UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C

. 20460 

### NOV 0 4 2014

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION MEMORANDUM
SUBJECT: FROM:

THRU:

TO: BEAD Chemical Profile (BCP) for Registration Review: Oxyfluorfen (11160 1) Sunil Ratnayake, Biologist

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_ 0 --" Biological Analysis Branch

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## v'\(('Yv<.ZJ---**~** Rafael A. Prieto, Environmental Protection Sl'¢9i ¥J6 

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# f.**~** Science Information and Analysis Branch

.

## ~~'Y'J)..l .. Stephen Smearrnan, Economist Economic Analysis Branch

# ~~ Biological and Economic Analysis Division (7503P) Arnet Jones, Chief Biological Analysis Branch Diann Sims,

# Chief**~** Science Information and Analysis Branch Timothy Kiely, Chief

# ~**~ ~**  Economic Analysis Branch Biological and Economic Anal is Division (7 ) Benjamin Askin, Chemical Review Manager Risk Management and Implementation Branch 1 Pesticide Re-evaluation Division (7508P)


### Peer Review Panel date: October 15,2014

Page 1SUMMARY Oxyfluorfen was first registered inthe United States in 1979. Oxyfluorfen is a member ofthe diphenyl-ether family ofherbicides. Itis applied pre and post-emergence to control broadleaf and grassy weeds on a wider variety ofuse sites such as tree, fruit, nut, vine, and field crops and non-agricultural sites. Based onthe available proprietary data, between the years of2008 to 2012, in terms ofthe number ofoxyfluorfenpounds applied to all crops the majority ofthe herbicide was applied to almonds (36%), grapes (20%) and walnuts (11 %). Interms ofthe percent crop treated for the top three sites that used oxyfluorfen, use ofoxyfluorfen was on average applied to 65% ofthe almond acreage, 35% ofthe grape acreage and 55% ofthe walnut acreage (Table 1). In addition, according to the most recent Screening-level Usage Analysis for oxyfluorfen, other crops with high average percent crop treated include onions (75%), garlic (70%), and pistachios (50%). While the annual average number ofpounds applied for these crops is lower than for top users such as almonds and grapes, the percent crop treated implies that oxyfluorfen is an important tool for growers ofthese crops in controlling weeds. Interms ofthe sites that use oxyfluorfen, usage ofoxyfluorfen has not changed considerably during the period from 1998 to 2012 (Table 1 ). In terms ofthe states withthe highest usage, California dominated with 93% ofthe total pounds applied nationally for the time period from 2008-2012 (Table 2).

INTRODUCTION The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an overview ofthe pest management roles and quantitative usage information for oxyfluorfen. The BCP includes summaries ofprevious BEAD products and available public and/or private use and usage data for oxyfluorfento describe the role ofthis chemical inpestmanagement. Additional information on use is available inthe oxyfluorfen Label DataReport. Informationprovided in this BEAD Chemical Profile (BCP) may be used by stakeholders (e.g., users and registrants), OPP risk assessors, and OPP risk managers, and the general public during the Registration Reviewprocess ofthis pesticide. USE SITES· The registered agricultural uses ofoxyfluorfen include a wide range offruits, including pome fruit, stone fruit, tropical fruit, subtropical fruit, nuttrees, vegetables and field crops, agricultural fallow land and conservationreserve, Christmas tree plantations, shelterbelt, deciduous trees, forest trees (softwoods, conifers), and grasses grown for seed. Oxyfluorfen is also registered for use on the following non-agricultural use sites: household/domestic dwellings, outdoor premises, industrial 

### I construction areas (outdoor), mulch, nonagricultural outdoor buildings/structures, nonagricultural rights-ofway/fencerowslhedgerows, non-agricultural uncultivated areas/soils, paths/patios, paved areas (private roads/sidewalks), nursery stock, ornamentals, and recreational areas.
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### FORMULATIONS AND APPLICATION METHODS Oxyfluorfen is formulated as an emulsifiable concentrate, granular, ready-to-use solution, soluble concentrate, and flowable concentrate. It is applied as bandtreatment, broadcast, and by chemigation. Application equipment includes handheld sprayers and tractor mounded conventional ground sprayers. 

### HISTORY OF OXYFLUORFEN AND BEAD PRODUCTS Oxyfluorfen was first registered for use inthe United States in 1979 for pre and post-emergent control ofbroadleafand grassy weeds in a variety offield, fruit, and vegetable crops, ornamental, as well as non- agricultural sites. There was a RED onthis chemical in 2002 (http:/ /www.epa.gov/oppsrrdl/REDs/oxyfluorfen red.pdO

. BEAD prepared a Screening Level Usage Analysis (SLUA) in April2014. A search ofthe BEAD database for previous BEAD products for oxyfluorfen indicates that there are no records ofprior BEAD benefits assessments or emergency exemption requests over the past 1 0 years for oxyfluorfen. Note that a lack ofemergency exemptionrequests does not indicate the relative importance ofthe chemical. 

### USAGE Agricultural Uses Usage Trends For the years from 1998 to 2012, oxyfluorfen annual agricultural usage averaged 1.2 million pounds ofactive ingredient (a.i.) treating an average of2.5 million acres, for an overall average application rate of0.48 pounds a.i. per acre. (Proprietary data, 1998-2012). The usage ofoxyfluorfen interms ofpounds applied has beenbasically constant, with a slight decrease when comparing total pounds applied overthe time period from 1998 to 2012 (Figure 1

). Overthe same time period the total acres treated (TAT) has trended upwards since 1998 (Figure 2). Overtime the number ofacres treated has increased as the number ofpounds applied has shown a downward trend especially since the 2002 RED which may indicate mitigation measures with rate reductions have taken effect (Tables 3 and 4).

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### Figure 1. 

### Total Pounds ofOxyfluorfen Applied (1998-2012) 1,600,000

co Cl'l Cl'l


### .... Cl'l Cl'l Cl'l


### .... 0 0 0 N 

### .... 0 0 N N 0 0 N 

### ..., 0 0 N**~** 0 N Source: EPA Proprietary Data, 1998-2012 

## .., 0 0 N 0.0 0 0 N ,.... 0 0 N co 0 0 N g) 0 N 0


### .... 0 N 

### Figure 2. Total Area treated (TAT) ofOxyfluorfen in Acres (1998-2012)
3,500,000

0 co Cl'l Cl'l


### .... Cl'l Cl'l Cl'l


### .... 0 0 0 N 

### .... 0 0 N N 

### g N 

### ..., 0 0 N**~** 0 N
Source: EPA Proprietary Data, 1998-2012 

## .., 0 0 N 0.0 0 0 N ,.... 0 0 N co 0 0 N Cl'l 0 0 N 0


### .... 0 N 

### .... .... 0 N



### .... .... 0 N

The rankings and percentages ofthetop crops (Table 1) and states (Table 2) have not significantly changed before and after the RED was issued in 2002.

Page4 N


### .... 0 N

N


### .... 0 N

### Table 1. 

### Crops with Highest Use ofOxyfluorfen in Terms ofPercent ofTotal Lbs. Applied for Years 1998-2002 (before the RED) and 2008-2012 (afterthe RED) and P tC T td

ercen rop rea e . 1998-2002 (pre-RED) 2008-2012 (post-RED) Crop %Lbs Crop %Lbs %Crop Treated* Almonds 34 

### Almonds 36 65 

### Wine Grapes 20 

### Wine Grapes 20 35



### Pistachios 9 

### Walnuts 11 55



### Walnuts 8 

### Pistachios 6 50



### Other 29 

### Other 27


## - Source: EPA Proprietary Data, 1998-2012 *Percent Crop Treated is based on proprietary data for theyears 2004-2012.
Table 2. States with Highest Use ofOxyfluorfen in Terms ofPercent ofTotalAcres Treated (TAT)forYears 1998-2002 and 2008-2012 1998-2002 (pre-RED) 2008-2012 (JJost-RED) State %Lbs State %Lbs California 91 

### California 93 

### Washington 3 

### Washington 3 

### Other 6 

### Other 4 

### Source: EPA Proprietary Data, 1998-2012. Agricultural Usage: Top Crops and application Rates Table 3. Oxyfluorfen Usage on Top Crops andAverage Application Rates from 1998- 2002 Crop Total TotalAcres Average AI Rate Pounds Applied Treated* (lbs AI/acres) Almonds 2,300,000 3,400,000 0.685 

### Wine Grapes 1,400,000 1,500,000 0.909



### Pistachios 600,000 600,000 1.130



### Walnuts 500,000 800,000 0.710 

### *Total Acres Treated sums all acres treated for a crop, including those acres that receive multiple treatments. Source: EPAProprietary Data, 1998-2002.

Page 5T bl 4 0 fl rti U a e . xyj uo en sa2e on 

### T C op rops andA vera2e A 

## r f Rt f**~PP1ICa** Ion a es rom 2008 2012 

# - Crop Total Total Acres Average AI Rate Pounds Applied Treated* (lbs AI/acres) Almonds 2,000,000 5,100,000 0.406 Wine Grapes 1,100,000 1,500,000 0.767

Pistachios 400,000 600,000 0.614

Walnuts 600,000 1,400,000 0.449 *Total Acres Treated sums all acres treated for a crop, mcludmg those acres that recetve multtple treatments. Source: EPA Proprietary Data, 2008-2012 The application rates have decreased for the years of2008-2012 (Table 4), compared to the 1998-2002 (Table 3) time span. Agricultural Use Intensity ofOxyfluorfen. Another measure ofusage is the use intensity. In this analysis, the use intensity is expressed as the average annual amount (in pounds) ofthe active ingredient applied per 1000 acres ofcrop acres grown. This differs from the application rate, which is expressed as the pounds a.i. applied pertreated area. Figure 3 spatially represents the use intensity ofoxyfluorfen in the United States during 2008-2012 timeframe. Oxyfluorfen is registered on for use on a wide variety offruit, tree nut and vegetable crops. The highest number ofpounds applied by crop is on almonds followed by grapes, walnuts and pistachios in that order. Figure 3 shows that the highest use intensity is found in California, with more than 8 lbs oxyfluorfen per 1,000 crop acres grown. That is probably because ofthe large amount oftree nuts and grapes that are commercially grown in California. Following California, the highest use intensities are found in Washington, Oregon, Arizona, Louisiana, New York and Georgia, with 0.5 to 8 pounds.

Page 6Figure 3. Annual average agricultural use intensity ofoxyflourfen (2008-2012).

PoundsActive Ingredient per 1,000 Crop Acres Grown 0NoData 0 <0.2 0

.2-0

.5

. 0.5-8


# - >8

The map included herein is primarily for the use ofthe risk assessors in the Environmental Fate and Effects Division. The map provides a very broad geographical view ofthe average annual amount (in pounds) ofthe active ingredient applied per 1,000 acres ofcrop acres grown. These data are included inthe maps because risk assessors are interested inthe amount ofa pesticide used across agricultural land. The calculated values presented inthe map are not equivalent to an application rate (lb ai/A). The data used to make these maps have several limitations. Any interpretation ofthe maps should consider the underlying data and the associated limitations carefully. The numerator (annual average pounds applied) is based onprivate market surveys ofpesticide use in agriculture averaged overthe last five years (Proprietary Data, 2008-2012). These surveys cover about 60 crops and are targeted in states that produce the majority ofthe crop. Although the surveys capture most ofthe use ofa particular active ingredient in agriculture, there are several limitations to these surveys.

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### Non-agricultural Usage Table 5. Oxyfluorfen**Non-A~** 

### ricultural Usa2e in Pounds A. I. ( 2002-20121 

### Site 2002 2004 2006 2012 Turfand Ornamental N/A NIA NIA 108,000 Nurseries 107,000 84,000 71,000 N/ A 

### =Not Available 

### Source: ProprietaryData, 2002-2012 Use ofoxyfluorfen onnursery stock has been declining since 2002 based onthe available proprietary data as seen above (Table 5).


### BIOLOGICAL ASPECTS RELEVANT TO OXYFLUORFEN N/A

.

Oxyfluorfen is a broad spectrum contact type herbicide in the diphenyl-ether family. Itis applied as pre-emergent and post-emergence treatments for control ofbroadleafweeds and some grass weeds in many crops listed above. When applied pre-emergence itprovides residual weed control. Oxyfluorfen is readily absorbed by leaves ofmost weed species and very little is absorbed bythe plant roots. According to Weed Science Society ofAmerica (WSSA) classification ofmode ofaction ofherbicides, oxyfluorfen is included in Group 14 (PPO inhibitors). It inhibits the enzyme protoporphyrinogen oxidase (WSSA, Undated). Inhibition of this enzyme interferes with chlorophyll production resulting in a rapid bleaching, necrosis and desiccation ofsusceptible weeds (Herbicide Handbook, 2014). 

### ROLE OF OXYFLUORFENINPESTMANAGEMENT Oxyfluorfen is applied for the control ofa broad spectrum ofweeds on agricultural and nonagricultural sites. There are a number ofcrops that rely onthe use ofthis herbicide for the control ofmanyproblematic weed species. From 2008 to 2012, about 36 percent ofthe almond crop was treated on average and for grapes about 20 percent ofthe crop was treated with oxyfluorfen. These and otherhigh value crops require good weed management for optimum yield and quality. As an example, little mallow 

### (Malvaparviflora), a weed known to be a problem in orchards and vineyards, can be controlled effectively by applying oxyfluorfen or oxyfluorfen 

### + glyphosate (University ofCalifornia IPM Guidelines, 2014 (1)). Although almonds and grapes are the top crops for oxyfluorfen interms ofpounds and acres treated, oxyfluorfen is also used on garlic and onions where weed control is important as they are slowgrowing, shallow-rooted crops that can suffer severe yield loss from weed competition. Oxyfluorfen is registered as a post-emergentherbicide in onion. Itcontrols small broadleaf weeds and some grasses. Oxyfluorfen (Goal2XL) formulation is used at the two- to four-leaf stage ofthe crop, but the Goal Tender formulation can be used atthe 1sttrue leafstage. (University ofCalifornia IPM Guidelines, 2014 (2)). Oxyfluorfen is also used for weed control in gardens and landscape management (Univ. ofCalifornia IPM, 2014 (3)).

Page 8According to the International Survey ofHerbicide Resistant Weeds, currently, only biotypes of two weed species; common ragweed (Ambrosia artemisiifolia), and tall waterhemp (Amaranthus tuberculatus) are reported to be resistant to the mode ofaction ofoxyfluorfen in the United States (Heap, Undated)

. However, it is not clear whether the resistance ofthese 2 weeds affects the use ofoxyfluorfen in the United States. DATA NEEDS The Agency currently does nothave important information on oxyfluorfen

. Obtaining the following information may improve future assessments conducted by the Agency related to the use and importance ofoxyfluorfen. NonAgricultural Use • National· poundage applied in a yearly basis on the rights-of-way and other nonagricultural use sites would be useful to our work.
REFERENCES Heap, I. Undated. The International Survey ofHerbicide Resistant Weeds. Online Publication. 2014. Available at: www.weedscience.org. Accessed on Feb 12, 2014 Proprietary Data, 1998-2012. University 'of California. 2014 (1). UC Pest Management Guidelines. Almond. Online Publication. Available at: http:/ /www.ipm.ucdavis.edu/PMG/r37002ll.html. Accessed on Sep. 24, 2014. University ofCalifornia. 2014 (2). UC Pest Management Guidelines. Onions and Garlic. Online Publication. Available at: http://www.ipm.ucdavis.edu/PMG/r58470011l.html. Accessed on Sep. 22, 2014

. University ofCalifornia

. 2014 (3). Weed Management in Landscapes. Online Publication. http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn744l.html. Accessed on Oct. 28, 2014. USEPA. 2002. Registration Eligibility Decision (R.E.D.) for Oxyfluorfen

. Online Publication. Available at: http:/ /www.epa.gov/oppsrrdl/REDs/oxyfluorfen red.pdf

. Accessed on Sep. 23rd, 2014. USEPA Oxyfluorfen Screening Level Usage Analysis (SLUA), April, 2014. WSSA (Weed Science Society ofAmerica). Undated. Summary ofHerbicide Mechanism of Action. Online Publication. Available at: http://wssa.net/wp-content /uploads/WSSA-Mechanism-of-Action.pdf. Accessed on Sep. 23, 2014.
Page 9APPENDIX A The map included herein is primarily for the use ofthe risk assessors in the Environmental Fate and Effects Division. The map provides a very broad geographical view ofthe amount (in pounds) ofthe active ingredient applied per 1,000 acres of"land in farms". These data are included in the maps because risk assessors are interested inthe amount ofa pesticide used across farmland. Because ofthe definition ofLand in Farms, as discussed below, the calculated values presented in the map are not equivalentto an applicationrate (lbs a.i./A). The dataused to make these maps have many limitations. Any interpretation ofthe maps should considerthe underlying data and the associated limitations carefully. The smallest areas shown onthe maps within each state are Crop Reporting Districts (CRD). CRDs are defined by USDA and each consists ofmultiple counties that have similar soils, growing conditions, and farming practices. The CRDs within many states have roughly the same area. Because it is not feasible to conduct an agricultural survey that samples every county in the United States, the use ofCRDs allow for a sample to be collected thatrepresent a much larger area with relatively homogeneous agricultural characteristics. The numerator (annual average pounds applied) is based onprivate market surveys ofpesticide use in agriculture averaged overthe last five years (Proprietary Data, 2007-2011). These surveys cover about 60 crops and are targeted in states thatproduce the majority ofthe crop. Although the surveys capture most ofthe use ofa particular active ingredient in agriculture, there are several limitations to these surveys. ·
• States withminorproduction ofa surveyed crop are not sampled • Not all types ofpesticides are surveyed inevery crop in every year • Many specialty crops with very small acreages are not included in the survey The result ofthese limitations is that CRDs that showno usage may actually have a small amount ofthe active ingredient being used. The denominator (1,000 Acres ofland in farms) was selected from the Census ofAgriculture (USDA, 2007) to represent agricultural acreage that is actively managed and includes most ofthe areas treated withpesticides. The category "Land in Farms" is defined by the Census of Agriculture as being made up offour components: • Total cropland • Permanentpasture • Total woodland • Land in farmsteads, buildings, livestock facilities, ponds, roads, wasteland, etc. This category includes land in the various USDA conservation programs. It should be noted that the Census ofAgriculture does not include grazing land rented (on a per-animal basis) from the Bureau ofLand Managementor Forest Service, thus it is an underestimate ofthe land being managed for agricultural purposes.
Page 10The reader shouldpay particular attention to the figure legends and realize that a map prepared for a particular chemical is not directly comparable to a map prepared for a different chemical. Scale and units ofmeasurement do matter and may be different between maps.

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