Document ID: EPA-HQ-OPP-2007-0513-0008
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-05-07T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, DC 20460

			OFFICE OF  PREVENTION, PESTICIDES,  AND TOXIC SUBSTANCES

 						

DRAFT

Triclosan

Occupational and Residential Exposure Assessment

Office of Pesticide Programs

Antimicrobials Division

U.S. Environmental Protection Agency

Date: April 17, 2008

TABLE OF CONTENTS 

  TOC \o "1-3" \h \z \u    HYPERLINK \l "_Toc125183615"  EXECUTIVE
SUMMARY	  PAGEREF _Toc125183615 \h  3  

  HYPERLINK \l "_Toc125183616"  1.0	 INTRODUCTION	  PAGEREF
_Toc125183616 \h  6  

  HYPERLINK \l "_Toc125183617"  1.1	Purpose	  PAGEREF _Toc125183617 \h 
6  

  HYPERLINK \l "_Toc125183618"  1.2	Criteria for Conducting Exposure
Assessments	  PAGEREF _Toc125183618 \h  6  

  HYPERLINK \l "_Toc125183619"  1.3	Chemical Identification	  PAGEREF
_Toc125183619 \h  8  

  HYPERLINK \l "_Toc125183620"  1.4	Physical/Chemical Properties	 
PAGEREF _Toc125183620 \h  8  

  HYPERLINK \l "_Toc125183621"  2.0	 USE INFORMATION	  PAGEREF
_Toc125183621 \h  8  

  HYPERLINK \l "_Toc125183622"  2.1	 Formulation Types and Percent
Active Ingredient	  PAGEREF _Toc125183622 \h  8  

  HYPERLINK \l "_Toc125183623"  2.2	 Summary of Use Pattern and
Formulations	  PAGEREF _Toc125183623 \h  9  

  HYPERLINK \l "_Toc125183624"  3.0	SUMMARY OF TOXICITY DATA	  PAGEREF
_Toc125183624 \h  9  

  HYPERLINK \l "_Toc125183625"  3.1	Acute Toxicity	  PAGEREF
_Toc125183625 \h  9  

  HYPERLINK \l "_Toc125183626"  3.2	Summary of Toxicity Endpoints	 
PAGEREF _Toc125183626 \h  10  

  HYPERLINK \l "_Toc125183627"  3.3	FQPA Considerations	  PAGEREF
_Toc125183627 \h  12  

  HYPERLINK \l "_Toc125183628"  4.0	RESIDENTIAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc125183628 \h  12  

  HYPERLINK \l "_Toc125183629"  4.1	Summary of Registered Uses	  PAGEREF
_Toc125183629 \h  12  

  HYPERLINK \l "_Toc125183630"  4.2	Residential Exposure	  PAGEREF
_Toc125183630 \h  12  

  HYPERLINK \l "_Toc125183631"  4.2.1	Residential Handler Exposures	 
PAGEREF _Toc125183631 \h  13  

  HYPERLINK \l "_Toc125183632"  4.2.2	Residential Post-application
Exposures	  PAGEREF _Toc125183632 \h  15  

	4.2.2.1
Textiles………………………………….……………………
..…………………………...… 15

	4.2.2.2	Plastic
(Toys)………...……….………….…………………………
………………………... 19

4.2.3	Data
Limitations/Uncertainties………………………………………
……………………….20

  HYPERLINK \l "_Toc125183633"  5.0	RESIDENTIAL AGGREGATE RISK
ASSESSMENT AND CHARACTERIZATION 	  PAGEREF _Toc125183633 \h  21  

  HYPERLINK \l "_Toc125183634"  6.0	OCCUPATIONAL EXPOSURE ASSESSMENT	 
PAGEREF _Toc125183634 \h  21  

  HYPERLINK \l "_Toc125183635"  6.1 	Occupational Handler Exposures	 
PAGEREF _Toc125183635 \h  22  

  HYPERLINK \l "_Toc125183636"  6.2  	Occupational Post-application
Exposures	  PAGEREF _Toc125183636 \h  25  

  HYPERLINK \l "_Toc125183642"  6.3	Data Limitations/Uncertainties	 
PAGEREF _Toc125183642 \h  25  

  HYPERLINK \l "_Toc125183643"  7.0	REFERENCES	  PAGEREF _Toc125183643
\h  25  

 EXECUTIVE SUMMARY 

	This document is the Occupational and Residential Exposure Chapter of
the Reregistration Eligibility Decision (RED) document for triclosan. It
addresses the potential risks to humans that result from the use in
occupational and residential settings.  Although individual
EPA-regulated uses have been assessed using standard Agency methodology
within this chapter, the National Health and Nutrition Surveys (NHANES)
biological monitoring data are available for assessing aggregate
exposure and risk. Therefore, although this human exposure chapter for
the triclosan RED characterizes exposures from individual EPA-regulated
uses, EPA views the NHANES data as more representative of aggregate
exposures to determine probability of co-occurrence of EPA and
FDA-regulated uses.

	Triclosan is used as a bacteriostat, fungistat, mildewstat, and
deodorizer. The EPA registered products containing triclosan as the
active ingredient (ai) are formulated as ready-to-use,
pelleted/tableted, emulsifiable concentrate, soluble concentrate, and
impregnated materials. Concentrations of triclosan in these products
range widely from 0.69% to 99%.  The EPA registered products are used in
commercial/ institutional/industrial, residential and public access, and
material preservatives.  The residential use includes a direct
application to HVAC coils (limited to commercial applicators). 
Additionally, triclosan is registered to be used as a material
preservative in such products as paints (in-can preservative), polymers
and plastics (e.g., toys, tooth brushes, etc), and textiles (e.g.,
footwear, clothing, etc).  There are many other FDA uses (e.g., hand
soaps, toothpaste) that are not under EPA’s regulatory jurisdiction
but for which reliable exposure data are available (U.S. Food and Drug
Administration, OTC docket 81N-033P, Vol. 41).   These exposures have
been considered in the aggregate risk assessment within the risk
assessment chapter for triclosan.  However, the FDA uses are not
assessed in this chapter.  

14-day dermal toxicity in mice.  Irritation was observed at 0.6
mg/kg/day equivalent to 100 μg/cm2.  The dermal study was based on a
99% ai formulation.  The residential uses of triclosan are the result of
diluted formulations.  Therefore, the short-term dermal irritation
observed for the 99% ai formulation was not appropriate for the dermal
risk assessment.  The intermediate-term dermal endpoint was determined
from the 90-day dermal rat study.  The route-specific dermal NOAEL from
this study is 40 mg/kg/day.  Because the toxicological endpoints
selected for inhalation, dermal, and oral routes of exposure are not
female-specific, a body weight of 70 kilograms is used in the
assessment.  EPA’s level of concern (LOC) for occupational and
residential triclosan dermal and oral routes of exposures is 100 (i.e.,
a margin of exposure (MOE) less than 100 exceeds the level of concern).
The level of concern is based on 10x for interspecies extrapolation and
10x for intraspecies variation.  The LOC for the inhalation route of
exposure is 1000 based on10x for interspecies extrapolation, 10x for
intraspecies variation, and a 10x for the use of a LOAEL.

 	This occupational and residential assessment was based on examination
of product labels describing their uses.  It has been determined that
exposure to residential handlers is restricted to the registered end use
product that is for paint containing triclosan as an in-can
preservative.  Occupational handlers may be exposed in the manufacturing
of other products (e.g., plastics, textiles) and during commercial HVAC
coil applications and commercial painters.  Additionally,
post-application exposures are likely to occur in residential settings
from contacting treated articles such as clothing and plastic toys.  The
representative scenarios selected by EPA for assessment were evaluated
using maximum application rates as stated on the product labels.  The
representative scenarios are believed to represent high-end uses
resulting in dermal, inhalation, and incidental oral exposures.

To assess the handler risks, EPA used surrogate unit exposure data from
the Chemical Manufacturers Association (CMA) antimicrobial exposure
study and the Pesticide Handlers Exposure Database (PHED).  Post
application/bystander exposures were assessed using EPA’s standard
assumptions (e.g., Health Effects Division’s (HED) Standard Operating
Procedures (SOPs) for Residential Exposure Assessment).  

Residential Handler Risk Summary

Dermal

	The residential handler dermal exposure scenarios are best represented
by the short-term duration (i.e., painting is intermittent in nature). 
The short-term dermal duration toxicological endpoint is based on dermal
irritation observed during the dosing of mice with a 99% ai product. 
The in-can paint preservation (1 % ai) is not considered to be as
irritating as the more concentrated test substance.  Therefore, the
residential handler assessment does not include the dermal pathway.  The
short-term dermal exposures are believed to exhibit minimal skin
irritation risk.  

Inhalation

		For the residential handler inhalation assessment, the inhalation
risks were calculated by comparing the daily inhalation dose to the
short-term inhalation endpoint.  The inhalation MOEs were above the
target MOE of 1000 for the paint brush scenario but below the target MOE
for the airless sprayer, and therefore, is of concern.  

Residential Post Application/Bystander Risk Summary

Dermal & Oral

	The residential post-application intermediate-term dermal and short-
and intermediate-term incidental oral risks were assessed for children
and/or adults coming in contact with treated clothing and plastic toys. 
The treated clothing was used to represent exposure to triclosan-treated
mattresses.  No risks were identified for these uses.  The MOEs were
equal to or greater then the target MOEs.  

Inhalation 

	Based on the low vapor pressure of triclosan and the lack of aerosol
generation over time by the application methods, inhalation exposure is
expected to be minimal. 

Occupational Handler Risk Summary

Dermal

The short-term dermal irritation exposures and risks were not estimated
for occupational handler exposures.  Instead, dermal irritation
exposures and risks will be mitigated using default personal protective
equipment requirements based on the toxicity of the end-use product.  

For the intermediate-term dermal risks, the MOE were above the target
MOE of 100, and therefore, not of concern except for commercial painters
and material preservative use for paper.  The intermediate-term MOEs for
using a paint brush/roller and an airless sprayer are 31 and 1,
respectively.  Because triclosan is used as a material preservative in
the paint, the use of chemical resistant gloves on the label is
impractical. 

Inhalation

	For the occupational handler inhalation exposure and risk assessment,
the MOEs were below the target MOE of 1000 for all scenarios except for
the brush application for paints.  The inhalation MOE for commercial use
of an airless sprayer for paints is 54, for liquid pour and liquid pump
during paint manufacturing 330 and 290, respectively, and for pulp and
paper the metering pump is 28.

Occupational Post Application/Bystander Risk Summary

	Based on the low vapor pressure of triclosan and the lack of aerosol
generation over time by the application methods, inhalation
post-application exposure are expected to be minimal.

Data Limitations and Uncertainties:

	There are a number of uncertainties associated with this assessment and
these have been reiterated from Sections 4.2.3 (residential) and 6.4
(occupational).  The major data limitations and uncertainties associated
with the 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,
EPA 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).  In certain
cases, no standard values were available for some scenarios. 
Assumptions for these scenarios were based on EPA estimates and could be
further refined from input from registrants. 

1.0	 INTRODUCTION tc \l1 "1.0	 INTRODUCTION 

		1.1	Purpose  tc \l2 "1.1	Purpose  

		In this document, EPA’s Antimicrobials Division (AD) presents the
results of its review of the potential human health effects of
occupational and residential exposure to triclosan (5-chloro-2-(2,4
dichlorophenoxy) phenol). This information is for use in EPA's
development of the triclosan Reregistration Eligibility Decision (RED)
document. 

		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 triclosan, both criteria are met.
Toxicological endpoints were selected for short- and intermediate-term
dermal, inhalation, and incidental oral exposures to triclosan.  There
is the potential for exposure in a variety of occupational and
residential settings.  Therefore, risk assessments are required for
occupational and residential handlers as well as for occupational and
residential post application exposures that can occur as a result of
triclosan use.

In this document, handler 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 (1 mg = 1,000 µg) of
active ingredient per pounds of active ingredient handled.  A series of
unit exposures have been developed that are unique for each scenario
typically considered in assessments (i.e., there are different unit
exposures for different types of application equipment, job functions,
and levels of protection).  The unit exposure concept has been
established in the scientific literature and also through various
exposure monitoring guidelines published by the USEPA and international
organizations such as Health Canada and OECD (Organization for Economic
Cooperation and Development).  

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

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

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

Where:  

E	=	Amount (mg ai/day) that is available for inhalation and dermal
exposure;

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/sq ft, lb ai/gal, lb ai/cu ft);
and

AT 	=	Normalized application area based on a logical unit treatment such
as square feet  (sq ft/day), gallons (gal/day), or pounds of
articles/products to be treated for material preservatives.

Daily Dose: The inhalation dose is calculated by normalizing the daily
exposure by body weight and adjusting, if necessary (not needed for
triclosan because of the availability of a dermal route-specific study),
with an appropriate dermal absorption factor.  An absorption factor of
100% was used for inhalation exposures because there are no data
available to refine this variable.  Daily dose was calculated using the
following formula:

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

			   BW						

Where:

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

E 		=	Amount (mg ai/day) that is available for inhalation or dermal
exposure;

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 risks for each applicable
handler scenario are calculated using a Margin of Exposure (MOE).  This
is the ratio of the daily inhalation dose or dermal 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	= 	Systemic toxicity level where no observed adverse
effects (NOAEL) or where the lowest observed adverse effects (LOAEL)
occurred in the study (mg ai/kg body weight/day); and

ADD 			= 	Average daily inhalation or dermal dose in a given scenario
(mg ai/kg body weight/day).

	In addition to the target MOEs presented in 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:

Triclosan products are widely used and have a large number of use
patterns that are difficult to completely capture in this document.  As
such, EPA has patterned this risk assessment on a series of likely
representative scenarios for each use site that are believed by EPA to
represent the vast majority of triclosan uses.

Based on the adverse effects for the endpoints, the body weight of 70 kg
is used for the dermal and oral routes of exposure.  

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. 	

Chemical Identification

		

		Triclosan (5-Chloro-2-(2,4-dichlorophenoxy)phenol) was first
registered with the EPA on June 19, 1969.  Triclosan is a diphenyl ether
derivative.  The CAS number is 3380-34-5 and the molecular structure is
provided in Figure 1.

  HYPERLINK "http://en.wikipedia.org/wiki/Image:Triclosan.png" \o
"Triclosan"    INCLUDEPICTURE
"http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Triclosan.png/
200px-Triclosan.png" \* MERGEFORMATINET   

 				Figure 1.  Molecular Structure of Triclosan

			

	

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

		Table 1.2 shows physical/chemical characteristics that have been
reported for triclosan.

Table 1.2.  Physical/Chemical Properties of Triclosan

Parameter	

Triclosan

Molecular Weight	290

Density	1.55E3 kg/m3 at 22 ˚C

Boiling Point	Solid

Water Solubility	12 ppm

Vapor Pressure	5.2E-6 mm Hg at 25 ˚C 

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 

≥99%.  

		2.2	 Summary of Use Pattern and Formulations

	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.  Based on a review of product
labels, triclosan is the active ingredient in products used in the
following Use Site Categories: 

(III)   SEQ CHAPTER \h \r 1 Commercial, institutional and industrial
premises and equipment, 

(IV)   SEQ CHAPTER \h \r 1 Residential and public access premises, and 

(VII)   SEQ CHAPTER \h \r 1 Material preservatives, 

	Specific uses within these use categories are identified in Table 2.1. 
Examples of EPA registered uses for triclosan include application to
textiles, plastics, paints, etc.  FDA uses of triclosan such as in hand
soaps and toothpaste are out of the scope of this chapter but are used
in the aggregate risk assessment.  From Table 2.1, EPA has selected
representative exposure scenarios to assess triclosan 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,
inhalation, or incidental ingestion exposure.  The representative
scenarios assessed in this document are shown in Table 4.1 (residential)
and Table 6.1 (occupational).

Table 2.1. Potential Use Scenarios Based on Product Labels for
Triclosan.

Use Site Category	

Example Use Sites	

Scenarios

Use Site Category 

III	

Commercial/ Institutional/Industrial	

Conveyor belts, fire hoses, dye bath vats, ice making equipment, HVAC
coils	

Application to HVAC coils

Painting (commercial painters)

Use Site Category IV

Residential and Public Access Premises	 

Used as an end-use product in carpet shampoos (also used in treated
articles)	

Painting

Exposure to treated articles (e.g., clothing, mattress, plastic toys)

Use Site Category VII

Material Preservatives	

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

adhesives

paints (latex)

textiles (cotton, wool, nylon, rayon, linen, fiber filling, mattress
ticking)

polymers and plastics

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 

The acute toxicity data for triclosan are summarized below in Table 3.1
(USEPA, 2007).

Table 3.1.  Acute Toxicity Profile for Triclosan

Guideline Number	Study Type/

Test substance (% a.i.)	MRID Number/

Citation	Results	Toxicity Category

870.1100

(§81-1)	Acute Oral- Rat Triclosan (99.7% a.i.)	43206501	LD50: >5000
mg/kg	IV

870.1200

(§81-2)	Acute Dermal- Rabbit

Triclosan (97% a.i.)	42306902

Phase III summary 92084037	LD50: >9300 mg/kg	IV

870.1300

(§81-3)	Acute Inhalation- Rat

Triclosan (100.5% a.i.)	42306902, 43310501	LC50: >0.15 mg/L	II

870.2400

(§81-4)	Primary Eye Irritation- Rabbit

Triclosan (97% a.i.)	 Phase III summary 92084040	 PIS: 92/110 (24
hours), 82/110 (72 hours)	II

870.2500

(§81-5)	Primary Dermal Irritation- Rabbit

Triclosan (% a.i.not provided)	42306903	PII: 3.5 at 72 hours 	III

870.2600

(§81-6)	Dermal Sensitization- Guinea Pig          Triclosan (99.7%
a.i.)	43206502	Not a Sensitizer	NA

	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 Triclosan (USEPA,
2007).  

Table 3.2.  Summary of Toxicological Dose and Endpoint Selection for
Triclosan.

Exposure

Scenario	Dose Used in Risk Assessment, UF 	Special FQPA SF* and Level of
Concern for Risk Assessment	Study and Toxicological Effects

Acute Dietary

(gen. pop.)	NOAEL = 30 mg/kg

UF = 100	FQPA SF = 1x	Chronic Toxicity study in Baboons

MRID 257773.  Effects of clinical signs of toxicity include vomiting,
failure to eat, and diarrhea.

Acute Dietary

(females 13+)	Endpoint not identified in the database

Chronic Dietary

(all populations)	NOAEL = 30 mg/kg

UF = 100	FQPA SF = 1x	Chronic Toxicity study in Baboons

MRID 257773.  Effects of clinical signs of toxicity include vomiting,
failure to eat, and diarrhea.

Short-Term/ Intermediate-Term Incidental Oral (1-30 days; 30 days- 6
months)	NOAEL = 30 mg/kg

UF = 100	FQPA SF = 1x	Chronic Toxicity study in Baboons

MRID 257773

Effects of clinical signs of toxicity include vomiting, failure to eat,
and diarrhea.

Dermal 

(short-term)	NOAEL = 0.6 mg/animal @ 99.3% active ingredient (100
µg/cm2)

UF = 10x	FQPA SF = 1x	14-day dermal toxicity study in the mouse 

MRID 44389708  

LOAEL = 1.5 mg/kg/day, based on treatment-related dermal irritation at
the treatment site and on increased liver weights

Dermal (intermediate term)	NOAEL = 40 mg/kg

UF = 100

	FQPA SF = 1x	90-day dermal toxicity study in rats. MRID 43328001. 
LOAEL = 80 mg/kg/day, based on increased incidence occult blood in the
urine.

Dermal (long-term)	NOAEL = 40 mg/kg

UF = 300

	FQPA SF = 1x	90-day dermal toxicity study in rats. MRID 43328001. 
LOAEL = 80 mg/kg/day, based on increased incidence occult blood in the
urine.

Inhalation (all durations)	LOAEL = 50 mg/m3 or 3.21 mg/kg/day

UF = 1000

Where mg/kg/day = ((0.0087 m3/hr * mg/m3 * 2 hr/day) /0.271 b.w.  	FQPA
SF = 1x	21-Day Inhalation Toxicity study in the rat.  MRID 0087996. 
Effects seen in males at LOAEL include increased total leucocyte count
and increased serum alkaline phosphatase.

Cancer (oral)	Not likely to be carcinogenic to humans (Health Effects
Division Carcinogencity Assessment Review Committee, July 2007). 

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

	3.3	FQPA Considerations 

	The hazard-based FQPA factor should be removed because the toxicology
data provided no indication of increased susceptibility of rats or
rabbits to in utero and/or postnatal exposure to triclosan and there is
no evidence of developmental anomalies, including abnormalities in the
development of the fetal nervous system, in the pre- and/or post-natal
studies.  Additionally, there are no data gaps for evaluation of
increased susceptibility to infants and children.  

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 

	There are no EPA registered products containing triclosan that can be
applied directly by the homeowner.  There is a homeowner application of
triclosan when it is used as an in-can preservative for latex paint
(e.g., EPA Reg. No. 42182-1).  Articles treated with triclosan as a
bacteriostat in occupational settings (e.g., EPA Reg. No. 70404-5) may
also have the potential for post-application residential exposure. 
Triclosan-treated articles that may routinely be used in the residential
market include, but are not limited to, material preservative uses in
mattresses, clothing, tooth brush bristles, plastic toys, garbage bags,
paper, playground equipment, sponges, furniture, footwear, etc. 
Additionally, triclosan can be used to control/prevent/inhibit the
growth of fungi/mildew/mold/bacteria on coils in residential heating,
ventilating, and air conditioning (HVAC) systems (e.g., EPA Reg. No.
82523-1).  HVAC coil applications of triclosan are restricted to service
contractors only.  There are no homeowner applications to HVAC coils.

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

	The exposure scenarios assessed in this document for the representative
uses of triclosan selected by EPA are listed 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(s).  It should be noted that for the calculation of
application rates in which 8.34 lb/gal is noted, the product is assumed
to have the density of water because no product-specific density is
available. Handler dermal and inhalation exposures are assessed for the
carpet shampoo and for the in-can preservative use in paint. 
Post-application dermal, inhalation, and/or incidental ingestion
exposures are assessed for treated articles including mattresses and
clothing.  Post-application/bystander inhalation exposures are expected
to be minimal for most uses because of the low vapor pressure and non
spray uses, except for the painting and HVAC coil uses.  The inhalation
bystander exposure to aerosols generated during painting are assumed to
be less then that of the applicator and are therefore not assessed
separately.  The HVAC coil applications are not expected to result in
post-application inhalation exposures because of the low vapor pressure
of triclosan and the HVAC treatment is limited to coils, not duct work. 





Table 4.1. Representative Uses Associated with Residential Exposure to
Triclosan.

Representative Use	Application Method	Exposure Scenario	Example
Registration Number	Application Rate

Paint (Latex)	Brush and airless sprayer	ST Handler:  adult dermal and
inhalation.	42182-1	0.1 lb ai/gallon

[up to 1% product x 99% ai x 10 lb/gal paint density = 0.099 lb
ai/gallon of paint]

Textiles 

(exposures to treated  articles are represented by exposure to mattress
and clothing)	NAa	ST Post-app: wearing treated clothing, adult dermal;
child incidental ingestion and dermal 	70404-5	Round to 2% ai in
finished textiles and mattresses.

(Rates range up to the finished product containing  2%  formulated
product by weight.  Triclosan product contains 99% ai. ) 

Plastic 

(exposures to plastic treated articles are represented by plastic toys)
NAa	ST Post-app: child incidental ingestion and dermal	42182-1	0.5% ai

(0.1% to 0.5% product x 99% ai)

Note: labels need to clarify that toys are limited to 0.5% 

(a ) The handlers scenarios were not assessed because the products can
only be applied occupationally.

		4.2.1	Residential Handler Exposures

	The residential handler scenarios described in Table 4.1 were assessed
to determine inhalation exposures.  Dermal exposures for the short-term
duration were not assessed because no systemic dermal toxicity was
observed.  Dermal irritation was observed in the toxicity study but for
the 99% ai test substance.  Residential uses are at or below 1% ai or
are impregnated into finished products.  The scenarios were assessed
using PHED and CMA data and the equations in Section 1.2, “Criteria
for Conducting Risk Assessment.”  A summary of the PHED and CMA data
sets are presented in Appendix A.

Unit Exposure Values: Unit exposure values were taken from the PHED data
presented in HED’s Residential SOPs (USEPA, 1997) and from the CMA
data from the EPA memorandum Evaluation of Chemical Manufacturers
Association Antimicrobial Exposure Assessment Study (USEPA, 1999).

    

For the airless sprayer scenario, the PHED inhalation unit exposure
value for a residential handler applying a pesticide using an airless
sprayer was used.  The unit exposure value (0.83 mg/lb ai) represents a
handler using an airless sprayer to stain the exterior of a house. 

For the brush/roller scenario, the PHED inhalation unit exposure value
for a residential handler is based on applying a fungicide in paint to
bathroom walls using a paint brush.  The unit exposure value is 0.28
mg/lb ai.

Quantity handled/treated: The quantities handled/treated were estimated
based on information from various sources, including EPA estimates. 

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 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).

Duration of Exposure: The duration of exposure for most handler
homeowner uses 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 painting is episodic in nature, not daily.  In
addition, homeowners are assumed to use different products with varying
activities, not exclusively triclosan treated products (e.g., in-can
paint preservative).

Results

	The resulting short-term inhalation exposures and MOEs for the
representative residential handler scenarios are presented in Table 4.2.
 The short-term dermal endpoint is based on dermal irritation effects
when a 99 percent active ingredient was applied for 14-days to a mouse.
Because the products applied by homeowners are equal to or less then 1
percent, a short-term dermal assessment was not deemed appropriate
(i.e., even at the exaggerated concentration in the toxicity study the
MOEs would not be of concern).  The calculated inhalation MOEs are above
the target MOE of 1000 for the paint brush but below the target MOE for
the airless sprayer (i.e., MOE = 180).  Therefore, the risk exceeds
EPA’s level of concern for painting.  Personal protective equipment
(PPE) such as respirators is not a viable option for residential uses.  

Table 4.2 Triclosan Short-Term Residential Handler Inhalation Exposures
and MOEs

Exposure Scenario

Application Method	Application Method	Application Ratea	Quantity
Handled/ Treated per dayb	

Unit Exposure

(mg/lb a.i.)	Daily Dose (mg/kg/day) c	MOE d 

(Target MOE = 1000)

Painting	Paint brush	0.1 lb ai/gal	2 gallons	0.28	0.0008	4,000

	Airless sprayer

15 gallons	0.83	0.018	180

a	Application rates are the maximum application rates determined from
EPA registered labels for triclosan.

b	Amount handled per day values are estimates or label instructions.	

c	Daily dose (mg/kg/day) = [unit exposure (mg/lb a.i.) x application
rate (% a.i. weight or lb ai/gal) x quantity treated (lb/day or gal/day)
x absorption factor (1.0 for inhalation)]/ Body weight (70 kg for
inhalation).

d	MOE = LOAEL / Daily Dose.  [Where short-term inhalation LOAEL = 50
mg/m3 or a dose of 3.21 mg/kg/day]. Target MOE = 1000.

	

 		4.2.2	Residential Post-application Exposures tc \l3 "4.4.2
Postapplication Exposure 

 	For the purposes of this screening-level assessment, post-application
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 post-application
scenarios assessed include wearing treated clothing (dermal
intermediate-term exposure to adults and children and incidental oral
exposure to children) and children playing with treated plastic toys
(incidental oral exposure).  The short-term dermal duration was not
assessed because no systemic toxicity was observed.  However, systemic
toxicity was observed for the intermediate-term oral endpoint and this
endpoint was selected to assess the dermal route of exposure.

	4.2.2.1		Textiles

Dermal Exposure to Adults and Toddlers from Contacting Treated Clothing

	There is the potential for dermal exposure to adults and children from
wearing clothing treated via factory impregnation of the chemical as a
preservative.  A post-application assessment assuming no laundering was
conducted as a conservative measure (i.e., the effect on dislodgeable
residues over time during washing is not quantifiable).  It should be
noted that not all articles of clothing are treated with triclosan
products or worn on a continuous basis.  In general, it is believed that
most treated textiles used in a residential setting will result in
exposures occurring over a short-term time duration (1 to 30 days)
because residents are assumed to be exposed to treated textiles with
varying active ingredients, not exclusively triclosan treated textiles. 
However, both the short- and intermediate-term exposure durations are
assessed for the clothing scenarios as this scenario is being used to
represent all textile uses that may occur over time (e.g., pillow cases,
mattresses, footwear, etc) where daily exposure may occur.  Long-term
duration was not assessed because dislodgeable triclosan residues are
not expected to be available continuously.

Exposure Calculations

Potential doses are calculated as follows:

PDD = W x % applied x % a.i. x % transfer

		           BW						

where: 

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

W 		= 	weight of clothing worn (g/day);

% applied	= 	percent of product applied (%);

% a.i.		= 	percent active ingredient in product (%); 

% transfer	= 	percent transferred (%); and 

BW		=	body weight (kg).

And

W = (SW/SSA) * BSA									

where:

W	=	weight of clothing worn (g/day);

SW 	=	weight of medium shirt (g);

SSA 	= 	surface area of medium shirt (cm2); and

BSA	=	surface area of body covered (cm2).

Assumptions

The product is applied at rates as high as 2% of weight of textile; the
highest application rate of 2% product corresponds with the highest
percent triclosan formulation (i.e., 99 percent active ingredient, EPA
Reg. No. 70404-5).

The median surface area of clothing contacting skin for a 3-year-old
toddler is 5,670 cm2 (total body surface area minus the head) (USEPA,
1997).  For adults, the median surface area is 16,900 cm2 (total body
surface area minus the head) (USEPA, 1997).  Note:  The Phase I comments
suggested that triclosan in textiles is primarily limited to sports
wear.  However, no refinements to the assessment have been made to
represent short pants and short-sleeved shirts because it is not a label
restriction and some sports wear may be long pants and long-sleeved
shirts (e.g., sweat pants and sweat shirts).

The textile density is 10 mg/cm2 based on the density of mixed cotton
and synthetics (HERA 2003).  It is assumed that the mixed
cotton/synthetic is used to cover the body for both adults and toddlers,
minus the head surface area.  Therefore, the total amount of fabric worn
per day is equal to the density of the fabric (10 mg or 0.01 grams per
cm2) times the surface area covered (5,670 cm2 for toddlers, 16,900 cm2
for adults), or 56.7 g/day for toddlers, and 169 g/day for adults. 
Note:  Phase I comments suggested that the surface area should be
adjusted for inside surface area of clothing contacting skin (i.e., 50%
adjustment).  However, adjustments were not made to the assessment
because the transfer of triclosan residues may come from both dermal
contact with the suggested inside surface of clothing as well as
sweat-soaked clothing which would appear to include the full fabric. 
Adjustments were also suggested for the fact that clothing is only worn
12 hours per day and triclosan represents less than 100% market share. 
These adjustments were not made for this screening-level single textile
use because insufficient information on residue transfer to a person’s
skin over time is not available and risks are determined for those
individuals wearing the treated clothing articles (i.e., not a
population adjusted risk assessment).  However, the aggregate assessment
using the NHANES biological monitoring data for triclosan is based on
real world exposures and is believed to be the best data available to
regulate the uses.  The aggregate assessment is presented in the
triclosan risk assessment chapter supporting the triclosan RED document.

Potential doses were calculated using residue transfer factor of 0.55%
from a leaching study developed by Sanitized, Inc, dated December 4,
2007.  The leaching study provided results for cotton (0.55% leached),
wool (0.06% leached), and two poly-based fabrics (0.00% for PA and 0.34%
for PES).  The cotton fabric leached the highest amount over a 48 hour
period at 20 degrees C.  The study used an acidic sweat solution at a pH
of 5.5 and the ISO 105/E04 method to extract the triclosan from the
various treated fabrics.

Toddlers (3 years old) are assumed to weigh 15 kg. This is the mean of
the median values for male and female toddlers (USEPA, 1997).  For
adults, a body weight of 70 kg has been assumed. (USEPA, 1997).  

Results

	The calculations of the intermediate-term dermal doses and MOEs for
adults and toddlers wearing treated clothing are shown in Table 4.5. 
The dermal MOEs for adults and toddlers are equal to or above the target
MOE of 100. 

	At this point in time, triclosan-treated mattresses are not assessed
separately but are not of concern as they are treated at the same
concentration as the textiles/clothing.

Table 4.5:  Dermal Intermediate-term Post-application Exposures and MOEs
for Toddlers and Adults Contacting Treated Clothing

Exposure Scenario	Weight of clothing worn (g/day)a	Percent triclosan in
product (%)	Percent of product applied (%)	Percent residue transferred
from clothing to skin (%)	Daily doseb  

(mg a.i./ kg/day)	Dermal MOEc (Target MOE=100)

Toddler	56.7	99%	2%	0.55 %	0.41	98

Adult	169	99%	2%	0.55%	0.26	150

a.	Weight of clothing worn (g/day) = (Density of fabric 0.01 g/cm2) *
(surface area of body covered, cm2) * 1 outfit/day

b.	Daily Dose (mg/kg/day) = [(weight of clothing worn, g/day) * (percent
a.i. in product, %) / 100 * (percent of product applied, %) / 100 *
(percent residue transferred from clothing to skin, %/100) * (dermal
absorption factor, 1) * (conversion factor, 1000 mg/g)] / (body weight,
15 and 70 kg).

c. 	Dermal MOE = NOAEL (mg/kg/day) / Daily Dose [Where intermediate-term
dermal NOAEL = 40 mg/kg/day].  Target MOE = 100.

Incidental Oral Exposure to Toddlers Mouthing Treated Textiles
(Clothing/Blankets)

Exposure Calculations 

	There is the potential for incidental oral exposure to toddlers from
mouthing textiles treated with triclosan.

Potential doses are calculated as follows:

PDD = C x SE x SA 

	    BW							

where: 

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

C 	= 	concentration on clothing (mg/cm2);

SE	=	saliva extraction efficiency (%);

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

BW 	= 	body weight (kg).

And

C = % a.i. x % applied x W x CF1 x CF2									

where:

C		=	concentration on clothing (mg/cm2);

% applied	= 	percent of product applied (%);

% a.i.		= 	percent active ingredient in product (%); 

W 		= 	weight of clothing (g/m2);

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

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

Assumptions

The product is applied at a maximum label rate of 2% of weight of
textile; the percent of triclosan in the formulation is 99%.  A
reduction of the application rate to 0.99% by weight is also included as
an indicator of reduced risk.

The textile density is 10 mg/cm2 (0.01 grams/cm2 or 100 grams/m2) based
on the density of mixed cotton and synthetics (HERA 2003).  

The leaching study for triclosan (see dermal scenario above) provided a
value of 0.55% leaching from cotton fabric.  However, the results from
leaching studies may underestimate the amount of residue transfer for
mouthing clothing because of the mouthing/sucking action of a child may
be more vigorous then leaching.  Nonetheless, the leaching study
(conducted for 48 hours) is believed to be more representative for
triclosan then the default value typically used for saliva extraction. 
The magnitude of the resulting MOE estimate should be sufficient based
on the use of the 48-hour leaching results versus a mouthing/sucking
action.  More research on residue transfer from mouthing is warranted.

The surface area of textiles mouthed by toddlers is 100 cm2, a 4 inch x
4 inch area (professional judgment).

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

Results

    Table 4.6 shows the calculation of the short- and intermediate-term
oral dose and oral MOE for toddlers mouthing treated textiles. The MOE
value is above the target MOE of 100 for the maximum concentration
allowed on the label (MOE = 4,200).  

	At this point in time, triclosan treated mattresses are not assessed
separately but are not of concern as they are treated at the same
concentration as the textiles/clothing. 

Table 4.6:  Incidental Oral Exposures and MOEs for Toddlers Wearing
Treated Textiles (Clothing/Blankets)

Weight of clothing (g/cm2)	% Product Applied	Concentration on clothinga
(mg/cm2)	Surface area mouthed (cm2/day)	

Saliva extraction efficiency 

(%)	Potential daily dose (mg a.i./kg/day)	Incidental Oral MOEc 

(Target MOE =100)

0.01	2%	0.198	100	0.55%	0.0073	4,200

a.	Concentration on clothing (mg/cm2) = (percent a.i. in product, %) /
100 * (percent product applied, %) / 100 * (weight of clothing, g/cm2) *
1,000 mg/g 

b.	Potential Daily Dose (mg/kg/day) = (concentration on clothing,
mg/cm2) * (surface area mouthed, cm2/day) * (saliva extraction
efficiency, %)/100 / (body weight, 15 kg).

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

	4.2.2.2 tc \l4 "4.4.2.3 		Plastics (Toys)

	Plastics and polymers used in toys can be treated with triclosan during
the manufacturing process.  Therefore children’s post application
incidental oral exposures to treated toys may occur.  It was assumed
that not all plastic toys are treated with triclosan and the toys that
are treated will not be used everyday therefore exposure would occur
intermittently.  Thus only short-term exposures durations were assessed.

Child Incidental Ingestion Exposure from Treated Plastic

	

Exposure Calculations

	

	Short-term exposures – There is potential for short- term incidental
ingestion exposures when children come into mouth plastic toys treated
with triclosan.  To determine short-term exposure of children to
triclosan in plastic toys, the following equations were used:

PDD = SR x SE x SA

	      BW							

where: 

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

SR 	= 	surface residue (mg/cm2);

SE	=	saliva extraction efficiency (unitless fraction)

SA	=	surface area of toy mouthed (cm2/day)

BW 	= 	body weight of a toddler (kg).

And

SR = % a.i x W x CF x F	

	         SA					

where:

SR	=	surface residue (mg a.i./cm2)

% a.i.	=	fraction active ingredient in toy by total weight (unitless)

W	=	weight of toy (g)

CF	=	conversion factor (1,000 mg/g)

F	=	fraction additive available at the surface of the toy (unitless)

SA	=	surface area of toy (cm2)

Assumptions

It is assumed that 500 cm2 is a representative surface area of plastic
that is mouthed (AD standard assumption).

Since chemical specific leaching data were not available, the actual
amount of active ingredient at the surface of the toy which is available
for mouthing is based on the following assumptions

The toy is manufactured from ABS or polystyrene plastic;

The diffusion of the active ingredient available at the surface of the
toy to the child’s mouth is allowed to reach equilibrium; and 

No more than 0.5% of the additive is available on the surface of the toy
for each mouthing event.

The weight of a 500 cm2 toy is 50 g, which is based on data showing that
a polyethylene highchair sample with a surface area of 12.7 cm2 weighs
1.3072 g (i.e., 0.1 g/cm2) (AD standard assumption).

The product contains 99% a.i. by weight and is used in plastic at a rate
of 0.5% product by weight of material; thus, the % a.i. in plastic is
99% ai x 0.5% = 0.5% ai.

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

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

Results

	Table 4.12 shows the calculations of the short-term incidental oral
exposure and MOE for children mouthing treated plastic toys.  The ST MOE
is above the target MOE of 100 and is not of concern.

Table 4.12.  Short-term Incidental Oral Exposure and MOE for Children
Mouthing Treated Plastic Toys

Duration	% a.i.	Plastic Weight (g)	Fraction of triclosan available on
plastic surface 

	Surface area mouthed (cm2)	Residue on Surface of plastic (mg/cm2)
Saliva extraction efficiency

	Exposure a 

(mg/kg/day)	MOE 

(Target MOE is 100) b

ST	0.5%	50	0.5%	500	0.0025	50%	0.042	710

ST = short-term duration (1 to 30 days)

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

(b)  MOE = NOAEL/exposure estimate [Where: ST incidental oral NOAEL = 30
mg/kg/day].  Target MOE = 100. 

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

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

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, EPA requires 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).  In certain
cases, no standard values were available for some scenarios. 
Assumptions for these scenarios were based on AD estimates and could be
further refined from input from registrants. 

RESIDENTIAL AGGREGATE RISK ASSESSMENT AND CHARACTERIZATION 

Residential aggregate exposure and risk assessment is addressed within
the preliminary risk assessment chapter.  Based on a review of EPA
product labels, triclosan is the active ingredient in products used in
paints, textiles (mattresses and clothing) and plastic toys,  Exposures
also include  those uses where there is the  possibility of indirect
food migration, including  paper/pulp use,  use in ice-making equipment,
adhesives, cutting boards, and counter tops  as well use in conveyer
belts. In addition to EPA-regulated uses, the aggregate assessment
accounts for non-EPA regulated uses of triclosan.  Non-EPA uses include
FDA uses such as toothpaste, hand soaps, and deodorants. 

Although individual EPA-regulated uses have been assessed in this
chapter using standard Agency methodology, the NHANES biological
monitoring data are available for assessing aggregate exposure and risk.
 EPA views the NHANES data as more representative of aggregate exposures
than determining probability of co-occurrence of EPA and FDA-regulated
uses.  tc \l1 "5.0	RESIDENTIAL AGGREGATE RISK ASSESSMENTS AND RISK
CHARACTERIZATION 

	

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 EPA 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.  It should be
noted that for the calculation of application rates in which 8.34 lb/gal
is noted, the product is assumed to have the density of water because no
product-specific density is available.   

	Potential occupational handler exposure for triclosan can occur in
three use sites:   commercial/institutional/industrial premises and
equipment, material preservatives, and industrial processes and water
systems.

Table 6.1.  Representative Exposure Scenarios Associated with
Occupational Exposures to Triclosan

Representative Use	Method of Application	Exposure Scenario	Example
Registration #	Application Rate

Commercial/Industrial/Institutional Premises (Use Category III)

HVAC coil applications	Airless sprayer	ST/IT Handler:

Inhalation	82523-1	6.1E-4 lb ai/10 ft2

(0.85 pints/10 ft2 x 1 gal/8 pts x 8.34 lb/gal x 0.69% ai)

Painting 

(commercial painters)	Paint brush,

Airless sprayer	ST/IT Handler:

Inhalation	42182-1	0.1 lb ai/gallon

[up to 1% product x 99% ai x 10 lb/gal paint density = 0.099 lb
ai/gallon of paint]

Material Preservatives (Use Category VII)

Paint

	Liquid pour,

Powder	ST/IT Handler: inhalation	42182-1	0.1 lb ai/gallon

[up to 1% product x 99% ai x 10 lb/gal paint density = 0.099 lb
ai/gallon of paint]

  SEQ CHAPTER \h \r 1 Industrial processes and water systems (Use
Category VIII)

Pulp and Paper 

	Metered pump

	ST/IT Handler: Inhalation

	70404-5

	2% ai by weight of paper product

(2% product by weight x 99% ai for paper mulch )

Note :  other labels for paper and paper board have lower rates,
42182-1 and 3090-165)

 

	6.1 	Occupational Handler Exposures

	The occupational handler scenarios included in Table 6.1 were assessed
to determine inhalation and dermal exposures.  The general assumptions
and equations that were used to calculate occupational handler
inhalation 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 as outlined in Section 1.2.  However, for the
occupational scenarios in which CMA data were insufficient, other data
and methods were applied. 

Triclosan short-term dermal irritation exposures and risks were not
estimated for occupational handler exposures.  Instead, dermal
irritation exposures and risks will be mitigated using default personal
protective equipment requirements based on the toxicity of the end-use
product.  The systemic dermal assessment is based on a dermal
route-specific endpoint, and therefore, dermal absorption adjustments
are not necessary.  The intermediate- and long-term dermal endpoints are
identical (but require different target MOEs to account for the
long-term duration).   

	

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

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

Paint manufacturing: CMA preservative data.  The dermal unit exposure is
0.135 mg/lb ai (gloved).  The inhalation unit exposure is 0.00346 mg/lb
a.i.  These unit exposure values are based on 2 replicates where the
test subjects were wearing a single layer of clothing and chemical
resistant gloves.   SEQ CHAPTER \h \r 1 Although these unit exposures
are based on minimal replicates, the exposure values are similar to the
ones found in PHED for a similar scenario.

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

Paint and pulp & paper:  CMA preservative pump data.  The dermal UE is
0.00629 mg/lb ai(with gloves) and the inhalation UE is 0.000403 mg/lb
ai.  The values are based on two replicates where the test subjects were
wearing a single layer of clothing and chemical resistant gloves.

For airless sprayer scenarios, the occupational PHED inhalation and
dermal unit exposure values for airless sprayer application (PHED
scenario 23) were used. The inhalation exposure value is 0.83 mg/lb ai. 
The dermal unit exposure is 38 mg/lb ai for ungloved replicates. PPE are
not considered for material preservatives in paint because the paint is
considered a treated article and as such there is no pesticide label on
the paint container to communicate PPE.

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 exposure is 180 mg/lb ai for no glove
replicates.  PPE are not considered for material preservatives in paint
because the paint is considered a treated article and as such there is
no pesticide label on the paint container to communicate PPE.

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:  20,000 lbs (approximately 2,000 gallons, weight based on a
density 10 lb a.i./gal) (standard AD assumption).

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

Pulp and Paper:  500 tons/day.

Paint:  200,000 lbs (approximately 20,000 gallons, weight based on a
density of 10 lb a.i./gal) (standard AD assumption).

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

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. (standard AD assumption).

For the airless sprayer in the HVAC coil scenario, it was assumed 1,000
ft2 of coil surface area is treated. 

Duration of Exposure: The MOEs were calculated for the short- and
intermediate-term durations for occupational handlers using the
appropriate endpoints in Table 3.2.   

Exposure Calculations and Results

	The resulting inhalation and dermal exposures and MOEs for the
representative occupational handler scenarios are presented in Table
6.2. The calculated dermal MOEs were above the target MOE of 100 for all
scenarios, except for the commercial painters (both by brush and airless
sprayer) and the pulp & paper use.  The inhalation MOEs are below the
target MOE of 1000 for the airless sprayer (paint), the paint
manufacturing, and the pulp and paper.

Table 6.2.  Short- and Intermediate-Term Inhalation Risks Associated
with Occupational Handlers

Exposure Scenario	

Method of Application

	

Unit Exposure

(mg/lb a.i.) 	Application Rate	Quantity Handled/ Treated per day	

Daily Dose (mg/kg/day)a	

MOEb 

(Target MOEs = 1000 inhalation, 100 dermal)

Inhalation 	Dermal 

	Inhalation 

	Dermal 

	Inhalation 

	Dermal 

  SEQ CHAPTER \h \r 1 Commercial, Institutional and Industrial Premises
and Equipment (Use Site Category III )

HVAC	Airless sprayer	0.83	38	6.1E-4 lb ai/10ft2	Large building 1000 ft2
0.00072	0.033	4,500	1,200

Painting (commercial)	Paint brush	0.26	180	0.1 lb ai/gal	5 gallons	0.002
1.3	1,600	31

	Airless sprayer	0.83	38

50 gallons	0.059	2.7	54	1

Material Preservatives (Use Site Category VII)

Paint (manufacturing process)	Liquid pour	0.00346	0.135 (gloves)	0.99%
ai	20,000 lbs	0.0098	0.38	330	110

	Liquid pump	0.000403	0.00629 (gloves)

200,000 lbs	0.011	0.18	290	220

Industrial Processes and Water Systems (Use Site Category VIII)

Pulp and Paper	Metering pump	0.000403	0.00629 (gloves)	2% ai	500 tons
0.115	1.8	28	22

	

a	Daily dose (mg/kg/day) = [unit exposure (mg/lb a.i.) x absorption
factor (1 for inhalation and 1 for dermal) x application rate x quantity
treated / Body weight (70 kg).

	b	MOE = LOAEL or NOAEL  (mg/kg/day) / Daily Dose [Where inhalation
LOAEL = 3.21 mg/kg/day for all inhalation exposure durations and the IT
dermal NOAEL is 40 mg/kg/day from a dermal route-specific study]. 
Target MOE = 1000 for inhalation and 100 for dermal.

		6.2  	Occupational Post-application Exposures

	Occupational post-application dermal and inhalation exposures are
assumed to be negligible based on the use patterns.  

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

	There are several data limitations and uncertainties associated with
the occupational handler and post application 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 requires that confirmatory data be submitted to support the
occupational scenarios assessed in this document.

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
personal communication with experts.  The individuals contacted have
experience in these operations and their estimates are believed to be
the best available without undertaking a statistical survey of the uses.
 In certain cases, no standard values were available for some scenarios.
 Assumptions for these scenarios were based on AD estimates and could be
further refined from input from registrants.

7.0	REFERENCES tc \l1 "7.0	REFERENCES 

DOE.  1997.  Energy Information Administration: Profile of Commercial
Buildings in 1995. 
http://www.eia.doe.gov/emeu/cbecs/char95/profile.html

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

USEPA. 1996.  Office of Research and Development, Descriptive Statistics
Tables from a Detailed Analysis of the National Human Activity Pattern
(NHAPS) Data; EPA/600/R-96/148, July 1996.   Data Collection Period
October 1992 - September 1994 . 

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

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.

  SEQ CHAPTER \h \r 1 USEPA. 1999.  Evaluation of Chemical Manufacturers
Association Antimicrobial Exposure Assessment Study (Amended on 8
December 1992).  Memorandum from Siroos Mostaghimi, PH.D., USEPA to
Julie Fairfax, USEPA. Dated November, 4 1999.  DP Barcode D247642.

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.  2007.  5-Chloro-2-(2,4-dichlorophenoxy)phenol (triclosan):
Toxicology Chapter for the Reregistration Eligibility Decision (RED)
document.



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,
1999b) 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):

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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.

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