UN ITED STATES ENVIRONMENTAL PR OTECTIO AGENCY WASHINGTON D.C.

, 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTIO N PREVENT I O N

P C C ode: 114401

, 1144 02 DP Barcode : 426394

Dat e: June 1 1

, 2015

MEMORA N D U M

SUBJECT :

TO:

FROM:

REVIEWED BY:

APP ROV E D BY: R eg istrati o n R ev iew: Pr e limin ary Environme nt al Fate a nd Eco l og ic a l Ri sk Assessment Endangered Species Effect s D eterm in ati o n for Aci fluorf en

Lata Venkateshwara, C h e mical Re v i ew Man age r Tracy Perry

, Team Leader K

e ll y Sherman

, Act in g Branch C hief Ri s k Managem e nt a nd Implem en tati on Branch TII P es ticid e Re-evaluation Divis i o n (7508P) ( 

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E n v i ronm e nta l Fate and Effects Divi s i o n (7507 P)

Monica W a it

, Ri s k A ssess ment Proce ss Lead e r Environmenta l Ri s k B ranch V I E n v ironm e ntal Fate and E ffect s Di v i s i on (7507P )

# ~cJ M a rk C o r bi n , B ranch Chief E n v ironmental Ri s k Br a n c h VI Env ironm en t a l Fate and E ffect s D i v i s ion (7507P ) 

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Th e E n v ironmenlal Fa t e a nd Effec t s Di v i sion (E F ED) ha s comp l eted a p r e li minary ri s k ass ess m e nt for lhe h e rbi cide acifluorfen ( PC Code I 14 40 I

, 11440 2). Ri s k conc lusions can be found within th e a na c h ed assessment but the fo ll ow in g unc e rtainti es should be n o ted.

U nc e rtaintie s

R eeva l uation of see dlin g e mer ge nce i s neces sa r y and l ack ofa frank va Ju e fo r all spec i es in c r eases uncertainty in t e rr es trial plant assess m e nt.2 The data for pollinators are incomplete; only an acute contact study is available for honey bees. This study does not result in an indication of risk, but as the newly r equired studies come in, potential risk to these taxa will be re

- evaluated.

There are no LOC exceedances for aquatic invertebrates for any of the uses of acifluorfen. However, there are no available data for sediment dwelling species, which increases the uncertainty regarding potential effects to aquatic invertebrates. Parent acifluorfen does not trigger the requirement of sediment data as it degrades rapidly in anaerobic conditions. However, acifluorfen rapidly transforms in anaerobic conditions to amino acifluorfen which may be of comparable toxicity to acifluorfen according to structural activity toxicity estimates (ECOSAR). Therefore, exposure and toxicity to sediment dwelling species is an uncertainty.3 

# Environmental Fate and Ecological Risk Assessment for the Registration Review of Acifluorfen

Acifluorfen 5

- [2

- Chloro

- 4

- (trifluoromethyl)phenoxy]

- 2

- nitrobenzoic acid CAS Registry Number 50594

- 66

- 6 PC Code s 114401, 114402 Date: June 11 , 201 5 D 4 26394

Prepared by: Andrew Shelby, Physical S cientist

, ERB VI Brian D. Kiernan, Biologist

, ERB VI U. S. Environmental Protection Agency Office of Pesticide Programs Environmental Fate and Effects Division Environmental Risk Branch IV

1200 Pennsylvania Ave., NW Mail Code 7507P Washington DC 20460 Reviewed by: Monica Wait

, RAPL, ERB V I Mark Corbin, Branch Chief, ERB VI4 

### Table of Contents
1. Executive Summary

................................ ................................ ................................ ............... 5 1.1. Nature of Chemical Stressor

................................ ................................ ................................ .................... 5 1.2. Risks to Non

- target Organisms

................................ ................................ ................................ ............... 5 1.3. Conclusions

- Exposure Characterization

................................ ................................ .............................. 6 1.4. Conclusions

- Effects Characterization

................................ ................................ ................................ .. 6 2. Problem Formulation

................................ ................................ ................................ ............ 7 2.1. Nature of Regula tory Action

................................ ................................ ................................ .................... 7 2.2. Stressor Source and Distribution

................................ ................................ ................................ ............ 7 2.2.1. Nature of Chemical Stressor

................................ ................................ ................................ ................ 7 2.2.2. Overview of Pesticide Usage

................................ ................................ ................................ ............... 8 2.3. Receptors

................................ ................................ ................................ ................................ ................... 9 2.3.1. Aquatic and Terrestrial Effects

................................ ................................ ................................ ............ 9 2.3.2. Ecosystems Potentially at Risk

................................ ................................ ................................ ............ 9 2.4. Assessment Endpoints

................................ ................................ ................................ ............................ 10 2.5. Conceptual Model

................................ ................................ ................................ ................................ ... 10 2.5.1. Risk Hypotheses

................................ ................................ ................................ ................................ 10 2.5.2. Conceptual Diagram

................................ ................................ ................................ .......................... 10 2.6. Analysis Plan

................................ ................................ ................................ ................................ ........... 12 2.6.1. Residues of Concern

................................ ................................ ................................ .......................... 12 2.6.2. Preliminary Identification of Data Gaps and Uncertainties

................................ ............................... 12 2.6.3. Multiple Active Ingredients, Mixtures and Formulated Products

................................ ..................... 13 2.6.4. Measures of Exposure

................................ ................................ ................................ ....................... 13 2.6.5. Measures of Effect

................................ ................................ ................................ ............................. 14 2.6.6. Integration of Exposure and Effects

................................ ................................ ................................ .. 15 3. Analysis

................................ ................................ ................................ ................................ . 16 3.1. Use Characterization

................................ ................................ ................................ .............................. 16 3.2. Exposure Characterization

................................ ................................ ................................ .................... 17 3.2.1. Environmental Fate and Transport Characterization

................................ ................................ ......... 17 3.2.2. Measures of Aquatic Exposure

................................ ................................ ................................ .......... 19 3.2.3. Measures of Terrestrial Exposur e

................................ ................................ ................................ ...... 23 3.3. Ecological Effects Characterization

................................ ................................ ................................ ...... 24 3.3.1. Aquatic Toxicity Assessment

................................ ................................ ................................ ............ 25 3.3.2 Terrestrial Effects Characterization

................................ ................................ ................................ ... 28 3.4. ECOTOX Open Literature

................................ ................................ ................................ .......................... 30 4.0 Risk Characterization

................................ ................................ ................................ ...... 30 4.1. Risk Estimation

................................ ................................ ................................ ................................ ....... 30 4.1.1. Aquatic Organisms

................................ ................................ ................................ ............................ 31 4.1.2. Terrestri al Organisms

................................ ................................ ................................ ........................ 34 4.2. Risk Description

................................ ................................ ................................ ................................ ...... 38 4.2.1 Exposure to Aquatic Organisms

................................ ................................ ................................ ........ 38 4.2.2 Risks to Aquatic Animals

................................ ................................ ................................ .................. 39 4.2.3 Risks to Aquatic Plants

................................ ................................ ................................ ...................... 40 4.2.4. Risks to Mammals

................................ ................................ ................................ ............................. 41 4.2.5. Risk to Birds

................................ ................................ ................................ ................................ ...... 41 4.2.6. Potential Effects to Terrestrial Invertebrates

................................ ................................ ..................... 42 4.2.7. Ri sk to Terrestrial Non

- target Plants

................................ ................................ ................................ . 42 4.3. Additional Uncertainties and Data Gaps

................................ ................................ .............................. 44 4.3.1. Fate and Transport

................................ ................................ ................................ ............................. 44 4.3.2. Effects

................................ ................................ ................................ ................................ ................ 44 6. References

................................ ................................ ................................ ............................. 465 1. Executive Summary

1.1. Nature of Chemical Stressor

Registration revi ew is currently underway for the herbicide sodium acifluorfen (s odium 5

- (2

- chloro

- a,a,a

- trifluoro

- p

- tolyloxy)

- 2

- nitrobenzoate; PC Code 114402) and acifluorfen free acid (PC Code 114401). Sodium acifluorfen rapidly dissociates in water to acifluorfen free acid , and therefore exposure and toxicity to both moieties will hereafter be ref erenced as "acifluorfen"

. Acifluorfen is a light dependent peroxidizing herbicide (LDPH). It has registered uses on soybean, peanuts , rice and strawberries with maximum singl e application rates up to 0. 375 pounds of active ingredient per acre ( lb a.i./A ) and maximum seasonal application rates as high

as 0.75 lbs a

. i

. /A

.

1.2. Conclusions: Risks to Non

- target Organisms

Terrestrial Plants . As expected with an herbicide, non

- t arget terrestrial plants are likely to be adversely affected by exposure to acifluorfen. Grass species (Poaceae) in the available plant studies are considerably less sensitive than non

- grass species (including non

- grass monocots). RQs for upland, semi

- aq uatic and spray drift only are 3.6, 20 and 10 for the strawberry applications, although the LOC of 1.0 is exceeded for all use patterns. Additionally, the distance off the field at which spray drift alone (from aerial applications) results in an exceedanc e of the LOC greater than 1000 feet for both the strawberry and soybean/peanut use patterns and 643 feet for the rice use pattern.

Birds and Surrogates (Reptiles and Terrestrial Amphibians ). Acute RQs exceed the RQ (0.5) for some size class/forage item co mbinations for the strawberry and soybean/peanut use patterns. However, there are no exceedances based on the subacute dietary endpoints. Chronic RQs exceed the LOC by up to 9

- fold and exceed for all use patterns.

Mammals . Although there are no exceedan ces of the acute LOC, chronic exposure RQs exceed the LOC (1.0) by up to 4

- fold (strawberry use).

Fish (and Aquatic

- phase Amphibians). RQs for acute exposure to fish do not result in any exceedances. However, the chronic RQ, adjusted by the 29X LDPH fac tor exceed the LOC by 6

- fold for the rice use. The LDPH adjustment factor is discussed more fully in the body of the
assessment.

Aquatic Invertebrates. There are no LOC exceedances for aquatic invertebrates for any of the uses of acifluorfen. However, t here are no available data sediment dwelling species, which increases the uncertainty regarding potential effects to aquatic invertebrates.

Honey Bees and Terrestrial Invertebrates . The data for these taxa are incomplete; only an acute contact study is av ailable for honey bees. This study does not result in an indication of risk, but as the newly required studies come in, potential risk to these taxa will be re

- evaluated.6 Aquatic Plants . There are no LOC exceedances for aquatic plants for any of the use s of acifluorfen. No adverse effects to aquatic plants are expected based on the available data.

1.3. Conclusions

- Exposure Characterization

Acifluorfen is expected to be persistent in both terrestri al and aquatic environments under aerobic and anae robic conditions, and is considered mobile to moderately mobile , and nonvolatile. Acifluorfen is persistent in a erobic soil, with measured half

- lives ranging from 100 to 200 days

. Acifluorfen is stable to hydrolysis and degrades readily via photolysis (t 1/2 =15 days)

. Acifluorfen does not bioconcentrate in aquatic organisms. Acifluorfen is expected to dissipate through spray drift, leaching

, runoff , and anaerobic metabolism

. Aquatic exposure estimates for acifluorfen are based on the exposure of the pa rent compound acifluorfen only

. In clusion of the only major degradate, amino acifluorfen

, in a total toxic residue (TTR) app r oach

r esults in less than a 10% increase in surface water EECs

, would not impact risk conclusions and is, therefore, not in cluded i n risk estimation. Inclusion of amino acifluorfen in a TTR approach would significantly impact pore water/benthic concentrations but are not presented due to lacking toxicity data on sediment dwelling species. Acute 1

- in

- 10 year estimated environmental

c oncentrations (EECs) in surface water for all modeled uses of acifluorfen ranged from 9 μg/L to 218 μg/L. Terrestrial animal exposure estimates are residue levels modeled by T

- REX and parameterized with maximum application rates

. Terrestrial plant exposu res are based on parent acifluorfen alone (see Section 2.6.4 )

.

1.4. Conclusions

- Effects Characterization

Aquatic Organisms

Acifluorfen is slightly toxic to fish and aquatic invertebrates on an acute exposure basis. Effects were seen in fish and aq uatic invertebrates from chronic exposure at concentrations of 1. 0 mg ai/L and above . Because acifluorfen is an LDPH whose chronic toxicity to aquatic animals may be enhanced under high ultraviolet ( uV ) light, effects may be greater at higher altitudes or lower latitudes and in clear

, shallow waters

. Aquatic plants exhibited inhibition of biomass when exposed to acifluorfen

. Terrestrial Organisms

Acifluorfen is classified as moderately toxic to birds and slightly toxic to mammals on an acute exposure ba sis. A two

- generation study on reproduction and fertility in the laboratory rat showed acifluorfen to cause chronic toxicity effects on parent s ( mortality ) and pups ( decreased weights )

. In birds

, there were effects on number hatched/live embryo from chro nic exposure

. No effects were reported from acute contact exposure to honey bees

. As expected with an herbicide, effects on biomass and stand height were observed in terrestrial plant studies. The vegetative vigor exposure route (foliar spray) and lif e stage is generally more sensitive to acifluorfen than the seedling emergence exposure route (soil exposure) and life stage

, based on the available studies . Sensitivity varies by species, with non

- grasses are generally more sensitive than grasse s.7 2. Problem Formulation

The purpose of problem formulation is to provide the foundation for the environmental fate and ecological risk assessment for the registration review risk assessment for the herbicide sodium acifluorfe n (s odium 5

- (2

- chloro

- a,a,a

- triflu oro

- p

- tolyloxy)

- 2

- nitrobenzoate; P C Code 114402) and acifluorfen free acid (PC Code 114401). As mentioned previously, s odium acifluorfen rapidly dissociates in water to acifluorfen free acid , and therefore exposure and toxicity to both moieties will herea fter be referenced as "acifluorfen". A cifluorfen is a non

- selective, post

- emergent contact herbicide used to control annual broadleaf weeds and some grasses in soybean, peanuts, rice and strawberries. The problem formulation sets the objectives for the r isk assessment, establishes a risk hypothesis and conceptual model depicting potential risk, and provides a plan for analyzing the data and characterizing the risk associated with the use s of acifluorfen (USEPA, 1998). This preliminary ecological risk ass essment draw s primarily from the Problem Formulation published in 2010 (DP 3 70340 ; 3/24/2010; available at regulations.gov in the public docket EPA

- HQ

- OPP

- 2010

- 0135

- 0003 ). Data submitted after the Problem Formulation are described in this assessment and u sed when appropriate.

2.1. Nature of Regulatory Action

The U.S. Environmental Protection Agency (EPA or the Agency) is required under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to ensure that the currently registered pesticide aciflu orfen remains eligible for registr a tion, and that it does not have the potential to cause unreasonable adverse effects to the environment

. T his assessment follows EPA guidance on conducting ecological risk assessments (USEPA, 1998) and , generally, the Off ice of Pesticide Program’s Overview Document, which contains guidance for assessing pesticide risks to non

target organisms (USEPA, 2004). Section 5 summarizes the Agency’s current approach to assessing risks from acifluorfen to F ederally

- listed threatene d and endangered (hereafter “listed”) species

. The end result of the EPA pesticide registration review process ( i.e. , the FIFRA regulatory action) is an approved product label. The label is a legal document that stipulates how and where a given pesticide may be used. Product labels (also known as end

- use labels) describe the formulation type ( e.g. , liquid or granular), acceptable methods of application, approved use sites, and any restrictions on how applications may be conducted. Therefore, the use s , o r potential

use s , described by the pesticide’s labels are considered “the action” being assessed. This assessment was prepared to support evaluation of the registration review of acifluorfen

.

2.2. Stressor Source and Distribution

2.2.1. Nature of Chem ical Stressor

Acifluorfen is a light dependent peroxidizing herbicide (LDPH). LDPHs are a class of weed control chemicals that act in plants by inhibiting the enzyme protoporphyrinogen oxidase (protox), which is the last common enzyme in the heme and chl orophyll biosynthetic pathways. Protox exists in both plants and animals, and the enzyme from both sources has been shown to be8 sensitive to many LDPHs. Acifluorfen is also known as polyphenol oxidase ( PPO ) inhibitor , in this case a diphenyl ether

.

Acif luorfen is registered for use on soybean, peanuts

, strawberries (annual and perennial) and rice

. This assessment is based on currently labeled maximum application rates for all uses. Maximum annual application rates range from 0.25 lb a .i./A (rice) to 0.7 5 lb a.i./A (strawberries). Specific use rates are discussed in Section 3.1

. These uses are not the only source of acifluorfen in the environment. Lactofen (PC Code 12888 8 ) , a unique pesticide active ingredient, rapidly metabolizes in aerobic soil (t 1/2 = 1 to 3 days) with the most significant major metabolite being acifluorfen (50% by mass )

. Acifluorfen and lactofen share some of the same registered uses including soybeans and peanuts for national Section 3 registrations . Acifluorfen is nationally reg istered for use on strawberries while lactofen is registered for strawberries in Oregon only with a Section 24c special local needs registration. For these common use sites

, concentrations of acifluorfen may be high er than what is estimated in this assess ment if an applicator applies different products containing both of these active ingredients to the same area

.

2.2.2. Overview of Pesticide Usage

Alt hough registered product labels indicate potential use of acifluorfen , usage data confirms that use is oc curring in the field and allow s for characterization of trends in use of acifluorfen over time at a national scale . Data are derived from USDA National Agricultural Statistics Service, private pesticide market research, and the California Department of Pe sticide Regulation. Usage d ata are summarized in Table 2.1

.

Table 2.1 . Screening Level Usage Estimates of Agricultural Uses of Acifluorfen as of July 7, 201 4

Average Annual Usage Percent Crop Treated Crop Lbs. A.I. Average Maximum
Peanuts 50,000 15 2 0 Rice 20,000 5 10 Soybeans 80,000 <1 <2.5 Strawberries <500 <1 <2.5

Soybeans , peanuts and rice are the dominant use pattern for acifluorfen

. Usage on strawberries has been comparatively minor

.9 2.3. Receptors

2.3.1. Aquatic and Terrestrial Effec ts

In ecological risk assessment, a receptor is a biological entity that is exposed to a stressor (USEPA, 1998). Consistent with the process described in the Overview Document (USEPA, 2004), this risk assessment uses a surrogate species approach in its e valuation of acifluorfen

. Toxicity data generated using surrogate test species, which are intended to be representative of broad taxonomic groups, are used to infer potential effects on a variety of species (receptors) included under these broader taxonom ic groupings. Table 2. 2 provides the general taxonomic groups and surrogate species tested to evaluate potential ecological effects of acifluorfen to broad classes of non

- target organisms. Within each of these taxonomic groups, a measure of effect is sel ected from among the available test data.

Table 2. 2 . Taxonomic Groups and Test Species Evaluated for Assessing Potential Ecological Effects of Acifluorfen

. Taxonomic Group Typical Species Birds 1 Mallard duck ( Anas platyrhynchos ) Bobwhite quail ( Col inus virginianus ) Mammals Norway rat ( Rat t us norvegicus ) Invertebrates Honey bee ( Apis mellifera L. ) Freshwater fish 2 Bluegill sunfish ( Lepomis macrochirus ) Rainbow trout ( Oncorhynchus mykiss ) Fathead minnow ( Pimephales promelas ) Freshwater invertebra tes Water flea ( Daphnia magna ) Midge ( Chironomus riparius ) Estuarine/marine fish Sheepshead minnow ( Cyprinodon variegatus ) Estuarine/marine invertebrates Mysid ( Americamysis bahia ) Eastern oyster ( Crassostrea virginica ) Terrestrial plants 3 Monocots

– Cr op species, such as corn ( Zea mays ) Dicots

– Crop Species, such as soybean ( Glycine max ) Aquatic plants and algae Duckweed ( Lemna gibba ) Freshwater Algae ( Pseudokirchneriella subcapitata )

1 Birds serve as surrogates for terrestrial

- phase amphibians and reptiles.

2 Freshwater fish may be surrogates for aquatic

- phase amphibians.

3 Four species of two families of monocots, of which one is corn; six species of at least four dicot families, of which one is soybeans. A root crop is required.

2.3.2. Ecosys tems Potentially at Risk

The ecosystems potentially at risk are often extensive in scope; therefore, it may not be possible to identify specific ecosystems during the development of a nation

- wide ecological risk assessment. However, in general terms, te rrestrial ecosystems potentially at risk could include the treated field and immediately adjacent areas that may receive drift and/ or runoff. Areas adjacent to the treated field could include cultivated fields, fencerows and hedgerows, meadows, fallow fie lds or grasslands, woodlands, riparian habitats, and other uncultivated areas.

Aquatic ecosystems potentially at risk include water bodies adjacent to or downstream from use10 sites, and might include lentic bodies such as ponds, lakes and reservoirs, or lotic ( flowing ) waterways such as streams or rivers as well as adjacent off

- channel habitats that may be permanently or intermittently connected to flowing waters. For uses in coastal areas, aquatic habitat also includes marine ecosystems, estuaries, emba yments, and near

- shore environments such as tidal marshes.

2.4. Assessment Endpoints

Assessment endpoints represent the actual environmental value that is to be protected, defined by an ecological entity ( e.g. , species, community) and its attribute or characteristics (USEPA, 1998). For acifluorfen , ecological entities of potential concern include the following: birds, amphibians, reptiles, mammals, freshwater fish and invertebrates, estuarine/marine fish and invertebrates,

non

- target terrestrial plants, terrestrial invertebrates, and aquatic vascular and non

- vascular plants. The attributes for each of these entities may include growth, survival, and reproduction ( Table 2. 3 in Section 2.6. 5 ).

2.5. Conceptual Model

For a pesticide to pose an ecological risk, it must reach ecological receptors in biologically significant concentrations. An exposure pathway is the means by which a pesticide moves in the environment from a source to an ecological receptor. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport mechanism, and a feasible route of exposure.

The conceptual model is intended to provide a written description and visual representation of anticipated relationships between acifluorfen , potential routes of exposure, and the predicted effects for the assessment endpoints. The conceptual model consists of two major components: risk hypotheses and a conc eptual diagram (USEPA, 1998).

2.5.1. Risk Hypotheses

For acifluorfen , the following generic ecological risk hypothesis is being employed for this screening

- level risk assessment:

Given the currently labeled uses of a cifluorfen and its environmental fate properties, there is a likelihood of exposure to non

- target terrestrial and aquatic organisms.

When used in accordance with the label, acifluorfen may result in adverse effects upon the survival, growth, and reprodu ction of non

- target terrestrial and aquatic organisms.

2.5.2. Conceptual Diagram

The conceptual model is a graphical representation of predicted relationships between ecological receptors, both listed (threatened and endange red) and non

- listed, and the stressors to which they may be exposed. A conceptual model specifies potential routes of exposure, biological receptor types, and effects endpoints of potential concern.11 Acifluorfen is applied as either a pre

- or post

- emerg ence herbicide

. Figure 2.1 depicts the stressors, exposure pathways, and potential effects to terrestrial organisms from currently labeled uses of acifluorfen

. Figure 2.2 depicts the stressors, exposure pathways, and potential effects to aquatic organism s from currently labeled uses of acifluorfen . For both figures, dotted lines indicate exposure pathways that are expected to have a low likelihood of contributing to ecological risk.

Figure 2.1. Conceptual model for acifluorfen effects on terrestrial organisms. 

### Stressor

Source

Receptors

Attribute Change Acifluorfen applied to use site

Direct Application/Spr ay Drift

Birds / Terrestrial

phase amphibia ns / reptiles / mammals Seeds

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in prey Habitat integrity Reduction in primary productivity Reduced cover Community change Terrestrial/riparian plants
grasses /forbs, fruit, terrestrial invertebrates Runoff

Mammals 

### Exposure Media Soil

Ingestion Ingestion

Ingestion Ingestion Dermal uptake/Ingestion Root uptake Wet/dry deposition

Birds / Amphibians

Ingestion12 Figure 2.2. Conceptual model for acifluorfen effects on aquatic organisms.

2.6

. Analysis Plan

2.6.1. Residues of Concern

Acifluorfen is relatively stable in the environment; no degradates or transformation products of enviro nmental concern have been identified. However, acifluorfen rapidly degrades to the persisten t degradate amino acifluorfen in anaerobic environments. Amino acifluorfen is not considered in risk estimation but inclusion as a toxic residue with acifluorfen is considered in risk characterization.

2.6.2. Preliminary Identification of Data Gaps and Uncertainties

With only one aerobic aquatic metabolism study and one anaerobic aquatic metabolism study available, a 3X adjustment is made to each half

- life to co nservatively account for the expected variability associated with those parameters and in accordance with EFED input param eter guidance

. Additional aerobic and anaerobic aquatic metabolism data on varied aquatic systems are likely to reduce the associated input parameter s since the 90 th percentile upper confidence limit 

### Stressor

Source

Receptors

Attribute Ch ange Acifluorfen applied to use site

Fish/aquatic

- phase amphibians Eggs Larvae Juveniles / Adults

Individual organisms Reduced survival Reduced growth Reduced reproduction Food chain Reduction in algae Reduction in prey Habitat integrity Reducti on in primary productivity Reduced cover Community change Surface water/

Sediment Runoff

Aquatic Animals Invertebrates Vertebrates 

### Exposure Media

Uptake/gills or integument

Ingestion Ingestion Wet/dry deposition Soil Groundwater

Uptake/gills

o r integument

Aquatic Plants Non

- vascular Vascular Uptake/cell, roots, leaves Riparian plant terrestrial
exposure pathways see

Figure 2.1 Spray Drift13 on the mean half

- life of all available metabolism studies is typically used as the input parameter (al though it is possible that additional data would indicate a longer half

- life )

. As prev iously stated, LDPHs are a class of weed control chemicals that act in plants by inhibiting the enzyme protoporphyrinogen oxidase (protox), which is the last common enzyme in the heme and chlorophyll biosynthetic pathways. Protox exists in both plants and animals and the enzyme from both sources has been shown to be highly sensitive to many LDPHs. Several studies have documented enhanced toxicity of LDPHs to fish in the presence of uV light compared to toxicity observed under standard laboratory lighting. Given that aquatic organisms are likely to be exposed simultaneously to LDPH and uV light in natural settings, concerns have been raised that guideline chronic exposure laboratory tests may underestimate the toxicity of LDPH s in the field. In the absenc e of chemical

- specific data on LDPH toxicity under enhanced uV lighting and until the analysis of the toxicity testing conducted by the LDPH T ask Force is complete, the Agency is applying an interim adjustment factor of 29X to adjust no observed adverse ef fect concentration (NOAEC) values to account for the potential enhanced toxicity of LDPH chemicals under natural sunlight (USEPA 2010a). This enhanced sensitivity to LDPHs is not necessarily limited to fish and could be observed in other taxa such as aqua tic invertebrates, birds, and mammals (Birchfield and Casida, 1997); however, the Agency is only applying an adjustment factor to fish at this time.

2.6.3

. Multiple Active Ingredients , Mixtures and Formulated Products

The Agency does not routinely incl ude in its risk assessments an evaluation of mixtures of active ingredients, either those mixtures of multiple active ingredients in product formulations or those in the applicator’s tank. In the case of multiple a.i. formulated product s (that is, a regis tered product containing more than one active ingredient), each active ingredient is subject to an individual risk assessment for regulatory decision regarding t hat active ingredient on a particular use site. If effects data are available for a formulated product containing more than one active ingredient, they may be used qualitatively or quantitatively in accordance with the Agency’s Overview Document (U.S. EPA 2004 ). Data on multiple a

. i

. product formulations was not discovered for acifluorfen.

2.6. 4. Measures of Exposure

Measures of exposure are based on aquatic and terrestrial models that estimate environmental concentrations of acifluorfen using labeled application rates and methods. For aquatic
exposure s, the Tier II model Surface Water Concen tration Calculator ( SWCC v1.106 ) was used to estimate screening

- level exposure concentrations in aquatic environments. The measure of exposure for aquatic species in surface water bodies receiving runoff and/or spray drift is a return frequency of 1

- in

- 10 years of the estimated environmental concentrations (EEC), based on 30

- year simulations. The maximum 1

- in

- 10 year return frequency concentration is used for estimating acute exposures to aquatic organisms (plants and animals); the 1

- in

- 10 year 21

- day

mea n concentration is used for assessing aquatic invertebrate chronic exposure; and the 1

- in

- 10 year 60

- day mean concentration is used for assessing chronic exposure for fish (and aquatic

phase amphibians for which fish serve as surrogates).

Terrestrial ex posure estimates for avian and mammalian risk assessments were derived using the14 T

- REX model (version 1. 5

. 2 ). T

- REX is used to calculate dietary

- and dose

- based EECs of acifluorfen for birds (and surrogates) and mammals inhabiting terrestrial areas. T

- RE X simulates a 1

- year time period. The default foliar dissipation half

- life of 35 days (Willis and McDowell 1987) is used as input to T

- REX

, when chemical

- specific data are not available; these data were not available for acifluorfen

. Exposure for terre strial plants inhabiting dry and semi

- aquatic areas ( e.g. , low

- lying wet areas that may dry up at times throughout the year), using TerrPlant v 1.2. 2 , is based on the following:

(1) the pesticide's water solubility and the amount of pesticide present on t he soil surface and its top one centimeter, (2) potential "sheet runoff" (one treated acre to an adjacent acre) for dry areas, (3) potential "channel runoff" (10 acres to a distant low

- lying acre) for semi

- aquatic or wetland areas, (4) fractional runoff va lues of 0.01, 0.02, and 0.05 for pesticide water solubilities of <10, 10

- 100, and <100 ppm, respectively (5) drift assumption of 1% for ground and 5% for aerial application

AgDRIFT ( v 2.01 ) is used to refine drift exposure to terrestrial plants, providing an estimate of the area of concern for these taxa surrounding the area of application.

2.6.5. Measures of Effect

Measures of effect are obtained from a suite of registrant

- submitted guideline studies that were conducted with a limited number of surro gate test species ( Table 2. 2 )

. No data regarding more sensitive endpoints for the apical endpoints used in this risk assessment were identified in a J anuary 2015 ECOTOX search conducted by the Office of Research and Development in Duluth for EFED.

The acute measures of effect used in th is screening

- level assessment are the LD 50 (median Lethal Dose), LC 50 (median Lethal Concentration) or EC 50 (median Effects Concentration). These are measures of acute toxicity which result in 50% of the respective effec t in tested organisms. The endpoints for chronic measures of exposure are generally the no observed adverse effect concentration (NOAEC) and the no observed adverse effect level (NOAEL). For plants, the EC 25 or IC 25 (inhibition concentration ) and NOAEL a re used as assessment endpoints. Toxicity studies were submitted for freshwater fish and invertebrates, estuarine/marine fish and invertebrates, aquatic plants, birds, mammals, bees, and t errestrial plants . The endpoints used for risk characterization ar e derived from studies which underwent review and were classified as “acceptable” (conducted under guideline conditions and considered to be scientifically valid) or “supplemental” (conditions deviated from guidelines but the results are considered to be

s cientifically valid).

Table 2. 3 lists the measures of environmental exposure and ecological effects used to assess the potential risks of acifluorfen to non

- target organisms.15 Table 2. 3 . Measures of Exposure and Measures of Effect Used in Assessing P otential Risks Associated with the Currently labeled Uses of Acifluorfen

.

Assessment Endpoint Surrogate Species and Measures of Ecological Effect 1 Measures of Exposure

Birds 2 Survival Lowest acute LD 50 (single oral dose test) and LC 50 (subacute dietary test) Upper

- bound residues on food items Reproduction and Growth Lowest NOAEC (21

- week reproduction test)

Mammals Survival Lowest acute LD 50 (single oral dose test) Reproduction and Growth Lowest NOAEC (2

- generation reproduction test)

Aquatic Animals (Fish and invertebrates) 3 Survival Lowest tested LC 50 or EC 50 (acute toxicity test) Peak EECs 4

Reproduction and Growth Lowest NOAEC (early life

- stage or full life

- cycle tests) 21

- day EECs for invertebrates and 60

- day EECs for fish 4

Terrestrial p lants 5 Survival and growth Lowest I C 25 (for non

- listed plants) and corresponding NOAEC (for listed plants) (endpoints derived for monocots and dicots from seedling emergence and vegetative vigor studies) Estimates of runoff and spray drift to non

- target ar eas

Insects 6 Survival (not quantitatively

assessed) Lowest honeybee LD 50 (acute contact test) Maximum application rate for honeybees and estimates of soil concentrations for earthworms
Aquatic plants (vascular and non

- vascular) Survival and growth Lowe st I C 50 (for non

- listed plants) and corresponding NOAEC or EC 05 (for listed plants) Peak EECs 4

1 The most sensitive species tested within taxonomic groups is used for screening

- level risk assessments.

2 Birds represent surrogates for terrestrial

- phase am phibians and reptiles.

3 Freshwater fish represent surrogates for aquatic

- phase amphibians.

4 Aquatic EECs are based on modeling described in Section 3.2.2.1

. 5 Four species of two families of monocots

- one is corn, six species of at least four dicot fami lies, of which one is soybeans.

6 Risk to terrestrial invertebrates from acifluorfen use is not evaluated, rather the potential hazard to honey bees (i.e. the available data) are qualitatively assessed.

2.6.6. Integration of Exposure and Effects

Exp osure and toxicity data are integrated in order to evaluate the risks of adverse ecological effects on non

- target species. For the screening

- level risk assessment of acifluorfen , the deterministic risk quotient (RQ) method is used to compare estimated exp osure concentrations (EECs) with measured toxicity values. The RQ method involves dividing point estimates of environmental concentrations by acute and chronic toxicity values. The resulting unitless RQs are then compared to the Agency’s Levels of Concer n (LOC) (USEPA, 2004) ( Table 2. 4 )

. These criteria are used to indicate when applications of acifluorfen , as directed on the current product labels, have the potential to cause adverse effects to listed and non

- listed non

- target organisms.16 Table 2.4. Age ncy Risk Quotient (RQ) Metrics and Levels of Concern (LOC) Per Risk Class.

RISK CLASS RISK DESCRIPTION RQ LOC Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non

- listed animals from acute
exposures Peak EEC/LC 50 1 0.5

Acute Listed Species Listed species may be potentially affected by acute
exposures Peak EEC/LC 50 1 0.05

Chronic Potential for effects to non

- listed and listed animals from chronic exposures 60

- day EEC/NOAEC (fish) 1 21

- day EEC/NOAEC (invertebrates) Aquatic Plants
Non

- Listed Potential for effects to non

- listed plants from exposures Peak EEC/LC 50 1 1
Listed Potential for effects to listed plants from exposures Peak EEC/NOAEC 1 Terrestrial Animals (mammals , birds and invertebrates )

Acute Potential for effects to non

- listed animals from acute
exposures EEC 2 /LC 50 (Dietary) 0.5 EEC/LD 50 (Dose)

Acute Listed Species Listed species may be potentially affected by acute
exposures EEC 2 /LC 50 (Dietary) 0.1 EEC/LD 50 (Dose)

Chronic Potential for effects to non

- listed and listed animals from chronic exposures EEC 2 /NOAEC 1

Terrestrial and Semi

- Aquatic Plants

Non

- Listed Potential for effects to non

- target, non

- listed plants from
exposures EEC/ EC 25 1

Listed Potential for effects to non

- target, listed plants from
exp osures EEC/ NOAEC 1 EEC/ EC 05

1 LC 50 or EC 50
.

3

. Analysis

3.1

. Use Characterization

Acifluorfen can be applied pre

- plant, pre

- emergence, post

- emergence, or as a burndown
treatment depending on the specific label language for a given use pattern. Early season applications conservatively represent burndown applications because application rates remain the same regardless of timing and the early season has more rainfall. Acifluorfen can be tank mixed with several other herbicides for either broadle af or grass

- specific control, depending on the objective.

Acifluorfen may be used on annual and perennial strawberries. It may be used on strawberr ies as a pre

- plant spray for annuals or a post

- emergence spray for perennial s at up to 0.375 lb a

. i

. /A for a single application with two applications per year (15 d ay minimum reapplication interval)

.17 U se patterns for acifluorfen are presented in Table 3.1

.

Table 3.1

. Use patterns and use rates for acifluorfen

.

Crop Registration (application timing) Max sing le application Max season application Minimum retreatment

interval (days) Peanuts Pre

- and post

- emergence 0.375 0.5 15 Soybeans Post

- emergence and burndown 0.375 0.5 15 Strawberries

- perennial Post

- emergent 0.375 0.75 15 Strawberries

- annual Pre

- plan t 0.375 0.75 15

Rice Post

- emergent 0.25 0.25 15 *

* M ultiple applications are allowed (if a lower than maximum single application rate is used during the first application), but the seasonal maximum application rate is 0.25 lbs a

. i

. /A

3.2. Exposure Cha racterization

3.2.1. Environmental Fate and Transport Characterization

The general physical/chemical properties of acifluorfen are summarized in Table 3.2

. Environmental fate and transport

- related properties of acifluorfen are characterized in further de tail in the following sections. The Agency’s understanding of these properties is informed by the available dataset. Many of the chemical properties and environmental fate parameters of acifluorfen listed in Table 3.2 are based on studies classified as s upplemental due to uncertainties or minor deviations from the test guideline

.

Table 3.2. General Physical

- Chemical and Environmental Fate Properties of Acifluorfen

Input Parameter Value Source/comment Molecular weight 361.66 g/mol Vapor pressure <1 E

- 7 torr @ 25 oC 41784601 Solubility in water 620.7 g/L @ 20C
Octanol

- Water Partition Coefficient 1.55 at pH 7 41891206 Hydrolysis half

- life Stable 00071584 00122757 00107479 Aqueous Photolysis half

- life 21.7 to 352 hours 41891208 42793502 44195001 4 4195002
Aerobic Soil metabolism half

- life 1 0 0 days 108 da ys 193 days 200 days 0014357218 Input Parameter Value Source/comment Anaerobic aquatic metabolism half

life 2.75 days 43155201 Water

- clay soil system under N 2 atmosphere, amino acifluorfen persisted through 375 day incubation
Aerobic Aquatic metabolism half

- life 114 days 42330601 E xtrapolated 35 day study Organic carbon normalized soil partition coefficient Koc 50, 57, 74, 165, 199 mL/g o.c. 42793501

Henry’s Law Constant 7.65 *10

- 10 atm

- m 3 /mol Calculated from vapor pressure and

so lubility

Laboratory studies

A cifluorfen is persistent in soil (aerobic soil metabolism half

- life of 170 days) and in aerobic aquatic environments (estimated aerobic half

- life of 117 days); it is less persistent in anaerobic conditions (aquatic half

- life estimated to be 2.75 days). A cifluorfen i s relatively mobile; K d s range from 0.148 to 3.10 g/mL. Adsorption and desorption were strongly correlated with soil clay content, organic carbon content, and cation exchange capacity. Acifluorfen undergoes photol ytic degradation in water with half

- lives ranging from 21.7 hours to 352 hours.

Thus acifluorfen may degrade rapidly in surface water bodies with clear and/or shallow water that is able to transmit adequate light. It is stable to hydrolysis, and photodeg radation on soil is not a major degradation route in the environment. Volatilization does not appear to be a significant dissipation pathway for acifluorfen (vapor pressure is <1E

- 7 torr ; Henry's Law constant is 7.65 x 10

- 10 atm m 3 /mol). Acifluorfen is n ot expected to bioaccumulate in aquatic organisms because of the low K ow .

Field studies

Available field studies for acifluorfen are summarized in Table 3.3

.

Table 3.3

. Field studies available for acifluorfen.

Study Value Comments Source
Terrestrial F ield Dissipation (Half

- life) 15 days 59 days After 2 months, residue levels were near detection levels Mississippi silt loam; leaching below 3

- in depth negligible during 179 days of study 00137756, 00143573

Aquatic Field Dissipation (Half

- life) 2.2

- 17.2 days In unvegetated rice fields in Mississippi and Louisiana 43270801

Small scale prospective ground water study Detected in ground water at up to 46 ppb Acifuorfen residues detected in suction lysimeters and in ground 4117280119 Study Value Comments Source
water in a soybean field in Wisconsi n

Small scale retrospective ground water study Residues leached through soil profile and under certain conditions were detected in ground water Five states: North Carolina, North Dakota, Indiana, Tennessee, and Virginia 41160001, 41409501, 41458 901, 41644901, 41833202, 42152201

3.2.1.5. Environmental Degradates

The primary degradate of acifluorfen under anaerobic conditions was the corresponding amine from the reduction of the nitro group (amino acifluorfen (5

- [2

- chloro

- 4(trifluoromethyl) phen oxy]

- 2

- aminobenzoic) acid). When samples were incubated under anaerobic conditions for up to 375 days, the degradates amino acifluorfen, acifluorfen acetamide (5

- [2

- chloro

- 4

- (trifluoromethyl) phenoxy]

- 2

- acetamidobenzoic acid), and desnitro acifluorfen ( 3

- [2

- chloro

- 4

- (trifluoromethyl) phenoxy]

- benzoic acid) were identified in the soi1:water systems

. Amino acifluorfen averaged 64

- 71% of the radioactivity applied at 25 through 375 days; maximum concentrations of the other degradates were <5% throughout t he study. These same three degradates were seen in the other metabolism studies; however, none were present at greater than 5% of the applied radioactivity. The amino acifluorfen degradate is less mobile than the parent; K d s range from 1.25 to 47 g/mL. Adsorption and desorption were strongly correlated between K ads and soil pH, with an increase in sorption corresponding to a decrease in pH. For sand, clay and loam soils a correlation existed between K ads and percent organic matter; however, this relatio nship did not hold for loamy sand soil. The loamy sand, however, had the highest level of sorption and the lowest pH value. This indicates that soil pH may have a stronger effect on sorption than organic matter. A correlation was not observed for % clay

.
3.2.2. Measures of Aquatic Exposure

3.2.2.1. Surface Water Exposure to Acifluorfen

The Tier II model Surface Water Concentration Calculator (SWCC, v1.106 ) was used to estimate screening

- level exposure concentrations in aquatic environments. The model simulates pesticide movement and transformation on and transport from an agricultural field resulting from crop applications. It subsequently simulates pesticide concentrations in water due to loading via runoff, erosion, and spray drift, assuming a stand ard 1

- ha pond, 2

- m deep (20,000 m 3 ) with no outlet that borders a 10

- ha treated field. Simulations are for 30 years, from which the Agency estimates peak values that are expected to recur on average once every ten years, based on time series of daily esti mated concentrations. SWCC and user’s manual are available from the U.S. Environmental Protection Agency Water Models web

- page (USEPA, 2015 ).

The Pesticides in Flooded Applications Model (PFAM, v1.104 ) was developed t o facilitate risk assessments for pes ticides used in flooded

- agriculture applications such as rice paddies and cranberr y bogs. PFAM was designed around the specific parameters that are typically available20 for a pesticide risk assessment, thereby simplifying the assessment process. The model makes use of fate properties of pesticides and allows for the specification of common management practices that are associated with flooded agriculture such as scheduled water releases and refills. It also allows for natural water level fluctuations resu lting from precipitation and evapotranspiration.

Exposure estimates generated using the standard pond are intended as surrogates for potential concentrations in a wide variety of vulnerable water bodies, including prairie potholes, playa lakes, vernal po ols, other wetlands, man

- made and natural ponds, and ephe meral and first

- order streams. Innumerable site

- specific factors may make such water bodies more or less vulnerable than the standard pond. Static water bodies that have larger ratios of pesticide

- treated drainage area to water body volume are generally expected to experience higher peak concentrations than the standard pond’s EECs. Such water bodies may be smaller in size, and/or have larger drainage areas , which will tend to result in higher conc entrations . However such water bodies
may also overflow at least occasionally and thus discharge pesticide in their effluent (unlike the standard pond , which is assumed to ha ve no discharge ), which will tend to result in lower concentrations

.

As watershe d size increases, it becomes increasingly unlikely that the entire ty of a watershed is planted with a single crop that is all treated simultaneously with a pesticide. Headwater streams may have peak concentrations that are higher than those predicted for the standard pond, but such concentrations will likely persist for only short periods of time or distance, as they are carried downstream and diluted with water originating elsewhere.

The general chemical and environmental fate data for acifluorfen listed in Table 3.2 were used for generating model input parameters for SWCC (listed in Table 3. 4 ). C hemical specific and model input values were chosen in accordance with current EFED guidance (USEPA, 2009).

Table 3. 4

. SWCC, PRZM

- GW, and PFAM input parame ter values for acifluorfen use on peanuts, soybeans, strawberries, and rice.

PARAMETER (units) VALUE(S) SOURCE COMMENT
Application Rate (kg a.i./ha) 1 st application
p eanuts , soybeans and s trawberries = 0. 42

2 nd application strawberries = 0.42

2 nd applic ation

peanuts and soybeans = 0.14 Maximum Rates

Peanuts

, soybeans (1 st ) and

s trawberries (1 st and 2 nd ) = 0.375 lb a.i./ac

Peanuts

, soybeans (2nd) = 0.125 lb a.i./ac

Reapplication Interval (days) 15

Number of Applications 221 PARAMETER (units) VALUE(S) SOURCE COMMENT
Molecular weight (g/mol) 361.66

Henry’s Law Constant (atm

m 3 /mol) 7.65*10

- 10 Calculated from vapor pressure and solubility

Vapor Pressure (torr @ 25 oC ) <1*10

- 7 41784601

Solubility in Water @ 20 O C, (mg/L or ppm) 620,000

Organic Carbon Soil Partition Coefficient (mL/g o.c.) K OC = 109 42793501 Mean of five K OC values: 50, 57, 74, 165, 199

Chemical Application Method Ground ground spray; pre

- plant or pre

emergence, post

- emergence, unincorporated
Depth of Incorporation (inches) 0

– Application efficiency (decimal) 0 .95 Aerial application permitted on label

Spray drift fraction (decimal) 0. 1 2 5

Retreatment Interval (days) 15

Date of initial application Peanuts: 15 days
pre

- emergence Soybeans: 15 days

pre

- emergence
Annual strawberries: 30 days pre

emergen ce Peanuts: pre

- and post

- emergent Soybeans: pre

- plant, post

- emergence, or post

- harvest (early season applications conservatively represent burndown applications as early season has more rainfall) Annual strawberries: pre

- plant

Perennial strawberries: post

emergence Rice: post

- emergent

Hydrolysis Half

- life (days) Stable 00071584 00122757

00107479

Aqueous Photolysis Half

- life @ pH 7 (days) 14.7 days 44195002

Aerobic Aquatic Metabolism Half

- life (days) 114 days 42330601 3X one aerobic aquatic met abolism half

- life per Input Parameter Guidance 122 PARAMETER (units) VALUE(S) SOURCE COMMENT
Anaerobic Aquatic Metabolism Half

- life (days) 8.25 43155201 Parent anaerobic soil metabolism half

- life = 2.75 days. Input is 3X half

- life considering one value is available

Aerobic Soil Metabolism Half

lif

e (days) 173 00143572 Upper 90% confidence limit on mean

o f 4 values: 100 days, 108 days, 193 days, and 200 days

1 “Input Parameter Guidance” refers to Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticide s; Version 2.1, October 22, 2009.

Inputs i n Table 3

. 5 are specific to PFAM parameterization. Inputs relevant to both PFAM and SWCC are summarized in Table 3. 4

.

Table 3. 5

. PFAM Inputs Specif ic Acifluorfen

Input Parameter Value Source Comment

Applicat ion rate 0.25 lbs a.i./A Number of Applications per Year 1

--- --- Application dates 8

- 18

--- Slow Release 1/day 0

-- No flow conservatively assumed
Drift Application 0

-- Drift not applicable for Tier 1 in the paddy concentrations Flood Tab Num ber of Flood Events 2 --

Flooding to 4 inches. Initial flood date selected to precede planting in Arkansas and California 1 Date of Event 1 (Month

- Day) 5

- 1 --
Turn Over (1/day) 0 Assumed

Days After Fill Level, Min Level (m) Wier (m)

0 0.1016 0.1270 140 0 0 1

- http://www.uaex.edu/publications/pdf/mp192/chapter

- 2.pdf (Accessed April 23, 2015)23 The modeled aquatic EECs resulting from the currently labeled acifluorfen use s were used for risk estimation in this assessment (Table 3.8)

. Representative scenarios for labeled uses were modeled. For pre

- emergence applications, an initial application date approximately two weeks prior to emergence was selected. Small alteration s in initial application date do not reflect a substantial change in the use pattern modeled but can significantly impact EECs. Peak, 21

- day average and 60

- day average concentrations are driven by the weather patterns occurring during and after the applic ation as reflected in 30

- year meteorological file geographically relevant to a given SWCC scenario. An alteration to the initial application of two to three days may include several rain events not captured otherwise. Such rain events would increase EECs providing a more conservative estimate.

Table 3. 6 . Modeled Aquatic Surface Water 1

- in

- 10

- year EECs for Currently L abeled Uses of Acifluorfen 1

SWCC Scenario (standard unless noted) Initial Application Date Relative to Emergence 1

- in

- 10 year peak daily , ppb 1

- in

- 10 year, peak 21

- day average, ppb 1

- in

- 10 year, peak 60

- day average, ppb

FL Strawberry

- 30 27.3 25.1 21.6 MS Soybean

- 15 14.2 13.7 12.7 NC Peanut

- 15 8.82 8.36 7.84 Rice from PFAM +15 218 1

- - 1 In

- the

- paddy concentration

3.2.2.2 Aquati c Spray Drift Exposure to Acifluorfen

Spray drift exposure to aquatic organisms is also a potential exposure pathway. However, with edge of field deposition of acifluorfen from maximum application rates

, even endangered species LOCs are not exceeded for any aquatic taxa. Therefore, f urther analyses were not conducted.

3.2. 3

. Measures of Terrestrial Exposure

3.2.3.1

. Terrestrial Wildlife

Exposure estimates for terrestrial organisms in the target area are derived using the T

- REX model (version 1. 5

. 2

, 03 / 22 / 2012 )

. T his model incorporates the Kenaga nomograph, as modified by Fletcher et al. (1994), which is based on a large set of field residue data. The upper limit values from the nomograph represent the upper bound of residue values from actual field

m easurements (Hoerger and Kenaga 1972). The Fletcher et al. (1994) modifications to the Kenaga nomograph are based on measured field residues from 249 published research papers, including information on 118 species of plants, 121 pesticides, and 17 chemica l classes. Based on these data, T

- REX assumes a default 35

- day foliar dissipation half

- life in the absence of other chemical

- specific data.

3. 2

. 3.2. Terrestrial Plants

Exposure of nontarget terrestrial and semi

- aquatic (wetland) plant species is typic ally estimated24 using OPP’s TerrPlant (v1.2.2 ; US EPA, 2006b ) model and is assumed to encompass areas outside the immediate use site. The TerrPlant model is used to derive EECs in runoff and drift for terrestrial and semi

- aquatic plants near areas where aci fluorfen has been applied. Runoff exposure is assessed in TerrPlant in two scenarios: sheet and channel runoff. In the sheet runoff scenario, the treated area generating runoff is assumed to drain into an area with equal size containing seedlings, result ing in 1, 2, or 5% of the a mount applied being deposited. In the channel runoff scenario, a ten

- to

- one ratio of treatment area to receiving area results in 10, 20, or 50% of the amount applied being deposited on soil with emerging or emerged seedlings. S pray drift is also a source of pesticide loading to non

- target areas. TerrPlant estimates EECs based on
app lication rate, application method, chemical solubility in water

, type of runoff and default assumptions of drift. Detailed information about TerrPl ant, as well as the tool, can be found on the EPA’s website at http://www.epa.gov/pesticides/science/models_pg.htm#terrestrial

. The AgDRIFT (v2.01; May 2001) spray drift model is used to assess exposures of terrestrial plants to acifluorfen deposited on terrestrial or aquatic habitats by spray drift at a given distance from the application area.

3.3

. Ecological Effects Characterization

In ecological risk assessments, e ffects characterization describes the types of effects a pesticide can have on aquatic and terrestrial organisms. To date, toxicity tests for amphibian s or reptiles
are not routinely required; birds are used as surrogates for reptiles and terrestrial

- phas e amphibians

, and freshwater fish are used as surrogates for aquatic

- phase amphibians. This characterization is based on the registrant

- submitted toxicity data for birds, mammals, fish, invertebrates, and plants for acifluorfen

. As described in the Agen cy’s Overview Document (USEPA 2004), the most sensitive endpoint for each taxon is used for risk estimation. For this assessment, evaluated taxa include, freshwater fish (surrogate for aquatic

- phase amphibians, freshwater invertebrates, aquatic plants, bi rds (surrogate for terrestrial

- phase amphibians), mammals, terrestrial invertebrates, and terrestrial plants.

Toxicity endpoints are established based on data generated from guideline studies submitted by the registrant, and from open literature studies that meet the criteria for inclusion into the ECOTOX database maintained by EPA/Office of Research and Development (ORD) (U.S. EPA, 2004). Open literature data presented in this assessment were obtained from ECOTOX information obtained in July 2011 . In order to be included in the ECOTOX database, papers must meet the following minimum criteria:

(1) the toxic effects are related to exposure from a single chemical ; (2) the toxic effects are on an aquatic or terrestrial plant or animal species; (3) there is a biologic al effect on live, whole organisms; (4) a concurrent environmental chemical concentration/dose or application rate is reported; and (5) there is an explicit duration of exposure.

Data that pass the ECOTOX screen are evaluated along with the registrant

- submitted d ata, and2 5 may be incorporated qualitatively or quantitatively into this assessment. In general, effects data in the open literature that indicate effects at lower concentrations than the registrant

- submitted data are considered. The degree to which open l iterature data are quantitatively or qualitatively characterized is dependent on whether the information is relevant to the assessment endpoints (survival, reproduction, and growth) identified in Section 2.8. For example, endpoints such as behavior modifi cations are likely to be qualitatively evaluated, because quantitative relationships between modifications and reduction in species survival, reproduction, and/or growth are not available.

In addition to registrant

- submitted and open literature toxicity information, other sources of information, including use of the acute probit dose

- response relationship to establish the probability of an individual effect and reviews of the Ecological Incident Information System (EIIS), are conducted to further refine the characterization of potential ecological effects associated with exposure to acifluorfen . A summary of the available aquatic and terrestrial ecotoxicity information, use of the probit dose

- response relationship, and the incident information for aciflu orfen are provided in Sections 4.1 through 4.4, respectively.

No toxicity data were available on specific acifluorfen mixtures with other pesticides; there is

one registered multi a

. i

. product that includes both acifluorfen and sodium bentazon (PC Code 10 3901)

.

3.3.1. Aquatic Toxicity Assessment

The most sensitive acute and chronic effects measurement endpoints associated with acifluorfen exposure to freshwater and estuarine/marine species are summarized in Table 3. 7

. All acceptable and supplemental stu dies available for acifluorfen are described in the 2010 Problem Formulation (USEPA 2010b)

. However, data received after 2010 or that supersedes data reported therein are described below.

Results of acute toxicity studies in freshwater and estuarine/mar ine fish indicate that acifluorfen is slightly

- to

- moderately toxic to aquatic invertebrates and fish on an acute exposure basis. Adult mortality was observed in the available fish early life stage ( ELS ) study.26 Table 3. 7 . Most Sensitive Acute and Chron ic Toxicity Data for Aquatic Organisms Exposed to Acifluorfen

Exposure Scenario Species Affected Endpoint Toxicity Measurement MRID (Classification)

Freshwater Fish Acute Rainbow trout ( Oncorhynchus mykiss ) Mortality 96

- hr LC 50 = 17 mg a.i./L Slope : N/A 00122752 (Acceptable)

Chronic Fathead minnow ( Pimephales promelas ) Mortality NOAEC = 1.0 mg a.i./L 48047402 (Supplemental)

Freshwater Invertebrates Acute Water flea ( Daphnia spp.) Immobility 48 hr EC 50 = 28.1 mg a.i./L Slope: N/A 00071901 (Accept able) Chronic Water flea ACR NOAEC = 1.3 mg ai/L Calculated Estuarine/Marine Fish Acute Sheepshead minnow ( Cyprinodon variegatus ) Mortality 96

- hr LC 50 = 39 mg total a.i./L Slope: N/A 00122753 (Acceptable)

Chronic No studies available No Data Estuar ine/Marine Invertebrates Acute Mysid shrimp (Americamysis bahia ) Mortality 96

- hr LC 50 = 3.8 mg a.i./L Slope: NA 00122755 (Acceptable)

Chronic Mysid shrimp NOAEC= 0.17 mg ai/L 49305701 ( Acceptable ) Aquatic Plants 14

- day
exposure Duckweed ( Lemna gibba ) Frond count 14

- day EC 50 = 0.378 mg a.i./L NOAEC = 0.180 mg a.i./L 41680702

120

- hour
exposure Green algae ( Selenastrum capricornutum ) None NOAEC >0.265 mg a.i./L 41680702

96

- hour
exposure Cyanobacteria ( Anabaena flos

aquae ) None 96

- hr EC 50 >0.355 mg a.i ./L 41680702

3.3.1.1 Toxicity to Fish

Acute Effects

In a 96

- h acute toxicity study, fathead minnow (Pimephales promelas) were exposed to acifluorfen at nominal concentrations of 0 (negative and solvent controls), 6.3, 13, 25, 50, and 100 mg a

. i

. /L un der static

- renewal (at 48 hours) conditions (MRID Number 48047401). Mean

measured concentrations were <LOQ ( 0.33, controls), 4.9, 11, 20, 40, and 83 mg a

. i

. /L. There were no mortality or sublethal effect s noted in this study. The 96

- h LC 50 was >83 mg

a

. i

. /L. No mortality or sub

- lethal effects were observed up to and including the highest27 concentration tested ( 83 mg a

. i

. /L ) . This study is not used in RQ calculation because the previously available rainbow trout endpoint is more sensitive (see Table 3. 7 ).

Chronic Effects

The 32

- day chronic toxicity of acifluorfen to the early life

- stage of fathead minnow ( Pimephales promelas ) was studied under flow

- through conditions (MRID 48047402). Fertilized eggs/embryos (l20/level, ca. 10 hours old) were exposed to nominal concentrations of 0 (negative and solvent controls), 0.063, 0.13, 0.25, 0.50, and 1.0 mg a

. i

. /L (adjusted for purity). Mean

- measured concentrations were <0.0053 ( LOQ, controls), 0.065, 0.13, 0.24, 0.53, and 1.0
mg a

. i

. /L, respectively. Since n o treatment

- related effects were indicated for any endpoint, the 32

- day NOAEC and LOAEC values were 1.0 and >1.0 mg a

. i

. /L, respectively. However, time to hatch was not evaluated as a toxicological endpoint and the exposure range was quite low for a fish early life stage toxicity test , thus the study was classified as Supplemental . Nonetheless, this study provides a frank no

- effect concentration that supersedes the non

- definitive endpoint reported in the Problem Formulation

.

3.3.1.2. Toxicity to A quatic Invertebrates

Chronic Effects

The 28

- day chronic toxicity of acifluorfen to mysids was studied under flow

- through conditions (MRID 48252402). Neonates less than 24 hours old were exposed to nominal concentrations of 0 (negative control), 0.13, 0.25, 0.5 0, 1.0, and 2.0 mg a

. i

. /L. Mean

- measured concentrations were <0.0052 ( LOQ, control), 0.14, 0.23, 0.52, 0.96, and 1.9 mg a

. i

. /L, respectively. The 7

- through 28

- day LC 50 (for F 0 survival) was >1.9 mg a

. i

. /L. Since no treatment

- related effects were indica ted for any endpoint, the 28

- day NOAEC and LOAEC values were 1.9 and >1.9 mg

a

. i

. /L, respectively. The study was classified as Supplemental because it was conducted below the limit of solubility and failed to establish a frank LOAEC. This study was condu cted using lactofen as the test substance

, and acifluorfen is a metabolite of lactofen.

Subsequently, another 28

- day chronic toxicity study with mysids (using a manufacturing use product ( MUP) was submitted (MRID 49305701). The mean

- measured concentrat ions in this study were <0.04 mg a

. i

. /L (LOQ; control), 0.17, 0.318, 0.628, 1.22, 2.47 and 4.92 mg a

. i

. /L

. Although total young per female was significantly affected at 1.22 mg a

. i

. /L, the NOAEC and LOAEC for the study were 0.170 mg a

. i

. /L and 0.318 mg a

. i

. /L based on F 0 length at 28 d ays (male and female). T his study is classified as Acceptable

. The endpoints reported we re corrected for purity.

As per the Problem Formulation, the NOAEC from the chronic mysid study is used to calculate an Acute

- to

- Chro nic Ratio (ACR) for freshwater invertebrates (daphnids). The ACR is a simple ratio of the acute toxicity endpoint for mysids (LC50 = 3.8 mg a

. i

. /L) over the mysid NOAEC (0.17 mg a

. i

. /L). The resultant ratio ( 22) is applied to the LC 50 for daphnids (28.1 mg a

. i

. /L) to estimate a chronic NOAEC for daphnids, 1.3 mg a

. i

. /L.28 3.3.2 Terrestrial Effects Characterization

T he most sensitive acute and chronic effects measurement endpoints associated with acifluorfen exposure to terrestrial animals are summarized in Table 3. 8

. The most sensitive measurement endpoints for terrestrial plants are presented in Table 3. 9

. All acceptable and supplemental studies available for acifluorfen received prior to 2010 are described in the Problem Formulation (USEPA 2010b). D ata received after 2010 or that supersedes data reported therein are described below.

Table 3. 8 . Acifluorfen Toxicity Measurement Endpoints Used in Risk Assessment for Terrestrial Animals.

Exposure Scenario Species Exposure Duration Toxicity Reference Value MRID (Classification a )
Mammals Acute (Dose

- based) Laboratory rat ( Rattus norvegicus ) Single oral dose LD 50 = 1540 mg a.i./kg bw 00071887

Chronic (Dietary

- based) Laboratory rat ( Rattus norvegicus ) Two

- generation NOAEC = 400 mg a

. i

. /kg

- diet LOAEC = 1800 mg a

. i

. /kg

- diet 00122743

Birds Acute (Dose

- based) Bobwhite quail Colinus virginianus 14

- day single oral dose LD 50 = 325 mg a.i./kg bw 00122747

Acute (Dietary

- based) Canary Serinus canaria 8

- day dietary LC 50 : > 6530 mg a

. i

. /kg diet 49213701 (Ac ceptable)

Chronic (Dietary

- based) Bobwhite quail C. virginianus Avian reproduction study NOAEC: 20 mg a

. i

. /kg diet LOAEC: 100 mg a

. i

. /kg diet 00107491

Terrestrial Invertebrates Acute (Contact) Honeybee 48

- hour LD 50 >100 μg a.i./bee NOAEC: 100 μg a.i./bee 46650202 (Acceptable)

a W here new data have been received.

Table 3. 9

. Acifluorfen Toxicity Measurement Endpoints for Terrestrial Plants.

Exposure Scenario Taxon Toxicity Reference Value Reference (Classification) a Seedling Emergence Grass ( ryegrass) I C 25 = in review NOAEC = in review MRID 41680701 (Acceptable) b
Non

- grass (cabbage) I C 25 = 0.0 3 2 lbs a.i./A NOAEC = 0.0 15 lbs a.i./A Vegetative Vigor Grass (corn) IC 25 = 0. 085 lbs a.i./A NOAEC = 0. 068 lbs a.i./A MRID s 4643140129 Exposure Scenario Taxon Toxicity Reference Value Reference (Classification) a
Non

- grass (radish IC 25 = 0. 0038 lbs a.i./A NOAEC = 0. 0009 lbs a.i./A (Supplement al) 48612401 ( Supplemental )

a W here new data have been received or status has changed

. b W hile the study was originally classified as Acceptable, a new review is now required.

3.3.2 .1. Toxicity to Birds

The acute dietary toxicity of acifluorfen to young adult (11

- to 16

- month old) canary ( Serinus canaria ) was assessed over 8 days (MRID 49213701; Acceptable) . Acifluorfen was administered to the birds in the diet at nominal concentra tions of 0 (vehicle control), 400, 800, 1600, 3200 and 6400 mg a

. i

. /kg. Mean

- measured concentrations were <60.0 (<LOD, control), 386, 775, 1570, 3280, 6530 mg a

. i

. /kg diet , respectively. No mortality was observed at any treatment level; thus, the 8

- day d ietary LC 50 exceeded 6530 mg a

. i

. /kg. There were reported effects on body weight and food consumption at the 6530 mg a

. i

. /kg diet level, thus the observational NOAEC is 3208 mg a

. i

. /kg

- diet. Acifluorfen is classified as practically non

- toxic to young adu lt canary ( Serinus canaria ).

3.3.2.3. Toxicity to Terrestrial Invertebrates

The acute contact toxicity of acifluorfen to the honey bee, Apis mellifera , was assessed in a 48

- h study (MRID 47919601; Acceptable). Bees were exposed to acifluorfen at nominal concentrations of 6.25, 12.5, 25.0, 50.0, and 100.0 μg a

. i

. /bee. By 48 hours, there was 0% mortality in the negative control and 2% mortality in the solvent control. The 6.25, 12.5, 25.0, 50.0, and 100 μg a

. i

. /bee treatment groups had 0, 2, 3, 5, and 5% mortality, respectively. Sublethal effects were limited to one immobile bee in the 50.0 μg a

. i

. /bee treatment group. The LD 50 value was >100 μg a

. i

. /bee and acifluorfen is classified as practically nontoxic to honeybees on an acute contact basis. Howev er, there remain data gaps, based on the recent pollinator guidance.

3.3.2.4. Toxicity to Terrestrial Plants

The effect of acifluorfen on vegetative vigor was derived from two studies. The first study (MRID 46431401

, Supplemental ) did not achieve definitive endp oints for three species (cucumber, radish and tomato). A subsequent study (MRID 48612401; Supplemental) was submitted for radish and cucumber. While the first was considered ‘Invalid’ in 2005, that classification was due to the lack of definitive endpoin ts. The study was reconsidered for this assessment and, as noted above, is now considered ‘Supplemental’, as data for many of the species is sufficient for use in risk assessment. The second study addressed some, but not all, of the deficiencies in the f irst study. A no

- effect value for tomato remains highly uncertain, although rerunning the statistic s may allow for the derivation of an IC 05 which could be used in an endangered species assessment. For the purposes of this assessment, the dataset is comp lete. The range of toxicity across all available species is reported in Table 3.10

.30 Table 3. 1 0 . Acifluorfen Vegetative Vigor Toxicity Endpoints for Terrestrial Plants (lbs a.i./A).

Crop Endpoint NO A E L IC 25

Ryegrass None 0.017 >0.034

Corn D ry Weight 0.068 0.085

Onion Dry Weight 0.068 0.12

Wheat Plant height 0. 0 085 >0.14

Cucumber Dry Weight 0.0009 0.0042

Lettuce Dry Weight 0.0022 0.0095

Cabbage Plant Height 0.017 0.028

Radish Dry Weight 0.0009 0.0038

Soybean Dry Weight 0.034 0.087

Tomato Dry Weight <0.034 * 0.046

* A no

- effect value sufficient for risk assessment has not yet been determined

T he effect of acifluorfen on the seedling emergence (MRID 41680701 ; Acceptab l e) of terrestrial plants is not com pletely reviewed. Although the study is considered ‘Acceptable’, the review (in 1999) relies, for many endpoints, on visual phytotoxicity. This endpoint is no longer considered acceptable for use in risk assessment , and therefore data for four species in the study must be reanalyzed. However, the most sensitive species, cabbage (IC 25 =0.021; NOAEC=0.015), is used in Risk Estimation. Based on the data reported in the DER, grass species are considerably less sensitive to acifluorfen on a seedling emergence basis.

3.4. ECOTOX Open Literature

A literature search in the Agency’s ECOTOX database ( January 2015 ) resulted in 89 paper s that passed the ECOTOX acceptability screen , all for plants. None of the papers could be directly related to FIFRA apical end points (IC 25 /EC 25 for growth or survival) and thus are not included in this assessment. However, many of the studies report no

- effect rates and these studies will be reviewed for the listed species effects determinations in a future endangered species ris k
assessment.

4. 0 Risk Characterization

4.1. Risk Estimation

Toxicity data and exposure estimates are used to evaluate the potential for adverse ecological effects on non

- target species. This assessment for acifluorfen relies on the deterministic RQ31 me thod to provide a metric of potential risks. The RQ provides a comparison of exposure estimates to toxicity endpoints ( i.e. , the estimated exposure concentrations are divided by acute and chronic toxicity values). The resulting unitless RQs are compared to the Agency’s LOCs, as shown in Table 2.3 . LOCs are used by the Agency to indicate when the use of a pesticide, as directed by the label, has the potential to cause adverse effects to non

- target organisms.

4.1.1. Aquatic Organisms

The highest scr eening

- level aquatic EECs based on the maximum application rates for each use pattern were used to derive RQs. These exposure estimates represent concentrations in surface water ( Table 3.7 ). Peak EECs are used to represent acute exposure to fish, aquatic invertebrates and aquatic plants, and the highest 21

- day and 60

- day average EECs represent chronic exposure to aquatic invertebrates and fish, respe ctively. EECs below represent parent acifluorfen only but inclusion of amino acifluorfen, the only major t ransformation product , as a toxic residue increases EECs by less than 10%. This was estimated by assuming stability to anaerobic aquatic metabolism, the only pathway by which amino acifluorfen formed as a major transformation product

.

4.1.1.1. Fish and I nvertebrates

Fish

Table 4.1 lists acute RQs calculated for fish (freshwater and estuarine/marine) and aquatic

- phase amphibians exposed to acifluorfen , based on the peak EECs generated from SWCC modeling scenarios. Results of acute toxicity studies in fr eshwater and estuarine/marine fish ( Table 3.13 ) indicate that acifluorfen is “highly toxic” to fish on an acute exposure basis. However, RQs for uses of acifluorfen fall below the Agency’s acute risk to listed species LOC (0.05), as well as the Agency’s a cute risk to non

- listed species LOC of 0.5.

Table 4.1. Acute Risk Quotients for Fish and Aquatic

- phase Amphibians Exposed to Acifluorfen at the Upper

- bound EECs Using the Most Sensitive of the Available Endpoints.

SWCC Scenario (standard unless noted) 1

- in

- 10 year peak daily, ppb RQs Freshwater LC 50 17 mg a

. i

. /L Estuarine/Marine LC 50 39 mg a

. i

. /L) FL Strawberry 27.3 0.002 0.0007 MS Soybean 14.2 0.0008 0.0004

NC Peanut 8.82 0.0005 0.0002

Rice 218 0.013 0.006

1 Acute risk to non

- listed species L OC for aquatic fish is 0.5

2 Acute risk to listed species LOC for aquatic fish is 0.05
As previously stated, LDPHs are a class of weed control chemicals that act in plants by inhibiting the enzyme protoporphyrinogen oxidase (protox), which is the last comm on enzyme in the heme and chlorophyll biosynthetic pathways. Several studies have documented enhanced toxicity of LDPHs to fish in the presence of uV light compared to toxicity observed under32 standard laboratory lighting. Given that aquatic organisms are likely to be exposed simultaneously to LDPH and uV light in natural settings, concerns have been raised that guideline chronic exposure laboratory tests may underestimate the toxicity of LDPH in the field and so , the Agency is applying an interim adjustme nt factor of 29X to adjust no observed adverse effect concentration (NOAEC) values to account for the potential enhanced toxicity of LDPH chemicals under natural sunlight (USEPA 2010 a ). This enhanced sensitivity to LDPHs is
not necessarily limited to fish and could be observed in other taxa such as aquatic invertebrates, birds, and mammals (Birchfield and Casida, 1997) ; however, the Agency is only applying an adjustment factor to fish at this time

. Chronic exposure RQs for fish were calculated with both the endpoint derived from the guideline ELS study (standard laboratory lighting) and with the 29X adjustment factor applied (enhanced uV ) . RQs for fish that may not receive high

- intensity uV light are below the Agency’s level of concern (1.0). RQs for fi sh with the LPDH adjustment factor exceed the LOC by up to 6

- fold ( rice use; Table 4. 2 )

. The risk conclusions for fish also apply to amphibians in aquatic habitat.

Although an acute toxicity study with the fathead minnow is available, it reports a non

- d efinitive endpoint, therefore an ACR cannot be calculated and potential risk to estuarine/marine fish cannot be quantified. However, given that the acute endpoint for sheepshead minnow is greater than that for the rainbow trout, RQs for estuarine/marine f ish would be lower than those for freshwater fish.

Table 4. 2

. Chronic Risk Quotients for Fish and Aquatic

- phase Amphibians Exposed to Acifluorfen at the Upper

- bound EECs Using the Most Sensitive of the Available Endpoints.

SWCC Scenario (standard unless noted) 1

- in

- 10 year 60d, ppb RQs Freshwater NOAEC 1.0 mg a

. i

. /L LDPH 29X factor FL Strawberry 21.6 0.02 0.626 MS Soybean 12.7 0.01 0.368

NC Peanut 7.8 0.008 0.227

Rice 218 0. 218 6.32

1 Chronic risk to listed and nonlisted LOC aquatic animals is 1 .0 . Bold indicates exceeds LOC

Aquatic Invertebrates

Based on the available acute studies, acifluorfen is categorized as practically nontoxic to Daphnia magna on an acute exposure basis

. RQs for daphnids are <0.01 and do not exceed the acute risk LOC fo r either nonlisted (0.5) or listed (0.05) species.

Mysids are more acutely sensitive to acifluorfen than daphnids, but RQs do not exceed the acute risk LOC for either nonlisted (0.5) or listed (0.05) species for most use patterns. The RQ for estuarine/ marine invertebrates (0.057) marginally exceeds listed species LOC for the rice use ( Table 4.3)

.33 Table 4.3. Acute Risk Quotients for Aquatic Invertebrates Exposed to Acifluorfen at the Upper

- bound EECs Using the Most Sensitive of the Available Endpoints

.

SWCC Scenario (standard unless noted) 1

- in

- 10 year peak daily, ppb RQs Freshwater LC 50 28.1 mg a

. i

. /L Estuarine/Marine LC 50 3.8 mg a

. i

. /L) FL Strawberry 27.3 0.001 0.007 MS Soybean 14.2 0.0005 0.004 NC Peanut 8.82 0.0003 0.002 Rice 218 0.0077 0 .057

1 Acute risk to non

- listed species LOC for aquatic fish is 0.5

2 Acute risk to listed species LOC for aquatic fish is 0.05

There are no chronic LOC (1.0) exceedances for aquatic invertebrates except for the rice use. Most use patterns result in RQs an order of magnitude below the LOC, but the rice use results in an RQ of 1.3 for estuarine/marine invertebrates.

4.1.1.2. Aquatic Plants

Although acifluorfen exhibit s effects on the aquatic vascular plant ( Lemna gibba ) , there is insufficient exposure for the LOC (1.0) to be exceeded for nonlisted vascular aquatic plants; the listed species RQ is 1.2, marginally exceeding the LOC

. Similarly, aquatic nonvascular plants are affected by acifluorfen exposure. The most sensitive among the available ta xa is the cyanobacteria, Anabaena flos

- aquae . The nonlisted species LOC is not exceeded for this species, with the highest RQ = 0.8 ( Table 4.4 )

. T he listed species RQ is not calculated as the endpoint used (NOAEC) is not reported in the Problem Formulati on

.

Table 4. 4 . Acute Risk Quotients for Aquatic Vascular and Nonvascular Plants Exposed to Acifluorfen at the Upper

- bound EECs Using the Most Sensitive of the Available Endpoints.

SWCC Scenario (standard unless noted) 1

- in

- 10 year peak daily, ppb RQs Vascular IC 50 0.378 mg a

. i

. /L Nonvascular IC 50 >0.355 mg a

. i

. /L) FL Strawberry 27.3 0.07 <0.1 MS Soybean 14.2 0.04 <0.05 NC Peanut 8.82 0.02 <0.03 Rice 218 0.58 < 0. 82

1 Plant LOC is 1.0. Bold indicates exceeds LOC34 4.1.2. Terrestrial Organisms

4.1.2.1. Mammals

Although acifluorfen is classified as slightly toxic to mammals on an acute exposure basis, the EECs based on the labeled use patterns d o not result in an exceedance of the acute risk LOC of 0.5. The highest RQ (15g mammals feeding on short grass) is 0. 0 4

, a factor of 10 below the LOC.

Based on the currently labeled maximum application rates, there are chronic dose

- based exposure concerns for mammals of all size class es for multiple use patterns RQs exceed the LOC by a factor of up to 3

. 4 X for 15 g mammals foraging on short grass in the strawberry scenario, with exceedances at all size classes. Table 4.5 lists maximum chronic EECs and RQs for all of the currently labeled use rates based on the upper 90 th percentile Kenaga values. The granivore forage class does not result in any exceedances for any of the use patterns and is not shown in the table. There are no exceedances of the LOC by dietary

- based RQs , which are not adjusted for body weight

.

Table 4.5. Chronic Dosed

- based Mammal ian RQs for the Uses of Acifluorfen. ( Bold value indicate an exceedance of the LOC. )

Size Class

(g) Short Grass Tall Grass Broadleaf Plants Fruits/Pods/Seeds Arthropods

EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ Strawberry (2@0.375 lbs

a

. i

. /A) 15d interva l 15 149.56 3.40 68.55 1.56 84.13 1.91 9.35 0.21 58.58 1.33 35 103.37 2.91 47.38 1.33 58.14 1.63 6.46 0.18 40.49 1.14

1000 23.97 1.56 10.98 0.71 13.48 0.88 1.50 0.10 9.39 0.61

Soybean and peanut (0.5 lbs

a

. i

. /A 15 92.36 2.10 42.33 0.96 51.95 1.18 5.77 0.13 36.17 0.82 35 63.83 1.79 29.26 0.82 35.91 1.01 3.99 0.11 25.00 0.70

1000 14.80 0.96 6.78 0.44 8.32 0.54 0.92 0.06 5.80 0.38

Rice (0.25 lb

a

. i

. /A 15 57.21 1.30 26.22 0.60 32.18 0.73 3.58 0.08 22.41 0.51 35 39.54 1.11 18.12 0.51 22.24 0. 63 2.47 0.07 15.49 0.44 1000 9.17 0.60 4.20 0.27 5.16 0.34 0.57 0.04 3.59 0.2335 4.1.2.2. Birds

Acifluorfen exhibits greater toxicity to birds than to mammals

, with an LD 50 of 325 mg ai/kg

- bw, classified as moderately toxic. At the currently register ed label rates, acute dose

- based RQs exceed the LOC (0.5 for nonlisted species) only for small (20 g) birds (and surrogates) foraging on short grass for the strawberry use ( Table 4. 6 ). There are no exceedances for the subacute dietary RQs for any size cla ss/forage item combination. E xceedance of the listed species LOC are not indicated.

Table 4. 6. Acute Dose

- based RQs for Birds (and Surrogates) for Acifluorfen

. ( Bold values indicate an exceedance of the listed LOC. )

Rate Size Class (grams) EECs a nd RQs

Short Grass

Tall Grass Broadleaf Plants/ Small Insects Fruits/Pods/ Seeds/ Large Insects Arthropods

EEC RQ EEC RQ EEC RQ EEC RQ Strawberry (2@0.375 lbs

a

. i

. /A) 15d interval 20 178.66 0.76 81.89 0.35 100.50 0.43 11.17 0.05 69.97 0.30
100 101.88 0.34 46.69 0.16 57.31 0.19 6.37 0.02 39.90 0.13

1000 45.61 0.11 20.91 0.05 25.66 0.06 2.85 0.01 17.86 0.04
Soybean and peanut 1@0.375 lbs

a

. i

. /A 1@0.125 lbs

a

. i

. /A 15d interval 20 110.32 0.47 50.57 0.22 62.06 0.27 6.90 0.03 43.21 0.18
100 62.91 0.21 28.83 0.10 35.39 0.12 3.93 0.01 24.64 0.08

1000 28.17 0.07 12.91 0.03 15.84 0.04 1.76 0.00 11.03 0.03

Rice 0.25 lbs

a

. i

. /A 20 68.33 0.29 31.32 0.13 38.44 0.16 4.27 0.02 26.76 0.11
100 38.97 0.13 17.86 0.06 21.92 0.07 2.44 0.01 15.26 0.0 5
1000 17.45 0.04 8.00 0.02 9.81 0.02 1.09 0.00 6.83 0.02

T here are chronic LOC exceedances for all use patterns for the short grass, tall grass and broadleaf plants and arthropods forage categories ( Table 4.8 ). Chronic RQs exceed the LOC by up to 8

- fold

. There are no exceedances for the fruit/pods/seeds forage class

.36 Table 4. 8 . Chronic Dietary

- based RQs for Birds (and Surrogates) for Acifluorfen

. ( Bold values indicate an exceedance of the LOC. ) EECs and RQs

Short Grass Tall Grass Broa dleaf Plants Fruits/Pods/ Seeds Arthropods

Rate (# apps; interval) EEC RQ EEC RQ EEC RQ EEC RQ EEC RQ Strawberry 2@0.375 lbs ai/A 15d interval 156.87 7.84 71.90 3.59 88.24 4.41 9.80 0.49 61.44 3.07

Soybean and peanut 1@0.375 lbs ai/A 1@0.125 lbs ai/A 1 5d interval 96.87 4.84 44.40 2.22 54.49 2.72 6.05 0.30 37.94 1.90

Rice 0.25 lbs ai/A 60.00 3.00 27.50 1.38 33.75 1.69 3.75 0.19 23.50 1.18

4.1.2.3. Terrestrial Invertebrates

A cifluorfen is classified as practically nontoxic to honeybees on an acute e xposure basis

. Only a

non

- definitive acute contact endpoint is available and , therefore RQs are not calculated. However, new data based on the recent pollinator guidance are expected at some point in the future and risk to terrestrial invertebrates will be revisited at that time.

4.1.2.4. Non

- target Terrestrial Plants

Potential risk to terrestrial non

- target vegetation are assessed by deriving RQs from terrestrial plant seedling emergence and vegetative vigor IC 25 and NO AE C endpoints using TerrPlant

. A s expected with an herbicide, there are LOC exceedanc e s for terrestrial plants. Because there are differences in the spray drift assumptions for aerial (5%) vs ground spray (1%) in TerrPlant

, the exposure estimates and subsequent RQs are dependent on appl ication type. RQs are calculated based on the highest single application rate for each group of uses, and the higher application rates result in higher RQs and LOC exc e edances . RQs are presented for ground application in Table 4. 9 and for aerial applicat ion in Table 4. 10

. Because there currently is not a ‘ grass’ endpoint for seedling emergence, the runoff RQs for this group are not calculated.37 Table 4. 9 . Terrestrial Plant RQs for G round Spray Applications of Acifluorfen

. ( Bold values indicate an LOC e xceedance. )

Application Rate lbs a

. i

. /A Plant Type Listed Status Dry Semi

- Aquatic Spray Drift

0. 75 Strawberry Grass non

- listed ND * ND <0.1 Grass listed ND ND 0.11
Non

- grass non

- listed 2.14 18.21 1. 97
Non

- grass listed 3.00 2 5.50 8.33

0.5 Soybean/ Peanut Grass non

- listed ND ND <0.1
Grass listed ND ND <0.1
Non

- grass non

- listed 1.43 12.14 1. 32
Non

- grass listed 2.00 17.00 5.56

0.25 Rice Grass non

- listed ND ND <0.1
Grass listed ND ND <0.1
Non

- grass non

- listed 0.71 6.07 0.66
Non

- grass list ed 1.00 8. 5 0 2.78

* Not determined

Table 4. 10 . Terrestrial Plant RQs for Aerial Spray Applications of Acifluorfen

. ( Bold values indicate an LOC exceedance.

Application Rate lbs a

. i

. /A Plant Type Listed Status Dry Semi

- Aquatic Spray Drift

0.75

. Straw berry Grass non

- listed ND * ND 0.44 Grass listed ND ND 0.55
Non

- grass non

- listed 3.57 19.64 9.87
Non

- grass listed 5.00 27.50 41.67

0.5 Soybean/Peanut Grass non

- listed ND ND 0.29
Grass listed ND ND 0.37
Non

- grass non

- listed 2.38 13.10 6.58
Non

- grass listed 3. 33 18.33 27.78

0.25 Rice Grass non

- listed ND ND 0.15
Grass listed ND ND 0.18
Non

- grass non

- listed 1. 19 6.55 3.29
Non

- grass listed 1.67 9.17 13.89

* Not determined38 4.1.2.5. Incident Database Review

A review of the Ecological I ncident Information System (EIIS) database for incidents involving acifluorfen and the acifluorfen degradate was conducted on April 16

, 2015

. There is one reported incident (I003654

- 012; unlikely) for acifluorfen from Union County North Carolina from a re gistered use (as an active ingredient) on beans (likely soybeans). The incident reports mortality in an unk n own number of unspecified fish species.

Similarly, a search of the Avian Incident Monitoring System (AIMS; http://www.abcbirds.org/abcprograms/policy/toxins/aims/aims/index.cfm ) was conducted on April 16, 2015 . AIMS is a database administered by the American Bird Conservancy that contains publicly available data on reported avian incidents involving pesticides. No incidents involving acifluorfen were found

. Pesticide registrants report certain types of incidents to the Agency as aggregate counts of incidents occurring per product per quarter. Unless further information regarding this aggregate incident is received , it will be assumed that it resulted from registered use . There are 43 aggregate plant incidents reported for acifluorfen between 1995 and 2003

.

4.2. Risk Description

The results of risk estim ation indicate that registered uses of acifluorfen result in LOC exceedance for chronic risk to fish (and thus aquatic

- phase amphibians ) under enhanced uV conditions and to estuarine/marine invertebrates. The LOC s for acute risk to listed estuarine/marine invertebrates and for listed aquatic vascular plants are also exceeded. A cute risk to birds is indicated and c hronic risk to both birds and mammals is indicated

. Risk is not expected for terrestrial invertebrates, based on the available data. As expect ed with an herbicide, risk to nontarget terrestrial plants is indicated. T here are exceedances of the acute LOC for listed birds in addition to the chronic risk.

4.2.1 Exposure to Aquatic Organisms

Surface water EECs resulting from applications of acifl uorfen to soybean , peanut, strawberry, and rice are conservative estimates of exposure for the currently labeled uses of acifluorfen as a broadcast herbicide. Application practices were modeled assuming maximum application rates and minimum application in tervals. Environmental fate inputs included 90 percent upper confidence limits on mean metabolism half

- life estimates. S cenario selection focused on runoff prone soils that drain to a standard pond lack ing an outlet.

EECs from the rice use represent c oncentrations within rice paddies and undiluted effluent from the paddies. Rice paddies can serve as habitat to aquatic invertebrates, fish, and amphibians 1

. Exposure to aquatic organisms may also occur in receiving waters outside the rice paddy but woul d decrease as effluent residues are degraded and diluted. Additionally, only a single EEC is

1 http://www.fao.org/rice2004/en/f

- sheet/factsheet7.pdf39 used in risk estimation , analogous to the ‘peak’ from SWCC. Thus, no degradation is accounted for in modeling chronic EECs

. Spray drift exposure to aquatic or ganisms is also a potential exposure pathway for acifluorfen

. However, with edge of field deposition of acifluorfen from maximum application rates even endangered species LOCs are not exceeded for any aquatic taxa.

4.2.2 Risks to Aquatic Animals

B a sed o n the available data, risk to freshwater or estuarine/marine fish is not expected on an acute exposure basis. The highest RQ from all modeled use patterns is 0. 012 , below the listed species LOC of 0.05

Based on toxicity data from a study conducted under standard laboratory lighting , chronic risk to fish would not be expected, as the highest RQ would be 0. 22

, roughly on e quarter of the LOC. When the interim adjustment factor of 29X is applied to the fish NOAEC from the guideline freshwater fish ELS study , RQs exceed the LOC by 6

- fold for the rice use pattern; other use patterns do not indicate risk.

However, as discussed earlier, several studies have documented enhanced toxicity of LDPHs (such as acifluorfen ) to fish in the presence of enhanced uV light compared to toxicity observed under standard laboratory lighting. Given that aquatic organisms are likely to be exposed simultaneously to LDPH and uV light in natural settings, concerns have been raised that standard laboratory tests may underestimate the toxicity of LDPH s in the field. This enhanced sensitivity to LDPHs may not be limited to fish and could be observed in other taxa such as aquatic invertebrates, birds, and mammals (Birchfield and Casida, 1997); however, the Agency is only applying an adj ustment factor to fish at this time. Uncertainties regarding the EECs for rice are discussed above.

As previously indicated, the 29X adjustment factor is considered an interim approach. In 2014, final study reports for the chemicals tested by t he LDPH Task Force indicated that, depending on the chemical and endpoint, the factor of enhanced uV toxicity varied from approximately 1 to 400x. EFED’s science policy panel looked at the available data and came to three conclusions:

1) High intensity uV ex posure elicits a greater toxic response than standard light exposure for LDPH chemicals 2) The LDPH mechanism of action under high intensity uV is independent of the standard light toxicity mechanism of action 3) Since the standard light and high intensity uV st udies demonstrate independent mechanisms of action, it is not appropriate to employ a factor to predict the uV enhanced toxicity of an LDPH for which a standard light study is available

Accordingly, the panel recommended that to approximate the toxicity o f LDPH chemicals under high intensity uV exposure conditions without additional research, the lowest molecular weight corrected NOAEC from high intensity uV testing (the molecular weight correction removes the variability introduced by active ingredient pa rticle size for the purposes of toxicity comparison) can be used as a correction factor. This correction factor can be multiplied by the molecular40 weight of any LDPH chemical to generate a conservative estimate of toxicity under high intensity uV

. Howeve r, in this assessment the 29X adjustment factor is still the vetted approach.

The exceedance of the LOC is based only on the freshwater ELS study. There are no chronic estuarine/marine fish data. However, based on the available acute toxicity studies, t he sheepshead minnow (surrogate for all estuarine/marine fish) is considerably less sensitive to acifluorfen exposure than the rainbow trout. While an ACR cannot be calculated because the acute value for sheepshead minnow is non

- definitive, logically a ch ronic value calculated with a less sensitive acute endpoint would also be less sensitive (higher)

. There are additional uncertainties regarding the chronic RQ exceedance. Not all fish and amphibians would be exposed to both acifluorfen and high uV light at the same time, but it has not yet been determined what factors might mitigate the effect. It would seem reasonable to assume that fish and amphibians inhabiting shallow, clear waterbodies would be more susceptible to chronic effects than those in deepe r , more turbid and/or better

- shaded waterbodies. Also, fish and amphibians inhabiting waterbodies at lower elevations or higher latitudes may also be less likely to exhibit chronic effects due to uV

- enhanced toxicity. According to the Agency’s website http://www.epa.gov/sunwise/doc/uvradiation.html , other factors to consider regarding the amount of uV light are time of day, time of year, stratospheric ozone and weather (cloud cover). T his ri sk assessment concludes that chronic exposure from the use of acifluorfen on rice may cause adverse effects to fish (and aquatic

- phase amphibians) under enhanced uV conditions

.

There are no exceedances for freshwater invertebrates based on the available d ata , with the highest RQ (for rice) being <0.01. There is a marginal LOC exceedance for acute effects to listed estuarine/marine invertebrate s , with an RQ as high 0.06 based on the EEC for the rice use

. No other use pattern results in any exceedance of t he LOC. It is unclear how often the rice EEC is representative of estuarine/marine habitats.

There are no chronic data available for freshwater invertebrates, but the estuarine/marine acute endpoint is two orders of magnitude lower than the acute daphnid endpoint. While an ACR can be applied , it would result in RQs an order of magnitude lower than the mysid. Based on the mysid endpoint, there are no exceedances for chronic exposure except for the rice use pattern

, with the highest RQ =1.3

.

The lack of chronic exceedances for aquatic invertebrates is based on guideline data conducted with normal lighting. It is not clear whether invertebrates experience similar enhanced toxicity from acifluorfen exposure in the presence of high uV light as fish have bee n observed to.

4.2.3 Risks to Aquatic Plants

Based on the available information for Lemna gibba , the uses of acifluorfen do not result in RQ exceed ances of the LOC for aquatic vascular plant s, with a maximum RQ (for aquatic nonvascular plants) of 0. 58; there is a marginal exceedance of the LOC for listed aquatic vascular plants for the rice use with an RQ of 1.2

. There are no exceedances for aquatic nonvascular plants based on the NOAEC, with the highest RQ being 0.82.41 4.2.4. Risks to Mammals

A s de scribed above, a cute RQs for mammals did not exceed any LOCs, including the listed species LOC. Based on the EEC values from T

- REX and the highest dose tested in the acute rat study, the highest RQ for 15 gram mammals foraging on short grass, the most sen sitive size class and forage item combination, is 0. 05 for the strawberry use

, which results in the highest exposure estimates for acifluorfen

. When assessing potential chronic risk to mammals, the dietary

- based NOAEC is converted to a dose

- based NOAEL using body weight data from the laboratory toxicity study, which can be scaled to different mammalian size classes. The dose

- based RQs are calculated using a body weight adjusted and consumption

- weighted equivalent dose, as determined in the study. The adjustments account for the fact that smaller

- sized animals have to consume more food in terms of their body weight than larger animals and that there is differential sensitivity to chemicals based on body size. By expressing the Kenaga nomogram

- estimated residues in terms of daily equivalent dose, estimated environmental concentrations can then be compared to the dose

- based NOAEL . For many applications, dose

- based RQs exceed the LOC , with the strawberry use pattern resulting in the most exceedance (highe st application rate) and rice resulting in the fewest (lowest application rate)

. The exceedances are as high 4X the LOC

. Although not presented here, risk estimates using mean EECs result in fewer exceedance; however, mean EECs are expected to be exceede d roughly half of the time.

There are no exceedances for dietary

- based based exposure but it should be noted t hat th e dose

based approach assumes that the uptake and absorption kinetics of a gavage toxicity study approximate the absorption associated with uptake from a dietary matrix. Toxic response is a function of duration and intensity of exposure and the importance of absorption kinetics across the gut and the importance of enzymatic activation/deactivation of a toxicant may be important and are likely variable across chemicals and species. For many compounds a gavage dose represents a very short

- term high intensity exposure, where dietary exposure may be of a more prolonged nature. The dietary

- based ap proach assumes that animals i n the field are consuming food at a rate similar to that of confined laboratory animals. Energy content in food items differs between the field and the laboratory as does the energy requirements of wild and captive animals

. This applies to birds as well as mammals.

4.2.5. Risk to Birds

The acute risk LOC for birds i s indicated only for small (20g) birds foraging on short grass for the strawberry and soybean/peanut use patterns (although there are more listed species exceedances). Given that the RQs are for species foraging wholly on the treated area, it can be expected that risk

- inducing exposure will attenuate quickly with distance from the field.

There are no exceedances based on the subacute dietary endpoint for birds , again suggesting that the dietary matrix may play a role in the toxicity of acif luorfen. But, as with mammals, the homogenous mixture fed in laboratory studies is not representative of field foraging conditions.42 Chronic RQs exceed the LOC by up to 9

- fold, and the exceedance are for all use patterns for birds foraging on short grass, tall grass broadleaf plants and arthropods. These risk estimates are generated using endpoints from studies where exposure was in the diet. Using mean EECs, the maximum RQs fall rough to one third of those derived from the upper

- bound EECs, but the

mean values are expected to be exceeded roughly half of the time.

Birds are generally used as surrogates for terrestrial

- phase amphibians and reptiles. However, these taxa are poikilotherms (body temperature varies with environmental temperature) while birds are homeotherms (temperature is regulated, constant, and largely independent of environmental temperatures). Therefore, they tend to have much lower metabolic rates and lower caloric intake requirements than birds or mammals. As a consequence, birds are likely to consume more food than amphibians o n a daily dietary intake basis, assuming similar caloric content of the food items. The refore, use of an avian food intake allometric equation as a surrogate to reptiles and amphibians may result in an over

- es timation of dietary exposure and risk for reptiles and terrestrial

- phase amphibians. Conversely, other exposure routes (such as dermal and inhalation) may be relatively more important than dietary exposure in reptiles and particularly amphibians; these ro utes are not assessed in T

- REX.

4.2.6. Potential Effects to Terrestrial Invertebrates

Given that data are available only for honeybees, this risk assessment make s the assumption that other insect taxa are similarly unaffected by acifluorfen exposure. However, this is a source of uncertainty for the assessment.

Acifluorfen is classified as practically nontoxic to honeybees on an acute contact exposure basis, with LD 50 > 100 μg a

. i

. /bee and virtually no sublethal effects observed. Therefore, RQs are no t calculated and the potential for risk is believed to be low. It should be noted that the EPA is issuing data call

- ins for multiple acute and chronic adult and larval honey bee studies across all registered pesticides for which exposure to bees is expect ed. Until those studies are submitted and reviewed, uncertainty rega rding effects to bees will remain.

4.2.7. Risk to Terrestrial Non

- target Plants

As expected with an herbicide, risk to nontarget plants is indicated. Based on the available data,
gras ses are less sensitive to acifluorfen than non

- grasses , and generally vegetative vigor is a more sensitive life

- stage than seedling emergence for acifluorfen

. While vegetative vigor exposure is considered to be via spray drift, seedling emergence exposure is considered to be via either (or both) spray drift and run off. However, modeled runoff plus spray drift to semi

- aquatic

areas , which are compared to seedling emergence endpoints, result s in the highest RQs. This scenario represents a 10 acre area run ning off into a one acre area. T he RQs for nonlisted plants range up to over 19 (aerial application at the strawberry rate ). As described above, frank seedling emergence endpoints for grasses are not currently defined so RQs are not determined; however, given that the data indicate that grasses are less sensitive than non

- grasses, RQs would be lower. Spray drift RQs are determined using the more sensitive of the seedling emergence or vegetative vigor endpoints, so RQs are determined, ranging up to 10 (ae rial application at the43 strawberry rate). The highest grass RQ is 0.55 for the same application. But lacking defined seedling emergence endpoints results in a large degree of uncertainty and care should be taken in interpreting this RQ

.

There is n o t cur rently a vetted way to refine the risk posed by runoff, but to some degree

, the exposure is reduced with distance from the application site. The TerrPlant assumptions for runoff, that sheet flow will result in a one

- to

- one area of exposure and that channe lized runoff will result in a ten

- to

- one ratio of areas exposed do not take distance from application into consideration and assume equal deposition across the nontarget area. These assumptions also consider only solubility, while other chemical attribute s, such as Koc, likely affect the amount of acifluorfen deposited on the nontarget areas.

Risk from drift alone can be refined using AgDRIFT. AgDRIFT was used to determine the distance from the edge of field where the nonlisted species RQ falls below the LOC for the species used in TerrPlant ( Table 4.1 ) for both aerial and ground application for the labeled uses of acifluorfen

. Model defaults for each scenario were used.

Table 4.1 Distance (feet) from the edge of field where the nonlisted species RQ fal ls below the terrestrial plant LOC for the most sensitive available endpoints.

Plant Species Application rate Endpoint Ground Aerial

lbs a

. i

. /A IC 25 Distance to LOC (in feet)

Grass (ryegrass) Strawberry 0. 3 75 1 0.085 2 6.6 26

Non

- grass (radish) 0.0038 95 >997

Grass (ryegrass) Soybean/peanut 0. 37 5 0.085 2 6.6 26

Non

- grass (radish) 0.0038 95 >997

Grass (ryegrass) Rice 0.25 0.085 2 3.3 10

Non

- grass (radish) 0.0038 59 643

2 A ssumed to be the lowest grass endpoint (vegetative vigor)

For acifluorfen , ve getative vigor appears to be a much more sensitive life stage than seedling emergence, thus greater impacts on this life stage may be expected to nontarget plants as well. Aerial applications result in considerably more drift than ground sprays, and so im pacts from aerial applications are expected farther from the field edge for aerial applications. Application rate is a key variable in determining the distance effective drift is expected to travel, so applications of 0. 3 75 lbs a

. i

. /A will have an impact at greater distance from the application area than applications of 0.25 lbs a

. i

. /A

, if the same application method is used ( e.g ., aerial spray)( Table 4.1 )

. Another key factor in drift distances is droplet size spectra. Coarser droplet sizes, as defined i n the ASTM 572S standard or similar methods, would decrease the distance off

- field beyond which effects from spray drift would not be expected.44 For grasses , most species are n o t expected to be at risk greater than 26 feet from the edge of the applicatio n area. However, risk to the most sensitive non

- grass species are expected at >997 feet from the field edge at both the strawberry and soybean /peanut rate s (0. 375 lbs a

. i

. /A) from aerial application s. For ground applications, risks are expected as far as 95 feet for species with sensitivities similar to radish. For acifluorfen, multiple applications are allowed. While the effect of multiple applications on the potential risk to plants is not currently quantified , it is reasonable to assume multiple appl ications would result in an increase in the risk estimates.

4.3. Additional Uncertainties and Data Gaps

4.3.1. Fate and Transport

With only one aerobic aquatic metabolism study and one anaerobic aquatic metabolism study available, a 3X adjustment is ma de to each half

- li fe to conservatively account for the expected variability associated with those parameters. Additional data on varied aquatic systems are likely to reduce the associated input parameter

, as the 90 percent upper confidence limit on the me an of the half

- lives is employed as a standard model input, though it is possible that an individual observation can correspond with a longer half

- life.

4.3.2. Effects

While a 29X factor is being applied to account for the LPDH mode of action and its p otential enhanced effect on fish from chronic exposure, there are no studies examining this effect on fish from acifluorfen . The degree to which the 29X factor over or under estimates the sensitivity of fish to acifluorfen is uncertain. It should be reit erated that use of the 29X factor is an interim approach

, which may be subject to change as the results of a broader investigation into the LDPH effect are considered.

It is not clear from the available data whether the LPDH mode of action enhances toxici ty to aquatic invertebrates (or terrestrial taxa) under high uV conditions. This assessment only applies an enhanced chronic toxicity factor for fish

.

Based on available data m ysids, a n estuarine/marine aquatic invertebrate, are considerably more sensiti ve to acifluorfen than daphnids, a freshwater invertebrate. It is possible that some freshwater invertebrates are more sensitive than the tested daphnids. If there are freshwater invertebrates as sensitive to acifluorfen as mysids, this assessment may un derestimate potential chronic effects to these taxa.

5. Federally Threatened and Endangered (Listed) Species Concerns

In November 2013, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the National Marine Fisheries Service (NMFS) (collecti vely, the Services) , and the U.S. D epartment of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks to listed species from pesticides. The Interim Approaches were developed jointly by the

a g encies in response to the N ational A cademy of S ciences’ (NAS) recommendations and reflect45 a common approach to risk assessment shared by the a gencies as a way of addressing scientific differences between the EPA and the Services. The NAS report outlines recommendations on specific scientific and technical issues related to the development of pesticide risk assessments that EPA and the Services must conduct in connection with their obligations under the Endangered Speci es Act (ESA) and FIFRA

. The joint Interim Approaches were released prior to a stakeholder workshop held on November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013 P esticide P rogram D ialogue C ommittee (PPDC) an d S tate

- FIFRA Issues Research and Evaluation Group ( SFIREG ) meetings, and held a stakeholder workshop in April 2014, allowing additional opportunities for stakeholders to comment on the Interim Approaches. As part of a phased, iterative process for develo ping the Interim Approaches, the agencies will also consider public comments on the Interim Approaches in connection with the development of upcoming Registration Review decisions. The details of the joint Interim Approaches are contained in the white paper “Interim Approaches for National

- Level Pesticide Endangered Species Act Assessments Based on the Recommendations of the National Academy of Sciences April 2013 Report,” dated November 1, 2013.

Given that the agencies are continuing to develop and work toward implementation of the Interim Approaches to assess the potential risks of pesticides to listed species and their designated critical habitat, this preliminary risk assessment for acifluorfen does not contain a complete ESA analysis that includes effects determinations for specific listed species or designated critical habitat. Although EPA has not yet completed effects determinations for specific species or habitats, for this preliminary asse ssment EPA conducted a brief screening

level assessment for all taxa of non

- target wildlife and plants that assumes for the sake of the assessment that listed species and designated critical habitats may be present in the vicinity of the application of aci fluorfen. This screening level assessment will allow EPA to focus its future evaluations on the types of species where the potential for effects exists once the scientific methods being developed by the agencies have been fully vetted. Once the agencies have fully developed and implemented the scientific methods necessary to complete risk assessments for endangered and threatened (listed) species and their designated critical habitats, these methods will be applied to subsequent analyses for acifluorfen a s part of completing this registration review.

6

. Endocrine Disruptor Screening Program (EDSP)

Acifluorfen w as not included in the first group of 67 chemicals issued an order to conduct Tier 1 EDSP testing. For additional information on the EDSP, visit http://www.epa.gov/endo/

.46 6. References

Birchfield, N.B., and J.E. Casida. 1997. Protoporphyrinogen oxidase of mouse and maize: Target site selectivity and thiol effects on peroxidizing herbicide action. Pesticide Biochemistry and Physiology 57 , 36

- 43.

USEPA 1998. Guidelines for Ecological Risk Assessment. EPA/630/R

- 95/002F. Published in 63 FR 26846; May 14, 1998. U.S. Environmental Protection Agency, Washington, DC. April, 1998.

USEPA. 2004. Over view of the Ecological Risk Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency. Endangered and Threatened Species Effects Determinations. Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Washington, D.C. January 23, 2004. Online at: http://www.epa.gov/oppfead1/endanger/consultation/ecorisk

- overview.pdf

USEPA

. 2006a. Standardized Soil Mobil ity Classification Guidance. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, Memorandum. Apr. 21, 2006.

USEPA. 2006b. User’s Guide: TerrP lant Version 1.2.2 (Terrestrial Residue Exposure model). United States Environmental Protection Agency. Environmental Fate and Effects Division. Office of Pesticide Programs. U.S. Environmental protection Agency. Washington, D.C. December 26, 2006.

USEPA

. 2008. White Paper on Methods for Assessing Ecological Risks of Pesticides with Persistent, Bioaccumulative and Toxic Characteristics. Submitted to the FIFRA Scientific Advisory Panel. October 28

- 31, 2008. Office of Pesticide Programs, Environmental Fate and Effects Division, Washington, D.C.

USEPA

. 2009. Guidance for Selecting Input Parameters in Modeling the Environmental Fate and Transport of Pesticides. U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances, Office of Pesticide Programs, Environmental Fate and Effects Division, Oct. 22, 2009. Online at: http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm

U SEPA. 201 0 a

. Interim Guidance on Light

- Dependent Peroxidizing Herbicides: Identification, DCI Justifcation, and Use of a Toxicity Adjustment Factor on Fish Chronic Endpoints

, Memorandum from Don Brady to EFED Staff

, August 2010 . US Environmental Protection Agency, OCSPP, Office of Pesticide Programs. Office of Pesticide Programs, Environmental Fate and Effects Division, Washington, D.C.47 USEPA. 2010b. Judkins, Donna and Stephanie Syslo. Registration Review

– Preliminary Problem Formulation for the Ecologi cal Risk and Drinking Water Exposure Assessments for Sodium Acifluorfen.

USEPA. 201 5 . Water Models. U.S. Environmental Protection Agency, Pesticides: Science and Policy, Models and Databases. Last updated April 29 , 201 5 . Online at: http://www.epa.gov/oppefed1/models/water/

USDA. 2000. USDA Crop Profiles. Hosted by the Integrated Pest Management Centers. Available online at: http: //www.ipmcenters.org/cropprofiles/index.cfm

.

Urban, D.J. and N.J. Cook, 1986. Hazard Evaluation Division Standard Evaluation Procedure Ecological Risk Assessment. EPA 540/9

- 85

- 001. U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington D.C.

6.1 Submitted Product Chemistry and Environmental Fate Studies

114401 Acifluorfen acid Fate/Chemistry Bibliography MRID

- Doc # Match 161

- 2 Photodegradation

- water
MRID Citation Reference

42793502 2037659 in 114402 folders Sute r, P. (1993) Artificial Sunlight Photolysis of Acifluorfen in Aqueous Media at pH 7.0: Lab Project Number: 92176: M9311: 93/5043. Unpublished study prepared by BASF Corp. in coop with BASF, Limburgerhof. 266 p.
161

- 3 Photodegradation

- soil
MRID Cit ation Reference

122759 See 2037617 in 114402 Gerecke, D.; Wargo, J. (1982) Photodegradation of Tackle (MC 10109) on a Soil Surface: ASD Report No. 82/045. (Unpublished study received Dec 20, 1982 under 359

- 708; submitted by Rhone

- Poulenc, Inc., Monm outh Junction, NJ; CDL:071323

- D)
162

- 1 Aerobic soil metabolism
MRID Citation Reference

122761 also listed as 137754 in PC Code 114402 2037619 in 114402 Piznik, M.; Wargo, J. (1982) Abbreviated Aerobic/Anaerobic Soil Metabolism Study with Ra diolabelled Tackle (MC

- 10978): ASD No. 82/047. (Unpublished study received Dec 20, 1982 under 359

- 708; submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071324

- B)48 71593 also listed in PC Code 114402 DER not located Ku, C.C.; Norris, F.A.; Mill er, K.M.; et al. (1980?) Metabolism of Carbon

- 14 Labelled MC 10978 in Georgia and New Jersey Soils un

- der Aerobic and Anaerobic Laboratory Conditions: Progress Memo

- randum PME

- 80.52. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; submitted by Mobil Chemical Co., Industrial Chemi

- cals Div., Richmond, Va.; CDL:244155

- D)
163

- 1 Leach/adsorp/desorption
MRID Citation Reference

42075601 DER not located

check
contract DERS Wing, C. (1987) Determination of Adsorption/Desorption Constant s of Acifluorfen: Lab Project Number: 12100: 88/5008. Unpublished study prepared by Cambridge Analytical Associates, Inc. 34 p.

42793501 2037650 in PC Code 114402 Suter, P. (1993) Adsorption and Desorption of Acifluorfen on Representative Agricultural So ils: Lab Project Number: 92177: M9312: 93/5042. Unpublished study prepared by BASF Corp. in coop with Agvise Labs and BASF, Limburgerhof. 109 p.

45686503 Open lit Gennari, M.; Negre, M.; Raimondo, E. (1994) Effect of Soil Properties on Adsorption and Des orption of Acifluorfen. Journal of Agricultural Food Chemistry 42:2329

- 2332. 114402 Acifluorfen Na Salt Fate/Chemistry Bibliography MRID

- Doc# Fate Studies= Folder F000648 161

- 1 Hydrolysis
MRID Citation Reference

71584 2037615 or 2037634 Norris, F.A.; Hassell, A.E. (1980) Hydrolytic Stability of MC

10978 in Buffered Aqueous Solutions: Technical Memorandum TME

- 80.17. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; sub

- mitted by Mobil Chemical Co., Industrial Chemicals Div., Rich

- mo nd, Calif.; CDL:244157

- B)

80127 DER not located Hofmann, C.K. (1979) Hydrolysis Study of RH

- 8817: TR 34H

79

- 15. (Unpublished study received Aug 6, 1981 under 707

- EX

98; sub

- mitted by Rohm & Haas Co., Philadelphia, Pa.; CDL:070260

- E)

122757 2037615 No rris, F.; Hassell, A. (1980) Hydrolytic Stability of MC

- 10978 in Buffered Aqueous Solutions: Technical Memorandum TME

80.17. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Mobil Chemical Co., submitted by Rhone

-49 Poulenc, Inc., Mon

- mout h Junction, NJ; CDL:071323

- B)

ACC 95735 2068708 Augenstein, L 1975 Hydrolysis study not found in OPPIN

92168032 Registrant
summary Keene, E. (1990) BASF Corporation Phase 3 Summary of MRID 00107479. A Hydrolysis Study with Carbon 14

- RH

- 6201: Technical Report No. 3423

- 75

- 66; 90/6151. Prepared by Rohm and Haas Company. 19 p.
161

- 2 Photodegradation

- water
MRID Citation Reference

41891208 2037646 Panek, M. (1991) Aqueous Photolysis of ?carbon 14|

- Sodium Acifluor

- fen: Lab Project Number: M902 4: M9118. Unpublished study pre

- pared by BASF Corp. 86 p.

42793502 2037649 Suter, P. (1993) Artificial Sunlight Photolysis of Acifluorfen in Aqueous Media at pH 7.0: Lab Project Number: 92176: M9311: 93/5043. Unpublished study prepared by BASF Corp. in coop with BASF, Limburgerhof. 266 p.

44195001 Supplemental to 41891208 Panek, M. (1993) Aqueous Photolysis of (carbon 14)

- Sodium Acifluorfen: Supplemental Report to MRID 41891208: Lab Project Number: 93/5220: M9024: M9314. Unpublished study prepared by B ASF Corp. 49 p.

44195002 Referenced DER not located Venkatesh, K. (1996) Further Characterization of Photolytic Degradation Products from the (carbon 14)

- Acifluorfen (NO2 Label) Artificial Sunlight Photolysis: Lab Project Number: 96/5112: 95037: M9610. U npublished study prepared by BASF Corp. 110 p.

71585 2037625 Norris, F.A.; Ku, C.C.; Hassell, A.E. (1980) Photodegradation of MC

- 10978 in Aqueous Solution: Progress Memorandum PME

- 80.50. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; sub

- mitt ed by Mobil Chemical Co., Industrial Chemicals Div., Rich

- mond, Va.; CDL:244157

- C)

122758 2037616 and 2037636 Somma, N. (1982) Photodegradation of Tackle in Aqueous Solution: ASD No. 82/048. (Unpublished study received Dec 20, 1982 under 359

- 708; submit ted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071323

- C)

137750 Response to review above Somma, N. (1983?) Tackle Herbicide: Reply to Environmental Fate Re

- views for Somma, N.; F. A. Norris and A. Guardigli

-- September, 1983

-- Photodegradation of Tackle in Aqueous Solution, Rhone

- Pou

- lenc, Inc., Monmouth Junction, NJ, ASD Report No.: 82/048, Acc. No. 071323: Ref. 83/BHL/857/AG. (Unpublished study re

- ceived Mar 19, 1984 under 359

- 708;50 submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:25 2764

- B)

ACC 95735 2068708 pg 5 Augenstein, 1979 Photolysis in Water
161

- 3 Photodegradation

- soil
MRID Citation Reference

71592 DER not located Ku, C.C.; Norris, F.A.; Sayles, B.A. (1980?) Photodegradation of MC 10978 on Soil Thin Layer Plat es: Progress Memorandum PME

- 80.54. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; sub

- mitted by Mobil Chemical Co., Industrial Chemicals Div., Rich

- mond, Va.; CDL:244155

- C)

107501 2068708 pg 10 2,4

- D and Aciflourfen Peirson, W.; Fisher, J. (1978) Long Term Laboratory Photolysis Study of RH

- 6201 on Soil: TR 34H

- 78

- 8. (Unpublished study re

ceived Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097720

- C)

44412901 Only referenced DER not located Venkatesh, K.; Oakley, W. (1997) Photolysis of (carbon 14)

- Acifluorfen (nitrogen dioxide and carbon trifluoride) on Soil: Lab Project Number: 96143: 97/5057. Unpublished study prepared by BASF Corp. and Agvise Labs. 137 p.

122759 may be for 114401 2037617 Gerecke, D.; Wargo, J. (1982) Photodegradation of Tackle (MC 10109) on a Soil Surface: ASD Report No. 82/045. (Unpublished study received Dec 20, 1982 under 359

- 708; submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071323

- D)

41688501 2037647 Looper, G. (1 990) Acifluorfen: Photodegradation on Soil: ?Phase 3 Summary|: Lab Project Number: ASD 82/045. Unpublished study prepared by Rhone

- Poulenc, Inc. 22 p.

107501 DER not located Peirson, W.; Fisher, J. (1978) Long Term Laboratory Photolysis Study of RH

- 6201 o n Soil: TR 34H

- 78

- 8. (Unpublished study re

ceived Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097720

- C)
162

- 1 Aerobic soil metabolism
MRID Citation Reference

122760 2037618 Wargo, J.; Ku, C.; Norris, F.; et al. (1982) Metabolism of Carbon

- 14 Labelled MC

- 10978 in Kansas, Virginia, Georgia and New Jersey Soils under Aerobic and Anaerobic Conditions: ASD No. 82/040. (Unpublished study received Dec 20, 1982 under 359

- 708; submit

- ted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071324

- A)51 137751 See 122760 above Wargo, J. (1983?) Metabolism of Carbon

- 14 Labelled MC

10978 in Kan

- sas, Virginia, Georgia and New Jersey Soils under Aerobic and Anaerobic Conditions (ASD No. 82/040): ?Response to Review|. (U npublished study received Mar 19, 1984 under 359

- 708; submit

- ted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:252764

- C)

143572 2037637 pg 12 in pdf Gemma, A.; Wargo, J. (1984) Metabolism of [Carbon

- 14]

- MC

10978 (Tackle) in Soil under Aerobic and A naerobic Conditions: Report No. 84/088. Unpublished study prepared by Rhone

Poulenc Inc. 144 p.

147720 2037637 pg 20 in pdf Norris, F.; Wargo, J.; Jordan, E.; et al. (1984) Mobility and Dissipation Rates of Tackle Herbicides as Determined from Field Expe riments: ASD No. 84/099. Unpublished study prepared by Rhone

- Poulenc Inc. 44 p.

71593 Progress report DER not located Ku, C.C.; Norris, F.A.; Miller, K.M.; et al. (1980?) Metabolism of Carbon

- 14 Labelled MC 10978 in Georgia and New Jersey Soils un

- der Aerobic and Anaerobic Laboratory Conditions: Progress Memo

- randum PME

- 80.52. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; submitted by Mobil Chemical Co., Industrial Chemi

- cals Div., Richmond, Va.; CDL:244155

- D)

137754 2037619 Piznik, M.; Wargo, J. (1983?) Abbreviated Aerobic/Anaerobic Soil Metabolism with 14C

- Tackle (MC

- 10978): ASD No. 82/047: ?Response to Review|. (Unpublished study received Mar 19, 1984 under 359

- 708; submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:252764

- F )

137755 2037620 Gemma, A.; Wargo, J. (1982?) The Metabolism and Fate of 14C

- MC

- 10978 in New Jersey Soil (ASD No. 82/051): ?Response to Review|. (Unpublished study received Mar 19, 1984 under 359

- 708; submit

- ted by Rhone

- Poulenc, Inc., Monmouth Junctio n, NJ; CDL:252764

- G)

122763 Acc 71324 2037621 Gemma, A.; Wargo, J. (1982) Tackle Soil Metabolism: Metabolic Fate of 14C

- MC

- 10978 in Maryland Silt Loam Soil: ASD No. 82/053. (Unpublished study received Dec 20, 1982 under 359

- 708; submit

- ted by Rhone

- Pou lenc, Inc., Monmouth Junction, NJ; CDL:071324

- D)

122762 Gemma, A.; Wargo, J. (1982) The Metabolic Fate of 14C

- MC

10978 in New Jersey Loamy Sand Soil: ASD No. 82/051. (Unpublished study received Dec 20, 1982 under 359

- 708; submitted by Rhone

- Poulenc, Inc. , Monmouth Junction, NJ; CDL:071324

- C)

ACC 95733 2068708 pg Fisher, 1976 Lab Soil Metabolism study52 19

32853 2037613 Rohm and Haas Company (1980) Blazer^(TM)I 2L Herbicide (707

- 149); Blazer^(TM)I 2S Herbicide (707

- 150): Environmental Chemistry Data

-- Sup plement to Registration File. (Unpublished study re

- ceived May 2, 1980 under 707

- 149; CDL:242395

- A)

122763 2037634 pg 18 of pdf Gemma, A.; Wargo, J. (1982) Tackle Soil Metabolism: Metabolic Fate of 14C

- MC

- 10978 in Maryland Silt Loam Soil: ASD No. 82/053. (Unpublished study received Dec 20, 1982 under 359

- 708; submit

- ted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071324

- D)

162

- 2 Anaerobic soil metabolism
MRID Citation Reference

143572 2037637 pg 12 in pdf Gemma, A.; Wargo, J. (198 4) Metabolism of [Carbon

- 14]

- MC

10978 (Tackle) in Soil under Aerobic and Anaerobic Conditions: Report No. 84/088. Unpublished study prepared by Rhone

Poulenc Inc. 144 p.

71593 See above in aerobic Ku, C.C.; Norris, F.A.; Miller, K.M.; et al. (1980?) Meta bolism of Carbon

- 14 Labelled MC 10978 in Georgia and New Jersey Soils un

- der Aerobic and Anaerobic Laboratory Conditions: Progress Memo

- randum PME

- 80.52. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; submitted by Mobil Chemical Co., Industria l Chemi

- cals Div., Richmond, Va.; CDL:244155

- D)

137754 2037619 Piznik, M.; Wargo, J. (1983?) Abbreviated Aerobic/Anaerobic Soil Metabolism with 14C

- Tackle (MC

- 10978): ASD No. 82/047: ?Response to Review|. (Unpublished study received Mar 19, 1984 under 3 59

- 708; submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:252764

- F)

76706 2068806 pg 2 of pdf or 2037551 Rogerson, T.D.; Hawke, J.A. (1981) Aerobic Aquatic Metabolism of ^14IC

- labeled RH

- 6201 (Blazer): Technical Report No. 36H

- 81

- 6. (Unpublish ed study received May 27, 1981 under 707

- 149; submit

- ted by Rohm & Haas Co., Philadelphia, Pa.; CDL:070115

- F)
162

- 3 Anaerobic aquatic metab.
MRID Citation Reference

42330603 DER not Panek, M. (1992) Carbon 14

- Sodiu m Acifluorfen Anaerobic53 located see study below Aquatic Metabolism Study: Status Report: Lab Project Number: 92/5073. Unpublished study prepared by BASF Corp. 18 p.

43155201 2068709 Panek, M.; Reese, C. (1994) Anaerobic Aquatic Metabolism of (carbon 14) Sodium Acifluorfen: Lab Project Number: 92062: M9326. Unpublished study prepared by BASF Corp. and Agvise, Inc. 108 p.
162

- 4 Aerobic aquatic metab.
MRID Citation Reference

42330601 2037648 Panek, M. (1992) Aerobic Aquatic Metabolism of ?carbon 14|

- Sodium Aciluorfe n: Lab Project Number: 91056: M9204. Unpublished study prepared by BASF Corp. 77 p.

107503 2068708 Caplan, J.; Schroader, K. (1978) 14C

- RH

- 6201 Activated Sludge Metabolism: Laboratory No. 7PL

- 1

- 1. (Unpublished study received Dec 14, 1978 under 707

- 149; p repared by Biospherics, Inc., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097720

- E)
163

- 1 Leach/adsorp/desorption
MRID Citation Reference

71591 2037622 or 2037634 pg 18 Norris, F.A.; Miller, K.M. (1978?) Mobility of MC 10978 in Fo ur Soil Types: Technical Memorandum TME

- 80.24. (Unpublished study received Jan 5, 1981 under 2224

- EX

- 18; submitted by Mobil Chemi

- cal Co., Industrial Chemicals Div., Richmond, Va.; CDL:244155

- B)

107496 2068708 pg 43 or pg 29 in PDF Fisher, J. (1978) Lea ching and Mobility Studies in Soil Treated with RH

- 6201: TR 34H

- 78

- 10. (Unpublished study received Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097719

- A)

ACC 95733 2068708 pg 32 in PDF Fisher, 1976 Leaching study in soi l in compilation below

–
Rohm & Haas Co. (1976) ?Analyses for Residues of RH

- 6201 and Other Products in Crops, Soil, and Animals|. (Compilation; unpub

- lished study received Jan 17, 1977 under 707

- EX

- 87; CDL:095734

- A; 095733; 095735)

107496 2068708 pg 3 2 in PDF Fisher, J. (1978) Leaching and Mobility Studies in Soil Treated with RH

- 6201: TR 34H

- 78

- 10. (Unpublished study received Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097719

- A)54 107497 2068708 pg 34 in PDF Garstka, T. (1978) The Adsorptive and Desorptive Behavior of RH

- 6201 on Drummer Silt Loam Soil: TR 34H

- 78

- 4. (Unpublished study received Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097719

- B)

122766 2037624 Norris, F.; Ku, C. (1981) Field Dissipation and Leaching Studies: Progress Memorandum PME

- 81.48. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Mobil Chemical Co., submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL: 071325

- C)

122764 See same citation 71591 Norris, F.; Miller, K. (1980) Mobility of MC 10978 in Four Soil Types: Technical Memorandum TME

- 80.24. (Unpublished study

re

- ceived Dec 20, 1982 under 359

- 708; prepared by Mobil Chemical Co., submitted by Rhone

- Poulenc, Inc., Monmouth Junct ion, NJ; CDL:071325

- A)

122765 2037623 Or 2037634 pg 19 in pdf Norris, F. (1982) Adsorption/Desorption of Acifluorfen Sodium (LS

- 80

- 1213, MC

- 10978) from a Silt Loam Soil: PDD No. 82/030. (Unpublished study received Dec 20, 1982 under 359

- 708; submit

- ted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071325

- B)

42793501 2037650 Suter, P. (1993) Adsorption and Desorption of Acifluorfen on Representative Agricultural Soils: Lab Project Number: 92177: M9312: 93/5042. Unpublished study prepared by BASF Co rp. in coop with Agvise Labs and BASF, Limburgerhof. 109 p.

44412902 2010545 2068710

- not signed Mills, C.; Goetz, A. (1997) Adsorption/Desorption of (carbon 14) BH 9048

- A (Amino Acifluorfen) on Soil: Lab Project Number: 96161: 97/5334. Unpublished stud y prepared by BASF Corp. 61 p.

92168033 Registrant
summary Keene, E. (1990) BASF Corporation Phase 3 Summary of MRID 00071591. Mobility of MC 10978 in Four Soil Types: Technical Memorandum TME

- 80.24; 90/6150. Prepared by Mobil Chemical Company. 16 p.
1 63

- 3 Volatility

- field
MRID Citation Reference

147720 2037637 pg 20 of pdf Norris, F.; Wargo, J.; Jordan, E.; et al. (1984) Mobility and Dissipation Rates of Tackle Herbicides as Determined from Field Experiments: ASD No. 84/099. Unpublished study prepared by Rhone

- Poulenc Inc. 44 p.
164

- 1 Terrestrial field dissipation55 MRID Citation Reference

94999 DER not located Cubbedge, S.D. (1980) Analysis for Residues of Mobil 10978 in Soil: Laboratory Nos. 80

- 2680

- 3

- 3 and 80

- 2865

- 3

- 1. I ncludes Mobil Chemical Method 157

- 80 dated Nov 6, 1980. (Unpublished study, including letters dated Jan 2, 1981 from G. Milad to Arleigh Hartkopf and Jan 5, 1981 from S.D. Cubbedge to Arleigh Hartkopf, received Feb 6, 1981 under 2224

- EX

- 18; prepared by Bio spherics, Inc., submitted by Mobil Chemical Co., Industrial Chemicals Div., Richmond, Va.; CDL:244384

- E)

107498 2068708 pg 38 in PDF Rogerson, T.; Zogorski, W.; Bradley, G.; et al. (1978) A Residue Decline Study of Soil Treated with 14C

- RH

- 6201 at Newton

, Pa., in 1977: TR 344

- 78

- 19. (Unpublished study received Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097719

- C)

107499 DER not located Rohm & Haas Co. (1978) Soil Detailed Analytical Reports: ?Blazer 2L Herbicide (Form erly RH

- 6201); Blazer 2S Herbicide|. (Compi

- lation; unpublished study received Dec 14, 1978 under 707

- 149; CDL:097719

- D)

122722 DER not located Rhone

- Poulenc, Inc. (1982) Tackle Herbicide: Residue Chemistry Pro

- file: ASD No. 821054. (Compilation; unpub lished study received Dec 20, 1982 under 359

- 708; CDL:071305

- A; 071307)

122762 2037636 pg 8 of pdf Gemma, A.; Wargo, J. (1982) The Metabolic Fate of 14C

- MC

10978 in New Jersey Loamy Sand Soil: ASD No. 82/051. (Unpublished study received Dec 20, 1982 unde r 359

- 708; submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071324

- C)

122766 2037624 Norris, F.; Ku, C. (1981) Field Dissipation and Leaching Studies: Progress Memorandum PME

- 81.48. (Unpublished study received Dec 20, 1982 under 359

- 708; prep ared by Mobil Chemical Co., submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL: 071325

- C)

137136 DER not located Norris, F.; Ku, C. (1981) Field Dissipation and Leaching of Tackle Herbicide in Four Soil Types: Project No. 15118. (Unpublished st udy received Jan 11, 1984 under 359

- 708; prepared by Mobil Chemical Co., submitted by Rhone

- Poulenc, Inc., Monmouth Junc

- tion, NJ; CDL:252141

- B)

137756 2037636 pg 10 of pdf Guyton, C.; Perez, G.; Berner, R.; et al. (1983) Soil Dissipation Data on Tackle under Field Conditions: 1982 Field Programs F

- 7 & F

- 10: ASD Report No. 83/025. (Unpublished study received56 Mar 19, 1984 under 359

- 708; submitted by Rhone

- Poulenc, Inc., Mon

- mouth Junction, NJ; CDL:252764

- H)

143573 addendum Guyton, C. (1984) Addendum to Report: Soil Dissipation Data on Tac

- kle under Field Conditions: 1982 Field Programs F

- 7 & F

- 10: ASD No. 84/100. Unpublished study prepared by Rhone

Poulenc, Inc. 21 p.

147720 2037637 pg 20 in pdf Norris, F.; Wargo, J.; Jordan, E.; et al. (1984) Mobili ty and Dissipation Rates of Tackle Herbicides as Determined from Field Experiments: ASD No. 84/099. Unpublished study prepared by Rhone

- Poulenc Inc. 44 p.

41172801 2037576 Norris, F. (1989) A Small Scale Prospective Field Dissipation and Groundwater Mon itoring Study with Acifluorfen

- Sodium, the Active Ingredient of Tackle Brand Herbicide and Blazer Brand Herbicide: Project ID: File No. 40576; Protocol No. MEF

87

- 010. Unpublish

- ed study prepared by Rhone

- Poulenc Ag Co. 813 p.

41833201 MRID incorrectly identified on study report 2070931 Blundell, K. (1991) A Small Scale Retrospective Ground

- water Monitoring Study and Limited Prospective Field Dissipation Study with Acifluorfen

- sodium, the Active Ingredient of Tackle Brand Herbicide and Blazer Brand Herbi cide: Interim Report: Lab Project No.: 429.03: 91/5048. Unpublished study prepared by BASF Corp., in cooperation with Blasland & Bouck Engineering, P.C. 122 p.
164

- 2 Aquatic field dissipation
MRID Citation Reference

76707 2068806 pg 10 of p df Zogorski, W.J., III (1981) A Study To Measure the Dissipation Rate of Blazer Residues in Water from Treated Rice Fields: Technical Report No. 36H

- 81

- 8. (Unpublished study received May 27, 1981 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, P a.; CDL:070115

- G)

43270801 DER not located Jordan, J.; Nelsen, T. (1994) 1992 Blazer Herbicide Aquatic Use Dissipation Study: Lab Project Number: 94/5075: 92126: ER94017. Unpublished study prepared by Jensen Agricultural Consultants, Inc.; Stoneville Ass oc., Inc. and Agvise Labs. 460
p. 164

- 5 Long term soil dissipation
MRID Citation Reference

41160001 2037582 Norris, F. (1989) A Small Scale Retrospective Groundwater57 Monitori

- ng Study and Limited Prospective Field Dissipation Study with A cifluorfen

- sodium...: File No. 40577: Protocol No. EC/P

- 89

- 001

- 7. Unpublished study prepared by Rhone

- Poulenc Ag Co. 360 p.
165

- 1 Confined rotational crop
MRID Citation Reference

42330602 Panek, M. (1992) Carbon 14

- Sodium Acifluorfen Conf ined Rotational Crop Study: Progress Report: Lab Project Number: 92/5072. Unpublished study prepared by BASF Corp. 9 p.

42785601 DER not located Panek, M.; Geiger, D.; Reese, C. (1993) Confined Rotational Crop (carbon 14)

- Sodium Acifluorfen: Lab Project Number: 91058: M9307: 93/5061. Unpublished study prepared by BASF Corp. Agricultural Research Center and Agvise, Inc. 213 p.

43372501 Amendment
to 42785601 Panek, M. (1994) (carbon 14)

- Sodium Acifluorfen Confined Rotational Crop, Storage Stability of Aci fluorfen and Metabolite 1: Amendment to BASF Report No M9307: Lab Project Number: 94/5114: 91058: M9425. Unpublished study prepared by BASF Agricultural Research Center. 34 p.

43666601 DER not located Geiger, D.; Goetz, A. (1995) Further Characterization Analysis of Metabolite 1 from the (Carbon

- 14)

- Sodium Acifluorfen Confined Rotational Crop: Lab Project Number: 94127: M9427: 91058. Unpublished study prepared by BASF Corp. 55 p.

122769 ACC 071326 2037627 Gemma, A.; Wargo, J.; Heinzelmann, G.; et al. ( 1982) Tackle Field Rotational Crop Study: The Potential Uptake of 14C

- MC 10978 in Various Crops Grown under Field Conditions in Soil Treated with 14C

- MC 10978: ASD Report No. 82/042. (Unpublished study re

- ceived Dec 20, 1982 under 359

- 708; submitted by Rh one

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071326

- B)

156220 ACC 256167 2037640 2037641 Hutchinson, C. (1984) [Carbon

- 14] Tackle (MC

- 10978) Confined Rotat

- ional Crop Study: Final Report: Project No. 171

- 107. Unpub

- lished study prepared by Wildlife Int ernational Ltd. 106 p.

164236 ACC 265702 2037643 Perez, G. (1986) Tackle Residue Data on Field Grown Rotational Crops (1982

- 1984): ASD No. 86/206: Ref No. 86/BHL/463. Unpub

- lished compilation prepared by Rhone

Poulenc Inc. 163 p.

2068708 pages 43

- 57 Augenstein

- and RogersonSeveral Rotational Crop Residue studies58 165

- 2 Field rotational crop
MRID Citation Reference

156220 2037640 Hutchinson, C. (1984) [Carbon

- 14] Tackle (MC

- 10978) Confined Rotat

- ional Crop Study: Final Report: Project N o. 171

- 107. Unpub

- lished study prepared by Wildlife International Ltd. 106 p.

92168034 Registrant
summary Keene, E. (1990) BASF Corporation Phase 3 Summary of MRID 00107504. Residue Studies on Rotational Crops From Plots Treated with Carbon 14 Blazer He rbicide: Rohm and Haas Technical Report No. 310

- 86

- 76; 90/6149. Prepared by Rohm and Haas Company. 22 p.

ACC 071326 2037626 Gemma, 1982 Greenhouse Rotational Crop study
165

- 3 Accumulation

- irrig crop
MRID Citation Reference

164236 203764 3 pg 2 Perez, G. (1986) Tackle Residue Data on Field Grown Rotational Crops (1982

- 1984): ASD No. 86/206: Ref No. 86/BHL/463. Unpub

- lished compilation prepared by Rhone

Poulenc Inc. 163 p.
165

- 4 Fish Bioacculmulation
122770 2037628 Thompson, C.; Cranor , W.; Lawman, K.; et al. (1981) Uptake, Depura

- tion and Bioconcentration of 14C

- MC 10978 by Bluegill Sun

- fish ...: ABC Report # 26610. Final bioconcentration rept. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Analytical Bio Chemist ry Laboratories, Inc., submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071327

- A)

122771 2037629 Forbis, A.; Boudreau, P.; Thompson, C.; et al. (1981) Uptake Depuration and Bioconcentration of MC

- 10978 by Channel Catfish (Ictalurus punctatus) in a Static System with Soil: ABC Report #26611. Final bioconcentration rept. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Analytical Bio Chemistry Laboratories, Inc., submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071 327

- B)

ACC 97722 2068708 pg 58 in PDF E& G Bionomics 1977 Fish Bioacculmulation

ACC 97722 2068708 pg Iwan, 1978 Bioconcentration Study with Catfish59 62 in PDF

107505 ACC 097722 Check 2068708 Fisher, J. (1978) Accumulation and Elimination of RH

- 6201 Res idues in Bluegill and Catfish: Agricultural Products Research Report No. 34

- 28. (Unpublished study received Dec 14, 1978 under 707

- 149; submitted by Rohm & Haas Co., Philadelphia, PA; CDL: 097722

- A)
166

- 1 Ground water

- small prospective
MRID Citati on Reference

92168035 Registrant
summary

- of 41172801 Keene, E. (1990) BASF Corporation Phase 3 Summary of MRID 41172801. A Small Scale Prospective Groundwater Monitoring Study with Acifluorfen

- Sodium

- The Active Ingredient in Tackle Herbicide and Blazer Herbicide: 90/6154. Prepared by RHONE

- POULENC AG CO. 26 p.

41172801 2037576 Norris, F. (1989) A Small Scale Prospective Field Dissipation and Groundwater Monitoring Study with Acifluorfen

- Sodium, the Active Ingredient of Tackle Brand Herbicide an d Blazer Brand Herbicide: Project ID: File No. 40576; Protocol No. MEF

87

- 010. Unpublish

- ed study prepared by Rhone

- Poulenc Ag Co. 813 p.

41160001 2037582 Norris, F. (1989) A Small Scale Retrospective Groundwater Monitori

- ng Study and Limited Prospect ive Field Dissipation Study with Acifluorfen

- sodium...: File No. 40577: Protocol No. EC/P

- 89

- 001

- 7. Unpublished study prepared by Rhone

- Poulenc Ag Co. 360 p.

42152201 2078945 5 studies in five states 2070931

- protocol Hiscock, A.; Cooper, S. (1991) A Sma ll Scale Retrospective and Limited Prospective Ground

- Water Monitoring Study with Aci

fluorfen

- Sodium, the Active Ingredient of Tackle Herbicide and Blazer Herbicide: Lab Project Number: 429.03: 894M11: 91/5206. Unpublished study prepared by Rhone

- Poulenc AG Co., Blasland and Bouck Engineers and BASF Corp. 415 p.
201

- 1 Droplet size spectrum
MRID Citation Reference

40036301 reviewed DER not located Spicer, L. (1986) Tackle Herbicide, Sodium Acifluorfen: Droplet Size Spectrum Studies: Study No . ASD 86/224. Unpublished study prepared by New Mexico State Univ. 78 p.
202

- 1 Drift field evaluation
MRID Citation Reference60 40036302 reviewed DER not located Merricks, D. (1986) Tackle Aerial Spray Drift Study: Lab. Proj. No. 1504. Unpubl ished study prepared by Agrisearch Inc. 92 p.

92168040 Registrant
summary Keene, E. (1990) BASF Corporation Phase 3 Summary of MRID 40036301. Tackle Herbicide, Sodium Acifluorfen Droplet Size Spectrum: Study No. 86/224; 90/6153. Prepared by Rhone

Poulenc Inc. 22 p.

92168041 Registrant
summary Keene, E. (1990) BASF Corporation Phase 3 Summary of MRID 40036302. Tackle Aerial Spray Drift Study: Project No. 1504; 90/6152. Prepared by RHONE POULENC AG CO. 21 p.

6.2. Submitted Ecotoxicity Studies



### 114402 Acifluorfen Na Salt Ec o Effects Bibliography MRID

- Doc# 71

- 1 Avian Single Dose Oral Toxicity

MRID Citation Reference

83058 2063997 Fink, R. (1976) Final Report: Acute Oral LD50

-- Mallard Duck: Proj

- ect No. 129

- 111. (Unpublished study received Jan 17, 1977 under 707

- EX

- 87; prepared by Wildlife International, Ltd., submitted by Rohm & Haas Co., Philadelphia, Pa.; CDL:095736

- AB)

122747 Fink, R.; Beavers, J.; Brown, R.; et al. (1981) Acute Oral LD50

-- Mallard Duck: 10318001: MEHSL Study No. 203 1

- 80. Final rept. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Wildlife International, Ltd. and Washington College, submit

- ted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071322

- A)

122748 2067127 Fink, R.; Beavers, J.; Bro wn, R.; et al. (1981) Acute Oral LD50

-- Bobwhite Quail: 10318001: MEHSL Study No. 2021

- 80. Final rept. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Wildlife International Ltd. and Washington College, submit

- ted by Rhone

- Poulenc, Inc ., Monmouth Junction, NJ; CDL:071322

- B) Test material= 25.6% ai Tackle 2S

92168001 Registrant summary Weinstein, S.; Habig, C. (1990) BASF Corporation Phase 3 Summary of MRID 00122748. Acute Oral LD50

-- Bobwhite Quail 10318001: Wildlife International Ltd. Project No. 155

- 113; 90/6147. Prepared by Wildlife International Ltd. 12 p. 

### 71

- 2 Avian Dietary Toxicity

MRID Citation Reference

83059 2064001 Fink, R. (1976) Final Report: Eight

- day Dietary LC50

-- Bobwhite Quail: Project No. 129

- 108. (Unpub lished study received Jan 17, 1977 under61 707

- EX

- 87; prepared by Wildlife International, Ltd., submitted by Rohm & Haas Co., Philadelphia, Pa.; CDL:095736

- AC)

122749 2067128 Fink, R.; Beavers, J.; Brown, R.; et al. (1981) Eight

- day Dietary LC50

-- Mallard D uck: 10318001: MEHSL Study No. 2011

- 80. Final rept. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Wildlife International Ltd. and Washington College, submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL: 071322

- C)

122750 206 7128 Fink, R.; Beavers, J.; Brown, R.; et al. (1981) Eight

- day Dietary LC50

-- Bobwhite Quail: 10318001: MEHSL Study No. 2001

- 80. Final rept. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by Wildlife International Ltd. and Washington Colle ge, submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL: 071322

- D)

161889 Registrant summary Waggoner, T. (1984) Toxicology Review of Acifluorfen. Unpublished compilation prepared by Rhone

- Poulenc Inc. 127 p.

92168002 Registrant summary Weinst ein, S.; Habig, C. (1990) BASF Corporation Phase 3 Summary of MRID 00122750. Eight

- Day Dietary LC50

-- Bobwhite Quail 10318001: Wildlife International Ltd. Project #155

- 111; 90/6146. Prepared by Wildlife International Ltd. 11 p.

92168003 Registrant summary Weinstein, S.; Habig, C. (1990) BASF Corporation Phase 3 Summary of MRID 00122749. Eight

- Day Dietary LC50

- Mallard Duck 10318001: Wildlife International Ltd. Project No. 155

- 112; 90/6145. Prepared by Wildlife International Ltd. 11 p.

83060 2064004 Fink, R. (1976) Final Report: Eight

- day Dietary LC50

- Mallard Duck: Project No. 129

- 109. (Unpublished study received Jan 17, 1977 under 707

- EX

- 87; prepared by Wildlife International, Ltd., sub

- mitted by Rohm & Haas Co., Philadelphia, Pa.; CDL:095736

- AD)

Acc. 0 71322 Possibly 122750 Fink, R. (1981) Eight

- Day Dietary LC50 to Bobwhite Quail; Project # 155

- 111; Prepared by Wildlife International LTD for Rhone

- Poulenc Inc., P.O. Box 125, Monmouth Junction, N.J. 08852 Acc. #071322 

### 71

- 4 Avian Reproduction

MRID Citation Reference

107491 2064003 Piccirillo, V.; Najarian, G. (1978) One

- generation Reproduction Study in Bobwhite Quail: RH

- 6201. Final rept. (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by Hazleton Laboratories America, Inc., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- B)

107492 2064002 Piccirillo, V.; Najarian, G. (1978) Final Report: One

- generation Reproduction Study in Mallard Ducks: ?RH

- 6201|: Project No. 417

- 373. (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by Hazleton Laboratories America, Inc., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- C) 

### 72

- 1 Acute Toxicity to Freshwater Fish

MRID Citation Reference62 71901 2063992 Buccafusco, R.J. (1976) Acute Toxicit y of RH

- 6201LC to Bluegill (~Lepomis macrochirus~), Rainbow Trout (~Salmo gairdneri~) and the Water Flea (~Daphnia magna~). (Unpublished study re

- ceived Jan 17, 1977 under 707

- EX

- 87; prepared by EG & G, Bio

- nomics, submitted by Rohm & Haas Co., Philadelp hia, Pa.; CDL: 095736

- AA)

107494 2063994 Kuc, W. (1977) The Acute Toxicity of RH 6201, Lot #SW 77/0101 (42.4% Active Ingredient) to the Channel Catfish, Ictalurus punctatus (Rafinesque): UCES Proj. # 11506

- 33

- 03. (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by Union Carbide Corp., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- E)

122751 2067129 LeBlanc, G.; Sousa, J. (1981) Acute Toxicity of 10318001 to Blue

- gill ...: Report #BW

- 81

- 1

- 811. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by EG & G, Bionomics, submitted by Rhone

Poulenc, Inc., Monmouth Junction, NJ; CDL: 071322

- E)

122752 2067130 LeBlanc, G.; Sousa, J. (1981) Acute Toxicity of 10318001 to Rainbow Trout ...: Report #BW

- 81

- 2

- 815. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by EG & G Bionomics, sub

- mitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL: 071322

- F)

124222 2064006 Spare, W.; Hutchinson, C. (1982) Early Life Stage Study with the Fathead Minnow ... Exposed to Blazer Aqueous Technical: Project No. 81

- 3

- 10060. Rev. final rept. (Unpublished study received Jan 21, 1983 under 707

- 149; prepared by Biospherics, Inc., sub

- mitted by Rohm & Haas Co., Philadelphia, PA; CDL:071374

- A)

92168054 Registrant summary Euba nks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00122751. Sodium Acifluorfen

-- Acute Toxicity Test Freshwater Fish: Bluegill Sunfish: Report No. BW

- 81

- 1

- 811; BASF Reg. Doc. No. 90/6325. Prepared by EG & G Bionomics. 12 p.

92168055 Registrant

summa ry Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00122752. Sodium Acifluorfen

- Acute Toxicity Test: Freshwater Fish: Rainbow Trout: Report No. BW

- 81

- 2

- 815; BASF Reg. Doc. No. 90/6324. Prepared by EG & G Bionomics. 12 p.

107493 Buccafusco, R. (1977) Acute Toxicity of RH

- 6201 Technical to Blue

gill (Lepomis macrochirus). (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by EG & G, Bionomics, submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- D) 

### 72

- 2 Acute Toxic ity to Freshwater Invertebrates

MRID Citation Reference

71901 2063992 Buccafusco, R.J. (1976) Acute Toxicity of RH

- 6201LC to Bluegill (~Lepomis macrochirus~), Rainbow Trout (~Salmo gairdneri~) and the Water Flea (~Daphnia magna~). (Unpublished stud y re

- ceived Jan 17, 1977 under 707

- EX

- 87; prepared by EG & G, Bio

- nomics, submitted by Rohm & Haas Co., Philadelphia, Pa.; CDL: 095736

- AA)

111963 2063996 Vilkas, A. (1977) Acute Toxicity of RH 6201, Lot #SW 77/0101 to the Freshwater Clam Elliptio compl anata: UCES Project # 11506

- 33

- 03. (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by Union Carbide Corp., submitted by Rohm & Haas Co., Phila

delphia, PA; CDL:097718

- H)63 122754 2067132 LeBlanc, G.; Surprenant, D. (1981) Acute Toxicity o f 10318001 to the Water Flea ...: Report #BW

- 81

- 1

- 807. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by EG & G, Bio

- nomics, submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071322

- H)

92168004 Registrant summary Weinstein, S.; Habig, C. (1990) BASF Corporation Phase 3 Summary of MRID 00122754. Acute Toxicity of 10318001 to the Water Flea (Daphnia magna): EG&G, Bionomics Project No. BW

- 81

- 1

- 807; 90/6144. Prepared by EG&G, Bionomics. 11 p.



### 72

- 3 Acute Toxicity to Estua rine/Marine Organisms

MRID Citation Reference

107495 2064000 Calmbacher, C. (1978) Acute Toxicity of RH6201 LC Formulation JR 6412 Lot #PL76/8111 (39.8% Active Ingredient) Fiddler Crab, Uca pugilator: UCES Project No. 11506

- 33

- 25. (Unpublished stud y re

ceived Dec 14, 1978 under 707

- 149; prepared by Union Carbide Corp., submitted by Rohm & Haas Co., Philadelphia, PA; CDL: 097718

- F)

111962 2063995 Vilkas, A. (1977) Acute Toxicity of RH 6201, Lot #SW 77/0101 (42.4% Active Ingredient) to the Grass Sh rimp, Palaemonetes pugio: UCES Proj. # 11506

- 33

- 03. (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by Union Carbide Corp., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- G)

111964 2063991 Vilkas, A. (1977) The Acute Toxicity of RH 6201, Lot #SW 77/0101 to the Eastern Oyster Crassostrea virginica: UCES Proj. # 11506

- 33

- 03. (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by Union Carbide Corp., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- I)

12 2753 2067131 Ward, G. (1981) Acute Toxicity of 1993

- 80 (Sample No. 10318001) to Sheepshead Minnows ...: Report No. BP

- 81

- 6

- 111. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by EG & G Bionomics, submitted by Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071322

- G)

122755 2067133 Hollister, T. (1981) Acute Toxicity of 1992

- 80 (Sample No. 10318001) to Mysid Shrimp ...: Report No. BP

- 81

- 6

- 97. (Unpublished study received Dec 20, 1982 under 359

- 708; prepared by EG & G Bionomics, submitted b y Rhone

- Poulenc, Inc., Monmouth Junction, NJ; CDL:071322

- I)

124223 2064012 Spare, W.; Hutchinson, C. (1982) The Acute Toxicity of Blazer Aqueous Technical 43% to the Sheepshead Minnow ...: Project No. 81

- 39709. Final rept. (Unpublished study received Ja n 21, 1983 under 707

- 149; prepared by Biospherics, Inc., submitted by Rohm & Haas Co., Philadelphia, PA; CDL:071374

- B)

41891207 2063998 Dionne, E. (1991) Acifluorfen

-- Sodium (BAS9048 H)

- Acute Toxicity to Eastern Oyster (Crassostrea virginica) Under Flow

- through Condi

tions: Final Report: Lab Project Number: 91/4/3736: ER91012: E9012. Unpublished study prepared by Springborn Laboratories, Inc. 60 p.64 42185901 Raw data

– supplemental information for 41891207 Dionne, E. (1991) Raw Data Associated with the Report Titled: (Acifluorfen

- Sodium (BAS 9048 H))

-- Acute Toxicity to Eastern Oyster (Crassostrea virginica) Under Flow Through Conditions: Lab Project Number: 91/5215: 91/5072: 91

- 4

- 3736. Unpublished study prepared by Springborn Laboratories, Inc. 153 p.

92168056 Registrant summary Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00122753. Acifluorfen

- Acute Toxicity Test for Estuarine Fish: Sheepshead Minnow: Report No. BP

- 81

- 6

- 111; BASF Reg. Doc. No. 90/6327. Prepared by EG & G Bionomics. 13 p.

92168057 Registrant summary Eubanks, M. (1990) BASF Corporation Phase 3 Summary of MRID 00122755. Acifluorfen

-- Acute Toxicity Test for Shrimp: Mysid: Report No. BP

- 81

- 6

- 87; Reg. Doc. No. 90/6326. Prepared by EG & G Bionomics. 12 p. 

### 72

- 4 Fish E arly Life Stage/Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

96558 Compilation Rohm & Haas Company (1982) Preliminary Data Package: ?Blazer|. (Compilation; unpublished study, including project no. 81

- 3

- 10060 and letters dated Mar 4, 1982 from W.C. Spare to Isadore J. Morici and Mar 10, 1982 from S.S. Burke to T.D. Rogerson, received Mar 11, 1982 under 707

- 149; CDL:070712

- A)

107493 2063993 Buccafusco, R. (1977) Acute Toxicity of RH

- 6201 Technical to Blue

gill (Lepomis macrochirus ). (Unpublished study received Dec 14, 1978 under 707

- 149; prepared by EG & G, Bionomics, submitted by Rohm & Haas Co., Philadelphia, PA; CDL:097718

- D)

124222 2064006 Spare, W.; Hutchinson, C. (1982) Early Life Stage Study with the Fathead Minnow ... Exp osed to Blazer Aqueous Technical: Project No. 81

- 3

- 10060. Rev. final rept. (Unpublished study received Jan 21, 1983 under 707

- 149; prepared by Biospherics, Inc., sub

- mitted by Rohm & Haas Co., Philadelphia, PA; CDL:071374

- A)

92168005 Registrant summary Clark, J. (1990) BASF Corporation Phase 3 Summary of MRID 00124222. Early Life Stage Study with the Fathead Minnow (Pimephales promelas) Exposed to BLAZER Aqueous Technical: 90/6323. Prepared by Biospherics Incorporated. 13 p. 

### 123

- 1 850.4150 Terres trial plant toxicity, Tier 1 (vegetative vigor)

MRID Citation Reference

46431401 Porch, J.; Krueger, H.; Holmes, C. (2004) BAS 9048 AH (Ultra Blazer): A Toxicity Test To Determine The Effects of the Test Substance on Vegetative Vigor of Ten Specie s of Plants: Final Report. Project Number: 147/221, 136139, 2004/5000788. Unpublished study prepared by Wildlife International, Ltd. 144 p. 

### 123

- 2 850.4250 Vegetative vigor, Tier II

MRID Citation Reference65 46431401 Porch, J.; Krueger, H.; Ho lmes, C. (2004) BAS 9048 AH (Ultra Blazer): A Toxicity Test To Determine The Effects of the Test Substance on Vegetative Vigor of Ten Species of Plants: Final Report. Project Number: 147/221, 136139, 2004/5000788. Unpublished study prepared by Wildlife Int ernational, Ltd. 144 p.

850.3020 Honey bee acute contact toxicity

MRID Citation Reference

46650202 Palmer, S.; Krueger, H.; Holmes, C. (2001) Sodium Acifluorfen : An Acute Contact Toxicity Study with the Honey Bee. Project Number: 147/198, 64274, 2001/5002329. Unpublished study prepared by Wildlife International, Ltd. 19 p.66