless sprayer in paint applications, it is assumed that 150
lbs (approximately 15 gallons) of treated paint will be used.  This is
based on the coverage of 200 ft2/gallon and a house size of 40 x 30 x 20
ft (surface area of 2,800 ft2).

For the brush/roller in paint applications, it is assumed that 20 lbs
(approximately 2 gallons) of treated paint 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.  	

For the airless sprayer and brush/roller scenarios for wood preservative
applications, it was assumed that a painter would brush or spray a
standard deck with approximate dimension of 300 sq. ft. (30’ x 10’)
once per day.

Duration of Exposure: The duration of exposure for most homeowner
applications of paint products is believed to be best represented by the
short-term duration (1 to 30 days).  The reason that short term duration
was chosen to be assessed is because the different scenarios (i.e.
methods of application) are assumed to be episodic, not daily.  

Results

	The resulting short-term exposures and MOEs for the representative
residential handler scenarios are presented in Table 4.2. The calculated
ST MOE was above the target dermal MOE of 100 for all scenarios except
airless sprayer painting (MOE 40).  The calculated IT MOE was below the
target dermal MOE of 300 for brush roller for wood preservative (MOE 80)
and painting (MOE 51) and airless sprayer painting (MOE 20). The
calculated inhalation MOE was above the target inhalation MOE of 300 for
all scenarios, except airless sprayer painting (MOE 230).  A
confirmatory inhalation toxicity study would be warranted based on these
results 

Table 4.2 Short-Term Diiodomethyl-p-tolylsulfone Residential Handlers
Exposures and MOEs 

Exposure Scenario

	

Method of Application	

Unit Exposure 

(mg/lb ai)	

Application Rate	

Quantity Handled/ Treated per day	

Absorbed Daily Dose (mg/kg/day)	

MOE 

Dermala	

Inhalation

	

Dermalb	

Inhalationc	

Dermal 	

Inhalation (Target = 300)e

ST (Target=100)d	IT (Target= 300)d

	

Wood Preservative	Brush/roller	

230	

0.284	0.00021 lb ai/sq ft	300 sq ft	2.52E-2	2.6E-4	160	80	7800

	Airless sprayer	

79	

0.83	0.00021 lb ai/sq ft	300 sq ft	8.6E-3	7.5E-4	466	233	2700

Painting	

Brush/roller	

230	

0.284	0.05 lb ai/gal	2 gal	3.9E-2	4.0E-4	103	51	5000

	

Airless sprayer	

79	

0.83	0.05 lb ai/gal	15 gal	1.0E-1	8.8E-3	40	

20	230

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

b	Dermal Daily Dose (mg/kg/day) = [dermal unit exposure (mg/lb ai) *
application rate * quantity handled *ABS (0.12) / body weight (70 kg).

c	Inhalation Daily Dose (mg/kg/day) = [inhalation unit exposure (mg/lb
ai) * application rate * quantity handled / body weight (70 kg).

d	Dermal MOE = NOAEL (mg/kg/day) / Daily Dose. Target dermal MOE is 100
for ST and 300 for IT (ST NOAEL 4 mg/kg/day  and IT LOAEL 2 mg/kg/day.

e 	Inhalation MOE = LOAEL (2 mg/kg/day) / Daily Dose. Target inhalation
MOE is 300.

 tc \l4 "4.4.2.5		Paints 

Dermal Exposures

Exposure Calculation Assumptions

	In addition, to painting activities, children may be exposed via the
dermal route to finger painting. Therefore, a dermal exposure assessment
was conducted to assess this exposure condition.  Short-term dermal
exposures for children fingerpainting were assumed to pose potential
risks.  Short-term exposure estimates based on surface area were derived
using the following equation: 

	PDR =  SA x % ai x FQ x FT x ABS

	         			BW

where: 

PDR	=	Potential dose rate (mg/kg/day)

SA		=	Surface area toddlers hands per event (cm2/event)

% ai	=	Fraction active ingredient in treated paint (unitless)

FQ		=	Frequency (events/day)

FT		=	Film thickness of paint on hands (mg/cm2)

ABS	=	Dermal absorption (%)

BW		=	Body weight (kg)

Assumptions

The median surface area of both hands is 350 cm2 for a toddler (age 3
years). This value represents the average of the 50th percentile total
surface area values for males and females in the 2<3 year and 3<4 year
age groups, multiplied by the average percentage of the total body
represented by hands for males and females (U.S EPA, 1997).

The percent active ingredient was calculated using information from the
registrant from the registrant indicating that 600 ppm (0.06% ai) of
diiodomethyl-p-tolylsulfone is in paint (Landenberg, 1997). 

Toddlers (age 3 years), used to represent the 1 to 6 year old age group,
are assumed to weigh 15 kg. This is the mean of the median values for
male and female children

For this exposure scenario, it was assumed that the amount of treated
paint present on the painter’s skin could be represented by an
estimate of the paint remaining on hands (i.e., wet film thickness)
following complete immersion into the paint with some wiping since the
toxicological endpoint is a systemic effect.  For short-term durations,
the film thickness of the paint on the hands was based on a study in
which both hands were dipped in mineral oil and then partially cleaned
with a rag (US EPA 1992).  The film thickness was chosen because the
dermal endpoint for short-term durations is based on systemic effects
and represents an estimate in the absence of more specific data.  This
approach will likely result in an underestimate of exposure because the
actual film thickness of paint is potentially higher than the film
thickness of mineral oil.  

Results

	Table 4.3 shows the calculation of the dermal exposures and MOEs for a
residential painter working with treated paint.  The calculated short-
and intermediate-term dermal MOEs are above the target MOE of 100 and
300, respectively and below the Agency’s level of concern. 



Table 4.3.  Short-term Dermal Exposures and MOEs for Toddlers Finger
Painting

Exposure Scenario	% ai	Film thickness (mg/cm2)	Frequency

(events/day)	Hand Surface Area

(cm2)	PDRa (mg/mg/kg/day)	ST MOEb

(Target MOE=100)	  IT MOEb

(Target MOE =300)

Painter - two hand immersion	

0.15

	1.75	

1

	350	0.0029	1360	680

a	PDR= (% ai x FT x FQx SA x ABS)/BW.  Dermal absorption or ABS is 12%. 

b 	MOE = NOAEL  (mg/kg/day) / Potential dose rate (mg/kg/day [Where: ST
NOAEL  =  4 mg/kg/day and IT NOAEL = 2 mg/kg/day , Table 3.2]. 

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

 	For the purposes of this screening level assessment, postapplication
scenarios have been developed that encompass multiple products, but
still represent a high end exposure scenario for all products
represented. As shown in Table 4.1, representative postapplication
scenarios assessed include contacting treated carpet and decks (dermal
and incidental ingestion exposure).  

	Note that the registrant indicated in the SMART meeting that they do
not support treated toys which would require a risk assessment since
rubber or plastic products could be potentially used for this product. 
If the registrant does not intend to support this use, the Agency
requires the following label language for treated polymer/plastics
labels: “Treated plastics can not be used to manufacture children’s
toys.” 

	At this time, AD does not have residue dissipation data or reliable use
pattern data, including the frequency and duration of use of
antimicrobial products in the residential setting. It should be noted
that because diiodomethyl-p-tolylsulfone has a relatively low vapor
pressure, post application inhalation exposures were not assessed.

	4.4.2.1 Treated Carpet  TC "4.4.2.1 Treated Carpet" \f C \l "4"  

	Carpet fibers can be treated with diiodomethyl-p-tolylsulfone during
the manufacturing process.  Therefore post application dermal and
incidental oral exposures to treated carpet fibers may occur.  Since the
carpet fibers are actually impregnated with diiodomethyl-p-tolylsulfone
and the carpeting can be used in a residential setting there is
potential for exposure to occur every day, assuming that
diiodomethyl-p-tolylsulfone has a relatively long half life in indoor
environments.  Therefore both short- and intermediate-term exposures
durations were assessed.  tc \l4 "4.4.2.1	Treated Carpet 

Child Dermal Exposure from Treated Carpet

Exposure Calculations

	Short- and intermediate-term exposures - There is the potential for
short- and intermediate-term dermal exposures leading to dermal
irritation when children come into contact with carpeting treated with
diiodomethyl-p-tolylsulfone. Potential exposures and MOEs were
calculated for children contacting treated carpet in residential homes
(short-term exposure).  To determine child short- and intermediate-term
exposure to diiodomethyl-p-tolylsulfone in carpeting, the following
equation was used:

 

where:

PDD 	= 	Potential daily dose (mg/kg/day)

D 	= 	Carpet weight density (oz/yd2)

CF1 	= 	Conversion factor (1.196x10-4 yd2/cm2)

SA 	= 	Body surface area contacting carpet (cm2)

WF1 	= 	Weight fraction of commercial product in carpet (oz product/oz
carpet)

WF2 	= 	Weight fraction of diiodomethyl-p-tolylsulfone in commercial
product (% a.i.)

WF3 	= 	Weight fraction of diiodomethyl-p-tolylsulfone transferred from
carpet to skin (unitless)

CF2 	= 	Conversion factor (28,350 mg/oz)

ET 	=  	Exposure time (hr/day)

CF3 	= 	Conversion factor (1 day/24 hr)

ABS	=	Dermal absorption (unitless)

BW 	= 	Body weight (kg)

Assumptions

The product contains 95% a.i. by weight and is used in carpet at a rate
of 5 lb/1000 lb product by weight of material thus, the % a.i. in carpet
is 95% x 0.5% = 4.75 %  (EPA Reg No. 464-670).

The carpet density is 36 oz/yd2 based on a standard assumption (USAF
2003). 

It is assumed that 5% of the diiodomethyl-p-tolylsulfone on the carpet
is transferred to skin contacting the carpet (US EPA 2001).

For short- and intermediate-term exposures, it was assumed that the skin
area contacting the carpet was 6570 cm2 (median SA of a toddler, US EPA
1997b).

For intermediate-term exposures, the exposure duration was assumed to be
8 hrs/day (US EPA 2001) 

The body weight of a child was assumed to be 15 kg (US EPA 1997b).

Results

	Table 4.4 shows the calculations of the short- and intermediate-term
dermal doses and MOEs for children contacting treated carpet.  Neither
of the MOEs is above the target MOE for the respective endpoint.  The
default residue transfer factor may not be representative of the actual
transfer value.  It is uncertain to what degree the residue is actually
being transferred because diiodomethyl-p-tolylsulfone is impregnated in
the matrix and it is unknown whether or not the matrix is actually
binding the diiodomethyl-p-tolylsulfone thereby reducing the potential
transfer.  Therefore, a residue transfer study may help to mitigate the
exposures and resulting MOEs.

Table 4.4.  Short- and Intermediate-term Dermal Exposures and MOEs for
Children Contacting Treated Carpet

Duration	% a.i.	Carpet density (oz/yd2)	Fraction transferred to skin
Skin surface area contacting carpet (cm2)	Exposure time (hrs/day)
Exposure a 

(mg/kg/day for ST/IT)	ST/IT MOE (Target MOE is 100 for ST, 300 for IT) b

ST	0.475%	36	5%	6,570	8	0.45	9

IT	0.475%	36	5%	6,570	8	0.45	4

a 	Potential exposure for ST is expressed as mg a.i. per cm2 of exposed
skin; absorbed daily dose is mg/kg/day.  Equations used to estimate
exposure are presented above.

b	MOE = NOAEL/exposure estimate [Where: short-term NOAEL =  4 mg/kg/day
and intermediate-term NOAEL = 2 mg/kg/day for dermal exposures, Table
3.2]. 

Child Incidental Ingestion Exposure from Treated Carpet

	

Exposure Calculations

	

	Short- and intermediate-term exposures – There is potential for
short- and intermediate-term incidental oral exposures when children
exhibiting hand-to-mouth behavior come into contact with carpeting
treated with diiodomethyl-p-tolylsulfone.  Incidental oral exposures and
MOEs were calculated for children contacting treated carpet in
residential or commercial day care settings.  To determine child short-
and intermediate-term incidental oral exposure to
diiodomethyl-p-tolylsulfone on carpeting, the following equation was
used:

 

where:

PDD 	= 	Potential daily dose (mg/kg/day)

D 	= 	Carpet weight density (oz/yd2)

CF1 	= 	Conversion factor (1.196x10-4 yd2/cm2)

SA 	= 	Surface area of the hands that contact both the treated area, and
the individual’s mouth (cm2/event)

WF1 	= 	Weight fraction of commercial product in carpet (oz product/oz
carpet)

WF2 	= 	Weight fraction in commercial product (oz
Diiodomethyl-p-tolylsulfone /oz carpet)

WF3 	= 	Weight fraction transferred from carpet to skin (unitless)

SE 	= 	Saliva extraction efficiency (unitless fraction)

FQ 	= 	Frequency of hand-to-mouth events (events/hr)

ET 	=  	Exposure time (hr/day)

CF2 	= 	Conversion factor (28,350 mg/oz)

BW 	= 	Body weight (kg)

Assumptions

The product contains 95% a.i. by weight and is used in carpet at a rate
of 0.5% product by weight of material thus, the % a.i. in carpet is 95%
x 0.5% = 0.475%  (EPA Reg No. 464-670).

The carpet density is 36 oz/yd2 based on a standard assumption (USAF
2003). 

The surface area of the hands that contact both the treated area and the
individual’s mouth per exposure event is 20 cm2/event (US EPA 2001).

It is assumed that 5% of the diiodomethyl-p-tolylsulfone on the carpet
is transferred to skin contacting the carpet (US EPA 2001).

The saliva extraction efficiency is assumed to be 50% (US EPA 2001).

The frequency of hand-to-mouth events is assumed to be 20 events/hr for
ST exposures and 9.5 events/hr for IT exposures (US EPA 2001).

The time of exposure is assumed to be 8 hrs/day (US EPA 2001).

The body weight of a child was assumed to be 15 kg.

Results

	Table 4.5 shows the calculations of the short- and intermediate-term
incidental oral exposures and MOEs for children contacting treated
carpet.  Neither of the MOEs is above the target MOE for the respective
endpoint.  As previously stated, a residue transfer study may help to
mitigate the exposures and risks.

Table 4.5.  Short- and Intermediate-term Incidental Oral Exposures and
MOEs for Children Contacting Treated Carpet

Duration	% a.i.	Carpet density (oz/yd2)	 Fraction transferred to skin
Saliva extraction efficiency	Surface area of hands (cm2)	Frequency of
hand-to-mouth events (events/hr)	Exposure time (hrs/day)	Exposure a 

(mg/kg/day)	ST/IT MOE (Target MOE is 100 for ST, 300 for IT) b

ST	0.475%	36	5%	50%	20	20	8	8.2E-2	49

IT	0.475%	36	5%	50%	20	9.5	8	3.9E-2	51

a 	Potential exposures are expressed as mg/kg/day; equations used to
estimate exposure are presented above.

b	MOE = NOAEL/exposure estimate [Where: short-term NOAEL =  4 mg/kg/day
and intermediate-term NOAEL = 2 mg/kg/day for dermal exposures, Table
3.2] 

		

			4.4.2.2		Treated Lumber  TC "4.2.2.3		Treated Lumber" \f C \l "4"  		

Scenarios

	According to the labels, typical end users for registered end users
include building lumber, furniture, frames, fences, decking, shingles
and siding, logs and poles.  For residential residential
post-application exposure to children and adults exposed to
diiodomethyl-p-tolylsulfone treated wood,  the highest concern expected
would be to children exposed to wood decking or playground equipment.
Currently, there are no study data that can be used to estimate either
exposure to adults from inhalation of wood dusts during construction of
wood decks or to children exposed to treated wood.  To complete an
assessment, dislodgeable wood residues would need to be generated (i.e.,
wipe studies).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.  Because children are more likely
than adults to contact wood surfaces, and because children have a higher
surface area to body weight ratio, they have been used to represent the
maximum exposed individual. The potential outdoor residential
post-application exposure pathways considered are outlined below:

Children

•	Dermal contact with diiodomethyl-p-tolylsulfone -treated wood
products (e.g., residential playground equipment and decks);

•	Incidental ingestion due to hand-to-mouth contact with
diiodomethyl-p-tolylsulfone -treated wood products;

•	Incidental ingestion of soil contaminated with
diiodomethyl-p-tolylsulfone;

•	Dermal contact with soil contaminated with
diiodomethyl-p-tolylsulfone (e.g., soil contaminated by treated decks
and playground equipment); and

Available data to assess the levels of diiodomethyl-p-tolylsulfone in
soil contaminated with treated wood do not exist at this time.  Because
of this data gap, EPA was not able to estimate dermal and incidental
ingestion residential post-application exposures to soil contaminated
with diiodomethyl-p-tolylsulfone -treated wood.  In this assessment,
incidental ingestion and dermal exposures to children from contact with
treated wood were estimated using surrogate data.  

At present, there are no available data to assess the levels of
diiodomethyl-p-tolylsulfone residues in soil contaminated from
diiodomethyl-p-tolylsulfone -treated wood (above ground fabricated
components of decks or playsets).  Because of this data gap, EPA was not
able to estimate residential post-application dermal and incidental
ingestion exposures to soil contaminated with
diiodomethyl-p-tolylsulfone.  In this assessment, incidental ingestion
and dermal exposures to children from contact with treated wood were
estimated using surrogate data.

Surrogate Data 	

	

	At this time there are no chemical-specific surface wipe residue data
available to assess the dermal and incidental exposure for children
playing on treated structures.  Up until this point in time, wood
surface residue data have not been estimated without a wood wipe study. 
EPA has decided to provide a screening-level assessment for a
reregistration decision using a conservative surface residue value of 1
μg/cm2 and call-in confirmatory data.  The 1 μg/cm2 value accounts for
the skin reduction factor, or “transfer efficiency” from a cloth
wipe (i.e., cloth wipe surface residues are higher than that available
to the skin).  This high end residue value is higher than the maximum
residue seen for chromium and non chromium-based wood preservatives.

	A deterministic screening-level assessment has been developed by EPA to
assess children’s exposure using the 1 μg/cm2 wood residue value
along with exposure algorithms and parameters from the probabilistic
Stochastic Human Exposure and Dose Simulation (SHEDS) model (USEPA
2005a).  SHEDS was developed by EPA to assess exposure to children
contacting CCA-treated structures (i.e., decks and play sets).  The
SHEDS report along with EPA’s response to the Science Advisory
Panel’s (SAP) review comments is located at   HYPERLINK
"http://www.epa.gov/heasd/sheds/cca_treated.htm" 
http://www.epa.gov/heasd/sheds/cca_treated.htm .

	Based on the results of the CCA assessment and preliminary calculations
for diiodomethyl-p-tolylsulfone, direct contact with the treated wood
exhibits the highest potential for exposure.  The leaching of wood
preservative into the soil and subsequent exposure is less then that
attributed to direct contact with the treated wood itself.  Therefore,
for screening-level assessment purposes, only the contact with the
treated wood is quantified.  If the risks are not of concern for
contacting the treated wood directly, then the soil exposure and
aggregate of the soil exposure with the direct wood exposure is expected
to be of minimal additional contribution

Outdoor Residential Dermal Contact with Diiodomethyl-p-tolylsulfone
-treated Wood Products

	Diiodomethyl-p-tolylsulfone is used to treat dimensional lumber,
potential dermal exposure to children can result from playing on
diiodomethyl-p-tolylsulfone -treated structures such as decks and/or
play sets.  The dermal toxicological endpoints of concern for
diiodomethyl-p-tolylsulfone are non cancer.  Therefore, the amortization
of exposure over time that is provided in the SHEDS model for CCA is not
appropriate for diiodomethyl-p-tolylsulfone.  The frequency of exposure
is believed to be best represented by the short-term duration (i.e., 1
to 30 days of continuous exposure).  However, the intermediate-term
duration is also presented to provide risk estimates for that portion of
the population that plays continuously on treated structures up to 6
months at a time 

	The potential daily dose (PDD) from the dermal route of exposure is
estimated using the following modified equation from the SHEDS report
(i.e., SHEDS Appendix 2 page A2-5):

	

PDD = SR x SA x DA x CF1				        

                  BW

where:

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

ssumption of 1 μg/cm2);

SA		=		Surface area of unclothed body areas assuming 100% contacts the
treated area (2,530 cm2 warm weather);

DA		=		Dermal absorption (12%);

CF1		=		Unit conversion factor (0.001 mg/µg); and

BW		=		Body weight (15 kg) (USEPA, 2000 and 2001).

Note:  The wood surface residue of 1 μg/cm2 represents a bounding
estimate of the steady state amount of residue on a hand wiping the
surface of treated wood.  A confirmatory study to determine the surface
residues of  diiodomethyl-p-tolylsulfone over time is needed to verify
the bounding estimate and refine the risk assessment.

	The results of dermal exposure assessment indicate an absorbed dose of 
0.02 mg/kg/day.  The short- and intermediate-term margin of exposures
(MOEs) are 198 and 99, respectively, with a target MOE of 100 for ST and
300 for IT.  Therefore, the screening-level assessment indicates no risk
of concern for the ST dermal route of exposure. However, a concern
exists with the IT dermal route of exposure.

Table 4.6 shows the results of the calculations.  

Table 4.6.  Residential Post-application Dermal Exposures with
Diiodomethyl-p-tolylsulfone -treated Wood Product

Wood Surface Residue Concentration from Propiconazole (ug/cm2)	Surface
area of unclothes body areas (cm2)	Dermal Absorption (unitless)	PDD
(mg/kg/day)a	ST Dermal MOEb

Target MOE = 100	IT Dermal MOEb

Target MOE= 300

1.0	2530	0.12	0.02	198	99

 μg/cm2 ) x 0.001 mg/ μg x SAexposed  x 12% ]/(Body Weight, 15 kg)

b	MOE  = NOAEL (mg/kg/day) / daily dose (mg/kg/day).  For dermal
exposures, the (systemic) ST NOAEL is 4 	mg/kg/day and IT NOAEL=2
mg/kg/day.  Target ST MOE = 100 and Target IT MOE = 300.

  SEQ CHAPTER \h \r 1 Outdoor Residential Hand-to-Mouth Contact with
Diiodomethyl-p-tolylsulfone --treated Wood Products

	Diiodomethyl-p-tolylsulfone is used to treat dimensional lumber,
potential dermal exposure to children can result from playing on
diiodomethyl-p-tolylsulfone -treated structures such as decks and/or
play sets.  The incidental oral toxicological endpoints of concern for
diiodomethyl-p-tolylsulfone are non cancer.  Therefore, the amortization
of exposure over time that is provided in the SHEDS model for CCA is not
appropriate for diiodomethyl-p-tolylsulfone.  The frequency of exposure
is believed to be best represented by the short-term duration (i.e., 1
to 30 days of continuous exposure).  However, the intermediate-term
duration is also presented to provide risk estimates for that portion of
the population that plays continuously on treated structures up to 6
months at a time.

	The potential daily dose (PDD) from the dermal route of exposure is
estimated using the following modified equation from the SHEDS report
(i.e., SHEDS Appendix 2 page A2-8):

PDD = SR x SA x FQ x ET x SE x CF1				        

                                BW

where:

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

transfer efficiency” (EPA high end assumption of 1 μg/cm2);

SA		=		Surface area of the hands that contact both the treated area, and
the individuals mouth (20 cm2/event) (USEPA, 2000 and 2001);

FQ		=		Frequency of hand-to-mouth events (mean 8.45 events/hr) (Table
10, page 62, USEPA 2005a); 

SE		=		Saliva extraction efficiency (50% unitless fraction) (USEPA, 2000
and 2001);

ET	         =			Exposure Time (mean 1 hr/day) (Table 49 page            
   165 USEPA 2005a);

μg/cm2 represents a bounding estimate of the steady state amount of
residue on a hand wiping the surface of treated wood.  A confirmatory
study to determine the surface residues of diiodomethyl-p-tolylsulfone
over time is needed to verify the bounding estimate and refine the risk
assessment.

	The results of incidental oral exposure resulting from hand-to-mouth
activity presented in Table 4.8 indicate a dose of 0.0056 mg/kg/day. 
The short- and intermediate-term MOEs are 710 and 355, respectively,
with a target MOE of 100 for ST and 300 for IT.   Therefore, the
screening-level assessment indicates no risk of concern for the oral
route of exposure.

	 

 μg/cm2 ) x Hand SA (20 cm2) x SEF (0.5) x Frequency (8.45 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 oral, LOAEL is
4 mg/kg/day.  Target MOE = 100.

c	MOE  = NOAEL (mg/kg/day) / daily dose (mg/kg/day).  For oral, NOAEL is
2 mg/kg/day.  Target MOE = 300.

			4.4.2.3		Treated HVACs

A separate exposure assessment entitled “Exposure Assessment for the
use of Diiodomethyl-p-tolylsulfone on  Heating, Ventilation, and Air
Conditioning Systems” is presented in Appendix B with the cited
references. Average daily doses (ADDs) of Diiodomethyl-p-tolylsulfone
from HVAC inhalation exposures were calculated based on the 100-hour
average and peak exposure concentrations predicted by the RISK model and
exposure factors obtained from EPA’s Exposure Factors Handbook and
EPA’s previous inhalation exposure assessment for MDF 200. A separate
exposure assessment was conducted for the use of
diiodomethyl-p-tolylsulfone.  The review is presented in Appendix B. The
equation used to calculate ADDs is shown below: 

ADD = (EC * IR * ED)/BW

Where:

EC 	= 	Exposure concentration predicted by the RISK model (mg/m3)

IR 	= 	Inhalation rate (m3/hr)

ED 	= 	Exposure duration (hr/day)

BW 	= 	Body weight (kg)

Inhalation rates used in the analysis were 0.5 m3/hr for adults in
residential buildings, 1.0 m3/hr for adults in commercial office
buildings, 0.4 m3/hr for children in residential buildings, and 0.8
m3/hr for children in school.  The exposure durations for the analysis
were 16 hr/day in residential buildings and 8 hr/day in commercial
office buildings or schools.  These inhalation rates and exposure
durations are consistent with EPA’s inhalation exposure assessment for
MDF 200.  The assumed body weights were 70 kg for adults and 15 kg for
children (i.e., the approximate mean weight of three year olds), which
are values obtained from EPA’s Exposure Factors Handbook (EPA 1997). 
The ADDs for each building scenario and application rate are shown in
Table 4.9.  ADDs were not calculated for children in office buildings or
adults in schools.

Table 4.9

Average Daily Doses of Diiodomethyl-p-tolylsulfone for Inhalation by
Adults and 

Children in Residential, Office, and School Buildings

Building Scenario	Adult	Child

	Average	Peak	Average	Peak

Application Rate 500 ft2/gallon

Residence	3.61E-03	4.78E-03	1.35E-02	1.79E-02

Office Building	4.24E-04	4.91E-04	na	na

School	Na	Na	1.97E-03	2.28E-03

Application Rate 1,000 ft2/gallon

Residence	3.60E-03	4.77E-03	1.34E-02	1.78E-02

Office Building	4.23E-04	4.90E-04	na	na

School	na	Na	1.96E-03	2.27E-03

na = not applicable

Table 4.10 presents MOEs calculated by dividing the LOAEL for
diiodomethyl-p-tolylsulfone (i.e., 2 mg/kg/day) by the ADDs shown in
Table 4.9.  MOEs below the target MOE of 3,000 are shown in bold
typeface.  MOEs for both adults and children, with both application rate
scenarios (i.e., 500 and 1,000 ft2/gallon), are below the target MOE. 
In addition, MOEs for children in schools are below the target MOE.  

Table 4.10

MOEs for Adults and Children Exposed to Diiodomethyl-p-tolylsulfone
Following HVAC 

System Treatment in Residential, Office, and School Buildings

Building Scenario	Adult	Child

	Average	Peak	Average	Peak

Application Rate 500 ft2/gallon

Residence	5.54E+02	4.18E+02	1.48E+02	1.12E+02

Office Building	4.71E+03	4.08E+03	na	na

School	na	Na	1.02E+03	8.79E+02

Application Rate 1,000 ft2/gallon

Residence	5.55E+02	4.19E+02	1.49E+02	1.12E+02

Office Building	4.72E+03	4.08E+03	na	na

School	na	Na	1.02E+03	8.80E+02

na = not applicable

	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 postapplication exposure assessments which
include the following:

Surrogate 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
Handler Exposure Database (USEPA, 1998) (See Appendix A for summaries of
these data sources). Most of the CMA data are of poor quality therefore,
AD requests that confirmatory monitoring data be generated to support
the values used in these assessments.  

The quantities handled/treated 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
standard assumptions, which can be further refined from input from
registrants. 

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

	This is included in the Preliminary Risk Assessment.

	5.2	Short and Intermediate Term Aggregate Risk tc \l2 "5.2	Short-,
Intermediate-, and Long-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. 

	In performing aggregate exposure and risk assessments, the Office of
Pesticide Programs has published guidance outlining the necessary steps
to perform such 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- and Intermediate-Term Aggregate Exposures
and Risks

	Short- and intermediate-term aggregate exposures and risks were
assessed for adults and children that could be exposed to
diiodomethyl-p-tolylsulfone residues from the use of products in
non-occupational environments.  The following lists summarize all of the
non-dietary, non-occupation potential sources of
diiodomethyl-p-tolylsulfone exposures for adults and children:

Adult diiodomethyl-p-tolylsulfone exposures sources:

Applying of diiodomethyl-p-tolylsulfone preserved paint in residential
settings by paint brush, roller, and airless sprayer.

Applying of diiodomethyl-p-tolylsulfone wood preservative in residential
settings with paint brush., roller and airless sprayer.

	

Child diiodomethyl-p-tolylsulfone exposures sources:

Exposure from finger painting.

Post-application exposure to diiodomethyl-p-tolylsulfone from carpets in
residential settings.

Bystander inhalation exposure to diiodomethyl-p-tolylsulfone in HVAC
systems.

Post-application exposure to diiodomethyl-p-tolylsulfone from wood
preservatives in residential settings.

	The use patterns of the products and probability of co-occurrence must
be considered when selecting scenarios for incorporation in the
aggregate assessment.  In the case of diiodomethyl-p-tolylsulfone, adult
homeowner painting and wood preserving activities occur only once or
twice a year, therefore the probability of co-occurrence and the
potential for exposure to residues from this use with other
diiodomethyl-p-tolylsulfone products on the same day is highly unlikely.
Therefore the adult scenarios were not aggregated.

	For children, both post-application exposure scenarios to carpet (ST
MOEs<100 and IT MOEs<300), wood preservatives (IT MOEs<300), and
bystander exposures to HVAC systems are of concern to the Agency. 
Incorporation of these scenarios into an aggregate assessment would also
result in risks of concern (ST MOEs<100 and IT MOEs<300).  Therefore, no
aggregate assessments were conducted.  Table 5.1 summarizes the
scenarios included in the short- and intermediate-term aggregate
assessments.

Table 5.1:  Summary of Exposure Scenarios Included in the Short- and
Intermediate-Term Aggregate Assessments

	Short-term Aggregate	Intermediate-Term Aggregate

Adults	Dermal:

Painting applicator

Wood preservative applicator

	NA

	Inhalation:

Painting applicator

Wood preservative applicator

Bystander inhalation from HVAC systems

	Inhalation:

Painting applicator

Wood preservative applicator

Bystander inhalation from HVAC systems

Children	Dermal:

Handler exposure to diiodomethyl-p-tolylsulfone for finger painting
activities

Post-application exposure to Diiodomethyl-p-tolylsulfone from carpets

Post-application exposure to diiodomethyl-p-tolylsulfone from wood
preservatives used in decks  	Dermal:

Handler exposure to diiodomethyl-p-tolylsulfone for finger painting
activities

Post-application exposure to diiodomethyl-p-tolylsulfone from carpets

Post-application exposure to diiodomethyl-p-tolylsulfone from wood
preservatives used in decks  

	Inhalation:

Bystander inhalation from HVAC systems

	NA

	Oral:

Postapplication hand-to-mouth exposure to wood preservatives on decks

Postapplication hand-to-mouth exposure from carpets 	Oral:

Postapplication hand-to-mouth exposure to wood preservatives on decks

Postapplication hand-to-mouth exposure from carpets

Since the short-term and intermediate-term toxicity endpoints for all of
the routes of exposure (oral and dermal) are based on the same study and
same toxic effect therefore, all short- and intermediate-term routes
would be aggregated together.  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) was utilized in
the assessment.  This method was used because the oral and dermal
endpoints have the same uncertainty factors or target MOEs. The target
MOE for short-term would be 100 and the intermediate-term would be 300. 
 The general equation used to estimate total or aggregate MOEs is:  

Aggregate MOE = 1 / ((1/MOEroute 1, scenario 1) + (1/ MOEroute1,
scenario 2) + (1/MOE route 1, scenario n) + (1/MOEroute 2, scenario 1) +
(1/MOEroute 2, scenario 2) + (1/MOEroute 2, scenario n) + (1/MOEroute n,
scenario n))

Where, route represents oral, dermal, or inhalation exposures, and
scenarios represents handler or post-application.

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

	The exposure scenarios assessed in this document for the representative
uses selected by AD are shown in Table 6.1. The table also shows the
maximum application rate associated with the representative use and the
appropriate EPA Registration number for the product label.  For
handlers, the representative uses assessed include application as a
preservative to materials (paints, paper, textiles (non-clothing),
building materials, and leather), and as a wood preservative (sapstain
non-pressure, and pressure treatment). Additionally, handler exposures
were assessed for the application of treated paint (paint brush/roller
and airless sprayer) and wood preservative (brush/roller). It should be
noted that for the calculation of application rates in which 8.34 lb
a.i./gal is noted, the product is assumed to have the density of water
because no product-specific density is available.  

	Potential occupational handler exposure can occur in various use sites,
which include; material preservatives and wood preservatives. 
Occupational exposure can occur during the preservation of materials
that are used for household, institutional, and industrial uses, along
with the preservation of wood.  The “preservation of materials”
refers to the scenario of a worker adding the preservative to the
material being treated (paint, textiles, etc.) through either liquid
pour or liquid pump methods.  Liquid pour refers to transferring the
antimicrobial product from a small container to an open vat.  Liquid
pump refers to transferring the preservative by connecting/disconnecting
a chemical metering pump from a tote or by gravity flow.  For the
preservation of wood, the procedure for treatment can occur in different
ways, such that multiple worker functions were analyzed. Due to the
complexity of the wood preservative analysis, the scenario specific
results for handler and postapplication exposures are presented in a
separate section, 6.4.





Table 6.1.  Representative Exposure Scenarios Associated with
Occupational Exposures to Diiodomethyl-p-tolylsulfone

Representative Use	

Method of Application	

Exposure Scenario	

Registration #	

Application Rate

Material Preservatives

Paint	

Preservation of paint

Liquid pour

Liquid pump

Professional painter

Brush/Roller

Airless sprayer

	

IT and ST Handler: dermal and inhalation

ST Prof Painter:

dermal and inhalation (aerosol and vapor)	

464-672	

0.049 lb ai/gal

Air Duct Coatings	

Sprayer	

IT and ST Handler: inhalation

Bystander inhalation

	

464-672	

0.049 lb ai/gal

Paper production	

Liquid pump	

IT and ST Handler: dermal and inhalation	

464-672	

0.388 lb ai/ton

Adhesives and Caulks

	

Liquid pour

Liquid pump	

IT and ST Handler: dermal and inhalation

	464-672	0.3 % ai per wt.

Emulsions

	

Liquid pour

Liquid pump	

IT and ST Handler: dermal and inhalation

 	464-670	0.143 % ai per event

Leather	

Liquid pour

Liquid pump	

IT and ST Handler: dermal and inhalation

 	464-673	0.4% ai per event

Plastics

Rubbers

	

Liquid pour

Liquid pump	

IT and ST Handler: dermal and inhalation

 	464-672	0.078 lb ai/gal

Slurries

	

Liquid pour

Liquid pump	

IT and ST Handler: dermal and inhalation	464-670	0.00475 lb ai/gal

Textiles	

Liquid pour

Liquid pump	

IT and ST Handler: dermal and inhalation

 	464-670	0.0048 lb ai/lb dry wt

Wood Preservatives

Wood Preservative  (pressure and non-pressure treated)	

Pressure Treatment

Brush

Airless Sprayer

Dip(Non-Pressure Treatment)	

IT and ST Handler and Postapplication: dermal and inhalation 

	464-673 (pressure treatment)

60061-009 (brush/airless sprayer)

	0.4 lb ai/cubic ft (pressure treatment)

0.00021 lb ai/sq ft (brush/airless sprayer)

	6.1 	Occupational Handler Exposures

	The 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 majority of the scenarios were assessed using CMA data and Equations
1-3.  However, for the occupational scenarios in which CMA data were
insufficient, other data and methods were applied. 

	

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

For the liquid pour scenarios for materials preservatives, the unit
exposure depends on the material being treated.  The following CMA unite
exposures were available and used for the assessment of the risk
associated with the treatment of the specified materials

Paint, Caulks, Slurries, Emulsions, Textiles, Rubbers/Plastics,
Leathers, Hides, Leather Products, and Paper: CMA preservative gloved
data.  The dermal UE is 0.135 mg/lb ai and the inhalation UE is 0.00346
mg/lb ai. The values are based on 2 replicates where the test subjects
were wearing a single layer of clothing and chemical resistant gloves.

For the liquid pump scenarios, the unit exposure depends on the material
being treated. The following CMA unite exposures were available and used
for the assessment of the risk associated with the treatment of the
specified materials

Paints, Caulks, Slurries, Emulsions, Textiles, Rubbers/Plastics,
Leathers, Hides, and Leather Products:  CMA preservative gloved data. 
The dermal UE is 0.00629 mg/lb a.i. and the inhalation UE is 0.000403
mg/lb a.i. for inhalation.  The values are based on two replicates where
the test subjects were wearing a single layer of clothing and chemical
resistant gloves.

Paper:   CMA pulp and paper gloved data.  The dermal UE is 0.00454 mg/lb
a.i. and the inhalation UE is 0.000265 mg/lb a.i. The values are based
on 7 replicates where the test subjects were wearing a single layer of
clothing and chemical resistant gloves. 

For roller/brush scenarios, the occupational PHED dermal and inhalation
unit exposure values for paintbrush applications (PHED scenario 22) were
used (single layer of clothing).  The inhalation exposure value is 0.28
mg/lb a.i. The dermal unit exposures are 180 mg/lb a.i. for ungloved
replicates and 24 mg/lb a.i. for gloved replicates. 

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

Quantity handled/treated: The quantity handled/treated values were
estimated based on information from various sources.  The following
assumptions were made:

For the liquid pour scenarios, the quantity of the chemical that is
handled depends on the material that is being treated.  The following
values were used for the different materials:

Paint and Plastics:  2,000 gallons (approximately 500 gallons per
batch/day and 4 batches per day standard assumption.

Paper:  500 tons based on standard assumption (500 tons x 2204.622
lb/ton = 1102311 lbs) 

Adhesives, Caulks, Slurries, Paper, and Textiles:  10,000 lbs is treated
based on standard assumption.

Hides, Leathers, and Leather Products: standard assumption of 1,000
hides/day (raceways), 200 hides/day (mixers), 400 hides/day (tanning
drum) and 65 lb/hide. 

For the liquid pump scenarios the quantity that is handled depends on
the material that is being treated.  The following values were used for
the different materials:

 

Paint and Plastics:  20,000 gallons (approximately 10,000 gallons/batch
and 2 batches/day) and this is based on standard assumptions.

Paper:  500 tons based on standard assumption (500 tons x 2204.622
lb/ton = 1102311 lbs) 

Adhesives, Caulks, Slurries, Paper, and Textiles:  10,000 lbs is treated
based on standard assumption.

Hides, Leathers, and Leather Products: standard assumption of 1,000
hides/day (raceways), 200 hides/day (mixers), 400 hides/day (tanning
drum) and 65 lb/hide.

For the roller/brush painting and wood preservative scenario, it was
assumed that 50 lbs (approximately 5 gallons of paint with a density of
10 lb/gal) of treated paint are used.

For the airless sprayer in the painting scenario, it was assumed that
500 lbs (approximately 50 gallons of paint with a density of 10 lb/gal)
of treated paint are used.

  	

For the airless sprayer and brush/roller scenarios for wood preservative
applications, it was assumed that a painter would brush or spray a
standard deck with approximate dimension of 300 sq. ft. (30’ x 10’)
once per day.

Duration of Exposure: The MOEs were calculated for the short- and
intermediate-term durations for occupational handlers using the
appropriate endpoints in Table 6.2

Table 6.2 Short and Intermediate Term Risks Associated with
Occupational Handlers using Diiodomethyl-p-tolylsulfone

Exposure Scenario	

Method of Application	

Unit Exposure (mg/lb a.i.)	

App. Rate	

Quantity Handled/ Treated per day	Absorbed Daily Dose (mg/kg/day)c	

Inhal. ST/IT	Baseline Dermal (Target MOE = 100 ST and 300 IT)a,d

	PPE-Gloves Dermal (Target MOE = 100 ST and 300 IT) b,d
Inhalation(Target MOE = 300 ST/IT)d 

Baseline Dermala	

PPE-Gloves Dermalb	

 Inhalation

	

Dermal ST/IT	

PPE-Gloves Dermalb

ST	

IT	

ST	

IT	Baseline	

PPE

Preservation of Paint	

Liquid Pour	50.3	

0.135	

0.00346	0.049 lb ai/gal	2,000 gal	8.5	0.023	

0.0049	<1	<2	175

	87

	409

	2047

	

Liquid Pump	0.454	

0.00629	

0.000403

20,000 gal	0.77	0.011	0.0057	5

	3

	375

	188

	351

	1757

Application of Paint by a Professional Painter	

Brush/ Roller	180	24	0.28	0.049 lb ai/gal	5 gal	0.076	0.01	9.9E-4	52

	26

	393

	197

	2024

	10118

	

Airless Sprayer	38	14	0.83

50 gal	0.16	0.059	0.029	25

	12

	67

	34

	68

	341

Preservation of Adhesives and Caulks	

Liquid Pour	50.3	

0.135	

0.00346	0.3% ai per event	10,000 lb	2.6	0.0069	0.0015	1.5

	<1

	576

	288

	1349

	6744

	

Liquid Pump	0.454	

0.00629	

0.000403

	0.023	3.2E-4	1.7E-4	171

	86

	12365

	6183

	11580

	57899

Preservation of Slurries	

Liquid Pour	50.3	

0.135	

0.00346	4.75E-3 lb ai/gal	10,000 lb (1199 gal)	0.49	1.3E-5	2.8E-5	8.1

	4

	3035

	1517

	7104

	35522

	

Liquid Pump	0.454	

0.00629	

0.000403

	0.0044	6.1E-5	3.3E-5	902

	451

	65133

	32566

	60995

	304976

Preservation of Emulsions	

Liquid Pour	50.3	

0.135	

0.00346	0.143% ai per event	10,000 lb	1.2	0.0033	7.0E-4	3.3

	1.6

	1213

	606

	2839

	14197

	

Liquid Pump	0.454	

0.00629	

0.000403

	0.011	1.5E-4	8.2E-5	361

	180

	26032

	13016

	24379

	121893



Preservation of Rubber and Plastics	

Liquid Pour	50.3	

0.135	

0.00346	0.078 lb ai/gal	2,000 gal	13	0.036	7.7E-3	<1

	<1

	111

	56

	261

	1305

	

Liquid Pump	0.454	

0.00629	

0.000403

20,000 gal	1.2	0.017	8.9E-3	3

	1.7

	239

	120

	224

	1120



Preservation of  Leather (Raceway)	

Liquid Pour	50.3	

0.135	

0.00346	

0.4% ai by weight	

65,000 lb	22	0.006	0.013	<1

	

<1

	

67

	34

	157

	786

	

Liquid Pump	0.454	

0.00629	

0.000403

	0.2	0.0028	0.0015	20

	10

	1441

	721

	1350

	6748

Preservation of  Leather (Mixer)	

Liquid Pour	50.3	

0.135	

0.00346	0.4% ai by wt	

13,000 lbs	4.4	0.012	2.5E-3	1

	<1

	336

	168

	786

	3930

	

Liquid Pump	0.454	

0.00629	

0.000403

13,000 lbs	0.04	5.6E-4	3E-4	100

	50

	7206

	3603

	6748

	33741

Preservation of  Leather (Tanning Drum)	

Liquid Pour	50.3	

0.135	

0.00346	0.4% ai by wt	26,000 lb 	8.9	0.024	5.1E-3	<1

	<1

	168

	84

	393

	1965

	

Liquid Pump	0.454	

0.00629	

0.000403

	0.08	0.0011	5.9E-4	50

	25

	3603

	1801

	3374

	16870

Preservation of  Textiles (Non-Clothing)	

Liquid Pour	50.3	

0.135	

0.00346	0.0048 lb ai/lb dry wt	10,000 lb	4.1	0.011	2.3E-3	1

	<1

	364	182	852	4259

	

Liquid Pump	0.454	

0.00629	

0.000403

	0.037	5.1E-4	2.7E-4	108

	54

	7810	3905	7314	36568

Preservation of  Paper	

Liquid Pump	0.454	

0.00629	

0.000403	0.388 lb ai per ton	500 tons	1.5E-03

	2.1E-05

	1.1E-05

	2652

	1326

	191413

	95707

	179254

	896271

Application of Wood Preservative by professionals	Brush/ Roller	180	

24	

0.28	2.1E-4

Lb ai/sq ft

	

300 sq ft	2.0E-2	2.6E-3	2.5E-4	205	102	1534	767	7888	39,442

	Airless Sprayer	38	14	0.83

	4.1E-3	1.5E-3	7.5E-4	969	484	2661	1315	2661	13,306

ST = short-term, IT = intermediate-term, N/A= No data available

a	Baseline Dermal:  Long-sleeve shirt, long pants, no gloves.

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

c	Absorbed Daily dose (mg/kg/day) = [unit exposure (mg/lb ai) *
absorption (1.0 for ST/IT inhalation and ST dermal, 0.12 for ST/IT
dermal) * application rate * quantity treated / Body weight (70 kg).

d	MOE = NOAEL  (mg/kg/day) / Absorbed Daily Dose [Where short-term NOAEL
= 4 mg/kg/day for dermal  and intermediate-term LOAEL = 2 mg/kg/day for
IT dermal and inhalation exposures]. 

NC = Not conducted: IT exposures were not assessed for professional
painters because it was assumed that professional painters will not use
Diiodomethyl-p-tolylsulfone preserved paint on a continuous
basisExposure Calculations and Results 			

	The calculated dermal and inhalation MOEs are shown in the executive
summary.

6.2  	Occupational Post-application Exposures

	

	Inhalation exposures are expected to occur to postapplication exposure
as a result of HVAC applications in industrial settings.  Refer to
“Exposure to Diiodomethyl-p-tolylsulfone from HVAC Applications” in
the handler section which discusses both handler and postapplication
exposures and risks (Section 5.0). In addition, both dermal and
inhalation occupational postapplication exposures are expected in wood
preservation industry. 

	

6.3 	Wood Preservation

	Diiodomethyl-p-tolylsulfone products that are intended to preserve wood
(pressure and non-pressure treatment).  As noted on label Reg # 464-670,
Diiodomethyl-p-tolylsulfone can be used “for control mildew, sapstain,
and wood rotting organisms.  Incorporate AMICAL into appropriate
vehicles to protect wood from stain and decay.   This particular use was
for formulating uses only.  Another label Reg # 10466-37, mentions that
diiodomethyl-p-tolylsulfone can be used for “control of mildew
sapstain, and wood rotting organisms at wood treatment facilities or
incorporated into other registered wood preservatives.  For typical uses
such as building lumber, furniture, frames, decking, fenses, shingles,
and siding logs and poles.”  

	The handler and post application scenarios that have been identified
and assessed for wood preservation were extracted from MRID 455243-04,
“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).  This proprietary sapstain
task force study (task force # 73154) includes the potential ways that
the Agency believes an individual can come into contact with preserved
wood, and therefore is included in this assessment.

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 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
and grade the dry lumber by hand (i.e. detect faults).  In the DDAC
study, graders graded wet lumber; therefore, the exposures to graders
using diiodomethyl-p-tolylsulfone are assumed to be the worst-case
scenarios.    

Trim saw operators operate the hula trim saw and this group consists of
operators and strappers.  

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.  

	The CMA unit exposure data were used to assess exposure and risks for
the job function that involves blender/spray operators.  The liquid pump
preservative unit exposures for gloved workers were used.  The dermal UE
was 0.00629 mg/lb ai and the inhalation UE was 0.000403 mg/lb ai. 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 standard Agency assumptions
for the amount of wood slurry treated because no chemical specific data
were available for diiodomethyl-p-tolylsulfone.  It was assumed that
batches of 7,000 gallons of wood slurry are treated in a batch for wood
blender type operations.  The Agency also assumed that eight batches of
wood slurry were treated per day (one per hour for an 8-hr work shift). 
The total amount of wood slurry treated per day would therefore be
56,000 gallons or 213 m3 (where, 56,000 gal/day = 7,000 gallons/batch x
8 batches/day; or 213 m3 = 56,000 gallons x 0.003785 m3/gallon).  Wood
chips were assumed to have a density of about 380 kg/m3 (SIMetric,
2005), and with this assumption, a potential amount of 178,000 lbs of
wood is expected to be treated (213 m3 x 380 kg/m3 x 2.2 lb/kg).  The
diiodomethyl-p-tolylsulfone product is to be applied at a rate 0.61-2%
by weight of the wood treated by weight and contains 48.45% a.i. or
0.96% total (Reg 464-472) and can also be applied at a rate 0.3-1% by
weight of the wood treated by weight and contains 48.45% a.i. or 0.48%
total (Reg 464-670).  Table 6.7 provides the short, intermediate term
MOEs for the workers adding the preservative to the wood slurry.  The ST
dermal MOE is above the target MOE of 100 and therefore do not pose a
concern.  However, the IT inhalation MOE (203) for the blender/spray
operators adding the chemical via closed-liquid pumping is less than
300.  Therefore and therefore a confirmatory inhalation toxicity study
is warranted based on these results.  In addition, the IT dermal MOE is
also less than 300.

Table 6.3 Short- and Intermediate-term Exposures and MOEs for Wood
Preservative Blender/spray Operators 

Exposure

Scenario

	CMA Dermal UE

(mg/lb ai)	CMA Inhal UE

(mg/lb ai)	App Rate

(% ai)	Quantity Treated

(lb/day)	

Daily Dermal Dose a (mg/kg/day)	

Daily Inhal. Dose a (mg/kg/day)	

Dermal MOE b	Inhalation MOE b

	ST	IT

	

Liquid Pump	0.00629	0.000403	0.96%	178,000	0.0184	0.0098	217	109	203

	0.48%

0.0093	0.0050	430	215	403

a Daily Dose = UE (mg/lb ai) x App Rate (% ai) x Quantity treated
(lb/day) x absorption factor (ST/IT dermal =    0.12, not necessary for
inhalation)/ BW (70 kg)

b MOE = NOAEL (mg/kg/day)/ Daily dose [Where short-term NOAEL = 4
mg/kg/day for dermal and

   the NOAEL for inhalation exposures and intermediate-term  = 2
mg/kg/day for dermal and inhalation exposures].    

   Target MOE is 100 for ST dermal and 300 for IT dermal and inhalation
exposures

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

	The CMA data were inadequate to represent the other job functions
associated with preservation on non-pressure treated wood.  As very
little chemical specific data were available regarding typical exposures
diiodomethyl-p-tolylsulfone as a wood preservative, surrogate data were
used to estimate exposure risks. This surrogate data was obtained from, 
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).  This study is proprietary (Task
Force # 73154); therefore, data compensation needs to be paid for use of
the data in this exposure assessment.  It was assumed that the workers
at facilities using diiodomethyl-p-tolylsulfone preservatives are
performing similar tasks as those monitored in the DDAC study.

The DDAC study examined individuals( exposure to DDAC while working with
antisapstains and performing routine tasks at 11 sawmills/planar mills. 
Dermal and inhalation exposure monitoring data were gathered for each
job function of interest using dosimeters and personal sampling tubes. 
Dosimeters and personal air sampling tubes were 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 C-1 in Appendix C.  To determine
diiodomethyl-p-tolylsulfone exposures, the average DDAC exposures
measured on individuals (in terms of total mg DDAC) were multiplied by a
modification factor of 0.5 to account for the difference in percent
active ingredient (48% diiodomethyl-p-tolylsulfone in the wood
preservative product versus 80% DDAC in the comparative wood
preservative product). The pound (lb) active ingredient handled by each
person or the percent active ingredient in the treatment solution was
not provided for these worker functions. 

The following equation was used to calculate daily dose for
diiodomethyl-p-tolylsulfone: 

Daily Dose = DDAC UE x CR x AB

BW

Where:

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

CR		=	Conversion ratio (48% Diiodomethyl-p-tolylsulfone / 80% DDAC);

AB	=	Absorption factor (12 % for ST/IT dermal and 100% for all other
durations); 	and

BW		=	Body weight (70 kg).

In using this methodology, the following assumptions were made:

DDAC and diiodomethyl-p-tolylsulfone 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. 

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
ug).  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 ug.

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.

μg/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), a sample duration of 8 hrs/day, and a
conversion factor of 1 mg/1000 µg.  Table C-1 in Appendix C presents
the inhalation and dermal DDAC exposures.

Average DDAC dermal and inhalation exposures were multiplied by a
conversion ratio of 0.60 to account for the differences in
diiodomethyl-p-tolylsulfone and DDAC concentrations [(48%
diiodomethyl-p-tolylsulfone / 80% DDAC)].  

Table 6.8 provides the short-,and intermediate-term doses and MOEs for
chemical operators, graders, millwrights, clean-up crews, and trim saw
operators.  

	Table 6.4 Short- and Intermediate-term Exposures and MOEs for Wood
Preservative Chemical Operators, Graders, Mill Wrights, and Cleanup
Staff

Exposure Scenarioa 

(number of volunteers)	Dermal UEb 

(mg/day)	Inhalation UEb 

(mg/day)	Conversion Ratioc 	Absorbed Daily Dosesd 

(mg/kg/day)	MOE= 100	MOE=300

Dermal	Inhalation	Dermal	Inhalation

ST 	IT	ST /IT/LT

Chemical Operator (n=11)	9.81	0.0281	0.6	0.010	0.00024	396	198	8304

Grader (n=13)	3.13	0.0295	0.6	0.0032	0.00025	1242	621	7910

Trim Saw (n=2)	1.38	0.061	0.6	0.0014	0.00052	2818	1409	3825

Millwright (n=3)	12.8	0.057	0.6	0.013	0.00049	304	152	4094

Clean-Up (n=6)	55.3	0.60	0.6	0.057	0.0051	70	35	389

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

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

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

Conversion Ratio = 48% diiodomethyl-p-tolylsulfone / 80% DDAC

Absorbed Daily Dose (mg/kg/day) = exposure (mg/day) * conversion ratio
(0.6) * absorption factor (012 for ST/IT dermal and 1.0 for inhalation)
/ body weight (70 kg). 

e.	MOE = NOAEL (mg/kg/day)/ Daily Dose [Where ST NOAEL = 4 mg/kg/day for
dermal exposures, and IT LOAEL = 2 mg/kg/day for IT dermal and all
durations of inhalation]. Target MOE is 100 for ST dermal and 300 for IT
dermal and  inhalation exposures.

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. 
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 calculations of the dermal and
inhalation unit exposures (2.99 and 0.046 mg/1% solution, respectively)
are presented in Table C-2 in Appendix C.  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 sample duration of 8
hrs/day.

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

Daily Dose = DDAC UE x AI x AB

BW

Where:

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

AI		=	Percent active ingredient in solution (0.96%);

AB	=	Absorption factor (12 % for IT/LT dermal and 100% for all other
durations); 	and

BW		=	Body weight (70 kg).

	Table 6.9 provides the short-, intermediate-, and long-term exposures
and MOEs for diptank operators. All of the dermal, inhalation, and total
MOEs were above the target ST MOE of 100 and IT MOE of 300.

 

	Table 6.5 Short- and Intermediate-term Exposures and MOEs for Wood
Preservative Diptank Operators

Exposure Scenarioa

(number of replicates))	Dermal Unit Exposureb

(mg DDAC/1% solution)	Inhalation Unit Exposureb

(mg DDAC/1%	Application Rate

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

(mg/kg/day)	MOEse (target MOE = 100)	MOEse (target MOE = 300)

Dermal	Inhalation	Dermal	Inhalation

ST 	IT	ST /IT

Chemical Operator (n=11)	2.99	0.046	0.96	0.0049	0.00063	813	406	3170

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 chemicals, not when operating the diptank.

b.	Dermal and inhalation unit exposures are from the DDAC study (MRID
455243-04). Refer to Table A-2 in Appendix A 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, 1997a.

c.	The application rate is 0.96%a.i. in treatment solution (formulated
product is applied at a rate of 48.45% of the weight of the wood
treated, and the product contains 2% a.i.)

d.	Absorbed Daily Dose (mg/kg/day) = unit exposure (mg/1% ai solution) *
percent active ingredient in solution * absorption factor (12% for
dermal ST/IT, and 100% for all other exposures/durations) / body weight
(70 kg).

e.			MOE = NOAEL (mg/kg/day)/ Daily Dose [Where ST NOAEL = 4 mg/kg/day
for dermal and the IT LOAEL = 2 mg/kg/day for dermal and all inhalation
durations]. Target MOE is 100 for ST dermal and 300 for IT dermal and
inhalation exposures.

Construction Workers

	Not enough data exists 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.

Pressure Treatment Scenarios (Handler and Post-Application)

	

	Diiodomethyl-p-tolylsulfone wood preservatives may be used to treat
wood and wood products using pressurized application methods,
specifically empty-cell vacuum pressure techniques.  Pressure treatment
solutions of diiodomethyl-p-tolylsulfone are predominantly water-borne
products. Typical registered product use rates for pressure treatment
are at levels of 0.25% ai. The maximum rate of application used in this
assessment is 1% ai solution based on product labeling for EPA Reg. Nos.
464-673 which indicate that water based treatment use solutions of up to
1% ai can be made.  The specified retention (as
diiodomethyl-p-tolylsulfone) for these applications is 0.05 -1 lb pcf or
0.02-0.4 lb ai pcf.

	Chemical-specific exposure data are not available on
diiodomethyl-p-tolylsulfone 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
diiodomethyl-p-tolylsulfone.  

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). 
The normalization by treatment solution concentration was performed to
extrapolate the measured exposures in the CCA study (monitored at ~0.5%
ai solution) to the maximum diiodomethyl-p-tolylsulfone treatment
solution concentration (1 % ai 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).  

	Note: The U.S. and Canadian sites indicate a 7x difference in the mean
dermal exposures (US site mean is 0.40 µg As/ppm compared to the
Canadian site mean of 2.84 µg As/ppm).  It is recommended that
additional analysis be performed to determine if the increased exposure
levels at the Canadian site can be attributed to differences in
site-specific engineering controls or facility design.



Table 6.6.  Dermal and Inhalation Exposure Values from a CCA Pressure
Treatment Study (Exposure Data used as Surrogate Unit Exposures for the
Diiodomethyl-p-tolylsulfone 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
handler exposure: 

Absorbed Daily Dose = 	UE x AI x AB 

	      	       BW

Where

UE	=	Unit exposure (mg As/ppm);

AI	=	Percent active ingredient (1% ai 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 risks for
diiodomethyl-p-tolylsulfone pressure treatment uses are presented in
Table 6.7.  The calculated ST dermal MOEs are all above the target MOE
of 100 and do not pose a risk concern.  Also, the inhalation ST/IT/LT
MOEs for all scenarios are above target MOE of 300 and  the IT dermal
MOEs are above the target MOE of 300.

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

Exposure Scenarioa	

Unit Exposurea 

((g As/ppm)

	

Application Rate 

(% ai solution) 	Absorbed Daily Dosesb 

(mg/kg/day)	MOEsc

	Dermal	Inhalation

Dermal	Inhalation	Dermal

ST Target = 100

IT Target= 300	Inhalation

ST/IT/LT

Target=300

ST	IT

	Occupational Handler

Treatment Operator (TO)	2.04	0.00257	1	0.035	3.67E-5	114	57	5.45E+4

Treatment Assistant (TA)	0.24	0.000802	1	0.0041	1.15E-5	972	486	1.75E+5

Occupational Post-application

All Job Functions

(Tram setter, stacker operator, loader operator, supervisor, test borer,
and tallyman) 	0.74	0.00160	1	0.013	2.29E-5	315	158	8.75E+4

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

a. 	Unit exposure values are taken from CCA study as shown above and in
Table 6.6.

g/μg) * absorption factor (0.12 for dermal; 100% for inhalation) / Body
weight (70 kg).

c.			MOE = NOAEL (mg/kg/day) / Daily dose [Where ST (systemic) NOAEL = 4
mg/kg/day for dermal and IT LOAEL = 2 mg/kg/day for inhalation]. Target
ST MOE is 100 for dermal exposure, IT MOE is 300 for dermal exposure,
and 300 for inhalation exposure.

		

6.4	Data Limitations/Uncertainties tc \l2 "6.3	Data
Limitations/Uncertainties 

	There are several data limitations and uncertainties associated with
the occupational handler and postapplication exposure assessments. 
These include:

Surrogate 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
Handler Exposure Database (USEPA, 1998) (See Appendix A for summaries of
these data sources).   Since the CMA data are of poor quality, the
Agency requests that confirmatory data be submitted to support the
occupational scenarios assessed in this document.

Currently, no exposure data are available to assess the bystanders’
inhalation exposure to diiodomethyl-p-tolylsulfone vapors in industrial
settings.  Appropriate air monitoring data in the manufacturing setting
are needed to support the preservative uses. 

For the wood preservative pressure treatment scenarios, surrogate CCA
exposure data were used for lack of chemical-specific exposure data for
this use pattern. For the wood preservative non-pressure treatment
scenarios, surrogate DDAC exposure data were used for the lack of
chemical-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 diiodomethyl-p-tolylsulfone, and
therefore the exposures could be used as surrogate data for workers that
treat wood with diiodomethyl-p-tolylsulfone based formulations.

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

The quantities handled/treated were estimated based on information from
various sources, including Agency standard assumptions, HED’s Standard
Operating Procedures (SOPs) for Residential Exposure Assessments (USEPA,
2000 and 2001), and professional judgment based on Agency understanding
of industrial practices.  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 with input from
registrants.  

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 Measurement and Assessment of Dermal and Inhalation
Exposures to Didecyl Dimethyl Ammonium Chloride (DDAC) Used in the
Protection of Cut Lumber (Phase III).  (MRID 455243-04, Task force
#73154).

Cinalli, Christina, et al. A Laboratory Method to Determine the
Retention of Liquids on the Surface of Hands.  Exposure Evaluation
Division. September 1992. 

Landenberg, B, 2007. “Screening Risk Assessment. Potential Exposure to
AMICAL™ From the use of Finger-Paints.” The Dow Chemical Company.

National Institute for Occupational Safety and Health (NIOSH): Criteria
for a Recommended Standard-Occupational Exposure to Metalworking Fluids.
 Department of Health and Human Services (DHHS) NIOSH Publication
#98-102 (1998).

SIMetric, 2005.  Mass, Weight, Density, or Specific Gravity of Bulk
Materials.  http://www.simetric.co.uk/si_materials.htm, last accessed
June 2005.

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

USEPA.  1997a.  Exposure Factors Handbook. Volume I-II.  Office of
Research and Development.  Washington, D.C.  EPA/600/P-95/002Fa.

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.

USEPA.  1999.  Evaluation of Chemical Manufacturers Association
Antimicrobial Exposure Assessment Study.  Memorandum from Siroos
Mostaghimi, Ph.D., USEPA, to Julie Fairfax, 

USEPA.  2000.  Residential SOPs.  EPA Office of Pesticide Programs Human
Health Effects Division. Dated April 5, 2000.

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. 

USEPA. 2003.  Assessment of the Proposed Bardac Wood Preservative
Pressure Treatment Use.  Memorandum from Tim Leighton and Siroos
Mostaghimi.  February 11, 2003.

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.

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

USEPA.  2005a.  A Probabilistic Exposure Assessment for Children Who
Contact CCA-Treated Playsets and Decks.  Final Report, February, 2005. 
US EPA Office of Research and Development, National Exposure Research
Laboratory.

Whatman, 2005.  Whatman Absorbent Sinks. 
http://www.whatman.com/products/?pageID=7.32.42, Accessed March 2005.

  

APPENDIX A: 

Summary of CMA and PHED Data tc \l1 "APPENDIX A: Summary of CMA data and
PHED 

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
28 February, 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 Occupational and Residential
Exposure Branch (OREB) of Health Effect Division (HED), Office of
Pesticides Program (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 a 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:

Exposure Assessment for the use of Diiodomethyl-p-tolylsulfone  on 
Heating, Ventilation, and Air Conditioning Systems

	UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

	WASHINGTON, D.C.  20460

	10/23/2007

						

	MEMORANDUM

	SUBJECT:	Exposure Assessment for the use of Diiodomethyl-p-tolylsulfone
on  Heating, Ventilation, and Air Conditioning Systems 

		From:		Siroos Mostaghimi, Ph.D., Senior Scientist

		Risk Assessment and Science Support Branch (RASSB)

		Antimicrobials Division (7510P)

			To:	Norm Cook, Chief

		Risk Assessment and Science Support Branch (RASSB)

					Antimicrobials Division (7510P) 	 

					  SEQ CHAPTER \h \r 1 Attached please find the exposure assessment
for the use of diiodomethyl-p-tolylsulfone on Heating, Ventilation, and
Air Conditioning (HVAC) Systems. 

 

Introduction 

This report presents an exposure assessment for the use of
Diiodomethyl-p-tolylsulfone as a mildewicide and algicide in coatings
(e.g., fire retardant insulation coatings) a applied to heating,
ventilation, and air conditioning (HVAC) ducts.  Indoor exposure
concentrations are calculated using EPA’s RISK model (V1.9).  

Section 1 of this report identifies the diiodomethyl-p-tolylsulfone use
scenario evaluated in this analysis, including a summary of relevant
diiodomethyl-p-tolylsulfone label information.  Section 2 identifies the
toxicity endpoints relevant to the analysis.  Section 3 presents
post-application exposure simulation using EPA’s RISK model, and
Section 4 presents average daily doses and margins of exposure for
exposed adults and children.  Lmitations and uncertainties are discussed
in Section 5.  Section 6 identifies referenced literature.

1. 	Diiodomethyl-p-tolylsulfone Use Scenarios

Diiodomethyl-p-tolylsulfone is registered for use as a fungicide,
algaecide, bacteriostat, insecticide, and miticide, and is used
primarily as a materials preservative for use sites including, but not
limited to, coatings, paints, metalworking fluids, paper, and textiles. 
The product is also used as a wood preservative and in septic systems,
drains, and pipes.  

This analysis evaluates post-application occupational and residential
exposures for coatings containing diiodomethyl-p-tolylsulfone applied to
HVAC systems.  Table 1 identifies relevant label directions for
diiodomethyl-p-tolylsulfone products.  The label directions provided in
Table 1 indicate that diiodomethyl-p-tolylsulfone may be used as a paint
additive or fire retardant coating.  For this analysis, it is assumed
that diiodomethyl-p-tolylsulfone is applied to HVAC ducts in three
building types: residences, office buildings, and schools.

2. 	Relevant of Toxicity Endpoints 

	Table 2 summarizes toxicity endpoints relevant to the use scenario
evaluated in this analysis.  Because the analysis evaluates inhalation
exposures following application of diiodomethyl-p-tolylsulfone as a
coating in HVAC systems, only inhalation toxicity data are relevant to
this analysis.  A Margin of Exposure (MOE) of 3000 for inhalation (all
exposure terms) is considered protective, and is based a 10x
inter-species extrapolation factor, a 10x intra-species variability
factor, a 10x factor for route-to-route extrapolation and a 3x factor
for using the LOAEL instead of the NOAEL.  

Table 1

Relevant Diiodomethyl-p-tolylsulfone Products and Label Instructions 

Product 

(Reg. No.)	Percent Active Ingredient	Label Directions

AMICAL 48

(EPA Reg. No. 464-670)	95 percent	AMICAL is an effective mildewcide and
algicide for exterior and interior paints, fire-retardant insulation
coating and air duct coatings … Generally AMICAL 48 will impart
protection when used at levels of between 1.6-5 lb product per 100
gallons of paint for severe situations while 1-3 lb AMICAL 48 per 100
gallons of paint are sufficient for less severe conditions …For mildew
control on fire-retardant coating, add AMICAL 48 at 0.0015-0.3%.at point
in production process to ensure sufficient mixing with other dry
ingredients.

AMICAL WP

(EPA Reg. No. 464-672)	48.45 percent	AMICAL WP Antimicrobial Agent is an
effective mildewcide and algicide for exterior and interior latex
paints, solvent-based paints, fire-retardant insulation coating and air
duct coatings … Generally AMICAL WP Antimicrobial Agent will impart
protection when used at levels of between 4.0-10.2 lb AMICAL WP
Antimicrobial Agent per 100 gallons of paint for severe situations while
3.0-6.1 lb AMICAL WP Antimicrobial Agent per 100 gallons of paint are
sufficient for less severe conditions. …For mildew control on
fire-retardant coating, add AMICAL WP Antimicrobial Agent at 0.02-0.61%
at point in production process to ensure sufficient mixing with other
dry ingredients.

AMICAL Flowable

(EPA Reg. No. 464-673)	40 percent	AMICAL Flowable Antimicrobial Agent is
an effective mildewcide and algicide for exterior and interior latex
paints, solvent-based paints, fire-retardant insulation coating and air
duct coatings … Generally AMICAL Flowable Antimicrobial Agent will
impart protection when used at levels of between 4.0-12.5 lb AMICAL
Flowable Antimicrobial Agent per 100 gallons of paint for severe
situations while 2.5-7.5 lb AMICAL Flowable Antimicrobial Agent per 100
gallons of paint are sufficient for less severe conditions. …For
mildew control on fire-retardant coating, add AMICAL Flowable
Antimicrobial Agent at 0.00375-0.75% at point in production process to
ensure sufficient mixing with other dry ingredients.

Intace Fungicide B-6773 (EPA Reg. No. 74075-1)	12.08 percent	Paints,
coatings, adhesives, caulks, sealant applications:  Add Intace Fungicide
B-6773 to the coating solution at levels of 2 gallons/1000 gallons to 20
gallons/1000 gallons.

Ultra-Fresh* 15 (EPA Reg. No. 10466-37)	15 percent	Use in paints: 
Ultra-Fresh* 15 is an effective mildewcide and algaecide for exterior
and interior latex and solvent based paints.  General use in paint
systems use 10.7-26.7 lb Ultra-Fresh* 15 per 100 gallons of paint.

Table 2

Toxicological Endpoints Selected for Post-application Inhalation
Exposure

Following Diiodomethyl-p-tolylsulfone Application in HVAC System Ducts

Exposure Scenario	Dose Used in Risk Assessment (mg/kg/day)	Target MOE
Study and Toxicological Effects

Inhalation                (All Exposure Terms)	Oral LOAEL = 2 mg/kg/day

	

MOE = 3000

(10x for inter-species extrapolation, 10x for intra-species variation,
10x for route-to-route extrapolation, 3x for using LOAEL)

	90-day Oral Toxicity - Dog MRID 42054403 and 43246402 based on
decreased body weight gain, decreased activity, dehydration, mucoid
ocular discharge, weakened appearance, abnormal feces, and degeneration
of the thyroid.

LOAEL = Lowest Observed Adverse Effect Level

MOE = Margin of Exposure

3. 	Post-application Exposure Simulation with AD Version of RISK Model

3.1	Antimicrobial Version of RISK Model

The EPA/OPP/AD version of the RISK (V1.9) model was used to assess the
post-application residential and occupational inhalation exposure
following application of diiodomethyl-p-tolylsulfone in HVAC system and
air ducts.  RISK V1.9 is designed specifically to analyze the impact of
the antimicrobials applied in the HVAC system on indoor air quality (EPA
2006).  The model requires minimal data input.  Specifically, the
following input data are required for the analysis:

Application rate of product (ft2/gal);

Content of active ingredient (ppm);

Vapor pressure of active ingredient (mm Hg);

Molecular mass of active ingredient (g/mole);

Toxicological endpoints.

The input data used in the exposure assessment are summarized in Table
3.

Table 3

Input Data Used in Diiodomethyl-p-tolylsulfone Exposure Assessments with
AD Version of Risk Model

Parameter	Value	Source

Application rate of product	500 and 1,000 ft2/gal	EPA 2007c

Content of active ingredient	6,022 ppm	From label information1

Vapor pressure of active ingredient	8.7E-7 mm Hg	USEPA 2007a

Molecular mass of active ingredient	422.02 g/mole	USEPA 2007b

Toxicity endpoint (inhalation)	2 mg/kg/day (LOAEL)	See Table 2

1 Content of active ingredient = [Maximum label use rate (i.e., 6.7 lb
AMICAL50 per 100 gallons paint)/100gal]*Percent active ingredient (i.e.,
75%) * lb to mg conversion (i.e., 453,592.4 mg/lb) * gal to L conversion
(i.e., 0.264 gal/L) = 6,022 mg/L (ppm)

The RISK model assumes that the carrier for an active ingredient (in
this case the carrier is water) will evaporate rapidly and the emission
is controlled by the remaining active ingredient.  Thus, the emission
rate is related to the vapor pressure of active ingredients.  Details on
the source emission model are provided in the model documentation (EPA
2006).  

The RISK model has three built-in exposure scenarios – residential,
commercial, and school.  All three built-in exposure scenarios are used
in this assessment.  Table 4 provides brief descriptions of these
scenarios.  A more extensive discussion of these scenarios can be found
in the model documentation (EPA 2006).  

In all model scenarios, it is assumed that the HVAC system is turned off
during application.

Table 4

Built-in Exposure Scenarios in the AD Version of the RISK Model1

Parameters	Residential	Commercial	School

Surface area of ducts required to be treated	800 ft2 (74m2)	26,000 ft2
(2,415 m2)	32,275 ft2 (3,000 m2)

Floor area of building	1,300 ft2 (118 m2)	56,700 ft2 (5,267 m2)	55,900
ft2 (196 m2)

Volume of building	12, 900 ft3 (300 m3)	567,000 ft3 (16,055 m3)	564,600
ft3 I16,000m3)

Air circulation rate	1,000 ft3/min (1,715 m3/hr)	54,300 ft3/min (93,167
m3/hr)	 

Air exchange with outside	0	9,345 ft3/min	1.0/hr air exchange rate with
outside air

Air exchange rate	0.3/hr	0.3/hr	0.3/hr (non-infiltration mode)

1 The parameter values shown in this table are built into the AD version
of the RISK model and are not accessible for editing or verification by
the model user.  The information presented in this table was identified
from EPA (2007c).

3.2	Model Predictions

	

The AD version of the RISK model simulates indoor air concentration of
active ingredients for 100 hours after the HVAC system is turned on
immediately following the treatment of HVAC system with
diiodomethyl-p-tolylsulfone.  The model was run for each of the three
available building type scenarios (i.e., residential, commercial office
building, and school).  In addition, each building type was run with two
application rate scenarios:  500 and 1,000 ft2/gal.

Table 5 presents the average and peak indoor air concentrations for each
building scenario and both application rates.  Peak and average
concentrations are shown for the first 24 and 100 hours following
application.  Table 5 also shows the time period in hours
post-application during which the peak concentrations occurred.  Figures
1 and 2 illustrate the indoor air concentration of
diiodomethyl-p-tolylsulfone as a function of time at the application
rates of 500 and 1,000 ft2/gal during the first 24 hours following
application.  With all building scenarios and application rates,
diiodomethyl-p-tolylsulfone slowly rose to and declined from peak
concentrations.  For example, in the residential building scenario with
an application rate of 500 ft2/gal, the peak concentration occurred
between approximately 27 and 35 hours after application.  This pattern
may be attributable to the low vapor pressure (8.7E-7 mm Hg) of
diiodomethyl-p-tolylsulfone. 

Table 5

Predicted Post-Application Air Concentrations of
Diiodomethyl-p-tolylsulfone

Building Scenario	Concentration in First 24 Hours (mg/m3)	Concentration
in First 100 Hours (mg/m3)	Hours After Application of Peak
Concentration1

	Average	Peak	Average	Peak

	Application Rate 500 ft2/gallon

Residence	2.51E-02	4.18E-02	3.16E-02	4.19E-02	27 - 35

Office Building	3.35E-03	4.29E-03	3.71E-03	4.29E-03	8 - 11

School	4.16E-03	5.33E-03	4.61E-03	5.33E-03	8 - 11

Application Rate 1,000 ft2/gallon

Residence	2.51E-02	4.18E-02	3.15E-02	4.18E-02	26 - 29

Office Building	3.35E-03	4.29E-03	3.70E-03	4.29E-03	8 - 10

School	4.16E-03	5.33E-03	4.60E-03	5.33E-03	8 - 11

1 Beginning and ending time periods are rounded to the nearest hour.

4.0	Post-application Exposure to Diiodomethyl-p-tolylsulfone from HVAC
Applications

Average daily doses (ADDs) of diiodomethyl-p-tolylsulfone were
calculated based on the 100-hour average and peak exposure
concentrations predicted by the RISK model (Table 5) and exposure
factors obtained from EPA’s Exposure Factors Handbook (EPA 1997) and
EPA’s previous inhalation exposure assessment for MDF 200 (EPA 2007c).
 The equation used to calculate ADDs is shown below: 

ADD = (EC * IR * ED)/BW

Where:

EC 	= 	Exposure concentration predicted by the RISK model (mg/m3)

IR 	= 	Inhalation rate (m3/hr)

ED 	= 	Exposure duration (hr/day)

BW 	= 	Body weight (kg)

Inhalation rates used in the analysis were 0.5 m3/hr for adults in
residential buildings, 1.0 m3/hr for adults in commercial office
buildings, 0.4 m3/hr for children in residential buildings, and 0.8
m3/hr for children in school.  The exposure durations for the analysis
were 16 hr/day in residential buildings and 8 hr/day in commercial
office buildings or schools.  These inhalation rates and exposure
durations are consistent with EPA’s inhalation exposure assessment for
MDF 200 (EPA 2007c).  The assumed body weights were 70 kg for adults and
15 kg for children (i.e., the approximate mean weight of three year
olds), which are values obtained from EPA’s Exposure Factors Handbook
(EPA 1997).  The ADDs for each building scenario and application rate
are shown in Table 6.  ADDs were not calculated for children in office
buildings or adults in schools.

Table 6

Average Daily Doses of Diiodomethyl-p-tolylsulfone for Inhalation by
Adults and 

Children in Residential, Office, and School Buildings

Building Scenario	Adult	Child

	Average	Peak	Average	Peak

Application Rate 500 ft2/gallon

Residence	3.61E-03	4.78E-03	1.35E-02	1.79E-02

Office Building	4.24E-04	4.91E-04	na	na

School	na	na	1.97E-03	2.28E-03

Application Rate 1,000 ft2/gallon

Residence	3.60E-03	4.77E-03	1.34E-02	1.78E-02

Office Building	4.23E-04	4.90E-04	na	na

School	na	na	1.96E-03	2.27E-03

na = not applicable

Table 7 presents MOEs calculated by dividing the LOAEL for
diiodomethyl-p-tolylsulfone (i.e., 2 mg/kg/day) by the ADDs shown in
Table 7.  MOEs below the target MOE of 3,000 are shown in bold typeface.
 MOEs for both adults and children, with both application rate scenarios
(i.e., 500 and 1,000 ft2/gallon), are below the target MOE.  In
addition, MOEs for children in schools are below the target MOE.  

Table 7

MOEs for Adults and Children Exposed to Diiodomethyl-p-tolylsulfone
Following HVAC 

System Treatment in Residential, Office, and School Buildings

Building Scenario	Adult	Child

	Average	Peak	Average	Peak

Application Rate 500 ft2/gallon

Residence	5.54E+02	4.18E+02	1.48E+02	1.12E+02

Office Building	4.71E+03	4.08E+03	na	na

School	na	na	1.02E+03	8.79E+02

Application Rate 1,000 ft2/gallon

Residence	5.55E+02	4.19E+02	1.49E+02	1.12E+02

Office Building	4.72E+03	4.08E+03	na	na

School	na	na	1.02E+03	8.80E+02

na = not applicable

5.	Uncertainties and Limitations

In all exposure assessments, there are uncertainties about the input
data values used.  In addition the following uncertainties and
limitations should be considered in using the exposure assessment
results from this assessment.

Emission source modeling – The RISK model assumes that the carrier
solvent for active ingredient is evaporated immediately, and that the
emission is from the active ingredient itself as controlled by vapor
pressure.  In reality, due to the fast wind speed inside air ducts,
active ingredients and solvent (water in this case) most likely are
carried into air at the same time and the peak concentration might
arrive at an earlier time than the model predicts.

The default residential scenario is based on EPA’s IAQ research house
in North Carolina.  The house is a typical ranch style three bedroom
house built in 1970s.  This house has a surface area 1,300 ft2 (118 m2)
and a surface area of air ducts of 800 ft2 (74 m2).  The ratio of air
duct area to the house surface area is two times higher than the value
of 27%, which is recommended by a manual published by The California
Energy Commission detailing California energy efficiency standards for
low-rise residential buildings (CEC 2001 and DOE 1997).  Thus, the
exposure assessment might be two times more conservative than an
assessment based on a current house configuration.

 

EPA, 2007a.  “AMICAL Environmental Fate Data Based on Jim Breithaupt
Power Point Presentation,” document provided by Siroos Mostaghimi,
U.S. Environmental Protection Agency, October 4, 2007.

EPA, 2007b. “AMICAL, Chemical Overview,” document provided by Siroos
Mostaghimi, U.S. Environmental Protection Agency, Document dated March
1, 2007.

EPA, 2007c.  “Occupational and Residential Exposure Assessment for
Alkyl dimethyl benzyl ammonium chloride (ADBAC), MDF-200 (Part B),”
memorandum to Marshall Swindell, U.S. Environmental Protection Agency,
from Siroos Mostaghimi, U.S. Environmental Protection Agency, January
29, 2007.

EPA.  2006.  Antimicrobial Version Documentation (RISK).  Version 1.9. 
Developed by Dr. Les Sparks of USEPA/NRMRL/ APPCD. Documentation of the
model is available at:   HYPERLINK
"http://www.epa.gov/appcdwww/iemb/risk.htm" 
http://www.epa.gov/appcdwww/iemb/risk.htm 

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

File:  C:\MyFiles\2007 reports\Amical\Risk Modeling\ Exposure Assessment
for the use of Amical on HVAC systems.

	CC: RASSB Chemical Files

	        Siroos Mostaghimi, RASSB



APPENDIX C:

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 Operatorsa

	

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μg/m3)	Potential exposured (mg/day)	Potential exposure (mg/day)	Air
Concentrationb,c (μg/m3)	Potential exposured (mg/day)	Potential
exposure (mg/day)	Air Concentrationb,c (μg/m3)	Potential exposured
(mg/day)	Potential exposure (mg/day)	Air Concentrationb,c (μg/m3)
Potential exposured (mg/day)	Potential exposure (mg/day)	Air
Concentrationb,c (μg/m3)	Potential exposured (mg/day)

1	3.5	10.4	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	10.4	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 study that values were obtained from for
this table (Bestari et al., 1999, MRID 455243-04).

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 μg/m3 using the
following equation: air concentration (μg/m3) = 5.6 (g/ [average flow
rate (L/min) * sampling duration (480 min) * 1000 L/m3.  Data was
obtained from Bestari et al (1999). Average flow rate of air was
collected from where that particular volunteer was.

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

Table C-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 Exposureb (mg)	Hand Exposureb (mg)	Total Dermal
Exposure (mg)	Normalized Total Dermal Unit Exposurec

(mg/ 1 % solution)	Air Conc.d (mg/m3)	Inhalation Exposuree (mg)
Normalized Inhalation Unit Exposurec

(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	0.04f	1.34	1.38	3.29	0.003	0.024	0.057

M8P4B	8	480	0.42	Rubber	0.04f	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 study that values were obtained from for
this table (Bestari et al., 1999, MRID 455243-04).

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

c.	Normalization of DDAC data for percent ai treatment.  Normalized Unit
Exposure (mg/1% ai solution) = Exposure (mg DDAC) / concentration in
diptank solution (% DDAC)

d.	All inhalation residues were <LOD (5.6 μg or 0.0056 mg/m3). 1/2 LOD
was used in all calculations (0.003 mg/m3). Air Concentration (mg/m3) =
5.6 μg / (~2 L/min flow rate x ~480 min) x 1000 L/m3 conversion x 0.001
μg/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 μg/cm2 = LOD of 0.079 mg.  ½ LOD reported (i.e.
0.04 mg)

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