UNITED ST ATES ENVIRONMENTAL PROTECTION AGENCY 

WASHING TON D.C., 20460 

APR 0 6 2015 

MEMORANDUM 

SUBJECT: Sulfentrazone Usage Information (PC # 129081). 

OfFICF OF CHEMICAL SAFETY 

AND POI I l.JTION PREVENTION 

FROM: Bill 

Biological 

Chism, 

Analysis 

Ph.D., Senior 

Branch 

Biologist ~ ~ 

Jihad . Alsadek, Ph.D., Economist . T ~A- >r~k 

Science Information and Analysis Branch 

Elizabeth Hill, M.S., Economist <:::) 

Economic Analysis Branch L ' 

Biological and Economic Analysis Division (7503P) 

THRU: 

Biological 

Arnet Jones, 

Analysis 

Chief 

Branch 

~~ . U 

Diann Sims, Chief j_f}~ Science Information and Analysis Branch 

Timothy Kiely, Chief (.+- ~ ~~, Economic Analysis Branch ~ ) . 

Biological and Economic Analysis Division (75 P) 

TO: Christine Scheltema, Chemical Review Manager 

Neil Anderson, Chief 

Risk Management and Implementation Branch III 

Pesticide Reevaluation Division (7505P) 

BEAD Product Review Panel date: February 11, 2015 
SUMMARY 

This document describes the use and usage of sulfentrazone which is undergoing registration 

reevaluation in the Office of Pesticide Programs. The Biological and Economic Analysis 

Division (BEAD) received a request by the Pesticide Reevaluation Division (PRD) to provide 

usage information to be used to develop risk assessment estimates. BEAD was asked to describe 

the key crops where sulfentrazone is used, its use rate in key states, the average and upper 

bounds of treatment rates, application timing, crops where applications are made by air, and use 

in California. 

BACKGROUND 

Sulfentrazone is a broad spectrum herbicide that inhibits the germination of propagules and seeds 

of broadleaf, grass, and sedge weeds. It is used on field crops, fruits, ornamentals, turf grass, and 

vegetable crops in many states. It is used on field crops, fruits, ornamentals, turf grass, and 

vegetable crops at rates from 0.01 to 0.38 lb ai/acre. This document describes the usage of 

sulfentrazone on a number of different crops in several states. The rates and acres treated may 

differ slightly between tables because of differences in the way in which the data were selected 

and summarized. 

Sulfentrazone is a soil-applied, pre-emergent and postemergence herbicide which can be applied 

either preplant incorporated, preemergence or postemergence to the weeds. Sulfentrazone is a 

ProtoPorphyrinogen Oxidase (PPO) Inhibitor (WSSA Group 14). This herbicide inhibits the 

protoporphyrinogen oxidase enzyme which is important in the production of chlorophyll which 

causes a peroxidation of lipids in the cell membrane leading to cell leakage. Sulfentrazone is 

absorbed primarily by the roots and leads to rapid foliar desiccation (WSSA, 2014). 

Because sulfentrazone inhibits seed and propagule germination, for pre-emergent treatment it 

needs to be applied as close to the soil surface as possible with the lowest possible amount of 

pesticide intercepted by leaf surfaces and the minimum amount of exposure to evaporation or the 

wind. For example, the Sulfentrazone XP herbicideTM label says to "apply large droplets1 

setting the boom at the lowest height which provides uniform coverage reduces the exposure of 

droplets to evaporation and wind." For postemergence applications uniform foliar coverage is 

critical for optimum weed control. 

USAGE 

Data on sulfentrazone usage is provided in Tables 1 through 5. Additional registered uses may 

exist but are not included because the available surveys do not report usage (e.g., small acreage 

crops). Lack ofreported pesticide usage data on a crop does not imply zero usage. Nonagricultural use sites (e.g., turf, other ornamentals, etc.) are generally not reported. 

1 The Sulfentrazone XP label lists the wrong size for large droplets it should read 350-450 microns not> 150 - 200 

microns. 

Page 2 
Table 1. Screening Level Usage Analysis (SLUA) Estimates of Agricultural Uses of 

S u lfi entrazone. R eportmg . Y ears: ·200 4-201" .) . 

Crop Average Annual Percent Cro D Treated 

Pounds (a.i.) Aoolied Avera2e Maximum 

1 Alfalfa 1,000 <1 <2.5 

2 Asparagus 1,000 15 30 

3 Barley <500 <1 <2.5 

4 Beans, Green <500 10 15 

5 Beans, Lima <500 10 15 

6 Cabbage <500 <2.5 5 

7 Com 5,000 <1 <2.5 

8 Cucumber <500 <2.5 <2.5 

9 Dry Beans/Peas 30,000 15 25 

10 Fallow 3,000 <1 <2.5 

11 Peanuts 1,000 <1 <2.5 

12 Peas, Green <500 <1 <2.5 

13 Potatoes 4,000 <2.5 <2.5 

14 Rice 4,000 <2.5 <2.5 

15 Soybeans 500,000 5 15 

16 Strawberries 1,000 5 10 

17 Sugarcane 3,000 <2.5 <2.5 

18 Sunflowers 100,000 . 50 65 

19 Tomatoes <500 <2.5 <2.5 

20 Tobacco 30,000 45 65 

21 Watermelons <500 <2.5 <2.5 

22 Wheat 3,000 <1 <2.5 

• Footnote: EPA. 2015 . See Appendix 1 for complete information. 

National average application rate, rate applications between the goth and 1 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. The average application rates range from 0.061 to 0.221 

lb ai/acre while applications rates falling between the goth and 1 ooth percentile range from 0.06 to 

0.31 lb ai/acre. 

Page 3 
Table 2. Sulfentrazone National Crop Acres Grown, Average Annual Total Acre Treatments, 

Label Maximum, Average Application Rate per Treatment, and Upper Percentile 

A .pp 1' 1catlon . R D ate. ata f rom 2008 - 2012 

Maximum Application 

Average Annual Average Single Average Rate 

Annual Application Application between Crop Crop Acres Total Acres From Label Rate (lb the SOth Grown Treated (lb ai/acre) ai/acre) and iooth 

Percentile1 

Asparagus 30,060 5,550 0.38 0.19 0.19 

Barley 3,174,200 150 0.19 0.09 0.09 

Cabbage 63,680 950 0.38 0.22 0.31 

Com 89,526,009 28,700 0.25 0.06 0.07 

Cucumbers 131,249 500 0.25 0.20 0.2 

Dry 2,737,479 414,000 0.25 0.09 0.12 Beans/Peas 

Lima Beans 36,345 950 0.19 0.08 0.07 

Peas 

(Fresh/Green/ 180,037 <50 0.19 0.13 0.13 

Sweet) 

Soybeans 76,297,988 3,084,800 0.38 0. 15 0.22 

Strawberries 54,314 2,200 0.38 0.22 0.25 

Sunflowers 1,955,000 1,233,950 0.25 0.11 0.16 

Tobacco 335,386 173,500 0.38 0.18 0.25 

Tomatoes 0.38 0.11 0.11 

Watermelons 130,460 400 0.25 0.11 0.13 

Winter Wheat 0.19 0.06 0.06 

Total 174,733,527 4,950,000 0.14 0.22 

Proprietary data, 2008-2012. Numbers may not add due to rounding. 

1 Represents the highest rate between the 801

h and l 001

h percentile (varies by crop). 

Crop application timing by state (Table 3) is designed to provide additional usage data on an 

individual crop basis for more refined risk assessments. In over 95% of cases, sulfentrazone is 

applied before planting but it is also occasionally applied early and late post emergence or in the 

late fall. Barley is the only crop in which sulfentrazone is exclusively applied in the late fall for 

chemical fallow. 

Page4 
Table 3. Application Timing, Percent of Total Acre Treatments by Crop and State, for 2008-

2012 

Early 

CROP STATE Before &Late Last 

Planting Post Fall 

Asparagus Michigan 100% 0% 0% 

Barley Montana 0% 0% 100% 

Cabbage North Carolina 100% 0% 0% 

Cabbage Wisconsin 100% 0% 0% 

Com Illinois 100% 0% 0% 

Com Indiana 100% 0% 0% 

Com Iowa 100% 0% 0% 

Com Minnesota 100% 0% 0% 

Com Missouri 100% 0% 0% 

Com Ohio 100% 0% 0% 

Cucumbers South Carolina 100% 0% 0% 

Dry Beans/Peas Colorado 100% 0% 0% 

Dry Beans/Peas Idaho 97% 0% 3% 

Dry Beans/Peas Minnesota 100% 0% 0% 

Dry Beans/Peas Montana 97% 0% 3% 

Dry Beans/Peas Nebraska 100% 0% 0% 

Dry Beans/Peas North Dakota 98% 0% 1% 

Dry Beans/Peas Washington 28% 72% 0% 

Lima Beans Delaware 100% 0% 0% 

Peas (Fresh/Green/Sweet) Wisconsin 100% 0% 0% 

Soybeans Arkansas 100% 0% 0% 

Soybeans Illinois 91% 0% 9% 

Soybeans Indiana 99% 0% 1% 

Soybeans Iowa 99% 0% 1% 

Soybeans Kansas 84% 0% 16% 

Soybeans Kentucky 100% 0% 0% 

Soybeans Louisiana 100% 0% 0% 

Soybeans Maryland 100% 0% 0% 

Soybeans Michigan 100% 0% 0% 

Soybeans Minnesota 100% 0% 0% 

Soybeans Mississiooi 100% 0% 0% 

Soybeans Missouri 87% 0% 13% 

Soybeans Nebraska 94% 0% 6% 

Soybeans North Carolina 100% 0% 0% 

Soybeans North Dakota 100% 0% 0% 

Soybeans Ohio 87% 0% 13% 

Soybeans Oklahoma 100% 0% 0% 

Page 5 
Early 

CROP STATE Before &Late Last 

Plantim! Post Fall 

Soybeans South Dakota 100% 0% 0% 

Soybeans Tennessee 100% 0% 0% 

Soybeans Wisconsin 100% 0% 0% 

Strawberries Michigan 100% 0% 0% 

Strawberries Oregon 100% 0% 0% 

Strawberries Pennsylvania 100% 0% 0% 

Strawberries Washington 100% 0% 0% 

Sunflowers Colorado 100% 0% 0% 

Sunflowers Kansas 99% 0% 1% 

Sunflowers Minnesota 100% 0% 0% 

Sunflowers Nebraska 100% 0% 0% 

Sunflowers North Dakota 97% 2% 1% 

Sunflowers South Dakota 96% 1% 3% 

Sunflowers Texas 100% 0% 0% 

Tobacco Florida 100% 0% 0% 

Tobacco Georgia 72% 28% 0% 

Tobacco Kentucky 96% 3% 0% 

Tobacco North Carolina 97% 3% 0% 

Tobacco Ohio 100% 0% 0% 

Tobacco Pennsylvania 100% 0% 0% 

Tobacco South Carolina 98% 2% 0% 

Tobacco Tennessee 99% 1% 0% 

Tobacco Virginia 100% 0% 0% 

Averaee 95.2% 0.5% 4.2% 

Footnote: Proprietary data 2008 - 2012. All numbers are rounded. Early and late post indicate 

an application approximately two to six weeks after planting. Fall application indicates a 

treatment the previous fall after the last crop is harvested. Fall applications can provide 

control of winter weeds. 

Crop aerial applications are reported for soybeans and sunflower (Table 4) and are designed to 

provide additional usage data on an individual crop basis for more refined risk assessments. A 

majority of aerial applications are made to soybeans, with most applications occurring in Illinois. 

Sunflowers are also treated aerially, with the highest proportion of acreage treated aerially 

occurring in North Dakota. Aerial applications were not reported for any other crop or state and 

can be assumed to be ground applications. 

Soybean aerial application rates range from 0.09 to 0.136 lbs. ai/acre at the state level, with aerial 

application to soybeans accounting for 2% of total soybean acres treated nationally. Sunflower 

aerial application rates range from 0.089 to 0.149 lbs. ai/acre at the state level, with aerial 

Page 6 
applications to sunflowers accounting for 5% of total sunflower acres treated nationally. 

Overall, total aerial applications of sulfentrazone made at the national level account for 2% of the 

total acres treated with sulfentrazone. 

Table 4. Sulfentrazone Aerial Application, Total Area Treated (acres), Percent Crop Treated, 

an d A •PP r . 1cat1on R ate (lb . a.1. . I acre, ) A verages fl or 2009 -2013 

Total Area Percent of Total Average Aerial 

Crop State Treated Area Treated that Application Rate 

Aeriallv is made Aeriallv (lb. ai/acre) 

Soybeans Arkansas 3,700 6% 0.090 

Soybeans Illinois 57,400 8% 0.136 

Soybeans Iowa 3,900 <1% 0.120 

Soybeans Ohio 28,100 2% 0.131 

Sunflowers Kansas 5,600 7% 0.089 

Sunflowers North Dakota 12,200 12% 0.122 

Sunflowers South Dakota 40,000 8% 0.149 

Footnote: Proprietary data 2009 - 2013. All numbers are rounded. All other applications are 

ground applied. 

Sulfentrazone usage in California by crop (Table 5) is designed to provide additional usage data 

on alternative crops that national level data did not capture which could allow for more refined 

risk assessments. Applications to alternative crops in California are relatively low, however it 

should be noted that application rates to asparagus are the highest rate shown at 0.37 lbs. ai/acre. 

Note that with 3,500 acres of mint grown in California in 2011, sulfentrazone could be used on 

as much as 20% of mint acres grown in the state (Wilson et al. , 2011 ). 

Tabl e 5 . S u lfi entrazone u sage · m c a ri fi orn1a, · 2010 - 2012 

Total Application 

Crop Area Rate 

Treated (lb ai/acre) 

Asparagus 77 0.37 

Landscape Maintenance 6.14 0.01 

Mint 718 0.25 

Ornamentals - Greenhouse Grown, Cut Flowers or Greens 14.21 0.13 

Ornamentals - Outdoor Grown Cut Flowers or Greens 2.6 0.07 

Ornamental Turf 265.10 0.17 

Strawberry Fruit 18 0.23 

Uncultivated Non-Ag Areas 3.5 0.25 

Source: California Department of Pesticide Regulation (CALDPR). 

Page 7 
REFERENCES 

EPA. 2013. Sulfentrazone (129081), Screening Level Usage Analysis (SLUA). February 27, 

2013. 

Proprietary data on pesticide usage, 2004-2012. 

Wilson, R., D.B. Marcum, K.M. Klonsky, and R.L. De Moura. 2011. Sample Costs to Establish 

a Mint Stand and Produce Peppermint Oil. University of California Cooperative Extension. 

http://coststudies.ucdavis.edu/files/PeppermintIM2011 .pdf. 

WSSA. 2014. Herbicide Handbook, Weed Science Society of America, Tenth Edition, 2014. 

Page 8 
APPENDIX 1. 

What 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 available 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 1 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 1, then the value is labeled <l. 

• 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 than 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 2012. 

• Private pesticide market research - pesticide usage data from 2004 to 2012. 

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

(PUR) data for 2004 to 2011. 

What are the limitations to the data? 

• 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. 

Page 9 
• 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 chemical, data collection errors, and experimental use permits (EUPs). 

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