UNITED STATES-ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MAR 1 4 2016 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

TO: 

BEAD Chemical Profile for Registration Review: Ethofumesate: 

(PC Code: 110601) 

Sunil Ratnayake, Ph.D., Biologist ~.. L--

Biological Analysis Branch ( , ~~ ~r;i,~ 

Jihad Alsadek, Ph.D., Economist v 

., --/' 1 

~ ' · .?JI"· . JA-~ 

Science Information and Analysis Branch 

Economic 

Stephen Smearman, 

Analysis Branch 

Economist 

~ 

L _ J. ~ 

Biological and Economic Analysis Division (7503P) 

Colwell Cook, Ph.D., Acting Chief d _ .4 ~ ~ tQl~cll took 

Biological Analysis Branch /''...... I · 

Diann Sims, Chief A~~ ~ ).,.J;w.,,,__-

Science Information and An~l~is Branch 

Timothy Kiely, Chief fYlOUMJ~ ~ ~ (1 fYllJfhf l(j€,;l 1 

Economic Analysis Branch 

Biological and Economic Analysis Division (7503P) 

Jordan Page, Chemical Review Manager 

Risk Management and Implementation Branch V 

Pesticide Re-evaluation Division (7508P) 

Peer Review Panel date: September 9, 2015 
SUMMARY 

Ethofumesate is a selective herbicide that was registered in the United States in 1977 (USEP A, 

2005). It can be applied as pre-plant, pre-emergence, and post-emergence treatments to control 

many economically important annual grasses and broadleaf weed species. It is used primarily on 

sugar beets and onions. According to the WSSA (Weed Science Society of America) 

classification of herbicides, ethofumesate belongs to the family ofbenzofuran herbicides (Group 

16). . 

Based on private market usage data from 2009-2013, usage averaged approximately 35,000 

pounds active ingredient (a.i.) applied annually on 104,000 acres. The average application rate 

a.i. (active ingredient) over this time period is 0.34 pounds a.i. /acre. From 2009 to 2013 the 

highest usage of ethofumesate was on onion and sugar beets. Minnesota, Oregon and California 

are the states with the most usage. There are isolated reported usage data for table grapes and 

apricots, but no reported usage data for carrots. There are no reported usage data for nonagricultural use sites. 

INTRODUCTION 

The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an 

overview of the pest management roles and quantitative usage information for ethofumesate. 

The BCP includes summaries of previous BEAD products and available public and/or private 

use and usage data for ethofumesate to describe its role in pest management. Information 

provided in this BCP may be used by stakeholders (e.g., users and registrants), OPP risk and 

benefit assessors, OPP risk managers, and the general public during the Registration Review of 

this herbicide. 

USE SITES 

Agricultural Use Sites 

Registered agricultural use sites include: carrots, garlic, onion, shallot and beets (sugar beets, 

garden beets, and table beets). 

Non-Agricultural Use Sites 

Non-agricultural use sites which are registered for ethofumesate application include: grasses 

grown for seed, ornamental lawns, turf, and ornamental sod farms. 

FORMULATIONS AND APPLICATION METHODS 

Ethofumesate is formulated as a flowable liquid concentrate, emulsifiable concentrate, and 

soluble concentrate/liquid. It may be applied pre-plant, pre-emergence or post-emergence. 

Application methods include banding, broadcast, soil-incorporation, and impregnated dry bulk 

fertilizer. 

Page 2 
HISTORY OF ETHOFUMESATE and BEAD PRODUCTS 

A search of the BEAD database for previous assessments for ethofumesate indicates that there 

are no records of prior benefits assessments or Section 18 Emergency Exemption Requests in the 

last 10 years. Recent Section 18 Emergency Exemption Requests might suggest that a chemical 

is important for the uses granted in the request; however, a lack of Section 18 Emergency 

Exemption Requests is not an indication of the relative importance of the chemical. 

USAGE 

Ethofumesate is an herbicide that was registered for use in the U.S. in 1977. A Registration 

Eligibility Decision (RED) was published in 2005 and revised in 2007. 

Figure 1 & 2 present total pounds a.i. applied and total area treated in acres over the 1998-2013 

time period (Market Research Data, 1998-2013). The use of ethofumesate, in terms of total 

pounds applied and total area treated in acres increased from 1998 through 2007, then decreased 

significantly from 2008 and 2009 before stabilizing in 2010-2013, as shown in Figures 1 & 2. 

Figure 1. Ethofumesate Usage in Total Pounds Active Ingredient A plied (1998-2013) 

"' ~ "! .!! 

::s - 0 ~ a. < 

Ci ...:: 

o< 

.... . 

1,200,000 

0 

8 8 8 8 N N N N 

Source: Market Research Data, 1998-2013 

Page 3 

8 8 ,..... 8 00 8 °' 0 8 s .-4 N M 

s s s N N N N N N N N N 

Years 
Fi ure 2. Ethofumesate Total Area Treated in Acres 1998-2013) 

2,500,000 

0 

; ; 8 8 8 8 8 8 8 8 8 ~ s ~ s s .-4 .-4 N N N N N N N N N , , N , , N N 

Years 

Source: Market Research Data, 1998-2013 

There were no reported usage data on onions during the 1998-2005 time frame. The reported use 

of ethofumesate during this period was totally on sugar beets. The use on sugar beets peaked in 

2004, and decreased thereafter until 2009. The wide adoption of glyphosate-resistant sugar beets 

began in about 2009 which coincides with the steep decline in ethofumesate usage. (Figure 3). 

The major use of ethofumesate is on sugar beets and onions. The use on onions remained almost 

constant and has slightly increased since 2009 (Figure 3). The agricultural use sites in terms of 

the number of average annual pounds used were sugar beets (300,000 lbs. a.i) followed by 

onions (10,000 lbs. a.i.) for 2004-2013 time period. The crops with the greatest percent crop 

treated include sugar beets, with an average of 30 percent crop treated annually and onions with 

an average of 20 percent crop treated annually. The annual percent crop treated for sugar beets 

and onions indicate that growers still find benefits for use on these crops, or at the very least, a 

reliance on ethofumesate to control pests on these crops. 

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Figure 3. Ethofumesate Usage in Pounds Active Ingredient Applied on Onions and Sugar 

Beets, 2000 - 2013. 

1.200.000 

0 

2<X>O 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 

-----C>nions ---..-susa r b eet.s 

'----------------------------------------------- - Source: Market Research Data, 2000-2013 

The use of ethofumesate is about 60% sugarbeets and 40% onions during the 2009-2013 time 

span, as shown in Table 1. 

Table 1. Comparison of Crops with Highest Use of Ethofumesate, Percent Pounds AI 

Applied (2000-2004 and 2009-2013) 

2000-2004 2009-2013 

Average Annual Usage= 489,000 lbs/yr Average Annual Usage= 35,000 lbs/yr 

Crop %Lbs Crop %Lbs 

Onions 57 

Sugar Beets 100 Sugar Beets 42 

Source: Market Research Data, 2000 -2013. 

Page 5 
In the 2000-2004 time frame, the states with the highest use of ethofumesate in terms of pounds 

applied were North Dakota and Minnesota, the largest producers of sugar beets. This changed in 

· the 2009 to 2013 time period when use declined in North Dakota and Idaho and increased in 

Minnesota, Oregon and California. 

Table 2. Comparison of States with Highest Use of Ethofumesate, in Terms of the Percent 

of Pounds Al Applied (2000-2004 and 2009-2013) 

2000-2004 2009-2013 

Average Annual Usage= 489,000 lbs/yr Average Annual Usage= 35,000 lbs/yr 

State %Lbs State %Lbs 

North Dakota 30 Minnesota 31 

Minnesota· 27 Oregon 23 

Idaho 13 California 18 

Montana 8 Idaho 8 

Wyoming · 7 North Dakota 8 

Nebraska 5 Texas 4 

Michigan 4 Washington 4 

Source: Market Research Data, 2000 -2013 

The average application rate (a.i.) for the top crops was the highest for onions at 0.44 lbs a.i./acre 

and the lowest for sugar beets at 0.25 lbs. a.i./acre as shown in Table 3. 

Table 3. Ethofumesate Use on Top Crops (2009-2013) 

Average Annual Average Annual 

Crop Pounds AI Total Acres 

Aoolied Treated* 

Onions 20,000 45,000 

Sugar Beets 15,000 59,000 

*Total Acres Treated sums all acres treated for a crop. 

Source: Market Research Data, 2009 -2013 

Geographic Distribution of Ethofumesate Use 

Average Annual A.I. Label A.I. 

Rate (lbs. a.i. /acre) Max. App. 

Ran2e Rate 

0.44 0.48-1.00 

0.25 1.45-3.78 

As the following map (figure 4) shows most use of ethofumesate is in Oregon and Minnesota. 

The map included herein is for general use in the registration review process. The map provides 

a very broad geographical view of the total acres treated (TAT) over 5 years of a pesticide on all 

agricultural crops. The map units are total acres treated, which accounts for all agricultural 

acreage treated with this chemical and includes multiple treatments to the same area. 

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1btal Acres lteated 

LJNDDall 

LJ <800 

- S>1-4,000 

- 4,001-11,600 

- 11,801-21,000 

• •21,001 

Figure 4. Total Acres Treated of Ethofumesate. 

(Source: Market Research Data, 2009-2013) 

The data used to make these maps have many limitations. Any interpretation of the maps should 

consider the underlying data and the associated limitations carefully. For example, there may be 

significant differences in the crop acres grown between states and there may be variation in the 

percent of each of the various crops treated by the pesticide. 

TAT is based on private market surveys of pesticide use in agriculture averaged over the last five 

years (Market Research Data, 2009-2013). These surveys cover about 60 crops and are targeted 

in states that produce the majority of the crop. Although the surveys capture most of the use of a 

particular active ingredient in agriculture, there are several limitations to these surveys. 

• States with minor production of a surveyed crop are not sampled 

• Not all types of pesticides are surveyed in every crop in every year 

• Many specialty crops with very small acreages are not included in the survey 

The result of these limitations is that states that show no acres treated may actually have a small 

' amount of the active ingredient being used. In some cases, the displayed TAT may be distorted 

because the surveyed crops and the reported pesticide usage (or TAT) does not accurately 

represent the actual pesticide usage on the crops produced in the state. 

Page 7 
The reader should pay 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 as 

the total acre treatment. intervals used in the legend will likely be different. 

CHEMICAL AND USE CHARACTERISTICS FOR ETHOFUMESATE 

Ethofumesate is a selective and systemic herbicide that belongs to the benzofuran family (Group 

16) of herbicides (WSSA, Undated). The mechanism of action of this herbicide is not well 

understood, although it appears to inhibit lipid synthesis (Herbicide Handbook, 2014). 

Ethofumesate is readily absorbed by roots and shoots of weed species. When ethofumesate is 

applied as a post-emergence treatment it is poorly absorbed by maturing leaves with a welldeveloped cuticle (Herbicide Handbook, 2014). 

ROLE OF ETHOFUMESATE IN PEST MANAGEMENT 

Ethofumesate is registered for the control of major grass and broadleaf weed species in sugar 

beets, garden beets, table beets, onions, garlic, shallots, and carrots. It is also applied for 

selective control of weeds in certain grass seed crops and commercial sod production in 

California, Idaho, Nevada, Oregon and Washington. 

Ethofumesate has a broad application window and can be applied as pre-plant, pre-emergence 

and post-emergence treatments. This herbicide controls broadleafweed species such as black 

nightshade (Solanum nigrum), common chickweed, (Stellaria media), common lambsquarters 

(Chenopodium album), Kochia (Kochia scoparia), redroot pigweed (Amaranthus retroflexus), 

Russian thistle (Sa/so/a Kali Var. tenuifolia) and wild buckwheat (Polygonum convolvulus). The 

major grass weed species controlled by ethofumesate are bamyardgrass (Echinoch/oa crus-galli), 

green foxtail (Setaria viridis), large crabgrass (Digitaria sanguinalis), and yellow foxtail (Setaria 

glauca) (Herbicide Handbook, 2014, Market Research Data). Based on Market Research Data 

for the period from 2011 to 2013, the top five pests in terms of total acres treated that 

ethofumesate is used to control are redroot pigweed, kochia, lambsquarters, chickweed and 

wormwood. 

According to Market Research data, the highest usage of ethofumesate was observed in 2004 on 

sugar beets (Figure 3). Shifting of use of ethofumesate to glyphosate to control weeds in sugar 

beet production may be the major factor contributed to the observed low usage of ethofumesate 

on sugar beets during the period from 2009 to 2013 (Figure 3). About 95 percent of U.S. sugar 

beet production in 2013 was glyphosate-resistant varieties (GMO Compass, 2013). 

Ethofumesate may be tank mixed with compatible herbicides with different modes of action 

which may help manage weed resistance to ethofumesate. There are no reports of any weed 

species with resistance to the mechanism of action of ethofumesate in the United States (Heap, 

2015). 

Page 8 
DATA NEEDS 

The Agency currently does not have important information on ethofumesate, such as pounds a.i. 

applied and percent crop treated on some of the registered crops, such as carrots, garlic, and 

garden and table beets. In addition, obtaining similar information on non-agricultural use sites 

such as grasses for seed, ornamental lawns and turf, and ornamental sod farms may improve 

future assessments.conducted by the Agency. 

REFERENCES 

BEAD, 2015. Ethofumesate Screening Level Usage Analysis (SLUA). Biological and 

Economic Analysis Division, Office of Pesticide Programs, US Environmental Protection 

Agency. July 20, 2015. 

Ethofumesate 4SC Product Label. 2014. Willowood LLC. 1600 NW Garden Valley Blvd. Suite 

# 120, Roseburg, OR 97471. Online Publication. Available at: 

http://www.willowoodusa.com/wp-content/uploads/2012/01 /Ethofumesate-4SC-SpecLabel.pdf. Accessed on June 26, 2015. 

GMO Compass. 2013. USA: Cultivation of GM plants. Online Publication. Available at: 

http://www.gmocompass.org/eng/agri _ biotechnology/gmo _planting/506.usa_ cultivation _gm _plants _2013 

.html. Accessed on Aug. 18, 2015. 

Heap, I. 2015. The International Survey of Herbicide Resistant Weeds. Online Publication. 

Available at: http://www.weedscience.org/summary/ResistbyActive.aspx. Accessed on 

June 25, 2015. 

Herbicide Handbook. 2014. 10th edition. Weed Science Society of America. Ethofumesate. Pp. 

184-185. 810 E. 10th Street, Lawrence, KS 66044-8897. 

Market Research Data (MRD). Various years. Data collected and sold by a private market 

research firm. Data collected on pesticide use for about 60 crops by annual surveys 

of agricultural users in the continental United States. Survey methodology 

provides statistically valid results, typically at the state level. · 

USDA- NASS, 2010. Available at: 

http://www.nass.usda.gov/Statistics by Subject/index.php?sector=CROPS. Accessed on 

July 20, 2015. 

USEPA. 2005. Registration Eligibility Decision (RED) for Ethofumesate. Available at: 

http://www.epa.gov/pesticides/reregistration/REDs/ethofumesate red.pdf. Accessed on 

June 23, 2015. 

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WSSA, (Weed Science Society of America). (Undated). Summary of Herbicide Mechanism of 

Action. Online Publication. Available at: http://wssa.net/wp-content/uploads/WSSAMechanism-of-Action.pdf. Accessed on August 18, 2015. 

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