![](media/image1.wmf){width="1.3576388888888888in"
height="1.375in"}UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

**[MEMORANDUM Date: September 12, 2006]{.underline}**

**SUBJECT:** Environmental Fate and Ecological Risk Assessment Chapter
(DP Barcode D310733) in Support of Phase I of the Reregistration
Eligibility Decision on Antimycin A (PC Code 006314)

**FROM:** Dirk Young, Ph.D., Environmental Engineer

Thomas Steeger, Ph.D., Senior Biologist

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507C)

Office of Pesticide Programs

**THROUGH:** Elizabeth Behl, Branch Chief

Environmental Risk Branch IV

Environmental Fate and Effects Division (7507C)

Office of Pesticide Programs

TO: Lance Wormell, Chemical Review Manager

Dirk Helder, Risk Manager

Special Review and Reregistration Division (7508C)

Office of Pesticide Programs

The Environmental Fate and Effects Division (EFED) has completed the
draft environmental fate and ecological risk assessment chapter (DP
Barcode D310733) in support of Phase I of the reregistration eligibility
decision on antimycin A (PC Code 006314). Conclusions regarding the
environmental fate, ecological effects and ecological risks associated
with the current uses of antimycin A can be found in the executive
summary of the attached document. EFED recommends that application of
antimycin directly to water only be made through close adherence to
established standard operating procedures intended to limit the extent
to which antimycin can move outside of treatment areas.

The risk assessment relies on a treatment rate of 25 µg/L. This is a
rough approximation of the maximum rate since the label was not
specific. This rate is based on the use closure memo dated October 26,
2005.

**Data Gaps**

**Table A1** identifies the status of environmental fate and transport
study requirements and **Table A2** identifies the status of ecological
effects study requirements. In a memo (DP Barcode D276036) dated July
20, 2001, aqueous photolysis (**Guideline §161-2**),
leaching-adsorption-desorption (**Guideline §163-1**), and anaerobic
aquatic metabolism (**Guideline §162-3**) studies were waived assuming
that antimycin is inactivated after the desired kill is achieved. The
only guideline studies that were required are hydrolysis (**Guideline
§161-1**) and aerobic aquatic metabolism (**Guideline §162-4**) focusing
on parent compound alone and not its degradates. Although hydrolysis
data are available on antimycin, there is considerable variability in
the data and degradation half-lives range from 30 minutes to 47 days.
Additionally, while there are anecdotal data suggesting that antimycin A
is inactivated through the use of an oxidant, *e.g.* potassium
permanganate, there are no data to identify the reaction products.
Although environmental fate data gaps have been identified, efforts are
underway by the U. S. Geological Survey, the EPA Office of Research and
Development and the Office of Pesticide Programs' Biologic and Economic
Assessment Division laboratories to address some of the uncertainties
regarding analytical method development and potential routes of
degradation.

[]{.mark}

Most of the ecological effects data gaps result from uncertainties
surrounding potential ecological risks associated with the chronic
effects of antimycin in aquatic animals (**Guideline §72-4**) and
terrestrial animals (avian **Guideline §71-4** and mammalian **Guideline
§83-4**). Additionally, there are no data to evaluate the toxicity of
antimycin to aquatic (**Guideline §123-2**) or terrestrial plants
(**Guideline §123-1**). These data are important in assessing direct and
indirect risks to Federally-listed endangered and/or threatened species.

**Labeling Recommendations**

According to the Label Review Manual, the following label statements are
recommended:

Non-Target Organism Statements

The following statement is required because the pesticide is intended
for outdoor use and contains an active ingredient which has a mammalian
acute oral LD~50~ ≤100 mg/kg:

> *\"This pesticide is toxic to mammals.\"*

The following statement is required because the pesticide is intended
for outdoor use and contains an active ingredient with a fish acute
LC~50~ and an aquatic invertebrate EC~50~ ≤1 ppm:

> *\"This pesticide is toxic to fish, aquatic invertebrates, oysters and
> shrimp."*

+------+-------+---------------+----------+--------------+-----------+
| **T  |       |               |          |              |           |
| able |       |               |          |              |           |
| A1.  |       |               |          |              |           |
| E    |       |               |          |              |           |
| nvir |       |               |          |              |           |
| onme |       |               |          |              |           |
| ntal |       |               |          |              |           |
| Fate |       |               |          |              |           |
| and  |       |               |          |              |           |
| T    |       |               |          |              |           |
| rans |       |               |          |              |           |
| port |       |               |          |              |           |
| Data |       |               |          |              |           |
| Requ |       |               |          |              |           |
| irem |       |               |          |              |           |
| ents |       |               |          |              |           |
| for  |       |               |          |              |           |
| A    |       |               |          |              |           |
| ntim |       |               |          |              |           |
| ycin |       |               |          |              |           |
| A**  |       |               |          |              |           |
+======+=======+===============+==========+==============+===========+
| **G  |       | **Data        | **MRID / | **Study      | **Are     |
| uide |       | Requirement** | ACC \#** | Clas         | Data      |
| line |       |               |          | sification** | Adequate  |
| \#** |       |               |          |              | for Risk  |
|      |       |               |          |              | Asse      |
|      |       |               |          |              | ssment?** |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Hydrolysis    | MRID     | Supplemental | YES       |
| 61-1 | .2120 |               | 46023101 |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Pho           | Waived   |              |           |
| 61-2 | .2240 | todegradation |          |              |           |
|      |       | in Water      |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Pho           | Waived   |              |           |
| 61-3 | .2410 | todegradation |          |              |           |
|      |       | on Soil       |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Pho           | Waived   |              |           |
| 61-4 | .2370 | todegradation |          |              |           |
|      |       | in Air        |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Aerobic Soil  | Waived   |              |           |
| 62-1 | .4100 | Metabolism    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Anaerobic     | Waived   |              |           |
| 62-2 | .4200 | Soil          |          |              |           |
|      |       | Metabolism    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Anaerobic     |          |              |           |
| 62-3 | .4400 | Aquatic       |          |              |           |
|      |       | Metabolism    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Aerobic       | 4        | Supplemental | YES       |
| 62-4 | .4300 | Aquatic       | 58959-01 |              |           |
|      |       | Metabolism    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Leac          | Waived   |              |           |
| 63-1 | .1240 | hing-Adsorpti |          |              |           |
|      |       | on/Desorption |          |              |           |
|      | 835   |               |          |              |           |
|      | .1230 |               |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Laboratory    | Waived   |              |           |
| 63-2 | .1410 | Volatility    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Field         | Waived   |              |           |
| 63-3 | .8100 | Volatility    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Terrestrial   | Waived   |              |           |
| 64-1 | .6100 | Field         |          |              |           |
|      |       | Dissipation   |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Aquatic Field | No data  |              |           |
| 64-2 | .6200 | Dissipation   | s        |              |           |
|      |       |               | ubmitted |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 835   | Forestry      | No data  |              |           |
| 64-3 | .6300 | Dissipation   | s        |              |           |
|      |       |               | ubmitted |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 850   | Accumulation  | In       |              |           |
| 65-4 | .1730 | in Fish       | Reserve  |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | None  | Accumula      | Waived   |              |           |
| 65-5 |       | tion-Aquatic, |          |              |           |
|      |       | Non-Target    |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | 8     | Small Scale   | Waived   |              |           |
| 66-1 | 35.71 | Prospective   |          |              |           |
|      |       | Groundwater   |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | None  | Small Scale   | Waived   |              |           |
| 66-2 |       | Retrospective |          |              |           |
|      |       | Ground Water  |          |              |           |
+------+-------+---------------+----------+--------------+-----------+
| 1    | None  | Large Scale   | Waived   |              |           |
| 66-3 |       | Retrospective |          |              |           |
|      |       | Ground Water  |          |              |           |
+------+-------+---------------+----------+--------------+-----------+

+-------------+----------+-------+---+------+---+----------+---------+
| **Table     |          |       |   |      |   |          |         |
| A2.**       |          |       |   |      |   |          |         |
| Ecological  |          |       |   |      |   |          |         |
| Effects     |          |       |   |      |   |          |         |
| Data        |          |       |   |      |   |          |         |
| R           |          |       |   |      |   |          |         |
| equirements |          |       |   |      |   |          |         |
| for         |          |       |   |      |   |          |         |
| Antimycin   |          |       |   |      |   |          |         |
| A.          |          |       |   |      |   |          |         |
+=============+==========+=======+===+======+===+==========+=========+
| **Guideline | **S      | *     | * |      | * |          | **Are   |
| \# and Data | pecies** | *Test | * |      | * |          | Data    |
| Re          |          | Mat   | M |      | S |          | A       |
| quirement** |          | erial | R |      | t |          | dequate |
|             |          | **^a^ | I |      | u |          | for     |
|             |          |       | D |      | d |          | Risk    |
|             |          | (%    | / |      | y |          | Assess  |
|             |          | a.i.) | A |      | C |          | ment?** |
|             |          |       | C |      | l |          |         |
|             |          |       | C |      | a |          |         |
|             |          |       | # |      | s |          |         |
|             |          |       | * |      | s |          |         |
|             |          |       | * |      | i |          |         |
|             |          |       |   |      | f |          |         |
|             |          |       |   |      | i |          |         |
|             |          |       |   |      | c |          |         |
|             |          |       |   |      | a |          |         |
|             |          |       |   |      | t |          |         |
|             |          |       |   |      | i |          |         |
|             |          |       |   |      | o |          |         |
|             |          |       |   |      | n |          |         |
|             |          |       |   |      | * |          |         |
|             |          |       |   |      | * |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| **Avian and |          |       |   |      |   |          |         |
| Mammalian   |          |       |   |      |   |          |         |
| Studies:**  |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 71-1, Acute | Mallard  | NS    | 1 |      | S |          | YES     |
|             | duck     |       | 3 |      | u |          |         |
| Avian Oral, |          |       | 5 |      | p |          |         |
| Quail/Duck  |          |       | 9 |      | p |          |         |
|             |          |       | 2 |      | l |          |         |
|             |          |       | 4 |      | e |          |         |
|             |          |       |   |      | m |          |         |
|             |          |       |   |      | e |          |         |
|             |          |       |   |      | n |          |         |
|             |          |       |   |      | t |          |         |
|             |          |       |   |      | a |          |         |
|             |          |       |   |      | l |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
|             | Bobwhite | NS    | 1 |      | S |          | YES     |
|             | quail    |       | 3 |      | u |          |         |
|             |          |       | 5 |      | p |          |         |
|             |          |       | 9 |      | p |          |         |
|             |          |       | 2 |      | l |          |         |
|             |          |       | 4 |      | e |          |         |
|             |          |       |   |      | m |          |         |
|             |          |       |   |      | e |          |         |
|             |          |       |   |      | n |          |         |
|             |          |       |   |      | t |          |         |
|             |          |       |   |      | a |          |         |
|             |          |       |   |      | l |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 71-2, Acute |          | No    |   |      |   |          |         |
| Avian Diet, |          | Data  |   |      |   |          |         |
| Quail/Duck  |          | Subm  |   |      |   |          |         |
|             |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 71-4, Avian |          | No    |   |      |   |          |         |
| Re          |          | Data  |   |      |   |          |         |
| production, |          | Subm  |   |      |   |          |         |
| Quail/Duck  |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 81-1, Acute | Rat      |       |   |      |   |          |         |
| Mammalian   |          |       |   |      |   |          |         |
| Oral LD~50~ |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 83-1,       | Rat      | No    |   |      |   |          |         |
| Chronic Tox |          | Data  |   |      |   |          |         |
| Rodent      |          | Subm  |   |      |   |          |         |
|             |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| *           |          |       |   |      |   |          |         |
| *Freshwater |          |       |   |      |   |          |         |
| Fish        |          |       |   |      |   |          |         |
| Studies:**  |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-1, Acute | Bluegill | 95.5% | 4 |      | S |          | YES     |
| Freshwater  | sunfish  |       | 0 |      | u |          |         |
| Fish        |          |       | 0 |      | p |          |         |
| Toxicity    | Green    |       | 9 |      | p |          |         |
|             | sunfish  |       | 8 |      | l |          |         |
|             |          |       | 0 |      | e |          |         |
|             | Rainbow  |       | - |      | m |          |         |
|             | trout    |       | 0 |      | e |          |         |
|             |          |       | 1 |      | n |          |         |
|             | C        |       |   |      | t |          |         |
|             | utthroat |       |   |      | a |          |         |
|             | trout    |       |   |      | l |          |         |
|             |          |       |   |      |   |          |         |
|             | Coho     |       |   |      |   |          |         |
|             | salmon   |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Lake     |       |   |      |   |          |         |
|             | trout    |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Goldfish |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Fathead  |       |   |      |   |          |         |
|             | minnow   |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Black    |       |   |      |   |          |         |
|             | bullhead |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Channel  |       |   |      |   |          |         |
|             | catfish  |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Mosquito |       |   |      |   |          |         |
|             | fish     |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | La       |       |   |      |   |          |         |
|             | rgemouth |       |   |      |   |          |         |
|             | bass     |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Yellow   |       |   |      |   |          |         |
|             | perch    |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | White    |       |   |      |   |          |         |
|             | crappie  |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
|             | Pa       |       |   |      |   |          |         |
|             | ddlefish |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-4(a),    |          | No    |   |      |   |          |         |
| Early       |          | Data  |   |      |   |          |         |
| Life-Stage  |          | Subm  |   |      |   |          |         |
| Fish        |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-5 Life   |          | No    |   |      |   |          |         |
| Cycle Fish  |          | Data  |   |      |   |          |         |
|             |          | Subm  |   |      |   |          |         |
|             |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| *           |          |       |   |      |   |          |         |
| *Freshwater |          |       |   |      |   |          |         |
| I           |          |       |   |      |   |          |         |
| nvertebrate |          |       |   |      |   |          |         |
| Studies:**  |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-2(a),    | W        | 95.5% | 4 |      | S |          | YES     |
| Acute       | aterflea |       | 0 |      | u |          |         |
| Freshwater  |          |       | 0 |      | p |          |         |
| I           | Scud     |       | 9 |      | p |          |         |
| nvertebrate |          |       | 8 |      | l |          |         |
| Toxicity    | Isopod   |       | 0 |      | e |          |         |
|             |          |       | - |      | m |          |         |
|             |          |       | 0 |      | e |          |         |
|             |          |       | 1 |      | n |          |         |
|             |          |       |   |      | t |          |         |
|             |          |       |   |      | a |          |         |
|             |          |       |   |      | l |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-4(b),    |          | No    |   |      |   |          |         |
| Life        |          | Data  |   |      |   |          |         |
|             |          | Subm  |   |      |   |          |         |
| Cycle       |          | itted |   |      |   |          |         |
| Aquatic     |          |       |   |      |   |          |         |
| I           |          |       |   |      |   |          |         |
| nvertebrate |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| **Estua     |          |       |   |      |   |          |         |
| rine/Marine |          |       |   |      |   |          |         |
| Fish        |          |       |   |      |   |          |         |
| Studies:**  |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-3, Acute | Spot     | 95.5% |   | 4    |   | Supp     | YES     |
| Estua       |          |       |   | 0098 |   | lemental |         |
| rine/Marine |          |       |   | 0-01 |   |          |         |
| Tox Fish    |          |       |   |      |   |          |         |
| LC50        |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-3, Acute | [        | []{.  |   |      |   |          |         |
| Estua       | ]{.mark} | mark} |   |      |   |          |         |
| rine/Marine |          |       |   |      |   |          |         |
| Tox         |          |       |   |      |   |          |         |
| I           |          |       |   |      |   |          |         |
| nvertebrate |          |       |   |      |   |          |         |
| LC50        |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-4,       |          | No    |   |      |   |          | []      |
| Chronic     |          | Data  |   |      |   |          | {.mark} |
| Estua       |          | Subm  |   |      |   |          |         |
| rine/Marine |          | itted |   |      |   |          |         |
| Tox Fish    |          |       |   |      |   |          |         |
| NOAEC       |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| []{.mark}   |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| **Estua     |          |       |   |      |   |          |         |
| rine/Marine |          |       |   |      |   |          |         |
| Aquatic     |          |       |   |      |   |          |         |
| Inver       |          |       |   |      |   |          |         |
| tebrates:** |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-3(b),    |          | No    |   |      |   |          | NO      |
| Acute       |          | data  |   |      |   |          |         |
| Estua       |          | subm  |   |      |   |          |         |
| rine/Marine |          | itted |   |      |   |          |         |
| Mollusk     |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-3(c),    | Pink     | 95.5% |   | 4    |   | Supp     | YES     |
| Acute       | Shrimp   |       |   | 0098 |   | lemental |         |
| Estua       |          |       |   | 0-01 |   |          |         |
| rine/Marine |          |       |   |      |   |          |         |
| Shrimp      |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 72-4,       |          | No    |   |      |   |          | NO      |
| Chronic     |          | data  |   |      |   |          |         |
| Estua       |          | subm  |   |      |   |          |         |
| rine/Marine |          | itted |   |      |   |          |         |
| Shrimp      |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| **          |          |       |   |      |   |          |         |
| Terrestrial |          |       |   |      |   |          |         |
| and Aquatic |          |       |   |      |   |          |         |
| Plants:**   |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 122-1,      |          | No    |   |      |   |          | NO      |
| Seedling    |          | Data  |   |      |   |          |         |
| Emergence   |          | Subm  |   |      |   |          |         |
| and         |          | itted |   |      |   |          |         |
| Vegetative  |          |       |   |      |   |          |         |
| Vigor       |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 122-2,      |          | No    |   |      |   |          | NO      |
| Aquatic     |          | Data  |   |      |   |          |         |
| Plant       |          | Subm  |   |      |   |          |         |
| Growth      |          | itted |   |      |   |          |         |
| (Tier I)    |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 123-1, Seed |          | No    |   |      |   |          | NO      |
| Germ,       |          | Data  |   |      |   |          |         |
| Seedling    |          | Subm  |   |      |   |          |         |
| Emergence,  |          | itted |   |      |   |          |         |
| Vegetative  |          |       |   |      |   |          |         |
| Vigor       |          |       |   |      |   |          |         |
|             |          |       |   |      |   |          |         |
| (Tier II)   |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 123-2       |          | No    |   |      |   |          | NO      |
| Aquatic     |          | Data  |   |      |   |          |         |
| Plant       |          | Subm  |   |      |   |          |         |
| Growth      |          | itted |   |      |   |          |         |
| (Tier II)   |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| **          |          |       |   |      |   |          |         |
| Terrestrial |          |       |   |      |   |          |         |
| Insect      |          |       |   |      |   |          |         |
| Testing:**  |          |       |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 141-2,      |          | No    |   |      |   |          | NO      |
| Honey Bee   |          | Data  |   |      |   |          |         |
| Residue on  |          | Subm  |   |      |   |          |         |
| Foliage     |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+
| 144-1,      |          | No    |   |      |   |          | NO      |
| Honey Bee   |          | Data  |   |      |   |          |         |
| Acute       |          | Subm  |   |      |   |          |         |
| Contact     |          | itted |   |      |   |          |         |
+-------------+----------+-------+---+------+---+----------+---------+

^a^ TGAI = technical grade active ingredient; TEP = typical end-use
product; ND = not determined, because purity was not reported or
original study was unavailable.

^b^ Study was classified as supplemental pending upgrade to acceptable.
The upgrade was denied, but for piscicidal uses EPA did not require a
repeat of the study due to the preponderance of data available.