UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASil lNGTON D.C., 20460 

I 

MAY 0 8 2015 OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

TO: 

Fenoxaprop and Fenoxaprop-ethyl Usage Information for Risk Assessment (PC # 

129092& 128701) 

Bill Chism, Ph.D., Senior Biologist 

Biological Analysis Branch 

Jihad Alsadek, Ph.D., Economist ~ A . 11-LM 

Science Information and Analysis Branch 

Michelle Ranville, Ph.D., Economis 

Economic Analysis Branch 

Biological and Economic Analysis 

Arnet Jones, Chief 

Biological Analysis Branch 

Diann 

Science 

Sims

In formation 

, Chief ~ and Analysis Branch 

Timothy 

Economic 

Kiely

Analys , Chis 

ief 

Branch ~ VV\ ~ 

Biological and Economic Analysi ivision (7503P 

Miguel Zavala, Chemical Review Manager 

Tracy Perry, Team Leader 

Kelly Sherman, Acting Chief 

Risk Management and Implementation Branch III 

Pesticide Reevaluation Division (7505P) 

BEAD Product Review Panel date: April 15, 2015 
SUMMARY 

This document describes the usage of fenoxaprop and fenoxaprop-ethyl which are undergoing 

registration re-evaluation in the Office of Pesticide Programs. The usage information is provided 

to describe how fenoxaprop formulations are used to help during risk mitigation discussions. 

BEAD was asked to describe the key crops where fenoxaprop formulations are used, its use rate, 

the average and upper bounds of treatment rates, application timing, and crops where 

applications are made by air. Our analysis did not find any evidence of the use of fenoxaprop on 

an in-season (same calendar year) rotational crop. 

Proprietary data (2004-2012) show use of fenoxaprop formulations on barley, soybeans, rice, and 

wheat. Use has declined over the last few years. Fenoxaprop-ethyl (PC Code 12870 I) is a post 

emergence herbicide used to selectively control annual and perennial grass weeds with labeled 

use sites on fallow, rice and soybeans. Fenoxaprop (PC Code 12909.2) has labeled use sites on 

fallow, barley, cotton, right-of-way, ornamentals, turf, rice, and wheat. Usage data in this 

document cover both active ingredients, fenoxaprop and fenoxaprop-ethyl, and are referred to 

collectively as fenoxaprop. Fenoxaprop inhibits acetyl CoA carboxylase enzyme (ACCase) 

(WSSA Group 1) and interferes with meristematic tissue development. 

Usage Data on Key Crops 

Table 1 shows that, while most of this herbicide is used in wheat crops, it is also applied to a 

relatively large percentage of the barley and rice crops. Approximately ten percent of the barley 

and wheat crops receive treatments with this herbicide, on average, indicating that fenoxaprop is 

important in controlling grass weeds in production of these crops. 

T a e bl 1 S creerung L l eve E . st1mates o f A . .gncu tura lU ses o f F enoxaprop, 2004 -2012 

Crop Average Annual Percent Crop Treated 

Lbs A.I. Avera2e Maximum 

Barley 20,000 10 20 

Rice 10,000 5 10 

Soybeans 20,000 <2.5 <2.5 

Wheat 200,000 10 25 

Footnote: All numbers are rounded. See Appendix I for sources. 

Acres Treated and Application Rates 

National average application rate, rate applications between the goth and I OOth percentile, acres 

treated, and acres grown (Table 2) are designed to provide additional usage data on an individual 

crop basis for refined risk assessments. This can be used to evaluate the opportunity for rate 

reductions as a mitigation option. The average application rates range from 0.033 to 0.093 lb 

ai/acre while between 80% and 100% of the acres are treated at or below 0.046 to 0.109 lb ai/acre. 

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Table 2. Fenoxaprop National Crop Acres Grown, Average Annual Total Acre Treatments, 

Maximum Label Rates, Average Application Rates per Treatment. and Upper Percentile 

Application Rates; 2009-20 I 3 

Maximum 

Average Average Single (and Average Application 

Seasonal) Application Rate between Crop Annual Crop Annual Total Application Rate 80'h and lOO'h Acres Grown 1 Acres Treated 1 

Label Rate (lb ai/acre) Percentile' 

(lb ai/acre) 

Barley 3.284,000 237,000 0.083 0.061 0.078 (0.083) 

Rice 2,694,000 171,000 0.108 0.093 0.109 (0.142) 

Soybean 76.105.000 250,000 0. 100 0.033 0.046 (0.128) 

Spring 12, 178,000 2,690,000 0.083 0.062 0.080 Wheat (0.083) 

Winter 34,723,000 76,000 0.083 0.055 0.069 Wheat (0.083) 

Sources: Average annual crop acres grown from USDA Census of Agriculture. Maximum single application 

rates from fenoxaprop product labels. A ll other information from Proprietary data. Numbers may not add 

due to rounding. 1 Rounded to nearest thousand. 

2 Represents the highest rate where between the so·· and I oo·· percent of the crop acres are treated (varies by 

crop). 

Application Method and Timing 

Table 3 shows that the majority of usage over the years 2009-20 I 3 was ground-applied. Only 

two crops, barley and rice, had a significant percentage of aerial application. Approximately 

eight percent of total acres treated for barley are applied aerially, and more than fifty percent of 

total acres treated for rice are applied aerially. It appears that the rice aerial applications were 

made to accommodate the large number of acres involved and not specifically because of wet 

fields since they were applied pre-flood and only a small number of acres were treated postnood. It appears that the barley and wheat aeria l applications were generally applied late post so 

that the large fields could be treated in a short amount of time when the weeds were most 

sensitive. 

Application timing information at the national level for both aerial and ground applications 

(Table 4) shows when a particular crop is treated. For refined risk assessments, this data shows 

when fenoxaprop is applied compared to when other species of plants and animals could be 

present. 

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T a bl e 3 F enoxaprop A ena . I an dG roun dU sage, p ercen t o fC rop A cres Treated, 2009-2013 

Barley Rice Soybeans Wheat, Wheat, 

Spring Winter 

Aerial 8% 53% 0% 1% 2% 

Ground 92% 47% 100% 99% 98% 

Source: Proprietary data 

T a bl e 4 . T 1mmgo . f A .pp I' 1cattons, A . ena I Pl us G roun d , 2009 -201"' .) . 

Crop and Time of Application4 

Barley 

Early Post 

Late Post 

Rice 

Before Crop Emergence-Pre-flood 

Early Postemergence-Pre-tlood 

Late Postemergence-Pre-tlood 

Late Postemergence-Post-flood 

Soybeans 

Prior to Planting 

Before Crop Emergence 

Early Post 

Late Post 

Wheat, Spring 

At Planting 

Before Crop Emergence 

Early Post 

Late Post 

Wheat, Winter 

Late Post 

Source: Proprietary data 

1 Rounded to nearest hundred. 

2 Rounded to nearest ten. 

Average Acres 

Treated 1 

237,200 

14,600 

222,600 

171,400 

11.600 

7,800 

117,600 

34,400 

249,800 

3,200 

12,000 

5,200 

229.400 

2,690,200 

8,200 

15,400 

2 10,200 

2,456.400 

76,200 

76,200 

Average Pounds Rate Al per Acre 3 

Al ! 

14,360 0.061 

920 0.062 

13,440 0.060 

16,040 0.093 

840 0.07 1 

760 0.098 

11,500 0.098 

2,940 0.085 

8,400 0.033 

120 0.035 

520 0.044 

120 0.023 

7,640 0.033 

166,260 0.062 

460 0.058 

960 0.062 

11 ,620 0.055 

153,220 0.062 

4,160 0.055 

4, 160 0.055 

3 The general application rates for each crop are weighted averages based on annual total acres treated. 4 Time of Application: Prior To Planting is an application applied just before the crop is planted. At Planting 

is an application applied during the planting operation. Before Crop Emergence is just before the 

seedling emerges from the soil. Early Post is just after crop emergence. Late Post is just before the crop 

canopy lays over (lay-by) and the crop shades out any weeds. Pre-flood and Post-flood refer to the time 

at which the rice field is permanently flooded which takes place when the seedlings have 4 to 5 leaves or 

at the development of2"d tiller. 

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Use Trends 

Figure I depicts use trends of fenoxaprop over the past ten years for-spring wheat, the crop with 

the highest usage. Usage was variable through 20 I 0 but steadily decreased in the years 20 l I 

through 2013. Figure 2 depicts usage of fenoxaprop over the past ten years for all other crops. 

Similarly, usage has made a clear downward trend on all crops except for rice. Usage on rice 

was below average in 20 13 but was steady in the preceding years. 

r;,40U,000 

Q(' l 'I fl "'(-:.' ' (\ I )0Q,{ 0 0 0 • "O ' t I' 

• • <; 

Figure 1. Fenoxaprop, Total Acres Treated, Spring Wheat, 2004-2013 

Source: Proprietary data 

900,000 

0 

2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 

Soybeans Rice _,,.__ Barley -+-Wheat, Winter 

Figure 2. Fcnoxaprop, Total Acres Treated, Other Crops, 2004- 2013 

Source: Proprietary data 

Page 5 
Multiple Crops in One Calendar Year 

When considering chronic exposure, the application of an herbicide to multiple crops during a 

calendar year can be of concern. EPA proprietary data do not show any fenoxaprop applications 

to common rotational crops in the same state. For the crops that are most commonly treated 

(e.g., barley, soybeans, rice, and wheat (winter and spring)), the only common rotational partners 

are soybeans followed by winter wheat. In this type of rotation the late postemergence 

fenoxaprop application would be made in the spring of the following year. Biologically, it 

makes sense that there would only be one crop per year treated with this herbicide because most 

grassy weeds would be at their most sensitive life stage during the spring and early summer. 

REFERENCES 

EPA. 2007. Fenoxaprop-p-ethyl Summary Document Registration Review: Initial Docket, August 

29, 2007, Docket Number: EPA-HQ-OPP-2007-0437. 

Proprietary data. 2004-2013. 

USDA. 2007. Census of Agriculture. Crop Acres Grown. 

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APPENDIX 1 

Wha t is a Screening Level Usage Analysis (SLUA)? 

• Available estimates of pesticide usage data for a particular active ingredient that is used on 

agricultural crops in the United States. 

• Pesticide usage data obtained from various sources. The data are then merged, averaged, and 

rounded so that the presented information is not proprietary, business confidential, or trade 

secret. 

What does it contain? 

• Pesticide usage data for a single active ingredient only. 

• Agricultural use sites (crops) that the pesticide is reported to be used on. 

• Available pesticide usage information from U.S. states that produce 80% or more of a crop, 

in most cases, or less than 80%, in rare cases, depending on the scope of the survey and 

ava ilable resources. 

• Annual percent of crop treated (average & maximum) for each agricultural crop. 

• Average annual pounds of the pesticide applied for each agricultural crop (i.e., for the states 

surveyed, not for the entire United States). 

What assumptions can I make about the reported data? 

• Average pounds of active ingredient applied - Values are calculated by merging pesticide 

usage data sources together; averaging across all observations, then rounding. Note: If the 

estimated value is less than 500, then that value is labeled <500. Estimated values between 

500 & <l ,000,000 are rounded to I significant digit. Estimated values of 1,000,000 or 

greater are rounded to 2 significant digits.) 

• Average percent of crop treated - Values are calculated by merging data sources together; 

averaging by year, averaging across all years, & rounding to the nearest multiple of 5. Note: 

If the estimated value is less than 2.5. then the value is labeled <2.5. if the estimated value is 

less than I, !hen !he value is labeled <I. 

• Maximum percent of crop treated - Value is the single maximum value reported across all 

data sources, across all years, & rounded up to the nearest multiple of 5. Note: If the 

estimated value is less Jhan 2.5, then the value is labeled <2.5. 

What are the data sources used? 

• USDA-NASS (United States Department of Agriculture's National Agricultural Statistics 

Service) - pesticide usage data from 2004 to 2013. 

• Private pesticide market research - pesticide usage data from 2004 to 2013. 

• California Department of Pesticide Regulation (DPR) Pesticide Use Reporting (PUR) 

data for 2004 to 2012. 

What a r e the limitations to the da ta? 

• Additional registered uses may exist but are not included because the available surveys do not 

report usage (e.g., small acreage crops). 

• Lack of reported usage data for the pesticide on a crop does not imply zero usage. 

• Usage data on a particular site may be noted in data sources, but not quantified . In these 

instances, the site would not be reported in the SLUA. 

• Non-agricultural use sites (e.g., turf, post-harvest, mosquito control, etc.) are not reported in 

the SLUA. 

• Some sites show some use, even though they are not on the label. This usage could be due to 

various factors, including, but not limited to Section 18 requests, existing stocks of the 

chemica l, data collection errors, and experimental use permits (EU Ps). 

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