Page 1 of 15 

### UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES
AND TOXIC SUBSTANCES



### September 24, 2009

MEMORANDUM

SUBJECT: Response to Comment s on the Reregistration Eligibility Decision for

Antimycin A

FROM: Lance Wormell, Chemical Review Manager

Dirk Helder , Chemical Review Manager

R isk Management Implementation Branch II

Pesticide Re

- evaluation Division (7508P)

THROUGH: Margaret Rice, Chief

R isk Management Implementation Branch II

Pesticide Re

- evaluation Division (7508P)

TO: Public Docket EPA

- HQ

- OPP

- 2006

- 1002

This document presents the Environmental Protection Agency‟s (EPA or “the Agency”) formal response to the comments receiv ed on the 2007 Reregistration Eligibility Decision (RED) for Antimycin A . These comments were received during the

60

- day public comment period that ended on August 13, 2007. During the comment period, EPA received responses from various stakeholders incl uding state fish management agencies, interest groups, members of the public, and the user community. Comments are presented in bold font and EPA‟s response is presented below each

comment.

Comment: The rationale for requiring a 7

- day interval before re stocking fish following a “total kill” treatment is unclear and the restriction is unnecessary. The restriction should allow for restocking after levels are below the limit of detection.

EPA response: No quantitative risk assessment for dietary exposure to antimycin A was done, thus the Agency‟s goal is to completely eliminate potential dietary exposure. The Agency believes a 7

- day prohibition on restocking fish following a total kill treatment

will ensure there are no concentrations of antimycin A in t he treated water and no

residues in fish harvested from those treated ponds. Dep ending on environmental conditions, the expected half

- life of antimycin A ranges from several minutes to approximately 12 hours. Based on the conservative estimate that antim ycin A will have aPage 2 of 15



### half

- life of 12 hours, the Agency estimates that greater than 99% of the compound will have degraded after 7 days and concentrations will be below the limit of detection and

fish can then be re

- stocked. The Agency is allowing the option of either waiting a minimum of 7 days after treatment before restocking fish or restocking fish after 3 consecutive monitoring samples taken no less than 4 hours apart demonstrate that antimycin A levels are below the limit of detection (0.015 ppb).

Comm ent: Consumption of fish should be prohibited for 12 months following a “partial kill” treatment to prevent dietary exposure to antimycin A residues in those

treated fish rather than specifying an exact cutoff in antimycin A water

concentration.

EPA resp onse: When data are not available to estimate residues of pesticides in food or feed, as is the case with antimycin A , the Agency typically requires a 12

- month pre

harvest interval. EPA considers 12 months to be sufficient time to allow residues to

dissi pate below levels that may pose a risk to human health unless data are available to indicate the contrary. A ntimycin A does not bioconcentrate in fish nor does it bioaccumulate in aquatic food chains. Antimycin A is applied only once, therefore, long

ter m or repeat exposure to antimycin A is not expected to occur. Based on the chemical‟s low likelihood to bioconcentrate and the fact that fish would only be exposed one time and for a short duration, the Agency agrees that a 12

- month harvesting restriction is necessary and will preclude dietary exposure to antimycin A residues in fish f ollowing

p artial kill treatments

.

Comment: Antimycin A is applied at a rate of 5

- 10 parts per billion (ppb) to kill unwanted fish in channel catfish ponds (i.e., ponds that are supplied with natural water sources and, consequently, contain unwanted fish species). The proposed 12

- month prohibition on consuming treated fish would either eliminate this use or, when fish from these ponds are used for stocking other water bodies

, result in the spreading unwanted fish species in public fishing lakes.

EPA response: The Agency believes antimycin A can safely be used in water bodies to

control unwanted fish but the use of antimycin A in public lakes or applications to fish

stocked in public lakes prior to the 12

- month pre

- harvest interval is not allowed

. No quantitative risk assessment for dietary exposure to antimycin A was done

, thus the Agency‟s goal is to eliminate potential dietary exposure. EPA considers 12 months to be

suff icient time to allow residues to dissipate below levels that may pose a risk to human health unless data are available to indicate the contrary. Based on the chemical‟s low likelihood to bioconcentrate and the fact that fish would only be exposed one time and for a short duration, the Agency believes the 12

- month harvesting restriction is necessary to preclude dietary exposure to antimycin A residues in surviving fish from use in aquaculture.

Comment: Recreational access should be allowed in flowing wa ters after the chemical has moved beyond the access point and p rohibiting recreational activities for 7 days after treatment is not necessary in flowing water and contact withPage 3 of 15



### standing water should only be prohibited when concentrations exceed the detectio n level of 0.015 ppb.

EPA response: Since no toxicity or exposure data are available to conduct a quantitative

risk assessment for recreation al exposure to antimycin A, the Agency‟s goal is to

eliminate any potential recreational exposure. Most flowing water also have stagnant

areas that receive little to no stream circulation where antimycin A concentrations could remain high (e.g., those pockets or edd ies treated with handheld sprayers)

. Depending on

environmental conditions and based on the conservat ive estimate that antimycin A will

have a half

- life of 12 hours, the Agency estimates that it will take 7 days for at least 99% of the compound to degrade and concentrations will be below the limit of detection. Therefore, t he Agency believes a 7

- day proh ibition on recreational access following an antimycin A is necessary in the absence of data to confirm that a shorter restriction would be protective.

Comment: Requiring PPE when reentering treated areas is not necessary when antimycin concentration s in the water are less than current detection level of

0.015 ppb.

EPA response: The Agency agrees that c oncentrations below the limit of detection ( 0 .015 ppb ) would not likely present a risk of concern to handlers re

- entering the treated area; however

, the current analytical method requires laboratory analysis, the results of which would not likely be available for several days

. Therefore, i n most cases water sampling would not be useful to determine concentrations in the water body following an application and prior to reentry into a treated water body by handlers. D epending on environmental conditions and based on the conservative estimate that antimycin A will

have a half

- life of 12 hours, the Agency estimates that it will take 7 days for at least 99%

of the compound to degrade below the limit of detection. Therefore, t he Agency will require PPE (waders, chemical

- resistant gloves and protective eyewear) f or handler s

re entering a treated water body within 7 days following an antimycin A application . The

PPE is similar to what most anglers wear when entering a stream environment and the Agency does not believe it is overly burdensome.

Comment: Requiring PPE when reentering a treated stream is unnecessary provided antimycin A has had sufficient time to pass through the treatment area

.

EPA response: Most treatment areas, including flowing water bodies, have stagnant areas that receive little to no stream circulation (e.g., those pockets or edd ies treated with handheld sprayers). D epending on environme ntal conditions, the expected half

- life of antimycin A ranges from several minutes to approximately 12 hours. Based on the conservative estimate that antimycin A will have a half

- life of 12 hours, the Agency

estimates that residues in water could exist fo r 7 days following an application and

handlers reentering a treated stream could be exposed to antimycin A concentrations

. Thus, the Agency is requiring PPE for handlers re entering a treated stream including waders, chemical

- resistant gloves and protectiv e eyewear. The PPE is similar to whatPage 4 of 15



### most anglers wear when entering a stream environment and the Agency does not believe it is overly burdensome.

Comment: Respirator requirements should be removed because they are not

warranted based on risk and will be overly burdensome for applicators

.

EPA response: U sing the existing database, EPA cannot conduct a quantitative risk assessment and, therefore, cannot conclude that inhalation exposure to handlers without a respirator result in risk below the Agency‟s level of concern (LOC). The Agency is requiring respiratory protection for those handlers most likely to have respiratory

exposure including mixers, loaders and handlers exposed to liquid concentrate and applicators using handheld equipment. EPA does no t believe dust mist respirators are overly burdensome for these handlers but will consider removing or reducing this restriction upon submission of exposure and toxicity data that demonstrate handler risk

below the LOC.

Comment: Deactivation with potass ium permanganate should not be required because potassium permanganate use may not always be necessary or desirable depending on the results of the pre

- treatment environmental analysis.

EPA response: The persistence of antimycin A can vary depending on e nvironmental conditions. Because of uncertainties associated with the potential effects on humans and because of the known effects of antimycin A on nontarget animals such as aquatic invertebrates, the Agency is attempting to limit nontarget exposure by r equiring antimycin A deactivation with potassium permanganate when the piscicide is applied to flowing water. Depending on flow rates, environmental conditions and treatment rates, antimycin A can potentially move beyond targeted treatment areas and expan d the affected area. The extent to which this would occur could be highly variable and uncertain. Exposure of nontarget organisms outside the treatment area is intended to be limited through rigorous application standard operating procedures used by trai ned fishery professionals and deactivating antimycin A with potassium permanganate. The Agency agree s there are some situations where deactivation is not possible or unnecessary, e.g. in a steep canyons and those situations will be outlined in the antimyc in

A SOP manual

.

Comment: Geographically specific restrictions on the use of antimycin A should not be implemented so that any take of l isted species may be authorized by the appropriate authority.

EPA response: The RED has not required any geographica lly specific restrictions

. Applicators using a ntimycin A in l isted species habitat must consult with the US Fish and Wildlife Service. The requirements for conducting formal or informal consultation, depending on the nature of the action and the potentia l species and/or habitat affected, will be presented in the a ntimycin A SOP manual.Page 5 of 15



### Comment: The prohibition of use in estuarine/marine environments should be

removed because uses and risks are similar for these environments.

EPA response: It is EPA ‟s understand ing that antimycin A is not used in

estuarine/marine environments and no data have been submitted on its fate and/or toxicity

to estuarine/marine environments/organisms. EPA will consider removing this restriction upon submission of updated labe ls with instructions for use in estuarine/marine

environments as well as data characterizing the f ate and toxicity of antimycin A in the

marine/estuarine environment.

Comment: All enforceable label language should appear on the product label and

the a nti mycin A Standard Operating Procedures (SOP) manual should contain only advisory/informational statements. Because piscicidal applications are so complex and because circumstances vary significantly, it is impossible to craft mandatory

detailed instruction s that will apply in every situation.

EPA response: The Agency believes a ntimycin A applications are often quite complex requiring many factors be considered by the certified applicators. The Agency agrees that labels should include enforceable language and may need to incorporate by reference more detailed, instructions in the antimycin A SOP manual.

Comment: Collection and disposal of dead fish should not be required.

EPA response: The labeling requirements state that, users should collect and bury dead fish where practical. It is not a requirement.

Comment: Rinsate from cleaning activities should be disposed of in the treatment

area.

EPA response: The Agency agrees r insate from cleaning activities should be disposed of

in the treatment area. The label table will be revised to make this clarification.

Comment: There is no guidance to differentiate between partial and complete kills (except in the concentrations and durations used and the sensitivities of the target species) and label language required by the RED that refers to partial kills should

be removed.

EPA response: It is EPA ‟s understand ing that antimycin A is currently used for both complete kills and selective kills , although selective kill applications are used only in aquacultur e. T herefore, detailed directions for use are required for both uses. In lieu of these instructions, the registrant may amend the product label to allow only complete kills and prohibit any other uses. Detailed guidance for conducting bioassays and desi gning treatment will be presented in the antimycin A SOP m anual.

Comment: The Certified Applicator should only be required to be in contact with the treatment operation and not onsite.Page 6 of 15



### EPA response: Because piscicidal applications are so complex and be cause circumstances vary significantly, the Certified Applicator must remain onsite during

treatment

.

Comment: Placarding instructions in the RED are excessive , especially for large

treatment areas

.

EPA response: The label table will be revised to acco unt for reduced placarding requirements for large or inaccessible treatment areas.

Comment: Handheld equipment should not be limited to backpack sprayers. Antimycin A is sometimes applied with electric or gasoline powered sprayers

mounted on vehicles.

EPA response: The label table will be revised to include instructions for “handheld equipment , handheld nozzles or other equipment.”

Comment: Chest waders may not be appropriate in all instances (depending on water depth, etc.) and should be changed to “waders.”

EPA response: The label table will be revised to specify “waders” instead of “chest

waders.”

Comment: The benefits and alternatives comparison of rotenone and antimycin A appears to be inaccurate. Both piscicides are used at low concentratio ns to remove nonnative fish from high alpine water bodies, rotenone could replace antimycin A in all situations, and the chemical cost is substantially higher for antimycin A.

EPA response: EPA agrees that both rotenone and antimycin A can and are used t o remove nonnative fish from high alpine water bodies as well as to selectively remove fish from standing water bodies. The Agency‟s assessment did not imply that rotenone is not used for this purpose, only that, rotenone is most often used to treat standi ng water, such as large ponds, lakes, and reservoirs. However, and while acknowledging that the cost for rotenone varies widely depending on application rates, the Agency believes that, in general, the cost of treating water bodies with rotenone and antimy cin A appears to be comparable (Kaul et al., 2006). The Agency would be interested in additional cost comparison by the respondents or any other cost analysis comparing rotenone and antimycin A, under similar conditions, and using application rates intende d to achieve comparable results.Page 7 of 15



### T able s 1 and 2 update and supers ede Table s 6 and 7, respectively, in the May 2007 RED (EPA 738

- R

- 07

- 007)

.

Table 1. Revised Label Changes Summary Table for Antimycin A Manufacturing

- Use Products 1

Description Amended Label ing Language for Manufacturing Use Products Placement on Label

For all Manufacturing

Use Products “Only for formulation into a piscicide (fish kill) for the following use(s)
[ MUP registrant, insert those uses that are being supported by the

RED ].”

“Only for formulation into products that are classified as Restricted Use.” Directions for Use

Additional Uses “This product may be used to formulate products for any additional use(s) not listed on the MUP label if the formulator, user group, or grower has com

plied with U.S. EPA submission requirements regarding support of such use(s).” Directions for Use

Environmental Hazards Statements Required by the RED and Agency Label Policies “This product is extremely toxic to fish and other aquatic organisms.”

“Do n ot contaminate water, food, or feed by storage or disposal.”

“Do not discharge effluent containing this product to sewer systems without notifying the local sewage treatment plant authority." Precautionary Statements

1 Note: Currently there is no registe red manufacturing use product for antimycin A.Page 8 of 15



### Table 2. Label Changes Summary Table for Antimycin A End

- Use Products Intended for Occupational and Residential Use
Description Amended Labeling Language for End

- Use Products Placement on Label

RUP “Rest ricted Use Pesticide

. ”

“Due to toxicity to fish and other aquatic organisms and the need for specialized applicator training.”

“For retail sale to and use by only Certified Applicators or persons under their direct supervision and only for those uses cov ered by the Certified Applicator‟s certification.” This statement must appear at the very top of the label's front panel [see 40 CFR 156.10(j)(2)(i) for more information]. No other wording or symbols may appear above the RUP statement.

SOP Manual “THE A PPLICATOR IS RESPONSIBLE FOR CONFORMING TO

THE LABEL. IMPORTANT GUIDANCE ON THE SAFE AND

EFFECTIVE USE OF THIS PRODUCT AND CONFORMING TO THE

LABEL IS PROVIDED IN THE ANTIMYCIN A STANDARD OPERATING PROCEDURES (SOP) MANUAL, AVAILABLE FROM

THE REGISTRANT.” I mmediately below the RUP statement on the label and on the cover page of the

a ntimycin A SOP Manual.Page 9 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

PPE Requirements Established by the

RED 1

for all Formulations “Pers onal Protective Equipment (PPE)

Some materials that are chemical

- resistant to this pro duct are” [ EUP registrant, insert correct chemical

- resistant material ] . “If you want more options, follow the instructions for category” [ EUP registrant, insert A, B, C, D, E, F, G, or H ] “on an EPA chemical

- resis tance category selection chart.

All mixe rs
, loaders and other handler s exposed to the concentrate through cleaning equipment or spills must wear: * long

- sleeved shirt and long pants,

* chemical

- resistant gloves, * shoes plus socks, * protective eyewear, and

* a dust mist filtering respirator (M SHA/NIOSH approval number prefix TC

21C), or a NIOSH approved respirator with any N, R, P, or HE filter, and

* a chemical

- resistant apron.

All applicators and other handlers must wear: * long

- sleeved shirt and long pants,

* chemical

- resistant gloves,

* sh oes plus socks, and * protective eyewear.

In addition, applicators using handheld equipment

, handheld nozzles or other equipment must wear:
* coveralls , and * a dust/mist filtering respirator (MSHA/NIOSH approval number prefix

TC

- 21C), or a NIOSH appro ved respirator with any N, R, P, or HE filter

.

Exception: Applicators exposed to splashing water or walking in water that is being treated must wear waders instead of coveralls . All other applicators and handlers may substitute waders for long pants if

necessary

. ” Precautionary Statements under the heading “Hazards to Humans and

Domestic Animals”Page 10 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

User Safety Requirements “Do not wear contact lenses while handling this product. Ocular contact with this product can melt a contact lens onto the eye.”

“ Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions for washables exist, use detergent and hot water. Keep and wash PPE separately from other laundry.”

“Discard clothing and other absorbent materials that have been d renched or heavily contaminated with concentrated product . Do not reuse them.” Precautionary Statements under the heading “Hazards to Humans and Domestic Animals” immediately following/below the PPE requirements

User Safety

Recommendations “User Safety R ecommendations”

“Certified Applicators applying or supervising any aspect of the application of this product should attend a training program for piscicide applications.”

“Users should wash hands before eating, drinking, chewing gum, using tobacco, or us ing the toilet.”

“Users should remove clothing/PPE immediately if pesticide gets inside. Then wash thoroughly and put on clean clothing.”

“Users should remove PPE immediately after handling this product. Wash the outside of gloves before removing. As soon as possible, wash thoroughly and change into clean clothing.” Precautionary Statements under the heading “Hazards to Humans and Domestic Animals” immediately following/below the Engineering

Controls.

(These statements must be placed in a

separate box .)

Environmental Hazards “Environmental Hazards”

“This product is extremely toxic to fish and other aquatic organisms.”

“Do no t contaminate water outside the treatment are a by cleaning of equipment or disposal of equipment wash waters.”

“Do not contam inate water outside the treatment area, food, or feed by storage or disposal.”

“Do not discharge effluent containing this pesticide into sewage systems without notifying the sewage treatment plant authority (POTW).” Precautionary Statements under the

head ing “Hazards to Humans and Domestic Animals” immediately following/below User Safety

RecommendationsPage 11 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

Personal Protective Equipment When Re

entering Treated Areas “Re

- entering the Treatment Area”

“ For the first 7 days after treatment, handlers re

- entering treated water

must wear at a minimum the following PPE:

* W aders and l ong

- sleeved shirt,

* c hemical

- resistant gloves, and * protective eyewear.” Direction for Use under the heading

“Re

- Entering the Treatment Area”

Complete and Selective

kills “Complete a nd Selective Kills”

“This product may be used to achieve a „complete kill‟ or a „ selective kill.‟ Complete kills are intended to eliminate all fish in the treatment

area whereas selective kills, used only in aquaculture, are intended to
eliminate or redu ce the number of only certain (more vulnerable) species. Detailed instructions for conducting complete and selective kills are presented in the a ntimycin A SOP Manual.” Directions for Use under the heading “Complete and Selective K ills”Page 12 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

General Applicati on Restrictions for all

Formulations “The Certified Applicator supervising the treatment must remain on

- site for the duration of the application.”

“ Do not allow recreational access (e.g., wading, swimming, boating, fishing ) within the treatment area while antimycin A is being applied and for 7 days after treatment .”

“ For „complete kill‟ use, d o not apply this product in a way that will result in treatment concentrations greater than 2 5 parts per billion. For „selective kill‟ use in aquaculture, d o not ap ply this product in a way that will result in treatment concentrations greater than 10 parts per billion. ”

“Do not apply this product in a way that will contact workers or other persons, either directly or through drift. Only protected handlers may be

i n the area during application.”

“Do not apply with any application method or equipment or in a manner not specified on this label or in the a ntimycin A SOP Manual .”

"This product must not be applied to estuarine or marine environments."

“Where practica l, users should collect and bury dead fish.” Directions for Use

Additional Requirements for Use in Aquaculture “ Additional Requirements for Use in Aquaculture ”

“When antimycin A is applied as a selective kill in aquaculture, t he

C ertified A pplicator sup ervising the application must inform the owner/operator of the aquaculture site being treated t hat surviving fish

must not be harvested for food or feed for a minimum of 12 months after

treatment.”

“When antimycin A is applied as a complete kill in aquacu lture, t he

C ertified A pplicator supervising the application must inform the owner/operator of the aquaculture site being treated t hat the water body

must not be restocked with fish for a minimum of 7 days after treatment

, OR once 3 consecutive monitoring s amples taken no less than 4 hours
apart demonstrate that antimycin A levels are below the limit of detection (0.015 ppb)

. ” Directions for Use under the heading

“ Additional Requirements for Use in Aquaculture ”Page 13 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

Drinking Water

Notification Requirements “Drin king Water Notification”

“ If drinking water intakes are present within the treatment area, or a hydrologic connection to wells exist, 7

- 14 days prior to application, the Certified Applicator or designee under his/her direct supervision must provide notifi cation to the party responsible for the public water supply or to individual private water users. Drinking water intakes within the treatment area must be closed during treatment and until 3 consecutive monitoring samples taken no less than 4 hours apart demonstrate that antimycin A levels are below the limit of detection (0.015 ppb).”

“Detailed instructions for public involvement, notifications , and monitoring are presented in the a ntimycin A SOP Manual.” Directions for Use under the heading “Drinking Wa ter Notification”Page 1 4 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

Notification Requirements for all applications except aquaculture applications “ Placarding of Treatment Areas , Except Aquaculture Applications ”

“The Certified Applicator in charge of the application (or someone under his/her supervisi on) must placard all access areas to the

treatment area. P lacards must be placed every 250 feet along the

shoreline of the treated area

, OR, at public access points (e.g., trailheads and roads and trails). Placards must contain the
information below:”

* “DANGER/PELIGRO”

* “DO NOT ENTER WATER /NO ENTRE: Pesticide Application” * The name of the product applied * The agency or entity performing the application * The purpose of the application * The start date and time of application

* The end date and time o f application

* The duration of the area closure

* “Recreational access (e.g., wading, swimming, boating, fishing

, etc. ) within the treatment area is prohibited while a ntimycin A is being applied and for 7 days after treatment .”

* “ Do not swim or wade in t reated water .”

* “Do not consume water or dead fish from treated water.” * The name, address, and telephone number of the responsible agency or entity performing the application

.

“Signs must remain legible during the entire posting period and must be

remo ved no earlier than 7 days after treatment and no later than 14 days

after treatment.” Directions for Use under the heading

“ Placarding of Treatment Areas ”Page 15 of 15

Description Amended Labeling Language for End

- Use Products Placement on Label

Deactivation wit h

Potassium Permanganate “Deactivation with Potassium Permanganate”

“ Flow in a stream and o utflow from a treated lake beyond the treatment

area must be deactivated with potassium permanganate to minimize exposure beyond the treatment area unless unnecessa ry. (See the

a ntimycin A SOP Manual for the definition of treatment area, examples when treatment with potassium permanganate is unnecessary and detailed guidance for deactivati ng a ntimycin A with potassium permanganate

. ) ” Directions for Use under the hea ding

“Deactivation with Potassium Permanganate (KMnO 4 )”

1 PPE that is established on the basis of Acute Toxicity of the end

- use product must be compared to the active ingredient PPE in this document. The more protective PPE must be placed in the product labeling. For guidance on which PPE is considered more protective, see PR Notice 93

- 7.