**UNITED STATES ENVIRONMENTAL PROTECTION AGENCY**

**WASHINGTON, DC 20460**

OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES

![](media/image1.png)

**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**

[EXECUTIVE SUMMARY 3](#__RefHeading___Toc125183615)

[1.0 INTRODUCTION 6](#__RefHeading___Toc125183616)

[**1.1** **Purpose** 6](#__RefHeading___Toc125183617)

[**1.2** **Criteria for Conducting Exposure Assessments**
6](#__RefHeading___Toc125183618)

[**1.3** **Chemical Identification** 8](#__RefHeading___Toc125183619)

[**1.4** **Physical/Chemical Properties**
8](#__RefHeading___Toc125183620)

[2.0 USE INFORMATION 8](#__RefHeading___Toc125183621)

[**2.1** **Formulation Types and Percent Active Ingredient**
8](#__RefHeading___Toc125183622)

[**2.2** **Summary of Use Pattern and Formulations**
9](#__RefHeading___Toc125183623)

[3.0 SUMMARY OF TOXICITY DATA 9](#__RefHeading___Toc125183624)

[**3.1** **Acute Toxicity** 9](#__RefHeading___Toc125183625)

[**3.2** **Summary of Toxicity Endpoints**
10](#__RefHeading___Toc125183626)

[**3.3** **FQPA Considerations** 12](#__RefHeading___Toc125183627)

[4.0 RESIDENTIAL EXPOSURE ASSESSMENT 12](#__RefHeading___Toc125183628)

[**4.1** **Summary of Registered Uses**
12](#__RefHeading___Toc125183629)

[**4.2** **Residential Exposure** 12](#__RefHeading___Toc125183630)

[4.2.1 Residential Handler Exposures 13](#__RefHeading___Toc125183631)

[4.2.2 Residential Post-application Exposures
15](#__RefHeading___Toc125183632)

4.2.2.1
Textiles................................................................................................\......
15

4.2.2.2 Plastic
(Toys).........\...................................................................................\...
19

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

[5.0 RESIDENTIAL AGGREGATE RISK ASSESSMENT AND CHARACTERIZATION
21](#__RefHeading___Toc125183633)

[6.0 OCCUPATIONAL EXPOSURE ASSESSMENT 21](#__RefHeading___Toc125183634)

[**6.1** **Occupational Handler Exposures**
22](#__RefHeading___Toc125183635)

[**6.2** **Occupational Post-application Exposures**
25](#__RefHeading___Toc125183636)

[**6.3** **Data Limitations/Uncertainties**
25](#__RefHeading___Toc125183642)

[7.0 REFERENCES 25](#__RefHeading___Toc125183643)

[]{#__RefHeading___Toc125183615 .anchor}**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.

The durations and routes of exposure evaluated in this assessment
include short-term (ST) and intermediate-term (IT). The inhalation
endpoint (ST/IT durations) is based on a 21-day rat inhalation study
with a LOAEL of 50 mg/m^3^ equivalent to 3.21 mg/kg/day. The adverse
effect for this endpoint is based on increased total leukocyte count and
increased serum alkaline phosphates observed in the male. For the
incidental ingestion exposure scenarios, the ST/IT oral endpoints (30
mg/kg/day) are based on adverse effects of clinical signs of toxicity
include vomiting, failure to eat, and diarrhea in a chronic toxicity
study in Baboons. No short-term dermal endpoint for systemic effects was
selected for triclosan, since no systemic effects were identified. A
short-term dermal irritation endpoint was identified. The short-term
irritation endpoint was determined from a 14-day dermal toxicity in
mice. Irritation was observed at 0.6 mg/kg/day equivalent to 100
μg/cm^2^. 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.

[]{.mark}

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]{.underline}

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]{.underline}

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]{.underline}

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]{.underline}

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]{.underline}

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]{.underline}

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.

[]{.mark}

***Data Limitations and Uncertainties:***

[]{.mark}

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:

[]{.mark}

-   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.

[]{#__RefHeading___Toc125183616 .anchor}**1.0 INTRODUCTION**

[]{#__RefHeading___Toc125183617 .anchor}**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.

[]{#__RefHeading___Toc125183618 .anchor}**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]{.underline} (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 ]{.underline}*[x *ABS*]{.underline} **(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]{.underline} **(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.

```{=html}
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```
-   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.

```{=html}
<!-- -->
```
-   The maximum application rates allowed by labels were assumed.

    3.  []{#__RefHeading___Toc125183619 .anchor}**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.

[![](media/image2.png){width="2.0833333333333335in"
height="0.9722222222222222in"}\
](http://en.wikipedia.org/wiki/Image:Triclosan.png) Figure 1. Molecular
Structure of Triclosan

[]{#__RefHeading___Toc125183620 .anchor}**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
  -----------------------------------------------------------------------

[]{#__RefHeading___Toc125183621 .anchor}

**2.0 USE INFORMATION**

[]{#__RefHeading___Toc125183622 .anchor}**2.1 Formulation Types and
Percent Active Ingredient**

Triclosan is used as a bacteriostat, fungistat, mildewstat, and
deodorizer. The products containing triclosan as the active ingredient
(a.i) 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%.

[]{#__RefHeading___Toc125183623 .anchor}**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:

-   \(III\) Number range CHAPTERCommercial, institutional and industrial
    premises and equipment,

-   \(IV\) Number range CHAPTERResidential and public access premises,
    and

-   \(VII\) Number range CHAPTERMaterial 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      | Example Use     | Scenarios                          |
| Category      | Sites           |                                    |
+---------------+-----------------+------------------------------------+
| **Use Site    | Conveyor belts, | -   Application to HVAC coils      |
| Category**    | fire hoses, dye |                                    |
|               | bath vats, ice  | -   Painting (commercial painters) |
| **III**       | making          |                                    |
|               | equipment, HVAC |                                    |
| Commercial/   | coils           |                                    |
| Institution   |                 |                                    |
| al/Industrial |                 |                                    |
+---------------+-----------------+------------------------------------+
| **Use Site    | []{.mark}       | -   Painting                       |
| Category IV** |                 |                                    |
|               | Used as an      | -   Exposure to treated articles   |
| Residential   | end-use product |     (e.g., clothing, mattress,     |
| and Public    | in carpet       |     plastic toys)                  |
| Access        | shampoos (also  |                                    |
| Premises      | used in treated |                                    |
|               | articles)       |                                    |
+---------------+-----------------+------------------------------------+
| **Use Site    | Used in the     | -   adhesives                      |
| Category      | production of   |                                    |
| VII**         | various         | -   paints (latex)                 |
|               | household,      |                                    |
| Material      | institutional   | -   textiles (cotton, wool, nylon, |
| Preservatives | and industrial  |     rayon, linen, fiber filling,   |
|               | items           |     mattress ticking)              |
|               |                 |                                    |
|               |                 | -   polymers and plastics          |
+---------------+-----------------+------------------------------------+

[]{#__RefHeading___Toc125183624 .anchor}**3.0 SUMMARY OF TOXICITY DATA**

[]{#__RefHeading___Toc125183625 .anchor}**3.1 Acute Toxicity**

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

+--------+-------------------+-------------+-----------------+--------+
| *      |                   |             |                 |        |
| *Table |                   |             |                 |        |
| 3.1.   |                   |             |                 |        |
| Acute  |                   |             |                 |        |
| To     |                   |             |                 |        |
| xicity |                   |             |                 |        |
| P      |                   |             |                 |        |
| rofile |                   |             |                 |        |
| for    |                   |             |                 |        |
| Tricl  |                   |             |                 |        |
| osan** |                   |             |                 |        |
+========+===================+=============+=================+========+
| **Gui  | **Study Type/**   | **MRID      | **Results**     | **To   |
| deline |                   | Number/**   |                 | xicity |
| Nu     | **Test substance  |             |                 | Cate   |
| mber** | (% a.i.)**        | *           |                 | gory** |
|        |                   | *Citation** |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute Oral- Rat   | 43206501    | LD~50~: \>5000  | IV     |
| 0.1100 | Triclosan (99.7%  |             | mg/kg           |        |
|        | a.i.)             |             |                 |        |
| (      |                   |             |                 |        |
| §81-1) |                   |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute Dermal-     | 42306902    | LD~50~: \>9300  | IV     |
| 0.1200 | Rabbit            |             | mg/kg           |        |
|        |                   | Phase III   |                 |        |
| (      | Triclosan (97%    | summary     |                 |        |
| §81-2) | a.i.)             | 92084037    |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Acute Inhalation- | 42306902,   | LC~50~: \>0.15  | II     |
| 0.1300 | Rat               | 43310501    | mg/L            |        |
|        |                   |             |                 |        |
| (      | Triclosan (100.5% |             |                 |        |
| §81-3) | a.i.)             |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Primary Eye       | Phase III   | PIS: 92/110 (24 | II     |
| 0.2400 | Irritation-       | summary     | hours), 82/110  |        |
|        | Rabbit            | 92084040    | (72 hours)      |        |
| (      |                   |             |                 |        |
| §81-4) | Triclosan (97%    |             |                 |        |
|        | a.i.)             |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Primary Dermal    | 42306903    | PII: 3.5 at 72  | III    |
| 0.2500 | Irritation-       |             | hours           |        |
|        | Rabbit            |             |                 |        |
| (      |                   |             |                 |        |
| §81-5) | Triclosan (%      |             |                 |        |
|        | a.i.not provided) |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+
| 87     | Dermal            | 43206502    | Not a           | NA     |
| 0.2600 | Sensitization-    |             | Sensitizer      |        |
|        | Guinea Pig        |             |                 |        |
| (      | Triclosan (99.7%  |             |                 |        |
| §81-6) | a.i.)             |             |                 |        |
+--------+-------------------+-------------+-----------------+--------+

[]{#__RefHeading___Toc125183626 .anchor}**3.2 Summary of Toxicity
Endpoints**

Table 3.2 summarizes the toxicological endpoints for Triclosan (USEPA,
2007).

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

+-------------+-------------+---------------+-------------------------+
| *           | **Dose Used | **Special     | **Study and             |
| *Exposure** | in Risk     | FQPA SF\* and | Toxicological Effects** |
|             | Assessment, | Level of      |                         |
| *           | UF**        | Concern for   |                         |
| *Scenario** |             | Risk          |                         |
|             |             | Assessment**  |                         |
+=============+=============+===============+=========================+
| **Acute     | NOAEL = 30  | FQPA SF = 1x  | Chronic Toxicity study  |
| Dietary**   | mg/kg       |               | in Baboons              |
|             |             |               |                         |
| **(gen.     | UF = 100    |               | MRID 257773. Effects of |
| pop.)**     |             |               | clinical signs of       |
|             |             |               | toxicity include        |
|             |             |               | vomiting, failure to    |
|             |             |               | eat, and diarrhea.      |
+-------------+-------------+---------------+-------------------------+
| **Acute     | Endpoint    |               |                         |
| Dietary**   | not         |               |                         |
|             | identified  |               |                         |
| **(females  | in the      |               |                         |
| 13+)**      | database    |               |                         |
+-------------+-------------+---------------+-------------------------+
| **Chronic   | NOAEL = 30  | FQPA SF = 1x  | Chronic Toxicity study  |
| Dietary**   | mg/kg       |               | in Baboons              |
|             |             |               |                         |
| **(all      | UF = 100    |               | MRID 257773. Effects of |
| pop         |             |               | clinical signs of       |
| ulations)** |             |               | toxicity include        |
|             |             |               | vomiting, failure to    |
|             |             |               | eat, and diarrhea.      |
+-------------+-------------+---------------+-------------------------+
| **          | NOAEL = 30  | FQPA SF = 1x  | Chronic Toxicity study  |
| Short-Term/ | mg/kg       |               | in Baboons              |
| Interm      |             |               |                         |
| ediate-Term | UF = 100    |               | MRID 257773             |
| Incidental  |             |               |                         |
| Oral (1-30  |             |               | Effects of clinical     |
| days; 30    |             |               | signs of toxicity       |
| days- 6     |             |               | include vomiting,       |
| months)**   |             |               | failure to eat, and     |
|             |             |               | diarrhea.               |
+-------------+-------------+---------------+-------------------------+
| **Dermal**  | NOAEL = 0.6 | FQPA SF = 1x  | 14-day dermal toxicity  |
|             | mg/animal @ |               | study in the mouse      |
| **(sh       | 99.3%       |               |                         |
| ort-term)** | active      |               | MRID 44389708           |
|             | ingredient  |               |                         |
|             | (100        |               | LOAEL = 1.5 mg/kg/day,  |
|             | µg/cm^2^)   |               | based on                |
|             |             |               | treatment-related       |
|             | UF = 10x    |               | dermal irritation at    |
|             |             |               | the treatment site and  |
|             |             |               | on increased liver      |
|             |             |               | weights                 |
+-------------+-------------+---------------+-------------------------+
| **Dermal    | NOAEL = 40  | FQPA SF = 1x  | 90-day dermal toxicity  |
| (i          | mg/kg       |               | study in rats. MRID     |
| ntermediate |             |               | 43328001. LOAEL = 80    |
| term)**     | UF = 100    |               | mg/kg/day, based on     |
|             |             |               | increased incidence     |
|             |             |               | occult blood in the     |
|             |             |               | urine.                  |
+-------------+-------------+---------------+-------------------------+
| **Dermal    | NOAEL = 40  | FQPA SF = 1x  | 90-day dermal toxicity  |
| (l          | mg/kg       |               | study in rats. MRID     |
| ong-term)** |             |               | 43328001. LOAEL = 80    |
|             | UF = 300    |               | mg/kg/day, based on     |
|             |             |               | increased incidence     |
|             |             |               | occult blood in the     |
|             |             |               | urine.                  |
+-------------+-------------+---------------+-------------------------+
| *           | LOAEL = 50  | FQPA SF = 1x  | 21-Day Inhalation       |
| *Inhalation | mg/m3 or    |               | Toxicity study in the   |
| (all        | 3.21        |               | rat. MRID 0087996.      |
| d           | mg/kg/day   |               | Effects seen in males   |
| urations)** |             |               | at LOAEL include        |
|             | UF = 1000   |               | increased total         |
|             |             |               | leucocyte count and     |
|             | Where       |               | increased serum         |
|             | mg/kg/day = |               | alkaline phosphatase.   |
|             | ((0.0087    |               |                         |
|             | m3/hr \*    |               |                         |
|             | mg/m3 \* 2  |               |                         |
|             | hr/day)     |               |                         |
|             | /0.271 b.w. |               |                         |
+-------------+-------------+---------------+-------------------------+
| **Cancer    | Not likely  |               |                         |
| (oral)**    | to be       |               |                         |
|             | c           |               |                         |
|             | arcinogenic |               |                         |
|             | to humans   |               |                         |
|             | (Health     |               |                         |
|             | Effects     |               |                         |
|             | Division    |               |                         |
|             | Car         |               |                         |
|             | cinogencity |               |                         |
|             | 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

[]{#__RefHeading___Toc125183627 .anchor}**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.

[]{#__RefHeading___Toc125183628 .anchor}

**4.0 RESIDENTIAL EXPOSURE ASSESSMENT**

[]{#__RefHeading___Toc125183629 .anchor}**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.

[]{#__RefHeading___Toc125183630 .anchor}**4.2 Residential Exposure**

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.        |           |              |           |                |
| Rep         |           |              |           |                |
| resentative |           |              |           |                |
| Uses        |           |              |           |                |
| Associated  |           |              |           |                |
| with        |           |              |           |                |
| Residential |           |              |           |                |
| Exposure to |           |              |           |                |
| T           |           |              |           |                |
| riclosan.** |           |              |           |                |
+=============+===========+==============+===========+================+
| Rep         | Ap        | Exposure     | Example   | Application    |
| resentative | plication | Scenario     | Reg       | Rate           |
| Use         | Method    |              | istration |                |
|             |           |              | Number    |                |
+-------------+-----------+--------------+-----------+----------------+
| Paint       | -   Brush | ST Handler:  | 42182-1   | 0.1 lb         |
| (Latex)     |     and   | adult dermal |           | ai/gallon      |
|             |           | and          |           |                |
|             |   airless | inhalation.  |           | \[up to 1%     |
|             |           |              |           | product x 99%  |
|             |   sprayer |              |           | ai x 10 lb/gal |
|             |           |              |           | paint density  |
|             |           |              |           | = 0.099 lb     |
|             |           |              |           | ai/gallon of   |
|             |           |              |           | paint\]        |
+-------------+-----------+--------------+-----------+----------------+
| Textiles    | -   NA^a^ | ST Post-app: | 70404-5   | Round to 2% ai |
|             |           | wearing      |           | in finished    |
| (exposures  |           | treated      |           | textiles and   |
| to treated  |           | clothing,    |           | mattresses.    |
| articles    |           | adult        |           |                |
| are         |           | dermal;      |           | (Rates range   |
| represented |           | child        |           | up to the      |
| by exposure |           | incidental   |           | finished       |
| to mattress |           | ingestion    |           | product        |
| and         |           | and dermal   |           | containing 2%  |
| clothing)   |           |              |           | formulated     |
|             |           |              |           | product by     |
|             |           |              |           | weight.        |
|             |           |              |           | Triclosan      |
|             |           |              |           | product        |
|             |           |              |           | contains 99%   |
|             |           |              |           | ai. )          |
+-------------+-----------+--------------+-----------+----------------+
| Plastic     | -   NA^a^ | ST Post-app: | 42182-1   | 0.5% ai        |
|             |           | child        |           |                |
| (exposures  |           | incidental   |           | (0.1% to 0.5%  |
| to plastic  |           | ingestion    |           | product x 99%  |
| treated     |           | and dermal   |           | ai)            |
| articles    |           |              |           |                |
| are         |           |              |           | **Note: labels |
| represented |           |              |           | need to        |
| by plastic  |           |              |           | clarify that   |
| toys)       |           |              |           | toys are       |
|             |           |              |           | limited to     |
|             |           |              |           | 0.5%**         |
+-------------+-----------+--------------+-----------+----------------+

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

[]{#__RefHeading___Toc125183631 .anchor} **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 90^th^ 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 ft^2^/gallon and
    a house size of 40 x 30 x 20 ft (surface area of 2,800 ft^2^).

**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]{.underline}**

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    |        |          |          |        |          |       |
| Tri    |        |          |          |        |          |       |
| closan |        |          |          |        |          |       |
| Shor   |        |          |          |        |          |       |
| t-Term |        |          |          |        |          |       |
| Resid  |        |          |          |        |          |       |
| ential |        |          |          |        |          |       |
| H      |        |          |          |        |          |       |
| andler |        |          |          |        |          |       |
| Inha   |        |          |          |        |          |       |
| lation |        |          |          |        |          |       |
| Exp    |        |          |          |        |          |       |
| osures |        |          |          |        |          |       |
| and    |        |          |          |        |          |       |
| MOEs** |        |          |          |        |          |       |
+--------+--------+----------+----------+--------+----------+-------+
| Ex     | Appli  | App      | Quantity | Unit   | Daily    | MOE   |
| posure | cation | lication | Handled/ | Ex     | Dose     | ^d^   |
| Sc     | Method | Rate^a^  | Treated  | posure | (mg      |       |
| enario |        |          | per      |        | /kg/day) | (T    |
|        |        |          | day^b^   | (mg/lb | ^c^      | arget |
| Appli  |        |          |          | a.i.)  |          | MOE = |
| cation |        |          |          |        |          | 1000) |
| Method |        |          |          |        |          |       |
+--------+--------+----------+----------+--------+----------+-------+
| Pa     | Paint  | 0.1 lb   | 2        | 0.28   | 0.0008   | 4,000 |
| inting | brush  | ai/gal   | gallons  |        |          |       |
+--------+--------+----------+----------+--------+----------+-------+
|        | A      |          | 15       | 0.83   | 0.018    | 180   |
|        | irless |          | gallons  |        |          |       |
|        | s      |          |          |        |          |       |
|        | prayer |          |          |        |          |       |
+--------+--------+----------+----------+--------+----------+-------+

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. \[Where short-term inhalation LOAEL = 50
mg/m^3^ or a dose of 3.21 mg/kg/day\]. Target MOE = 1000.

[]{#__RefHeading___Toc125183632 .anchor} **4.2.2 Residential
Post-application Exposures**

For the purposes of this screening-level assessment, post-application
scenarios have been developed that encompass multiple products, but
still represent 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]{.underline}**

Potential doses are calculated as follows:

PDD = [W x % applied x % a.i. x % transfer]{.underline}

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 (cm^2^); and
>
> BSA = surface area of body covered (cm^2^).

**[Assumptions]{.underline}**

-   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 cm^2^ (total body surface area minus the head)
    (USEPA, 1997). For adults, the median surface area is 16,900 cm^2^
    (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/cm^2^ 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 cm^2^) times the surface area covered (5,670 cm^2^
    for toddlers, 16,900 cm^2^ 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]{.underline}**

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.

+------+-------+---------+-------+-------------+---------+---------+
| **T  |       |         |       |             |         |         |
| able |       |         |       |             |         |         |
| 4.5: |       |         |       |             |         |         |
| De   |       |         |       |             |         |         |
| rmal |       |         |       |             |         |         |
| I    |       |         |       |             |         |         |
| nter |       |         |       |             |         |         |
| medi |       |         |       |             |         |         |
| ate- |       |         |       |             |         |         |
| term |       |         |       |             |         |         |
| Post |       |         |       |             |         |         |
| -app |       |         |       |             |         |         |
| lica |       |         |       |             |         |         |
| tion |       |         |       |             |         |         |
| E    |       |         |       |             |         |         |
| xpos |       |         |       |             |         |         |
| ures |       |         |       |             |         |         |
| and  |       |         |       |             |         |         |
| MOEs |       |         |       |             |         |         |
| for  |       |         |       |             |         |         |
| Todd |       |         |       |             |         |         |
| lers |       |         |       |             |         |         |
| and  |       |         |       |             |         |         |
| Ad   |       |         |       |             |         |         |
| ults |       |         |       |             |         |         |
| Co   |       |         |       |             |         |         |
| ntac |       |         |       |             |         |         |
| ting |       |         |       |             |         |         |
| Tre  |       |         |       |             |         |         |
| ated |       |         |       |             |         |         |
| Cl   |       |         |       |             |         |         |
| othi |       |         |       |             |         |         |
| ng** |       |         |       |             |         |         |
+======+=======+=========+=======+=============+=========+=========+
| Expo | W     | Percent | Pe    | Percent     | Daily   | Dermal  |
| sure | eight | tr      | rcent | residue     | dose^b^ | MOE^c^  |
| Scen | of    | iclosan | of    | transferred |         | (Target |
| ario | clo   | in      | pr    | from        | (mg     | M       |
|      | thing | product | oduct | clothing to | a.i./   | OE=100) |
|      | worn  | (%)     | ap    | skin (%)    | kg/day) |         |
|      | (g/da |         | plied |             |         |         |
|      | y)^a^ |         | (%)   |             |         |         |
+------+-------+---------+-------+-------------+---------+---------+
| Tod  | 56.7  | 99%     | 2%    | 0.55 %      | 0.41    | 98      |
| dler |       |         |       |             |         |         |
+------+-------+---------+-------+-------------+---------+---------+
| A    | 169   | 99%     | 2%    | 0.55%       | 0.26    | 150     |
| dult |       |         |       |             |         |         |
+------+-------+---------+-------+-------------+---------+---------+

a\. Weight of clothing worn (g/day) = (Density of fabric 0.01 g/cm^2^)
\* (surface area of body covered, cm^2^) \* 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]{.underline}**

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]{.underline}

BW

where:

> PDD = potential daily dose (mg/kg/day);
>
> C = concentration on clothing (mg/cm^2^);
>
> SE = saliva extraction efficiency (%);
>
> SA = surface area mouthed (cm^2^/day); and
>
> BW = body weight (kg).

And

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

where:

> C = concentration on clothing (mg/cm^2^);
>
> \% applied = percent of product applied (%);
>
> \% a.i. = percent active ingredient in product (%);
>
> W = weight of clothing (g/m^2^);
>
> CF1 = unit conversion factor (1,000 mg/g); and
>
> CF2 = unit conversion factor (0.0001 m^2^/cm^2^).

**[Assumptions]{.underline}**

-   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/cm^2^ (0.01 grams/cm^2^ or 100
    grams/m^2^) 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 cm^2^, 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]{.underline}**

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:     |      |        |         |         |         |           |
| In       |      |        |         |         |         |           |
| cidental |      |        |         |         |         |           |
| Oral     |      |        |         |         |         |           |
| E        |      |        |         |         |         |           |
| xposures |      |        |         |         |         |           |
| and MOEs |      |        |         |         |         |           |
| for      |      |        |         |         |         |           |
| Toddlers |      |        |         |         |         |           |
| Wearing  |      |        |         |         |         |           |
| Treated  |      |        |         |         |         |           |
| Textiles |      |        |         |         |         |           |
| (Clot    |      |        |         |         |         |           |
| hing/Bla |      |        |         |         |         |           |
| nkets)** |      |        |         |         |         |           |
+----------+------+--------+---------+---------+---------+-----------+
| Weight   | \%   | C      | Surface | Saliva  | Po      | I         |
| of       | Pro  | oncent | area    | ext     | tential | ncidental |
| clothing | duct | ration | mouthed | raction | daily   | Oral      |
| (        | App  | on     | (cm^    | eff     | dose    | MOE^c^    |
| g/cm^2^) | lied | cloth  | 2^/day) | iciency | (mg     |           |
|          |      | ing^a^ |         |         | a.i./   | (Target   |
|          |      | (mg/   |         | (%)     | kg/day) | MOE =100) |
|          |      | cm^2^) |         |         |         |           |
+----------+------+--------+---------+---------+---------+-----------+
| 0.01     | 2%   | 0.198  | 100     | 0.55%   | 0.0073  | 4,200     |
+----------+------+--------+---------+---------+---------+-----------+

a\. Concentration on clothing (mg/cm^2^) = (percent a.i. in product, %)
/ 100 \* (percent product applied, %) / 100 \* (weight of clothing,
g/cm^2^) \* 1,000 mg/g

b\. Potential Daily Dose (mg/kg/day) = (concentration on clothing,
mg/cm^2^) \* (surface area mouthed, cm^2^/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 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]{.underline}**

**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]{.underline}

BW

where:

> PDD = potential daily dose (mg/kg/day);
>
> SR = surface residue (mg/cm^2^);
>
> SE = saliva extraction efficiency (unitless fraction)
>
> SA = surface area of toy mouthed (cm^2^/day)
>
> BW = body weight of a toddler (kg).

And

SR = [% a.i x W x CF x F]{.underline}

SA

where:

> SR *=* surface residue (mg a.i./cm^2^)
>
> \% 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 (cm^2^)

**[Assumptions]{.underline}**

-   It is assumed that 500 cm^2^ 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 cm^2^ toy is 50 g, which is based on data
    showing that a polyethylene highchair sample with a surface area of
    12.7 cm^2^ weighs 1.3072 g (i.e., 0.1 g/cm^2^) (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]{.underline}**

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.

+-----+----+----+-------+------+--------+-------+-------+----------+
| *   |    |    |       |      |        |       |       |          |
| *Ta |    |    |       |      |        |       |       |          |
| ble |    |    |       |      |        |       |       |          |
| 4.  |    |    |       |      |        |       |       |          |
| 12. |    |    |       |      |        |       |       |          |
| S   |    |    |       |      |        |       |       |          |
| hor |    |    |       |      |        |       |       |          |
| t-t |    |    |       |      |        |       |       |          |
| erm |    |    |       |      |        |       |       |          |
| I   |    |    |       |      |        |       |       |          |
| nci |    |    |       |      |        |       |       |          |
| den |    |    |       |      |        |       |       |          |
| tal |    |    |       |      |        |       |       |          |
| O   |    |    |       |      |        |       |       |          |
| ral |    |    |       |      |        |       |       |          |
| Ex  |    |    |       |      |        |       |       |          |
| pos |    |    |       |      |        |       |       |          |
| ure |    |    |       |      |        |       |       |          |
| and |    |    |       |      |        |       |       |          |
| MOE |    |    |       |      |        |       |       |          |
| for |    |    |       |      |        |       |       |          |
| Ch  |    |    |       |      |        |       |       |          |
| ild |    |    |       |      |        |       |       |          |
| ren |    |    |       |      |        |       |       |          |
| Mo  |    |    |       |      |        |       |       |          |
| uth |    |    |       |      |        |       |       |          |
| ing |    |    |       |      |        |       |       |          |
| T   |    |    |       |      |        |       |       |          |
| rea |    |    |       |      |        |       |       |          |
| ted |    |    |       |      |        |       |       |          |
| P   |    |    |       |      |        |       |       |          |
| las |    |    |       |      |        |       |       |          |
| tic |    |    |       |      |        |       |       |          |
| Toy |    |    |       |      |        |       |       |          |
| s** |    |    |       |      |        |       |       |          |
+-----+----+----+-------+------+--------+-------+-------+----------+
| Du  | \% | P  | Fra   | Sur  | R      | S     | Exp   | MOE      |
| rat | a. | la | ction | face | esidue | aliva | osure |          |
| ion | i. | st | of    | area | on     | extra | ^a^\  | (Target  |
|     |    | ic | tric  | mou  | S      | ction | (     | MOE is   |
|     |    | We | losan | thed | urface | effic | mg/kg | 100) ^b^ |
|     |    | ig | avai  | (cm  | of     | iency | /day) |          |
|     |    | ht | lable | ^2^) | p      |       |       |          |
|     |    | (  | on    |      | lastic |       |       |          |
|     |    | g) | pl    |      | (mg/   |       |       |          |
|     |    |    | astic |      | cm^2^) |       |       |          |
|     |    |    | su    |      |        |       |       |          |
|     |    |    | rface |      |        |       |       |          |
+-----+----+----+-------+------+--------+-------+-------+----------+
| ST  | 0. | 50 | 0.5%  | 500  | 0.0025 | 50%   | 0.042 | 710      |
|     | 5% |    |       |      |        |       |       |          |
+-----+----+----+-------+------+--------+-------+-------+----------+

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**

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.

5.  []{#__RefHeading___Toc125183633 .anchor}**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.

[]{#__RefHeading___Toc125183634 .anchor}**6.0 OCCUPATIONAL EXPOSURE
ASSESSMENT**

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.        |             |            |          |                  |
| Rep         |             |            |          |                  |
| resentative |             |            |          |                  |
| Exposure    |             |            |          |                  |
| Scenarios   |             |            |          |                  |
| Associated  |             |            |          |                  |
| with        |             |            |          |                  |
| O           |             |            |          |                  |
| ccupational |             |            |          |                  |
| Exposures   |             |            |          |                  |
| to          |             |            |          |                  |
| Triclosan** |             |            |          |                  |
+=============+=============+============+==========+==================+
| Rep         | Method of   | Exposure   | Example  | Application Rate |
| resentative | Application | Scenario   | Regi     |                  |
| Use         |             |            | stration |                  |
|             |             |            | \#       |                  |
+-------------+-------------+------------+----------+------------------+
| **Co        |             |            |          |                  |
| mmercial/In |             |            |          |                  |
| dustrial/In |             |            |          |                  |
| stitutional |             |            |          |                  |
| Premises    |             |            |          |                  |
| (Use        |             |            |          |                  |
| Category    |             |            |          |                  |
| III)**      |             |            |          |                  |
+-------------+-------------+------------+----------+------------------+
| HVAC coil   | Airless     | ST/IT      | 82523-1  | 6.1E-4 lb ai/10  |
| a           | sprayer     | Handler:   |          | ft^2^            |
| pplications |             |            |          |                  |
|             |             | Inhalation |          | (0.85 pints/10   |
|             |             |            |          | ft^2^ x 1 gal/8  |
|             |             |            |          | pts x 8.34       |
|             |             |            |          | lb/gal x 0.69%   |
|             |             |            |          | ai)              |
+-------------+-------------+------------+----------+------------------+
| Painting    | Paint       | ST/IT      | 42182-1  | 0.1 lb ai/gallon |
|             | brush,      | Handler:   |          |                  |
| (commercial |             |            |          | \[up to 1%       |
| painters)   | Airless     | Inhalation |          | product x 99% ai |
|             | sprayer     |            |          | x 10 lb/gal      |
|             |             |            |          | paint density =  |
|             |             |            |          | 0.099 lb         |
|             |             |            |          | ai/gallon of     |
|             |             |            |          | paint\]          |
+-------------+-------------+------------+----------+------------------+
| **Material  |             |            |          |                  |
| Pr          |             |            |          |                  |
| eservatives |             |            |          |                  |
| (Use        |             |            |          |                  |
| Category    |             |            |          |                  |
| VII)**      |             |            |          |                  |
+-------------+-------------+------------+----------+------------------+
| Paint       | Liquid      | ST/IT      | 42182-1  | 0.1 lb ai/gallon |
|             | pour,       | Handler:   |          |                  |
|             |             | inhalation |          | \[up to 1%       |
|             | Powder      |            |          | product x 99% ai |
|             |             |            |          | x 10 lb/gal      |
|             |             |            |          | paint density =  |
|             |             |            |          | 0.099 lb         |
|             |             |            |          | ai/gallon of     |
|             |             |            |          | paint\]          |
+-------------+-------------+------------+----------+------------------+
| **Number    |             |            |          |                  |
| range       |             |            |          |                  |
| CHAPTE      |             |            |          |                  |
| RIndustrial |             |            |          |                  |
| processes   |             |            |          |                  |
| and water   |             |            |          |                  |
| systems     |             |            |          |                  |
| (Use        |             |            |          |                  |
| Category    |             |            |          |                  |
| VIII)**     |             |            |          |                  |
+-------------+-------------+------------+----------+------------------+
| Pulp and    | Metered     | ST/IT      | 70404-5  | 2% ai by weight  |
| Paper       | pump        | Handler:   |          | of paper product |
|             |             | Inhalation |          |                  |
|             |             |            |          | (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)    |
+-------------+-------------+------------+----------+------------------+

[]{#__RefHeading___Toc125183635 .anchor}**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. Number
        range CHAPTERAlthough 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.

```{=html}
<!-- -->
```
-   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.

```{=html}
<!-- -->
```
-   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).

```{=html}
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```
-   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 ft^2^ 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]{.underline}**

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>
<colgroup>
<col style="width: 13%" />
<col style="width: 14%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 9%" />
<col style="width: 10%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 8%" />
<col style="width: 6%" />
</colgroup>
<thead>
<tr class="header">
<th colspan="10"><strong>Table 6.2. Short- and Intermediate-Term
Inhalation Risks Associated with Occupational Handlers</strong></th>
</tr>
<tr class="odd">
<th rowspan="2">Exposure Scenario</th>
<th rowspan="2">Method of Application</th>
<th colspan="2"><p>Unit Exposure</p>
<p>(mg/lb a.i.)</p></th>
<th rowspan="2">Application Rate</th>
<th rowspan="2">Quantity Handled/ Treated per day</th>
<th colspan="2">Daily Dose (mg/kg/day)<sup>a</sup></th>
<th colspan="2"><p>MOE<sup>b</sup></p>
<p>(Target MOEs = 1000 inhalation, 100 dermal)</p></th>
</tr>
<tr class="header">
<th>Inhalation</th>
<th>Dermal</th>
<th>Inhalation</th>
<th>Dermal</th>
<th>Inhalation</th>
<th>Dermal</th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td colspan="10"><strong>Number range CHAPTERCommercial, Institutional
and Industrial Premises and Equipment (Use Site Category III
)</strong></td>
</tr>
<tr class="even">
<td>HVAC</td>
<td>Airless sprayer</td>
<td>0.83</td>
<td>38</td>
<td>6.1E-4 lb ai/10ft<sup>2</sup></td>
<td>Large building 1000 ft<sup>2</sup></td>
<td>0.00072</td>
<td>0.033</td>
<td>4,500</td>
<td>1,200</td>
</tr>
<tr class="odd">
<td rowspan="2">Painting (commercial)</td>
<td>Paint brush</td>
<td>0.26</td>
<td>180</td>
<td rowspan="2">0.1 lb ai/gal</td>
<td>5 gallons</td>
<td>0.002</td>
<td>1.3</td>
<td>1,600</td>
<td>31</td>
</tr>
<tr class="even">
<td>Airless sprayer</td>
<td>0.83</td>
<td>38</td>
<td>50 gallons</td>
<td>0.059</td>
<td>2.7</td>
<td>54</td>
<td>1</td>
</tr>
<tr class="odd">
<td colspan="10"><strong>Material Preservatives (Use Site Category
VII)</strong></td>
</tr>
<tr class="even">
<td rowspan="2">Paint (manufacturing process)</td>
<td>Liquid pour</td>
<td>0.00346</td>
<td>0.135 (gloves)</td>
<td rowspan="2">0.99% ai</td>
<td>20,000 lbs</td>
<td>0.0098</td>
<td>0.38</td>
<td>330</td>
<td>110</td>
</tr>
<tr class="odd">
<td>Liquid pump</td>
<td>0.000403</td>
<td>0.00629 (gloves)</td>
<td>200,000 lbs</td>
<td>0.011</td>
<td>0.18</td>
<td>290</td>
<td>220</td>
</tr>
<tr class="even">
<td colspan="10"><strong>Industrial Processes and Water Systems (Use
Site Category VIII)</strong></td>
</tr>
<tr class="odd">
<td>Pulp and Paper</td>
<td>Metering pump</td>
<td>0.000403</td>
<td>0.00629 (gloves)</td>
<td>2% ai</td>
<td>500 tons</td>
<td>0.115</td>
<td>1.8</td>
<td>28</td>
<td>22</td>
</tr>
</tbody>
</table>

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.

[]{#__RefHeading___Toc125183636 .anchor}**6.2 Occupational
Post-application Exposures**

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

[]{#__RefHeading___Toc125183642 .anchor} **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.

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-   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[]{#__RefHeading___Toc125183643 .anchor}.

    **7.0 REFERENCES**

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

Number range CHAPTERFreeman, 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.

Number range CHAPTERUSEPA. 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**

*[Chemical Manufacturers Association (CMA) Data:]{.underline}*

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):]{.underline}*

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' policy to
use surrogate or generic exposure data for pesticide applicators in
certain circumstances because it is believed that the physical
parameters (e.g., packaging type) or application technique (e.g.,
aerosol can), not the chemical properties of the pesticide, attribute to
exposure levels. \[Note: Vapor pressures for the chemicals in PHED are
in the range of E-5 to E-7 mm Hg.\] Chemical specific properties are
accounted for by correcting the exposure data for study specific field
and laboratory recovery values as specified by the PHED grading
criteria.

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