**UNITED STATES ENVIRONMENTAL PROTECTION
AGENCY**![](media/image1.png){width="1.6243055555555554in"
height="1.5416666666666667in"}

**WASHINGTON, D.C. 20460**

**OFFICE OF**

**PREVENTION, PESTICIDES AND**

**TOXIC SUBSTANCES**

October 17, 2007

**[MEMORANDUM]{.underline}**

**SUBJECT:** Product Chemistry Chapter for the Triclosan Reregistration
Eligibility Decision (RED) Document

**DP Barcode:** 335401 **Reregistration Case No.:** 2340

**FROM:** Srinivas Gowda, Microbiologist/Chemist

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

**TO:** Mark Hartman, Branch Chief

Diane Isbell, Team Leader

Heather Garvie, Chemical Review Manager

Regulatory Management Branch II

Antimicrobials Division (7510P)

Timothy McMahon, Risk Assessor

**THRU:** Siroos Mostaghimi, Team Leader, Team one

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510P)

Norman Cook, Branch Chief

Risk Assessment and Science Support Branch (RASSB)

> Antimicrobials Division (7510P)

**[Chemical Name]{.underline}** **[PC Code]{.underline}**
**[CAS#]{.underline}** **[Common Name]{.underline}**

5-Chloro-2-(2,4-dichlorophenoxy)phenol 54901 3380-34-5 Triclosan

Attached is the Product Chemistry Chapter for the Triclosan RED
Document.

**TRICLOSAN**

**[REREGISTRATION ELIGIBILITY DECISION]{.underline}**

**[PRODUCT CHEMISTY CHAPTER]{.underline}**

**[PC Code: 54901; Case No. 2340]{.underline}**

**[REGULATORY HISTORY]{.underline}**

5-Chloro-2-(2,4-dichlorophenoxy)phenol (Triclosan) was first registered
with the EPA on June 19, 1969. Presently, there are 20 active products,
no inert products, and 4 pending products under PC Code 054901, which
are listed in Table 1 under Appendix. This chemical is a diphenyl ether
derivative primarily used in cosmetics, toilet soaps, and antiseptics.
It is also used as a bacteriostat and fungistat in plastics, polymers,
textile and implantable medical devices to give these materials
\"antibacterial properties.\"

**[CHEMICAL IDENTIFICATION]{.underline}**

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

**Figure 1. Molecular Structure of Triclosan**

**Common Name:** Triclosan

**Chemical Name:** 5-Chloro-2-(2,4-dichlorophenoxy)phenol

**Other Name(s):** 2,4,4'-Trichloro-2'-hydroxydiphenyl ether

Phenol, 5-chloro-2-(2,4-dichlorophenoxy)-

5**-**Chloro-2-(2,4-dichlorophenoxy)phenol

Irgasan DP-300R

Irgaguard B1000

VIV-20

**CAS Registry Number:** 3380-34-5

**OPP Chemical Code:** 54901

**Case Number:** 2340

**Empirical Formula:** C~12~H~7~C~l3~0~2~

**Molecular Weight:** 289.541

**Technical Grade**

**Manufacturers:** Ciba Specialty Chemicals Corp

Harmet International/Vivimed Labs Limited

**End Use**

**Manufacturers:** Aeris Technologies Ltd.

Ciba Specialty Chemicals Corp.

Huntsman International, LLC

Microban Products Company

Rohm and Haas Company

Sanitized Inc.

S.C. Johnson & Son Inc.

Thomson Research Associates

Troy Chemical Corp.

Vikon Chemical Co.

Vivimed Labs Limited

**Percent Active Ingredient**

**In Technical Grade Product: \>**99.0% (Ciba) and 99.9%
(Harmet/Vivimed)

**Formulation Types**

**Registered: Technical Grade Active Ingredient:**

> Technical Chemical
>
> **Manufacturing Product:**
>
> Formulation Intermediate
>
> **End Use Products:**

Ready-to-Use

Pelleted/Tableted

Emulsifiable Concentrate

Soluble Concentrate

Impregnated Materials

**Chemical Properties:** Triclosan is a white crystalline powder with a
faint odor and melting point of 56.5^°^C (133.7°F). Triclosan is solid
and, therefore, has no boiling point. Triclosan has a log K~ow~ of 4.8
at 25^o^C and a low vapor pressure of 5.2E-6 mm Hg at 25˚C and 2.2E-6 mm
Hg at 20˚C. Triclosan is soluble in water at 0.012 g/l (12 ppm) at 20˚C.
Triclosan is readily soluble in alkaline solutions and many organic
solvents. It has a bulk density of 1.55 x 10^3^ kg/m^3^ at 22˚C.

**PRODUCT CHEMISTRY DATA REQUIREMENTS FOR REREGISTRATION OF TRICLOSAN**:

Product chemistry data requirements and results are summarized in Tables
2 and 3 under, "APPENDIX".

**FINDINGS/CONCLUSIONS:**

All product chemistry data requirements have been fulfilled for the
active ingredient triclosan. See Tables 2 and 3 under, "APPENDIX". RASSB
has no objections to the reregistration of triclosan with respect to
product chemistry data requirements.

**APPENDIX:**

**Table 1. Registered Active Products of Triclosan**

  ----------------- ---------------- ------------------------------------
  **EPA Reg. No.**  **Percent Active **Registrant**
                    Ingredient**     

  2829-139          99%              Rohm & Hass Company

  2829-145          10%              Rohm & Hass Company

  3090-165          10%              Sanitized Inc.

  3090-215          99%              Sanitized Inc

  3090-219          7.5%             Sanitized Inc.

  4822-429          0.06%            S.C. Johnson & Son Inc.

  5383-127          99%              Troy Chemical Corp.

  6390-25           2%               Vikon Chemical Company, Inc.

  10466-24          1.6%             Thomson Research Associates

  10466-27          3%               Thomson Research Associates

  10466-38          99%              Thomson Research Associates

  10466-42          1%               Thomson Research Associates

  42182-1           99%              Microban Products Company

  70404-2           99%              Ciba Specialty Chemicals Corporation

  70404-5           99%              Ciba Specialty Chemicals Corporation

  73951-1           99.9%            Vivimed Labs Limited

  82523-1           0.69%            Aeris Technologies LTD

  83884-7           10%              Huntsman International, LLC

  83884-9           99%              Huntsman International, LLC

  83884-10          99%              Huntsman International, LLC
  ----------------- ---------------- ------------------------------------

**Table 2: Manufacturing and Impurity Data for Triclosan**

> **Product Identity, Composition, and Analysis**

+--------+--------+------------+------+--------+-----+-------------+
| **Old  | **New  | **Req      | *    | **     | *   | **Details   |
| Gui    | Gui    | uirement** | *Use | MRID** | *St | or          |
| deline | deline |            | Patt |        | atu | D           |
| No.**  | No.**  |            | ern^ |        | s^1 | eficiency** |
|        |        |            | 2^** |        | ^** |             |
+--------+--------+------------+------+--------+-----+-------------+
| 61-1   | 83     | Product    | 3    | 42     | A   | Refer to    |
|        | 0.1550 | identity   | ,4,7 | 027901 |     | Chemical    |
|        |        | and        |      |        |     | Ide         |
|        |        | c          |      | 45     |     | ntification |
|        |        | omposition |      | 358501 |     | on page 2   |
+--------+--------+------------+------+--------+-----+-------------+
| 61-2a  | 83     | D          | 3    | 42     | A   | CBI         |
|        | 0.1600 | escription | ,4,7 | 027901 |     |             |
|        |        | of         |      |        |     |             |
|        |        | materials  |      | 45     |     |             |
|        |        | used to    |      | 358502 |     |             |
|        |        | produce    |      |        |     |             |
|        |        | the        |      |        |     |             |
|        |        | product    |      |        |     |             |
+--------+--------+------------+------+--------+-----+-------------+
| 61-2a  | 83     | D          | 3    | 42     | A   | CBI         |
|        | 0.1620 | escription | ,4,7 | 027901 |     |             |
|        |        | of         |      |        |     |             |
|        |        | production |      | 45     |     |             |
|        |        | process    |      | 358502 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 487201 |     |             |
+--------+--------+------------+------+--------+-----+-------------+
| 61-2a  | 83     | D          | 3    | 42     | A   | CBI         |
|        | 0.1650 | escription | ,4,7 | 027901 |     |             |
|        |        | of         |      |        |     |             |
|        |        | f          |      | 45     |     |             |
|        |        | ormulation |      | 358502 |     |             |
|        |        | process    |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 487201 |     |             |
+--------+--------+------------+------+--------+-----+-------------+
| 61-2b  | 83     | Discussion | 3    | 42     | A   | CBI         |
|        | 0.1670 | of         | ,4,7 | 027901 |     |             |
|        |        | formation  |      |        |     |             |
|        |        | of         |      | 42     |     |             |
|        |        | impurities |      | 027902 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 43     |     |             |
|        |        |            |      | 277802 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 358503 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 358504 |     |             |
+--------+--------+------------+------+--------+-----+-------------+
| 62-1   | 83     | P          | 3    | 42     | A   | CBI         |
|        | 0.1700 | reliminary | ,4,7 | 027902 |     |             |
|        |        | analysis   |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 358504 |     |             |
+--------+--------+------------+------+--------+-----+-------------+
| 62-2   | 83     | Certified  | 3    | 42     | A   | CBI         |
|        | 0.1750 | limits     | ,4,7 | 027901 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 43     |     |             |
|        |        |            |      | 277802 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 43     |     |             |
|        |        |            |      | 533901 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 358503 |     |             |
|        |        |            |      |        |     |             |
|        |        |            |      | 45     |     |             |
|        |        |            |      | 358505 |     |             |
+--------+--------+------------+------+--------+-----+-------------+
| 62-3   | 83     | E          | 3    | 42     | A   | Reverse     |
|        | 0.1800 | nforcement | ,4,7 | 027902 |     | Phase HPLC  |
|        |        | analytical |      |        |     | Method      |
|        |        | method     |      | 45     |     |             |
|        |        |            |      | 358506 |     | Gas         |
|        |        |            |      |        |     | Chr         |
|        |        |            |      |        |     | omatography |
+--------+--------+------------+------+--------+-----+-------------+
| 64-1   | 83     | Submittal  | 3    |        | N/A |             |
|        | 0.1900 | of samples | ,4,7 |        |     |             |
+--------+--------+------------+------+--------+-----+-------------+

> ^1^A = Acceptable; N/A = Not Applicable.
>
> ^2^Use Pattern:
>
> \(3\) Commercial, institutional and industrial premises and equipment
>
> \(4\) Residential and public access premises
>
> \(7\) Materials preservatives
>
> **Table 3: Physical and Chemical Properties for Triclosan**

+-------+-------+---------------+------+-------+-----+----------------+
| **Old | **New | **            | *    | **M   | *   | **Results or   |
| Guid  | Guid  | Requirement** | *Use | RID** | *St | Deficiency**   |
| eline | eline |               | Patt |       | atu |                |
| No.** | No.** |               | ern^ |       | s^1 |                |
|       |       |               | 2^** |       | ^** |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-2  | 830   | Color         | 3    | 420   | A   | White Crystals |
|       | .6302 |               | ,4,7 | 27902 |     |                |
|       |       |               |      |       |     |                |
|       |       |               |      | 453   |     |                |
|       |       |               |      | 58502 |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-3  | 830   | Physical      | 3    | 420   | A   | Crystalline    |
|       | .6303 | state         | ,4,7 | 27902 |     | Powder         |
|       |       |               |      |       |     |                |
|       |       |               |      | 453   |     |                |
|       |       |               |      | 58502 |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-4  | 830   | Odor          | 3    | 420   | A   | Faint Odor     |
|       | .6304 |               | ,4,7 | 27902 |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-5  | 830   | Melting Point | 3    | 420   | A   | 56.5˚C         |
|       | .7200 |               | ,4,7 | 27904 |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-6  | 830   | Boiling Point | 3    |       | N/A |                |
|       | .7220 |               | ,4,7 |       |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-7  | 830   | Density, Bulk | 3    | 420   | A   | 1.55 x 10^3^   |
|       | .7300 | Density, or   | ,4,7 | 27904 |     | kg/m^3^ at     |
|       |       | Specific      |      |       |     | 22˚C           |
|       |       | Gravity       |      |       |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-8  | 830   | Water         | 3    | 420   | A   | 0.012 g/l at   |
|       | .7840 | solubility:   | ,4,7 | 27904 |     | 20˚C           |
|       |       | column        |      |       | A   |                |
|       |       | elusion       |      |       |     | \> 65g/100g    |
|       |       | method;       |      |       |     | fat at 37°C    |
|       |       | **shake flask |      |       |     |                |
|       |       | method.**     |      |       |     |                |
|       |       |               |      |       |     |                |
|       |       | Fat           |      |       |     |                |
|       |       | Solubility:   |      |       |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-8  | 830   | Solubility in | 3    |       | N/A | Readily        |
|       | -xxxx | organic       | ,4,7 |       |     | soluble        |
|       |       | solvents      |      |       |     |                |
|       |       |               |      |       |     | (Source:       |
|       |       |               |      |       |     | TOXNET)        |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-9  | 830   | Vapor         | 3    | 420   | A   | 5.2E-6 mm Hg   |
|       | .7950 | Pressure      | ,4,7 | 27904 |     | at 25˚C        |
|       |       |               |      |       |     |                |
|       |       |               |      |       |     | 2.2E-6 mm Hg   |
|       |       |               |      |       |     | at 20˚C        |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-10 | 830   | Dissociation  | 3    | 420   | A   | pK~a~=8.14 at  |
|       | .7370 | constants in  | ,4,7 | 27904 |     | 20°C           |
|       |       | water         |      |       |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-11 | 830   | Partition     | 3    | 420   | A   | Log P~o/w~ =   |
|       | .7550 | coefficient   | ,4,7 | 27902 |     | 4.8 at 25˚C    |
|       |       | (n-octanol /  |      |       |     |                |
|       |       | water), shake |      | 420   |     |                |
|       |       | flask method. |      | 27904 |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-12 | 830   | pH            | 3    |       | N/A |                |
|       | .7000 |               | ,4,7 |       |     |                |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-13 | 830   | Stability to  | 3    | 420   | A   | No thermal     |
|       | .6313 | normal and    | ,4,7 | 27902 |     | effect.        |
|       |       | elevated      |      |       | A   |                |
|       |       | temperatures. |      | 430   |     | []{.mark}      |
|       |       |               |      | 22601 | A   |                |
|       |       | Stability to  |      |       |     | Stable when    |
|       |       | metals        |      | 432   |     | exposed to     |
|       |       |               |      | 77801 |     | Metals.        |
|       |       | Stability to  |      |       |     |                |
|       |       | metal ions    |      |       |     | Triclosan      |
|       |       |               |      |       |     | exposed to     |
|       |       |               |      |       |     | zinc and zinc  |
|       |       |               |      |       |     | ions showed    |
|       |       |               |      |       |     | the same       |
|       |       |               |      |       |     | decrease in %  |
|       |       |               |      |       |     | a.i. as        |
|       |       |               |      |       |     | control.       |
|       |       |               |      |       |     |                |
|       |       |               |      |       |     | Triclosan      |
|       |       |               |      |       |     | exposed to     |
|       |       |               |      |       |     | iron ions      |
|       |       |               |      |       |     | showed a       |
|       |       |               |      |       |     | greater        |
|       |       |               |      |       |     | decrease in %  |
|       |       |               |      |       |     | a.i. than the  |
|       |       |               |      |       |     | control.       |
+-------+-------+---------------+------+-------+-----+----------------+
| 63-17 | 830   | Storage       | 3    | 453   |     | No             |
|       | .6317 | stability     | ,4,7 | 58502 |     | deterioration  |
|       |       |               |      |       |     | after 12       |
|       |       |               |      |       |     | months storage |
+-------+-------+---------------+------+-------+-----+----------------+

> ^1^ A = Acceptable; N/A = Not applicable.
>
> ^2^Use Pattern:
>
> \(3\) Commercial, institutional and industrial premises and equipment
>
> \(4\) Residential and public access premises
>
> \(7\) Materials preservatives

**BIBLIOGRAPHY**

**[MRID]{.underline} [Citation ]{.underline}**

42027901 LoMenzo, J. (1991) Irgasan DP 300: Product Identity and
Composition. Unpublished study prepared by Ciba-Geigy Corp.

42027902 Basingthwaite, J. (1983) Irgasan DP 300: Batch Analysis and
Analytical Methodology. Unpublished study prepared by Ciba-Geigy Ag.

42027904 Vogel, A. (1990) Irgasan 300 DP: Report on Melting
Point/Melting Range. Unpublished study prepared by Ciba-Geigy Ltd.

43022601 Morrissey, M. (1993) Stability Determination of Irgasan DP 300
in the Presence of Metal: Final Report: Lab Project Number: HWI
6117-246. Unpublished study prepared by Hazleton Wisconsin, Inc.

43277801 Morrissey, M. (1994) Stability Determination of Irgasan DP300
Exposed to Metal Ions: Final Report: Lab Project Number: HWI 6117-261.
Unpublished study prepared by Hazleton Wisconsin, Inc.

43277802 Schatowitz, B. (1990) Additional Data Required by the US EPA
for the Results of the Analysis of Irgasan DP300 for Dioxins/Furans: Lab
Project Number: 102290. Unpublished study prepared by Ciba-Geigy Ltd.

43533901 Schatowitz, B. (1995) Additional Data Required by the U.S. EPA
for the Product Analysis of Irgasan DP 300: Lab Project Number: 11995.
Unpublished study prepared by Ciba Research Services.

45358501 Harvey, W. (2001) Product Identity and Composition: Triclosan.
Unpublished study prepared by Vivimed Labs LTD. 3 p. {OPPTS 830.1550}

45358502 Harvey, W. (2001) Description of Production Process: Triclosan.
Unpublished study prepared by Vivimed Labs LTD. 64 p. {OPPTS 830.1620}

45358503 Harvey, W. (2001) Discussion of Formation of Impurities:
Triclosan. Unpublished study prepared by Vivimed Labs LTD. 18 p. {OPPTS
830.1670}

45358504 Harvey, W. (2001) Preliminary Analysis: Triclosan. Unpublished
study prepared by Vivimed Labs LTD. 19 p. {OPPTS 830.1700}

45358505 Harvey, W. (2001) Certified Limits: Triclosan. Unpublished
study prepared by Vivimed Labs LTD. 21 p. {OPPTS 830.1750}

**BIBLIOGRAPHY**

**[MRID]{.underline} [Citation ]{.underline}**

45358506 Harvey, W. (2001) Enforcement Analytic Method: Triclosan.
Unpublished study prepared by Vivimed Labs LTD. 5 p. {OPPTS 830.1800}

45472801 Harvey, W. (2001) Summary of Physical/Chemical Properties:
Triclosan. Unpublished study prepared by Har-Met International, Inc. 4
p.

Sign-off Date : 10/17/07

DP Barcode No. : D33540l