UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 

## OCT 12 2011

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### SUBJECT: BEAD Chemical Profile for Registration Review: Halosulfuron-methyl (128721)


### FROM:

THRU:

TO: Sunil Ratnayake, Biologist Biological Analysis Branch Jihad Alsadek, Economist Science Information and Analysis Branch StephenSmearman,Economist 

# 1,
_ .....

# ~~ Economic Analysis Branch 

## !btJI( / Biological and Economic Analysis Division (7503P) Arnet Jones, Chief

# ~~ Biological Analysis Branch
. 

# U Diann Sims, Chief

# j)**~** Science Information and Analysis Branch**~** Timothy Kiely, Chief
. \A A Biological andEconomic

# ~ Division (750 Economic Analysis Branch vV'\...
Kaitlin Keller, Chemical Review Manager Risk Management and Implementation Branch 3 Pesticide Reevaluation Division (7508P) 

### Product Review Panel date: Sep. 07, 2011 INTRODUCTION The purpose ofthis document is to convey usage information and a broad overview ofthe pest managementroles ofpesticides that are beginning to undergo registrationreview. The anticipated audience consists ofthe team ofEPA staffcurrently evaluating the registration status ofhalosulfuron-methyl (128721), and eventually the general public. This documentbuilds uponthe data already provided in the "Usage and Label Use DataPackages" that are also provided to Registration Review teams by BEAD. The document is based oninfonuation and data available to BEAD as ofSep. 07,2011. Halosulfuron-methyl belongs to the sulfonylureaherbicide family and it inhibits the activity of acetolactate synthase enzyme which is important for synthesis ofbranched chain amino acids (leucine, isoleucine, and valine). Halosulfuron-methyl is a post-emergence herbicide and itis applied after emergence oftarget weeds. This herbicide has a greater selectivity atvery low rates and generally recommended for the control ofannual and perennial sedges. 

### USE SITES Agricultural Use Sites Halosulfuron-methyl is applied for weed control innut crops, ornamentals, field crops, vegetable crops, forage crops and turf. Non-Agricultural Use Sites Recreational areas, race tracks, non-crop areas, tennis courts, play grounds, right ofway areas, and in golfcourses. COMMON FORMULATIONS AND APPLICATION METHODS Halosulfuron-methyl is fonuulated as water dispersible granules and emulsifiable, flowable and soluble concentrates
USAGE Agricultural From 2008-2010, the annual total agricultural usage averaged approximately 30,000 pounds active ingredient for 1,000,000 treated acres. During this time frame, the crops with the mostuse in tenus oftotal pounds ofactive ingredient applied are rice (53%), com (19%), sugarcane (7%) and green beans 

### (4%). These crops also have the highesttotal areatreated (TAT) for this timeframe. On average, the states with the most agricultural usage intenus ofpounds a.i. applied are Arkansas (23%), Louisiana (17%), Texas and Florida (9% each), and Wisconsin (7%). (Proprietary Data, 2008-2010).

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### USE TRENDS Figurel provides usage trends interms ofpounds active ingredient applied. The use of halosulfuron-methyl on green beans was stable during the years 2008-2010. The use on com, rice, and other cropsl increased during this time frame. Use on sugarcane was stable from 2008- 2009 andthere was a significant decline 

### inuse in2010. Figure 1. Halosulfuron-methyl Agricultural Usage Data, 2008-2010 45,000 ..,----------------------

• Green Beans PoundsA.I. • Corn • Rice • Sugarcane • Other 

### o 2008 2009 2010 Years
Source: Proprietary Data, 2008-2010 IOther crops include cucumber, drybeans, and soybeans (3% each), pumpkins and watermelons (2% each), and tomatoes, fallow, sweet corn, and squash (1% each).



### 3Figure 2 sho.ws the lo.ng tennuse o.fhalo.sulfuro.n-methyl fro.m 1998-2010. Halo.sulfuro.n-methyl was fIrst registered inMay1985. In general usage has fluctuated o.n all crops thro.ugho.ut this timeframe. Fro.m 1998

- 1999, usage was primarily o.n co.rn, rice, and o.ther crops. Figure 2. 

### Halosulfuron-methyl Long TermAgricultural Usage Data, 1998-2010 70,000

PoundsA.I.



### o

Source:

# ~

# ~**~ ~** **~** 0 M N m**~ ~** **~ ~** **~ ~**  0 0 0 0 0 0 0 0**~ ~**  0 0 0 0 0 0 0 0 M M N N N N N N N N Years Proprietary Data, 1998-2010 Non-Agricultural • Green Beans • Corn
• Rice • Sugarcane 

# 1J 

## j • Other

The use o.fhalo.sufuro.n-methyl in go.lfco.urses increased from less than 500 lbs. a.i. in 2002 to. 2,000 lbs. a.i. in 2004 and then declined to. 1,000 lbs. a.i. in 2006. Fo.r turffanns, use was almo.st 1,000 lbs. a.i. in 2004 and 2006. There was less than 500 lbs. a.i. used o.n institutio.nal turfand fo.r landscape in 2004 and 2006. Lawn care o.perato.rs (LeOs) used less than 500 lbs. a.i. o.f halo.sulfuro.n-methyl in 2002 and 2004, and abo.ut 3,000 lbs. a.i. in 2006. Kline and Company, Inc. 2002-2006


### BIOLOGICAL ASPECTS RELEVANT TO HALOSULFURON-METHYL Halo.sulfuro.n-methyl belo.ngs to. the sulfo.nylurea herbicide family which inhibits the activity o.f acetolactate synthase enzyme 

### (ALS) and presence o.f44 weed species resistant to. ALS inhibito.rs has beenrepo.rted inthe United States (Heap et al. 2011). Ho.wever, no. repo.rts co.uld be fo.und o.n develo.pment o.fweedresistance, specifIcally to. halo.sulfuro.n. Herbicide injury: in so.ybean due to. o.ff-site mo.vement o.fhalo.sulfuro.n has beenrepo.rted as a result o.fhalo.sulfuro.n applicatio.ns in rice fIelds 

### inMississippi (Nandula et al., 2009).



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### mSTORY OFBEAD ASSESSMENTS FORHALOSULFURON-METHYL Seven Section 18 requests for halosulfuron-methyl have beenreviewed by BEAD since 2001. The requests for halosulfuron-methyl were to control nutsedge, pigweed and otherbroad leaf weeds because otherherbicides used onthese crops did not provide adequate control. The following is a list ofthe Section 18's requested by year and the use site. 01-WA-21: DP Barcode (273883)

- Review ofRequest for Emergency Exemption of Halosulfuron-methyl (Sandea) in Washington, Oregon 

### & Idaho for Use onAsparagus to Control YellowNutsedge. BEAD determined that the situation was urgent and non-routine. 01-MI-12; DP Barcodes (D274633, D274635)

- Review ofRequest for Emergency Exemption of Halosulfuron-methyl (Sandea) in Michigan for Use onAsparagus to Control YellowNutsedge and PS II resistant, Redroot Pigweed. BEAD determined that the situation was urgent and nonroutine. 01-CA-0038; DP Barcode (D278475 

### & D278474)

- Review ofRequest for Emergency Exemption ofHalosulfuron-methyl (Sandea) in California for Use onAsparagus to Control YellowNutsedge. BEAD determined that the situation was urgent and non-routine. 02-FL-07; DP Barcode (D281476)

- Review ofRequest for Emergency Exemption for Use of Halosulfuron-methyl (Sandea) to Control Nutsedge inTomatoes in Florida. BEAD determined that the situation was urgent and non-routine because methyl bromide was being phased out. 04-MS-00I0; DP Barcode (D301955)

- Review ofaRequest for EmergencyExemption of Halosulfuron in Mississippi and Louisiana for Use on Sweet Potatoes to Control Purple Nutsedge. BEAD determined that the situation was urgent and non-routine. 04-LA-0007; DP Barcode (D301958)

- Review ofa Request for Emergency Exemption of Halosulfuron in Mississippi and Louisiana for Use on Sweet Potatoes to Control Purple Nutsedge. BEAD determined thatthe situation was urgent and non-routine. 04-NC-0009; DP Barcodes (D303202 and 343705)

- Review ofa Request for Emergency Exemption ofHalosulfuron inNorth Carolina for Use on Sweet Potato to Control Purple Nutsedge. BEAD determined that the situation was urgent and non-routine. The Section 18 requests found in the BEAD data base suggest that there were benefits to using halosulfuron-methyl to control nutsedge and pigweed in asparagus, sweet potatoes, and tomatoes. In addition the Section 18s there were numerous benefits assessments for methyl bromide across a wide range ofcrops for numerous weed species inwhichhalosulfuron-methyl was considered ' as one ofthe alternatives to methyl bromide because at the time, methyl bromide was being phased out.

5DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ON HALOSULFURONMETHYL Obtaining additional infonnation onthe following items would improve future BEAD assessments ofthe importance ofhalosulfuron-methyl and may be required as part ofthe registration review ofthis pesticide. Airports, grounds (all), fallow, fann storage areas, tank fanns, industrial/commercial/recreational, lumber, race tracks, fencerows, right-of-way, roadsides, schools, and tennis courts. REFERENCES Heap, I, H. Glick, L Glasglow, and W. Vencill. 2011. Herbicide Resistant Weeds by Country and Site ofAction. 2011. http://www.weedscience.org/summary/countrysummary.asp Proprietary Data, 1998-2010 Kline and Company, Inc. 2002-2006 Nandula, V. K., Poston, D. H., Reddy, K. N. and K. Whiting. 2009. Response ofSoybeanto Halosulfuron Herbicide
. Int. Journal ofAgronomy. Volume 2009, Article ID 754510



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