UN ITED STATES ENVIRONMENTAL PROTECTION AGENCY WAS H I NGTON D .C . , 20460



### MEMORAND UM 

### NOV 2 9 20 1 0 Of FICE O F C HEMICAL S AFETY AN D POLLunoH PREVE N110N



### SU BJ ECT: F ROM:

T HR U: B EAD C h e mic a l Pr ofil e f or Registrat i on R eview : C l o ransul a m - m e th y l ( 1 29 1 16) S unil R atnayake , B io logi st 

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. L , I , B i o log ic a l A nalys is Branc h "'
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# j\ Sep ehr H addad , E nviro nmenta l Sc ienti s t 

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# 1.1/, J Scie nce I nf o rm at io n and An a ly s i s Br an ch 

# VI-

# I~ An drew Lee , Eco nomi st

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# C
. J Ec ono mi c Ana lysis B ran ch 

# l/f/ "" Biologi cal an d E co n o mi c An a ly sis D ivisio n ( 03 P ) Arnet J ones , C hief

# jp;1<"**+-** B io lo g ical Ana ly sis B ran ch 

## (.J?<-- D iann Si m s, C hief Sc ience In formati on and Analy sis B ranch T imothy K ie ly , C hie f {,).... 

## [;I,\. Eco nomic A nalys i s B ran ch 'J 

# J B io lo g i cal and Eco nom ic A na lysi s D ivision (7 P) T O: C ar issa C yra n C h e mical R eview M anager Pe sti cide Reeva lu a tion Di vi s i on ( 7508 P) 

### P eer Revi ew Pan el D ate: M ay 1 9 ,2010 INT RO D UCTION C lo ransulam

- methy l bel ongs t o s ulfo nan illide he rb icide gro up and it inh ibits the 

### enzy m e ac e to lactate s y nthetase ( A LS)
. C lo ransulam

- methy l w as first regi ste red i n 1 997 b y D o w E lan co and i t i s labe led f o r bro adle afwe ed c on tr o l i n so ybeans
. It co ntrols broadle a fweed s pecies s uch as g ian t ragw eed ( A m b ros ia I rifi da ), co mm o n ragweed ( Amb rosia an emisi if olia), h orse weed ( Co n yza C anadensis), s ic k lepo d (C assia ob t us if o l ia}, c oc klebur ( Xan lh ium s tr umariu m ), v e lve t le af ( Abu l ilon the ophr ast iv wi ld mu s tard ( Bra ssica /cab e r ) and j im so nweed Da tu ra s tra mon i um s pecie s. Thi s herbi cid e i s applie d a s pre-p lant in c orpora ted , pr e -plant s urf a ce , pre-emergen ceand po st -e mergence applicatio ns . Mode of action of this h erbicide i s i nhibition of th e acetolactate s ynthase (AL S) enzy me . 

### P RI MARY U SE SITE S Th is c hemical i s onl y u sed o n soy beans. 

### C OMMON FORM ULATIONS AND APPLICATIO N MET HODS' Fo rmulations in clude : dry flowable (wa ter d ispers ible gra nules) , we ttable p owder , and so luble co ncentrate (so lid)
. T hi s che mical i s applied as ground spray, broadcas t, bum down trea tment , soil trea tment ( s urface , i ncorporated , broadcast) , and ban d treatment. 

### U SAGE/U SE TRE NDS C loran s ularn Agr icultura l Us age Based o n private mar ket pe sticide u sage data fro m 1 998-2008, th e annua l total agric ultural u s age ave raged approximately 44 , 000 p ounds active ingredient for 2.5 m illion acre s (GfK Kynetec , 1 998-2008). D uring th e 11 year ti me per iod , a ll u se in terms ofto tal pou nds of act ive in gredient ap plied was on s oybeans ( GfK Kynetec , 1998 -2008)
. C lo ransu lam is n ot used on n onag ricultural s it es . Figure I pro vides u sage i n term s of pounds app lied an nually fro m 1998 -2 008 , for c hloransulam 's o nly agric ultural market , w hich i s soy bean s. F igure 2 below s how s ave rage u s age by s tate d uring th e 11 year time period for s t ate s wit h the most agr icu ltural u s age in terms of pounds act ive i ngredient (A.I .) app lied
. Thes e are : I owa, Illi nois, O hio, Indiana, M innesota , N ebr aska, an d M i sso uri. ( GfK Ky netec , 1 998-2008).

2F I GURE 1. C lor ansulam U s a e Po und s A I**0, OOO** **-r ~~~** **-----------------------**

Poun ds A I



### o 1 998 1 999 2000 20 01 2 002 2 003 2004 2 005 2 006 2007 200 8 Y ear S o u rce: G fK K yn e tec , 1 9 98-2008 F IG URE 2
. AV ERAGE USAGE BY S TATE 1 99 8-2 0 08

7 % g l QW A
• IL LINOIS DO HIO D INOIA NA

. M INNE SOT t1 NEB RA SKA

• MI S S OURI 1 5%
S o urce: G fK K ynetec , 1 9 98-200 8 PREVIO US BEAD ASSESSM ENTS T he re are no p re vi ous BEA D a ssess m e nt s o n thi s c he mi ca l includ ing S ectio n 1 8 s , b e nefit o r alt ernative as sess me nt s whic h h a d a ro l e in ri sk-benefit de c isions s uc h as can ce llat io n s o r re tentio n of re gistered use s, red uction in rate s , and s h o rte r RE Is.



### 3OTHER ISSUES S UC H AS R ESIS TANCE, P LANT OR P UBLIC H EALTH C LAIMS Th e mod e of a ction o f th is h erbicide i s inhibiti on o f the enzym e a cetolactase sy nthase (ALS). Th e introduction o f s ulfonylur eas in 1 9 80 5 was f oll owed b y oth er ALS inhib itors s uch as imi dazo linones , an d tri az olop yrim idine s u l fonamides ( Patzoldt e t al , 20 0 1). A LS inhibit ors w ere wid ely u sed in crop production. Low rates , l ow mamm alian t oxicity , fl exib le a pplication t iming, and broad s pec trum of weed co ntrol w ere th e a dvant ages o f u sin g th ese herbi cides
. Ho wev er , wi de u se o f A LS inhibit ors c ontributed t o the de vel opment of resistance b io

-types t o th ese he rbicide s . Re s istant we ed s pecies i nclude : co mmon ragweed s Ambrosia artemis iifolia, g iant ragweeds 

### (A mbrosia trifida), pri ckly lettuce 

### (lec tuca ser riola) , kochia 

### ( Kochia sc oparia) , s mooth pi gweed (A m aranthus hyb ridus ), Livid am aranth (A m aranthu s li vidu s} Red ste m (Ammania aur iculate) d owny bro me (Bramus teetarum), and lamb squarters (Chenopodiu m album) (Int ernational S urvey of Her bicide R esistant W eeds, 2 0 1 0). BEAD SPECIFIC REG ISTRA nON REVIEW ISSUES

- BEAD DA TA GAPS FOR FUTURE ASSESSMENTS AND BEAD WORKPLAN REFERENCES G fK Ky netec (1 998-2008) p roprietary dat a. FirstRate. 2 010. S pecimen Lab el. DowAg roScie nce s LL C
. Internationa l Surv ey o f Herbicide Resis tant W eeds
. 20 10
. http :/ /www .weedscience
. org/ln .asp P atzoldt , W
. 

### L., T ranel, P
. J
. , A lexander , P 

### L., a nd P . R. S chm itzer. 2 001. A co mmon ragweed p opulation re sistant to cl orans ulam-m ethyl. Wee d S ci
. Vo 1. 49, N o.4 , pp . 48 5-490.



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