UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

Date:  13-AUGUST-2009

SUBJECT:	Rimsulfuron.  Petitions for New or Amended Uses and Tolerances
on Genetically Modified Field Corn and Soybeans.  Summary of Analytical
Chemistry and Residue Data.

PC Code:  129009	DP Barcode:  D360852

Decision No.:  400402	Registration No.:  352-748 

Petition No.:  8F7431 and 8F7440	Regulatory Action:  Section 3
Registration

Risk Assessment Type:  NA	Case No.:  NA

TXR No.:  NA	CAS No.:  122931-48-0

MRID No.:  47548201, 47548202, 47548203, 47548204, 47562001 and 47548207
40 CFR:  180.478 

		              									

FROM:	Debra Rate, Ph.D., Biologist

		Alternative Risk Integration and Assessment (ARIA) Team

		Risk Integration, Minor Use, and Emergency Response Branch (RIMUERB)

		Registration Division (RD; 7505P)  SEQ CHAPTER \h \r 1 

		

THROUGH:	William Cutchin, Acting Senior Branch Scientist

		ARIA

		RIMUERB/RD (7505P)

		Douglas Dotson, Ph.D., Chemist

		Risk Assessment Branch II (RABII)

		Health Effects Division (HED; 7509P)

TO:		Jim Tompkins, RM 25

		Herbicide Branch (HB)

Registration Division (RD; 7505P)

		



I.	CONCLUSIONS

Regulatory Recommendations 

 DuPont™ Resolve ® SG Herbicide (EPA No. 352-748)) on DuPont™
Optimum® GAT® herbicide-tolerant corn and soybeans.  ARIA recommends
for the following permanent tolerances:

Corn, field, grain	0.1 ppm

Corn, field, forage	0.4 ppm

Corn, field, stover	2.5 ppm

Soybean, hay	1.2 ppm

Soybean, forage	0.25 ppm

Soybean, seed 	0.01 ppm

Soybean, hulls	0.04 ppm

Grain, aspirated fractions	4.5 ppm

In addition, in order to ensure that legal uses of rimsulfuron under
FIFRA do not result in illegal residues in food under the FFDCA, ARIA
recommends for the following tolerance expression to be implemented for
rimsulfuron under 40 CFR 180.478:

(a) General. Tolerances are established for residues of the herbicide
rimsulfuron, including its metabolites and degradates, in or on the
commodities in the table below.  Compliance with the tolerance levels
specified below is to be determined by measuring only rimsulfuron (N
-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyridi
nesulfonamide). 

Residue Chemistry Deficiencies

860.1550 Proposed Tolerances

A revised Section F must be submitted to reflect the recommended
tolerance levels in/on corn, field, grain at 0.1 ppm and request a
tolerance in/on grain, aspirated fractions at 4.5 ppm as specified below
in Table 8.  Also, the requested tolerances for corn, aspirated grain
fraction and soybean, aspirated grain fractions are not necessary and
must be removed from the revised Section F.

II.	ACTION REQUESTED

DuPont has submitted petitions supporting the use of rimsulfuron on
field corn and soybeans that are genetically tolerant to sulfonylurea
herbicides (PP#s 8F7440 and 8F7431).  These petitions have been
submitted in conjunction with related petitions for use of tribenuron
methyl and chlorimuron ethyl on genetically modified field corn and
soybeans in support of an end-use product containing all three
sulfonylurea herbicides.  The petitioner is proposing the establishment
of the following permanent tolerances for residues of rimsulfuron:

Corn, aspirated grain fraction	1.02 ppm

Corn, field, forage	0.4 ppm

Corn, field, grain	0.01 ppm

Corn, field, stover	2.5 ppm

Soybean, aspirated grain fractions 	4.51 ppm

Soybean, forage	0.25 ppm

Soybean, hay	1.2 ppm

Soybean, hulls	0.035 ppm

Soybean, seed 	0.01 ppm

III.	EXECUTIVE SUMMARY

Tolerances for residues of rimsulfuron
[N-((4,6-dimethoxypyrimidin-2-yl)aminocarbonyl)-3-(ethylsulfonyl)-2-pyri
dinesulfonamide] are listed in 40 CFR 180.478 and are expressed in terms
of rimsulfuron only.  Permanent tolerances are established for residues
of rimsulfuron at levels ranging from 0.01 ppm in/on various tree
fruits, tree nuts and grapes to 0.1 ppm in/on potatoes and field corn
commodities [40 CFR §180.478(a)].  

  SEQ CHAPTER \h \r 1 The nature of the residue of rimsulfuron in plants
and livestock has been adequately delineated based on metabolism studies
conducted with rimsulfuron in field corn, potatoes, tomatoes, lactating
goat, and laying hen.  The metabolic pathways were found to be similar
in plants and livestock.  The major route of rimsulfuron
metabolism/degradation involves sulfonylurea bridge contraction, with
sulfonylurea bridge cleavage as a minor metabolic route.  Based on the
results of the studies, HED has concluded that the residue of concern in
plant and livestock commodities is rimsulfuron.  

  SEQ CHAPTER \h \r 1 An adequate method is available to enforce the
established tolerances, a high performance liquid chromatography with
ultraviolet (HPLC/UV) detection with column switching.  The method,
AMR-1241-88, has a limit of quantitation (LOQ) of 0.05 ppm. 
Subsequently, DuPont proposed two additional methods using liquid
chromatography with tandem mass spectroscopy (LC/MS/MS) for tolerance
enforcement: Method DuPont-15033 for watery and dry crop matrices, and
Method DuPont-15027 for oily crop matrices.  These methods were also
adequate for data collection, as shown in the submitted studies.  The
validated LOQ is 0.010 ppm in each matrix.  Adequate independent
laboratory validation (ILV) data were submitted for both methods.  

Adequate field trial data have been submitted for genetically modified
field corn and soybean reflecting treatment at 1x the proposed rate. 
The submitted crop field trial data were collected using the proposed
enforcement methods and are supported by adequate storage stability
data.  Residues of rimsulfuron were <LOQ (<0.01 ppm) in/on all samples
of corn grain and soybean seed collected at the appropriate preharvest
interval (PHI).  The data indicate that the proposed tolerances for
field corn and soybean commodities are adequate; however, the current
tolerance in/on corn, field, grain at 0.1 ppm will be maintained for
residue harmonization.  

The available corn and soybean processing data for rimsulfuron are
adequate.  As residues did not concentrate in corn grits, meal, starch
or refined oil, and concentrated only slightly in corn flour, separate
tolerances are not required for processed corn commodities.  For
soybeans, residues did not concentrate in meal or refined oil;
therefore, separate tolerances are not required for these processed
fractions.  However, residues did concentrate in hulls.  Based on the
highest average field trial (HAFT) residues for soybeans (0.01 ppm) and
the processing factor for hulls (3.5x), the maximum expected residues in
hulls are 0.035 ppm.  A separate tolerance should be established for
soybean hulls at 0.04 ppm.  Rimsulfuron residues were shown to
concentrate in AGF from both corn grain (102x) and soybean seeds (454x).
 Based on the HAFT residues of field corn grain (0.01 ppm) and soybean
seeds (0.01 ppm), the maximum expected residues in AGF would be 1.0 ppm
for corn grain and 4.5 ppm for soybean seeds.  As residues in soybean
AGF are higher than for corn grain, the tolerance for AGF should be set
at 4.5 ppm based on the soybean residue data.  

Based on the metabolism studies, the recommended tolerances for corn and
soybean commodities, the established tolerances on other livestock
feedstuffs, and the calculated dietary burdens, ARIA concludes that
tolerances for livestock commodities are not needed to support the newly
requested uses on field corn and soybean.

Adequate confined rotational crop data are available to support minimum
plant-back intervals up to 18 months, depending on the end-use product. 
As the label for rimsulfuron currently specifies minimum plantback
intervals compatible with these plantback intervals, data requirements
for rotational crops are fulfilled and tolerances are not required for
rotational crops.  

Background

Rimsulfuron is a sulfonylurea herbicide (Group 2) that works via
inhibition of acetolactate synthase (ALS).  It is currently registered
to E. I. du Pont de Nemours and Co. (DuPont) for use on potatoes, field
corn, tomatoes, grapes, various tree fruits, and tree nuts for pre and
post-emergence control of annual grasses, broadleaf weeds, and yellow
nutsedge.  Permanent tolerances are established for residues of
rimsulfuron at levels ranging from 0.01 ppm in/on various tree fruits,
tree nuts and grapes to 0.1 ppm in/on potatoes and field corn
commodities [40 CFR §180.478(a)].  The chemical structure and
nomenclature of rimsulfuron are presented in Table 1.  The
physicochemical properties of the technical grade of rimsulfuron are
presented in Table 2.

™ SG Herbicide; EPA Reg. No. 352-748)



Table 2.  Physicochemical Properties of Technical Grade Rimsulfuron.

Parameter	Value	Reference

Melting point	172-173(C	Reviewed in DP# 193018, M. Nelson, 23/NOV/1993; 

Also, MRID No. 4752805.

All product chemistry requirements reported to be fulfilled.

pH	4.32 to 5.89 (1% dilution in water)

	Density	1.5032 ± 0.0016 g/cm3

	Water solubility	pH 5:  0.135 ± 0.005 g/L (25°C)

pH 7:  7.3 ± 0.03 g/L (25(C)

pH 9:  5.56 ± 0.05 g/L (25(C)

pH 4-4.5:  0.024 ± 0.001 g/L (20(C)

	Solvent solubility (25°C)	N,N-dimethylformamide	241 ± 1 g/L

Dimethyl sulfoxide		113 ± 3 g/L

Methylene chloride		35.5 ± 0.4 g/L

Acetonitrile		17.2 ± 0.5 g/L

Acetone		14.8 ± 0.5 g/L

Ethyl acetate		2.85 ± 0.17 g/L

Methanol		1.55 ± 0.11 g/L

Toluene		0.363 ± 0.022 g/L

Xylene		0.093 ± 0.008 g/L

n-Hexane		<0.01 g/L

	Vapor pressure (25°C)	 <10-5 Pa

	Dissociation constant, pKa	4

	Octanol/water partition coefficient, Log(KOW)	pH 5:  1.94

pH 7:  0.0342

at 230 nm, ε = 1.78 x 104 (log ε = 4.25) and at 290 mm, ε = 1.81x 102
(log ε = 2.26)

pH 2.10 at 290 nm, ε = 2.03 x102 (log ε = 2.31)

pH 5.03 at 240 nm, ε = 2.24 x 104 (log ε = 4.35) and at 290 nm, ε =
4.81 x 102 (log ε = 2.68)

	

IV.	RESULTS/DISCUSSION

860.1200 Directions for Use

DuPont has submitted a proposed label for a 25% WDG formulation,
DuPont™ Resolve ® SG Herbicide (EPA No. 352-748), proposed for use on
DuPont™ Optimum® GAT® herbicide tolerance corn and soybeans.  A
summary of the proposed use directions is presented in Table 3.  

Table 3.  Summary of Directions for Use of Rimsulfuron.

Applic. Timing	Form.

	Applic. Rate 

lb ai/A	Max. No. Applic. per Season	RTI1

(days)	Max. Seasonal Applic. Rate 

lb ai/A	PHI

(days)	Use Directions and Limitations

Soybean

Preplant burndown, preemergence, postemergence and/or post harvest	25%
WDG	0.06	1	--	0.06	14 – forage and hay	Apply using a crop oil
concentrate at 1.0 % v/v, or a nonionic surfactant at 0.25% v/v

Field Corn

Preplant burndown, preemergence, postemergence and/or post harvest	25%
WDG	0.06	2	--	0.06	7	Apply using a crop oil concentrate at 1.0 % v/v, or
a nonionic surfactant at 0.25% v/v

1  RTI = Retreatment interval

Conclusions.  The label directions are adequate to allow evaluation of
the residue data relative to the labeled uses.  The available field corn
and soybean data support the proposed 7-day PHI for all corn commodities
and the proposed 14-day PHI for soybean forage and hay.  A separate PHI
is not required for soybean seeds, as the application must be made on or
before flowering (stage R2).

860.1300 Nature of the Residue - Plants and Livestock

  SEQ CHAPTER \h \r 1 MARC Decision Memo, 11/FEB/1998, L. Cheng, G.J.
Herndon; and DP# 200158, M.J. Nelson, 29/MAR/1994

MARC Briefing Memo, 04/FB/1998, L. Cheng; and DP# 200157, M.J. Nelson,
17/MAR/1994

The nature of the residue in plant and livestock commodities is
adequately understood based on metabolism studies conducted with
rimsulfuron, labeled in the pyridine or pyrimidine ring, in field corn,
potatoes, tomatoes, lactating goat, and laying hen. 

The metabolic pathways were found to be similar in plants and livestock.
 The major metabolic route of rimsulfuron metabolism/degradation
involves sulfonylurea bridge contraction, with sulfonylurea bridge
cleavage as a minor metabolic route.  The metabolites detected were
IN-70941, IN-70942, IN-E9260, IN-J290, IN-69190 (goat), IN-H1043 (goat),
IN-T5831 (potato), IN-JF999 (hen, tomato), and unresolved polar/nonpolar
products.  Based on the results of the studies, HED has concluded that
the residue of concern in plant and livestock commodities is
rimsulfuron.  

860.1340 Residue Analytical Methods

Enforcement methods:  Currently, an HPLC/UV method exists for the
enforcement of tolerances for residues of rimsulfuron in/on corn,
potato, and tomato commodities.  The method, AMR-1241-88, involves
extraction of samples with pH 7 potassium phosphate buffer and methanol
(75:25, v:v).  The extract is acidified to pH 2.5-3.5 (using
concentrated phosphoric acid) and filtered for analysis by HPLC/UV with
column switching, using a phenyl column for clean-up chromatography
followed by an Rx column for analytical chromatography.  The LOQ is 0.05
ppm.

Data-Collection methods:  Samples were analyzed for all sulfonylurea
residues (chlorimuron-ethyl, rimsulfuron and tribenuron-methyl) using an
LC/MS/MS method, DuPont-13412 RV1, “Analytical Method for the
Determination of Nicosulfuron, Thifensulfuron Methyl, Ethametsulfuron
Methyl, Rimsulfuron, Tribenuron Methyl, and Chlorimuron Ethyl in Oil
Crop Matrices Using SPE Purification and LC/MS/MS Detection.”

Conclusions.  The submitted LS/MS/MS method (Method 13412, Revision 1)
is adequate for enforcing tolerances.  No new DER was written for the
submitted method (MRID 47562001), as it has been previously reviewed in
conjunction with a petition for thifensulfuron-methyl (DP# 330813, S.
Hummel, 08/AUG/2006).  The current submission incorporates the ILV
comments as previously requested by HED.  The method does not require a
PMV trial, and can be forwarded to FDA.

860.1360 Multiresidue Methods

DP#s 184551 etc., M. Nelson, 25/FEB/1994

Rimsulfuron is not recovered by FDA Multiresidue Methods.  The
multiresidue method test results have been forwarded to FDA.

860.1380 Storage Stability

DP#s 184551, M. Nelson, 25/FEB/1994

DP#s 212624, M. Nelson, 05/APR/1995

Adequate storage stability data were submitted previously for
rimsulfuron   SEQ CHAPTER \h \r 1 in/on field corn grain and forage
(PP#1F4005; DP# 184551, 25/FEB/1994, M.J. Nelson) and field corn meal,
field corn refined oil, potato chips, and potato granules (DP#s 212624,
05/APR/1995, M.J. Nelson).  The data indicate that residues of
rimsulfuron are stable for up to 24 months in/on field corn grain and
forage stored at -20(C and for up to 6 months in field corn meal and oil
and potato chips and granules stored at -20(C. 

A storage stability study was conducted concurrently with the field corn
study.  Control samples of homogenized field corn stover were fortified
with rimsulfuron at 0.1 ppm.  The fortified samples were stored under
the same conditions (-20ºC) as the field trial samples.  Samples were
analyzed immediately after fortification, and after 1, 3, 6, 10 and 12
months of storage.  There was no decline in residue during frozen
storage; therefore, rimsulfuron is considered to be stable in field corn
stover for up to 12 months. 

The storage intervals and conditions of samples from the crop field
trial and processing studies submitted to support this petition are
presented in Table 4.  

Table 4.  Summary of Storage Conditions and Intervals of Samples from
Crop Field Trial and Processing Studies.  

Matrix 	Storage Temperature (°C)	Actual Storage Duration (months)
Interval of Demonstrated Storage Stability (months)

Corn Forage	-16	10.9	12

Corn Stover

10.5-12.2

	Corn Grain

11.3

	Soybean Forage	-20	8.3	24

Soybean Hay

9.2	10

Soybean Seed

6.9	24

Corn Grain	-16	6.7	24

Corn grain AGF and processed fractions

<1	NA

Soybean seed	-16	2	24

Soybean AGF and processed fractions

<1	NA

AGF = Aspirated Grain Fraction

NA = Not Applicable.

Conclusions. The submitted concurrent storage stability study is
adequate and indicates that residues of rimsulfuron are stable in
homogenized field corn commodities for up to 12 months.  This and
existing storage stability data adequately support the intervals
incurred in the field trials and processing studies.  

Samples of field corn and soybean processed commodities were stored
frozen from collection to analysis and were analyzed within 30 days of
collection.  Therefore, supporting storage stability data are not
required for these commodities.

860.1400 Water, Fish, and Irrigated Crops

There are no proposed or registered uses that are relevant to this
guideline topic.

860.1460 Food Handling

There are no proposed or registered uses that are relevant to this
guideline topic.

860.1480 Meat, Milk, Poultry, and Eggs

Based on the recommended tolerances for corn and soybean commodities and
the established tolerances on other livestock feedstuffs, the dietary
exposures of livestock to rimsulfuron residues were calculated using the
most recent guidance from HED (June 2008) concerning revisions of
feedstuffs in Table 1 (OPPTS 860.1000) and constructing reasonably
balanced dietary burdens (RBD) for livestock.  The calculated RBDs are
0.80 ppm for beef cattle, 0.87 for dairy cattle, 0.088 ppm for poultry
and 0.099 ppm for swine (Table 5).  

In the available goat metabolism study, total radioactive residues (TRR)
were <0.06 ppm in milk and tissues, 0.13 ppm in kidney, and 0.14 ppm in
liver following 3 consecutive days of dosing at a rate equivalent to
10-12 ppm in feed (11-14x the RBD).  However, rimsulfuron was not
detected in these tissues due to extensive metabolism and excretion. 
Based on the data from the goat metabolism study, ARIA concludes that a
cattle feeding study is not required for the current petitions [40 CFR
180.6(a)(3)].

≤0.01 ppm in eggs, fat and skin, <0.01-0.02 ppm in muscle, 0.10-0.16
ppm in liver following 5 consecutive days of dosing with 14C-rimsulfuron
at rates equivalent to 9.6-12 ppm in feed (109-136x the RBD).  Parent
rimsulfuron was detected only in liver at 0.02-0.03 ppm.  Based on the
data from the hen metabolism study, ARIA concludes that residues of
rimsulfuron are unlikely to be quantifiable in poultry commodities at a
10x feeding level.  Therefore, a poultry feeding study is not required
for the current petitions [40 CFR 180.6(a)(3)].

Table 5.  Calculation of Dietary Burdens of Rimsulfuron Residues to
Livestock.

Feedstuff	Type1	% Dry Matter2	% Diet2	Recommended Tolerance (ppm)
Dietary Contribution (ppm)3

Beef Cattle

Field corn, stover	R	83	15	2.5	0.452

Field corn, grain	CC	88	75	0.1	0.085

Grain, aspirated fractions	CC	85	5	4.5	0.265

Soybean, seed	PC	89	5	0.01	0.001

TOTAL BURDEN	--	--	100	--	0.803

Dairy Cattle

Field corn, stover	R	83	15	2.5	0.452

Field corn, forage	R	40	10	0.4	0.100

Soybean, hay	R	89	20	1.2	0.270

Field corn, grain	CC	88	45	0.1	0.051

Soybean seed	PC	89	10	0.01	0.001

TOTAL BURDEN	--	--	100	--	0.874

Poultry

Field corn, grain	CC	88	75	0.1	0.085

Soybean, seed	PC	89	20	0.01	0.002

Soybean meal	PC	92	5	0.01	0.001

TOTAL BURDEN	--	--	100	--	0.088

Swine

Field corn, grain	CC	88	85	0.1	0.097

Soybean, seed	PC	89	15	0.01	0.002

TOTAL BURDEN	--	--	100	--	0.099

1  R:  Roughage; CC:  Carbohydrate concentrate; PC:  Protein
concentrate.

2  OPPTS 860.1000 Table 1 Feedstuffs (June 2008).  

3  Contribution = ([tolerance /% DM] X % diet) for beef and dairy
cattle; contribution = ([tolerance] X % diet) for poultry and swine.

Conclusions.  Based on the metabolism studies and the dietary burden,
ARIA concludes that tolerances for livestock commodities are not needed
to support the newly requested uses on field corn and soybean.

860.1500 Crop Field Trials

47548201.de2.doc (Field corn), D. Rate, 21/JUL/2009

47548202.de2.doc (Soybeans), D. Rate, 21/JUL/2009

DuPont submitted field trial data supporting the use of rimsulfuron (25%
WDG) on genetically modified corn and soybeans as a single or split
postemergence application totaling 0.06 lb ai/A.    SEQ CHAPTER \h \r 1
The results from these field trials are discussed below, and the residue
data are summarized in Table 6.

Table 6.  Summary of Residue Data from Field Corn and Soybean Field
Trials with Rimsulfuron (WDG).

Commodity	Trt# 1	Total Applic. Rate

(lb ai/A)	PHI (days)	Residue Levels (ppm) 1





n	Min.	Max.	HAFT 2	Median	Mean	Std. Dev.

Field Corn (proposed use = 0.06 lb ai/A total application rate, 7 day
PHI)

Forage	1	0.06-0.07	6-8	46	<0.01	0.52	0.38	0.03	0.07	0.09

Stover

	23-63	46	<0.01	0.14	0.13	0.01	0.02	0.03

Grain

	26-63	46	<0.01	<0.01	<0.01	<0.01	<0.01	NA

Forage	2	0.06	6-8	46	<0.01	0.16	0.16	0.02	0.03	0.0381

Stover	3	0.06-0.07	5-22	46	<0.01	2.4	2.0	0.31	0.51	0.57

Grain

	5-12	46	<0.01	<0.01	<0.01	<0.01	<0.01	NA

Grain	5	0.06	5-12	46	<0.01	<0.01	<0.01	<0.01	<0.01	NA

Forage	6	0.06-0.07	23-71	46	<0.01	<0.01	<0.01	<0.01	<0.01	NA

Stover

	50-106	46	<0.01	0.03	0.03	0.01	0.01	0.01

Grain

	55-106	46	<0.01	<0.01	<0.01	<0.01	<0.01	NA

Soybean (proposed use = 0.06 lb ai/A total application rate, 14 day PHI
for forage and hay)

Forage 4	1	0.06	0	38	0.99	8.60	8.45	3.70	3.82	1.56



	7	6	0.032	0.33	0.31	0.048	0.13	0.14



	14 5	38	0.02	0.21	0.21	0.09	0.09	0.04



	21	6	<0.003	0.032	0.0175	0.009	0.012	0.012

Hay 4



	0	38	1.90	36.00	35.00	11.00	12.39	8.38



	7	6	0.051	0.56	0.50	0.094	0.216	0.22



	14 5	38	0.06	1.09	1.06	0.33	0.37	0.25



	21	6	<0.003	0.055	0.042	0.016	0.021	0.022

Seed

	68-107	44	<0.01	<0.01	<0.01	0.01	0.01	NA

Seed	4	0.06	5-8	44	<0.01	0.17	0.16	0.01	0.02	0.03

Seed	5	0.06	5-8	44	<0.01	0.04	0.03	0.01	0.01	0.01

1	Trts #2 and #5 for field corn were split applications and Trt #5 for
soybeans was a split application.

2	The LOQ is 0.01 ppm for each commodity.  For all calculations, the
method LOQ (0.01 ppm) was used for residue values <LOQ.

3	HAFT = Highest Average Field Trial.

4	Residue data for soybean forage and hay from Trials 5, 6, 20 and 21
were not included in the dataset as samples from these tests were
collected either prior to application or at 7 DAT, rather than at the
targeted 0 DAT.

5	The 14-day residue data for soybean forage and hay were calculated
using the 0-day data and data from the residue decline tests.

NA = not applicable

  

Corn.  A total of 24 field corn trials, including five different
treatment regimes, were conducted in NAFTA Zones 1, 2, 5, 5B and 6
during 2006.  In each trial, rimsulfuron (25% WDG) was applied to field
corn as a single broadcast foliar application at 0.02-0.07 lb ai/A at
either approximately 7 days prior to normal forage harvest (Trt #1), 7
days prior to grain harvest (Trt #3), or at growth stage R1-R2 (Trt #6).
 In two additional plots, rimsulfuron (25% WDG) was applied as two
broadcast foliar applications (split application) at 0.01-0.03 lb
ai/A/application for a total of 0.02-0.07 lb ai/A.  The first
application was made at stage R1-R2 and the second application was made
at 7 days prior to forage harvest (Trt #2) or 7 days prior to grain
harvest (Trt# 5).  The retreatment intervals (RTIs) were 16-65 days for
Trt#2 and 26-100 days for Trt#5.  All applications were made using
ground equipment at volumes of 5-30 gal/A, and included the use of a
non-ionic surfactant at 0.25% v/v.

Single control and duplicate treated samples of the appropriate
commodities were harvested from each test at the appropriate stage of
maturity.  For Trt #1, forage was harvested at 6-8 days after treatment
(DAT), stover was harvested at 23-63 DAT and grain was harvested at
26-63 DAT.  For Trt #6, forage was harvested at 23-71 DAT, stover was
harvested at 50-106 DAT and grain was harvested at 55-106 DAT.  For Trt
#3, only samples of stover and grain were harvested at 5-22 and 5-12
DAT, respectively.  For Trt #2, only forage was harvested at 6-8 DAT,
and for Trt #5, only grain was harvested at 5-12 DAT.  Duplicate
repeated samples of forage and/or stover were also collected from Trts
#1, #3 and #6 from five field trials.  For Trt #1, forage samples were
collected repeatedly from 0-22 DAT and stover samples were collected
repeatedly from 23-84 DAT.  For Trt #3, stover samples were collected
repeatedly from 6-28 DAT.  For Trt #6, forage samples were collected
repeatedly from 0-68 DAT.

Samples were stored frozen for up to 12.2 months prior to analysis. 
Adequate storage stability data are available indicating that
rimsulfuron is stable at -20°C for up to 24 months in corn grain and
forage and 12 months in corn stover.  These data support the durations
and conditions of sample storage from the corn field trials.

Residues of rimsulfuron in/on corn grain, forage and stover were
determined using an adequate LC/MS/MS method (Method 13412, Revision No.
1).  The method LOQ is 0.01 ppm and the limit of detection (LOD) is
0.003 ppm for each corn commodity.

Following a single broadcast foliar application at 0.06-0.07 lb ai/A (1x
rate) applied ~7 days prior to normal forage harvest (Trt #1),
rimsulfuron residues were <0.01-0.52 ppm in/on 46 samples of forage
harvested at 6-8 DAT, <0.01-0.14 ppm in/on 46 samples of stover
harvested at 23-63 DAT and <LOD in/on all 46 samples of grain harvested
at 26-63 DAT.  Average residues were 0.07 ppm for forage, 0.02 ppm for
stover, and <0.01 ppm for grain, and HAFT residues were 0.38 ppm for
forage, 0.13 ppm for stover, and <0.01 ppm for grain.

≤0.01 ppm for forage, stover, and grain, and the HAFT residues were
<0.01 ppm for forage and grain and 0.03 ppm for stover. 

When the single foliar application was applied at a 1x rate ~7 days
prior to normal grain maturity (Trt #3), residues were <0.01 ppm in/on
all samples of grain harvested at 5-12 DAT, with only 5 samples having
residues above the LOD (0.003-0.006 ppm).  Residues were <0.01-2.4 ppm
in/on 46 samples of stover harvested at 5-22 DAT.  Average residues were
<0.01 ppm for grain and 0.51 ppm for stover, and the HAFT residues were
<0.01 ppm for grain and 2.0 ppm for stover. 

For the split applications, residues in/on forage and grain were lower
than for the single application.  Residues were <0.01-0.16 ppm in/on 46
samples of forage harvested at 6-8 DAT (Trt #2) and ≤0.003 ppm in/on
46 samples of grain harvested at 5-12 DAT (Trt #5).  Average residues
for the split application were 0.03 ppm for forage and <0.01 ppm for
grain, and HAFT residues were 0.16 ppm for forage and <0.01 ppm for
grain. 

In the five residue decline trials, rimsulfuron residues in/on forage
(Trt #1 and #6) showed a rapid decline within the first 7 days after
treatment and then declined more slowly until residues were essentially
≤0.01 ppm by 21 DAT.  Changes in residue levels in/on stover (Trt #1
and #3) were more sporadic than for forage, but residues in/on stover
generally declined or remained steady at longer post-treatment
intervals.

Soybean.  A total of 23 soybean field trials, each including three
different treatment regimes, were conducted in NAFTA Zones 2, 4 and 5
during 2006.  In each trial, rimsulfuron (25% WDG) was applied to
soybeans as a single broadcast foliar application at 0.06 lb ai/A (1x
rate) at growth stage R1-R2 (Trt #1) or approximately 7 days prior to
normal seed harvest (Trt #4).  In a third plot, rimsulfuron (25% WDG)
was applied as two broadcast foliar applications (split application) at
0.03 lb ai/A/application and RTIs of 6-10 days, for a total of 0.06 lb
ai/A (1x rate).  The split applications were made at approximately 14
and 7 days prior to normal seed harvest (Trt #5).  All applications were
made using ground equipment at volumes of 5-27 gal/A, and included the
use of a non-ionic surfactant at 0.25% v/v.

For Trt #1, single control and duplicate treated samples of forage and
hay were harvested on the day of application (0 DAT), and seeds were
harvested at normal maturity (68-107 DAT).  Repeated samples of forage
and hay were also collected from three trials at 0, 1, 3, 7, 14 and 21
DAT to evaluate residue decline.  For Trts #4 and #5, single control and
duplicate treated samples of seeds were harvested at 5-8 DAT.  Samples
were stored frozen for up to 9.2 months prior to analysis, and adequate
storage stability data are available indicating that rimsulfuron is
stable at -20°C for up to 24 months in corn grain and forage and 12
months in corn stover.  These data support the durations and conditions
of sample storage from the soybean field trials.

Residues of rimsulfuron in/on soybean seed, forage and hay were
determined using an adequate LC/MS/MS method (Method 13412, Revision No.
1).  The method LOQ is 0.01 ppm and the LOD is 0.003 ppm for each
soybean commodity.

Following a single broadcast foliar application at 0.06 lb ai/A (1x
rate) at growth stage R1-R2 (Trt #1), rimsulfuron residues were
0.99-8.60 ppm in/on 38 samples of forage and 1.90-36.0 ppm in/on 38
samples of hay harvested at 0 DAT, and residues were <0.01 ppm in/on all
44 samples of seed harvested at 68-107 DAT.  Average residues were 3.82
ppm for forage, 12.4 ppm for hay, and 0.01 ppm for seeds.  The HAFT
residues were 8.45 ppm for forage, 35.0 ppm for hay, and <0.01 ppm for
seeds.  [Note: although residue data were submitted from 23 tests (46
samples), residue data for forage and hay from 4 tests were excluded
from the dataset because of anomalies in the sampling intervals]  

When the single foliar application was made at 0.06 lb ai/A (1x rate)
approximately 7 days before normal crop maturity (Trt #4), residues were
<0.01-0.17 ppm in/on 44 samples of seeds harvested at 5-8 DAT.  Average
residues in/on seeds were 0.02 ppm, and the HAFT residues were 0.16 ppm.
 For the split application (Trt #5), residues in/on seeds were lower
than for the single application.  For Trt #5, residues were <0.01-0.04
ppm in/on 44 samples of seeds harvested at 5-8 DAT.  Average residues
in/on seeds were 0.01 ppm, and HAFT residues were 0.03 ppm. 

In both forage and hay, rimsulfuron residues declined rapidly within the
first week after application and then declined more slowly thereafter. 
For all three decline tests, residues in/on forage ranged from 0.99 ppm
to 8.6 ppm (average 3.7 ppm) at 0 DAT, 0.032 ppm to 0.33 ppm (average
0.13 ppm) at 7 DAT, and <LOD to 0.032 ppm (average 0.012 ppm) at 21 DAT.
 Residues ranged in/on hay from 1.9 ppm to 36 ppm (average 12.8 ppm) at
0 DAT, 0.051 ppm to 0.56 ppm (average 0.21 ppm) at 7 DAT, and <LOD to
0.055 ppm (average 0.024 ppm) at 21 DAT. 

The use pattern being supported on soybeans by DuPont is Trt #1;
however, the petitioner is requesting a 14-day PHI for forage and hay
rather than a 0-day PHI, which is supported by the available residue
data.  Based on the data from the residue decline studies, DuPont used
the rate constant from the decline curve with the longest rate of
decline to extrapolate possible residue values for soybean forage and
hay at the proposed 14-day PHI.  The following formula was used to
calculate 14-day residue values for forage and hay:

	ln(residues at 14 days) = m(14) + ln(residues at 0 DAT) 

Based on the residue decline data, the rate of decline (m) was
calculated to be -0.265 ppm/day for soybean forage and -0.250 ppm/day
for soybean hay.  The extrapolated 14-day residue values for forage and
hay are presented in Appendix I and summarized in Table 6.  ChemSAC met
on 24/JUN/2009 to discuss the use of decline data for tolerance setting
purposes.   The ChemSAC determined that in this case the use of decline
data is acceptable since this is for an animal feed item and not a human
food item, and the data extrapolation made use of the decline study
which gave the most conservative residue number.  Placing the residue
data as calculated using the above formula into the MRL spreadsheet
indicates the requested tolerances are appropriate.  Therefore, ARIA
recommends for the proposed rimsulfuron tolerances of 0.25 ppm in/on
soybean forage and 1.2 ppm in/on soybean hay.  

Conclusions.  The available corn and soybean field trial data are
acceptable and support the proposed use patterns for rimsulfuron (WDG)
on genetically modified field corn and soybeans.  An adequate number of
tests were conducted on each crop in the appropriate geographical
regions.  All samples were analyzed for the residue of concern using an
adequate method, and sample storage conditions and intervals were
supported by the available storage stability data.

The field trial data support the proposed 7-day PHI for corn commodities
and the proposed 14-day PHI for soybean forage or hay.  As the use on
soybeans prohibits applications after the R2 stage, a specific PHI for
soybean seeds is not required.  The data support tolerances of 0.4 ppm
in/on corn forage, 2.5 ppm in/on corn stover, 0.25 ppm in/on soybean
forage, 1.2 ppm in/on soybean hay, and 0.01 ppm in/on soybean seeds. 
Although the residue data support a 0.01 ppm tolerance for field corn
grain, there is an existing 0.1 ppm tolerance for rimsulfuron on field
corn grain that harmonizes with the current Mexican MRL for corn (0.1
mg/kg).  The existing tolerance on corn grain will cover the proposed
use of rimsulfuron on corn.  A revised Section F should be submitted to
reconcile the requested tolerance in/on corn, field, grain with the
recommended/existing tolerance of 0.1 ppm.  

860.1520 Processed Food and Feed

47548203.de2.doc (corn), D. Rate, 21/JUL/2009

47548204.de2.doc (soybean), D. Rate, 21/JUL/2009

Corn.  Four field trials were conducted in IA, IL and NE during 2006 to
generate field corn grain for use in processing (2 tests) or for
generating AGF (2 tests).  In the two tests used to generate AGF
samples, rimsulfuron (25% WDG) was applied either as a single broadcast
foliar application ~7 days prior to normal grain maturity at a rate of
0.063 lb ai/A (1x rate) or as a split application at 0.031 lb
ai/A/application, at growth stage R1-R2 and again at 7 days prior to
harvest, for a total application rate of 0.063 lb ai/A (1x rate).  In
the two tests used to generate grain for processing, rimsulfuron was
applied as a single broadcast foliar application 7 days prior to normal
harvest at 0.31 lb ai/A (5x rate).  All applications were made using
ground equipment at volumes of 16-20 gal/A, and included the use of a
non-ionic surfactant at 0.25% v/v.  

stored frozen for ≤30 days prior to analysis.  These sample storage
conditions and durations are supported by the available storage
stability data.

 

Residues of rimsulfuron in/on corn grain, AGF and processed fractions
were determined using an adequate LC/MS/MS method (Method 13412,
Revision No. 1).  The method LOQ is 0.01 ppm and the LOD is 0.003 ppm
for each corn commodity.

In the AGF tests, rimsulfuron residues were ND in/on grain harvested at
5 days following the split foliar application at a 1x rate and were
0.004-0.006 ppm in/on grain harvested at 7 days following a single
broadcast application at a 1x rate (Table 7).  Residues in/on AGF
samples were 0.035 ppm for the spilt application and 0.51 ppm for single
application, indicating that rimsulfuron residues concentrate in corn
AGF.  However, an accurate processing factor could only be determined
for the single application, as residues in/on grain were ND for the
split application.  The processing factor of corn AGF was 102x.

were ≤LOD in one of the trials; therefore, processing factors could
not be determined for this trial.  For the other trial, residues
averaged 0.024 ppm in/on grain, 0.028 ppm in flour, 0.007 ppm in grits,
0.023 ppm in meal, and <LOD (<0.003 ppm) in starch and oil.  As a
result, rimsulfuron residues concentrated only slightly (1.15x) in
flour, and were reduced in grits (0.3x), meal (0.9x), starch (<0.2x) and
oil (<0.2x).

Soybean.  Three soybean field trials were conducted in IL, MN and NE
during 2006 to generate soybean seed samples for processing (2 tests)
and for generating AGF (2 tests).  In the tests used to generate AGF
samples, rimsulfuron (25% WDG) was applied as either a single broadcast
foliar application 7 days prior to harvest at a rate of 0.06 lb ai/A (1x
rate), or as a split application at 0.03 lb ai/A/application at 14 and 7
days before harvest, for a total of 0.06 lb ai/A (1x rate).  In the two
tests used to generate seeds for processing, rimsulfuron (25% WDG) was
applied as a single broadcast foliar application 7 days prior to harvest
at a rate of 0.31 lb ai/A (5x rate).  All applications were made using
ground equipment at volumes of 15-25 gal/A, and included the use of a
non-ionic surfactant at 0.25% v/v.  

≤-12°C for up to 2 months prior to analysis, and samples of each
processed fraction and the AGF were stored frozen for ≤30 days prior
to analysis.  These sample storage conditions and durations are
supported by the available storage stability data.

 

Residues of rimsulfuron in/on soybean seeds, AGF and processed fractions
were determined using an adequate LC/MS/MS method (Method 13412,
Revision No. 1).  The method LOQ is 0.01 ppm and the LOD is 0.003 ppm
for each soybean commodity.

In the 1x rate test using the single broadcast application, rimsulfuron
residues averaged 0.005 ppm in/on the seeds and 2.25 ppm in AGF, for a
concentration factor of 450x.  In the 1x rate test using the split
foliar application, rimsulfuron residues averaged 0.0035 ppm in/on the
seeds and 1.6 ppm in AGF, for a concentration factor of 457x.  The
average concentration factor for rimsulfuron in soybean AGF was
therefore 454x.

In the 5x tests, rimsulfuron residues in/on whole seeds were <LOD in one
test and 0.11 ppm in the other test.  For the test with quantifiable
residues in/on seeds, residues averaged 0.018 ppm in meal, 0.39 ppm in
hulls, and <0.003 ppm in refined oil.  Rimsulfuron residues concentrated
in hulls and were reduced in meal and refined oil.  Processing factors
were 3.5x for hulls, 0.16x for meal, and <0.03x for refined oil.

  SEQ CHAPTER \h \r 1 Table 7.  Summary of Processing Factors for
Rimsulfuron.

RAC	Processed Commodity	Processing Factor

Corn Grain	AGF	102x

	Grits	0.3x

	Meal	0.9x

	Flour	1.15x

	Starch	<0.2x

	Refined oil	<0.2x

Soybean Seed	AGF	457x

	Meal	0.2x

	Hulls	3.5x

	Refined oil	<0.03x



Conclusions.  The available corn and soybean processing data for
rimsulfuron are adequate.  As residues did not concentrate in corn
grits, meal, starch or refined oil and concentrated only slightly in
corn flour, separate tolerances are not required for processed corn
commodities.  

For soybeans, residues did not concentrate in meal or refined oil;
therefore separate tolerances are not required for these processed
fractions.  However, residues did concentrate in hulls.  Based on the
HAFT residues for soybeans (0.01 ppm) and the processing factor for
hulls (3.5x), the maximum expected residues in hulls are 0.035 ppm.  A
separate tolerance should be established for soybean hulls at 0.04 ppm.

 

Rimsulfuron residues were shown to concentrate in AGF from both corn
grain (102x) and soybean seeds (454x).  Based on the HAFT residues of
field corn grain (0.01 ppm) and soybean seeds (0.01 ppm), the maximum
expected residues in AGF would be 1.0 ppm for corn grain and 4.5 ppm for
soybean seeds.  As residues in soybean AGF are higher than for corn
grain, the tolerance for AGF should be set at 4.5 ppm based on the
soybean residue data.  A revised Section F should be submitted to remove
the request for corn, aspirated grain fractions and soybean, aspirated
grain fractions and replaced with a request for grain, aspirated
fractions at 4.5 ppm.  Also the proposed tolerance for soybean, hulls
should be adjusted from 0.035 ppm to 0.04 ppm in the revised Section F.

  SEQ CHAPTER \h \r 1 860.1650 Submittal of Analytical Reference
Standards

An analytical reference standard for rimsulfuron (expires 04/APR/2011)
is currently available at the EPA National Pesticide Standards
Repository (personal communication with Theresa Cole, ACB, 06/JUL/2009).

860.1850/860.1900 Confined and Field Accumulation in Rotational Crops

DP# 206712, M. Nelson, 24/AUG/1994

Adequate confined rotational crop data are available to support minimum
plant-back intervals up to 18 months, depending on the end-use product. 
As the label for rimsulfuron currently specifies minimum plantback
intervals compatible with these plantback intervals, data requirements
for rotational crops are fulfilled and tolerances are not required for
rotational crops.  

860.1550 Proposed Tolerances

Tolerances for residues of rimsulfuron are currently expressed in terms
of rimsulfuron.  Permanent tolerances are established for residues of
rimsulfuron at 0.01 ppm in/on grapes, pome fruits, stone fruits, citrus
fruits, tree nuts and pistachios, 0.05 ppm in/on tomatoes, 0.09 ppm
in/on almond hulls, and 0.1 ppm in/on potatoes and field corn grain,
forage and stover [40 CFR §180.478(a)].  No tolerances are established
for residues in either animal commodities or rotational crops.  The
proposed and recommended tolerances are presented in Table 8.

As residues were <LOQ in/on all samples of corn grain collected at the
appropriate PHI, the existing 0.1 ppm tolerance for corn grain will
cover the proposed use on field corn.  For field corn forage and stover
and soybean forage and hay, tolerances were calculated using the
tolerance harmonization spreadsheet (Appendix I).  The residue data
supporting the 7-day PHI were used to calculate tolerances for field
corn forage and stover.  For soybean forage and hay, the 0-day residue
data were extrapolated to a 14 day PHI based on the observed residue
decline data.  The calculated 14-day residues were then used to
determine the appropriate soybean tolerances.  The recommended
tolerances for soybean seed was set at the method LOQ (0.01 ppm) as
residues were <LOQ in/on all samples of soybean seed harvested at the
appropriate PHI. 

  

As residues did not concentrate in corn grits, meal, starch or refined
oil and concentrated only slightly in corn flour, separate tolerances
are not required for processed corn commodities.  Also, separate
tolerances are not required for soybean meal and oil as residues did not
concentrate in these processed fractions.  However, residues did
concentrate in soybean hulls.  Based on the HAFT residues for soybeans
(0.01 ppm) and the processing factor for hulls (3.5x), the maximum
expected residues in hulls are 0.035 ppm.  A separate tolerance should
be established for soybean hulls at 0.04 ppm.

 

Rimsulfuron residues were shown to concentrate in AGF from both corn
grain (102x) and soybean seeds (454x).  Based on the HAFT residues of
field corn grain (0.01 ppm) and soybean seeds (0.01 ppm), the maximum
expected residues in AGF would be 1.0 ppm for corn grain and 4.5 ppm for
soybean seeds.  As residues in soybean AGF are higher than for corn
grain, the tolerance for AGF should be set at 4.5 ppm based on the
soybean residue data.

Based on the calculated dietary burdens of livestock for rimsulfuron
residues and the available data from the goat and hen metabolism
studies, finite residues of rimsulfuron are not expected to occur in
livestock commodities [40 CFR 180.6(a)(3)].  Therefore, tolerances for
livestock commodities are not required for the current petition.

 

There are no established or proposed Codex maximum residue limits (MRLs)
for residues of rimsulfuron (Appendix II).  However, there are Canadian
MRLs for rimsulfuron residues on tomatoes and blueberries and Mexican
tolerances for residues on potatoes, tomatoes and corn.  The Mexican
tolerance for corn (0.1 mg/kg) is identical to the existing U.S.
tolerance for corn grain.  

Table 8.  Tolerance Summary for Rimsulfuron.

Commodity	Proposed Tolerance (ppm)	Recommended Tolerance (ppm)	Comments;
Correct Commodity Definition

Corn, field, grain	0.01 1	0.1	Maintained at 0.1 ppm to stay harmonized
with the MRL in Mexico.

Corn, field, forage	0.4 1	0.4

	Corn, field, stover	2.5 1	2.5

	Corn, aspirated grain fractions	1.02	None

	Soybean, hay	1.2	1.2

	Soybean, forage	0.25	0.25

	Soybean, seed	0.01	0.01

	Soybean, hulls	0.035	0.04

	Soybean, aspirated grain fractions	4.51	None

	Grain, aspirated fractions	None	4.5

	1	There are existing tolerances of 0.1 ppm for rimsulfuron residues
in/on field corn grain, forage and stover.

V.	REFERENCES

  SEQ CHAPTER \h \r 1 PP#1F4005.  Rimsulfuron in/on Field Corn and
Potatoes.  Review of Crop Rotation Restrictions on Proposed Labels, DP#
206712, M. Nelson, 24/AUG/1994.

  SEQ CHAPTER \h \r 1 PP#1F4005/EPA Reg. No. 000352LLL. DPX-E9636
technical.  Review of Product Chemistry Data Submitted in Support of
Registration of New Chemical Herbicide (Rimsulfuron), DP# 193018, M.
Nelson, 23/NOV/1994.

HED Metabolism Committee Meeting of 3/23/94. Riinsulfuron (E9636;
DPX—E9636), DP# 200158, M.. Nelson, 29/MAR/1994.

PP#1F4005. RIMSULFURON (E9636; DPX—E9636). Briefing for the MED
Metabolism Committee Meeting of 3/23/94.  DP# 200157, M. Nelson,
17/MAR/1994.

PP# 1F4005. Rimsulfuron in/on Corn and Potatoes.  Petition f or First
Permanent Tolerances.  DP# 184551, M. Nelson, 25/FEB/1994.

ID# 352—555. DuPont Rimsulfuron Technical.  ID# 352—556. DuPont
Matrix® Herbicide.  ID# 352—571. DuPont Basis® Herbicide.  Letter of
2/14/95 With Storage Stability Data.  DP# 212624, M. Nelson,
05/APR/1995.

Thifensulfiiron methyl. Addition of Uses on Rice and Sorghum (PRIA R19;
352-611; PP#4F6889). Summary of Analytical Chemistry and Residue Data. 
DP# 330813, S Hummel, 08/AUG/2006.

  SEQ CHAPTER \h \r 1 Attachments:  

Appendix I - Tolerance Assessment Calculations

Appendix II-International Residue Limit Status sheet 

Appendix I - Tolerance Assessment Calculations

For each of the crops listed below, the Guidance for Setting Pesticide
Tolerances Based on Field Trial Data (SOP), along with the tolerance
spreadsheet, was used for calculating recommended tolerances.  As
specified in the SOP, the minimum of the 95% upper confidence limit
(UCL) on the 95th percentile and the point estimate of the 99th
percentile was selected as the tolerance value in cases when the dataset
was large (greater than 15 samples) and reasonably lognormal.  For
datasets that were small (≤15 samples) and reasonably lognormal, the
upper bound estimate of the 95th percentile based on the median residue
value was compared to the minimum of the 95% UCL on the 95th percentile
and the point estimate of the 99th percentile, and the minimum value was
selected as the tolerance value.  For datasets that were not lognormal,
the upper bound on the 89th percentile was selected as the tolerance
value (distribution-free method).  The rounding procedures specified in
the SOP were also used.

The Agency’s Guidance for Setting Pesticide Tolerances Based on Field
Trial Data was utilized for determining the appropriate tolerance levels
for corn forage and stover harvested at 6-8 DAT and soybean forage and
hay harvested a 0 DAT and extrapolated to 14 DAT.  However, the
tolerance spreadsheet was not used to calculate the tolerance for corn
grain or soybean seed as residues were <LOQ in all samples from these
commodities.  The maximum likelihood estimation (MLE) procedures were
needed to impute censored values for corn forage and stover because
field trial sample results were below LOQ on more than 10% of the
samples.  The datasets for corn and soybean are presented in Table I-1
and I-2.

The datasets used to assess possible tolerances for rimsulfuron residues
in/on corn forage harvested at 6-8 DAT, corn stover harvested at 5-7
DAT, and soybean forage and hay harvested at 0 DAT and extrapolated to
14 DAT consist of field trial data representing applications of the
appropriate formulation at ~1x the maximum proposed use rates.  As
specified by the Guidance for Setting Pesticide Tolerances Based on
Field Trial Data SOP, the field trial application rates were within 25%
of the maximum label application rates.  

Corn.  The censored datasets for rimsulfuron residues in/on corn forage
harvested at 6-8 DAT and corn stover harvested at 5-7 DAT were entered
into the tolerance spreadsheet.  Visual inspection of the lognormal
probability plots (Figures I-1 and I-3) indicated that the dataset for
corn forage is lognormal, but the dataset for corn stover is not
reasonably lognormal.  These assumptions were confirmed by the
approximate Shapiro-Francia test statistic (Figures I-2 and I-4).  For
the proposed 7-day PHI, the recommended tolerances for corn forage and
stover are 0.4 and 2.5 ppm, respectively.

Soybean.  The datasets for rimsulfuron residues in/on soybean forage and
hay harvested at 0 DAT and extrapolated to 14 DAT were entered into the
tolerance spreadsheet.  Visual inspection of the lognormal probability
plots (Figures I-5, I-7, I-9 and I-11) indicated that the datasets for
forage and hay at both harvest intervals are not lognormal.  The results
of the approximate Shapiro-Francia test statistic confirm these
assumptions (Figures I-6, I-8, I-10 and I-12).  

The recommended tolerances for rimsulfuron in/on soybean forage and hay
harvested at 0 DAT are 9 and 40 ppm, respectively.  If the residue data
from 0 DAT are extrapolated out to a 14 DAT, the recommended tolerances
for soybean forage and hay are 0.25 ppm and 1.2 ppm, respectively.

Table I-1.		Rimsulfuron Residues in Field Corn.

Regulator:	Rimsulfuron	Rimsulfuron

Chemical:	Corn Forage (MLE)	Corn Stover (MLE)

Crop:	6-8 days	5-7 days

PHI:	0.06 lb ai/A	0.06 lb ai/A

App. Rate:	DuPont	DuPont

Submitter:	MRID 47548201	MRID 47548201

MRID Citation:	Residues	Residues

	0.003	0.035	0.003	0.31

	0.005	0.038	0.004	0.32

	0.006	0.039	0.005	0.33

	0.007	0.040	0.006	0.34

	0.007	0.041	0.008	0.34

	0.008	0.044	0.009	0.51

	0.010	0.045	0.033	0.55

	0.012	0.047	0.036	0.61

	0.019	0.050	0.10	0.63

	0.019	0.063	0.11	0.65

	0.020	0.065	0.11	0.69

	0.021	0.066	0.11	0.77

	0.023	0.072	0.12	0.78

	0.023	0.085	0.13	0.79

	0.025	0.100	0.13	0.86

	0.026	0.100	0.14	0.90

	0.026	0.110	0.21	0.95

	0.027	0.190	0.21	1.1

	0.027	0.190	0.23	1.3

	0.027	0.220	0.24	1.4

	0.029	0.230	0.25	1.8

	0.034	0.240	0.29	2.2

	0.034	0.520	0.31	2.4

Values <LOQ (0.01 ppm) are listed in bold.



Figure I-1.	Lognormal Probability Plot for Residues of Rimsulfuron in/on
Corn Forage Harvested 6-8 DAT.

Figure I-2.	Data Summary Table for Residues of Rimsulfuron in/on Corn
Forage Harvested 6-8 DAT.

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Figure I-4.	Data Summary Table for Residues of Rimsulfuron in/on Corn
Stover Harvested 5-7 DAT.



Table I-2.		Rimsulfuron Residues in/on Soybean Forage and Hay.

Regulator:	Rimsulfuron

Chemical:	Soybean Forage	Soybean Hay

Crop:	0 days	14 days (extrapolated)	0 days	14 days (extrapolated)

PHI:	0.06 lb ai/A	0.06 lb ai/A	0.06 lb ai/A	0.06 lb ai/A

App. Rate:	DuPont	DuPont	DuPont	DuPont

Submitter:	MRID 47548202	MRID 47548202	MRID 47548202	MRID 47548202

MRID Citation:	Residues	Residues	Residues	Residues

	0.99	0.024	1.9	0.057

	1.0	0.024	2.1	0.063

	2.1	0.051	2.2	0.066

	2.2	0.054	2.2	0.066

	2.5	0.061	4.5	0.136

	2.5	0.061	4.9	0.148

	2.7	0.066	5.9	0.178

	2.7	0.066	6.0	0.181

	2.9	0.071	6.3	0.190

	3.0	0.073	6.9	0.208

	3.1	0.076	7.0	0.211

	3.1	0.076	8.3	0.251

	3.1	0.076	8.6	0.260

	3.2	0.078	9.3	0.281

	3.3	0.081	9.8	0.296

	3.3	0.081	10	0.302

	3.3	0.081	11	0.332

	3.4	0.083	11	0.332

	3.6	0.088	11	0.332

	3.8	0.093	11	0.332

	3.8	0.093	11	0.332

	4.0	0.098	12	0.362

	4.0	0.098	12	0.362

	4.1	0.100	12	0.362

	4.1	0.100	13	0.393

	4.1	0.100	13	0.393

	4.2	0.103	13	0.393

	4.2	0.103	14	0.423

	4.2	0.103	14	0.423

	4.4	0.108	15	0.453

	4.6	0.113	15	0.453

	4.6	0.113	15	0.453

	4.8	0.117	20	0.604

	4.8	0.117	23	0.695

	6.2	0.152	28	0.846

	6.2	0.152	31	0.936

	8.3	0.203	34	1.027

	8.6	0.211	36	1.087



Figure I-5.	Lognormal Probability Plot for Residues of Rimsulfuron in
Soybean Forage Harvested at 0 DAT.

Figure I-6.	Data Summary Table for Residues of Rimsulfuron in Soybean
Forage Harvested at 0 DAT.

Figure II-7.	Lognormal Probability Plot for Residues of Rimsulfuron in
Soybean Forage Extrapolated to a 14-day PHI.

Figure I-8.	Data Summary Table for Residues of Rimsulfuron in Soybean
Forage Extrapolated to a 14-day PHI.

Figure I-9.	Lognormal Probability Plot for Residues of Rimsulfuron in
Soybean Hay Harvested at 0 DAT.

Figure I-10.	Data Summary Table for Residues of Rimsulfuron in Soybean
Hay Harvested at 0 DAT.

Figure I-11.	Lognormal Probability Plot for Residues of Rimsulfuron in
Soybean Hay Extrapolated to a 14-day PHI.

Figure I-12.	Data Summary Table for Residues of Rimsulfuron in Soybean
Hay Extrapolated to a 14-day PHI.

Appendix II - International Residue Limit Status

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: N-[[(4,6-dimethoxy-2-pyrimidinyl)
amino]carbonyl]-3-(ethylsulfonyl)-2-pyridinesulfonamide	Common Name: 
Rimsulfuron	(  Proposed tolerance

 Reevaluated tolerance

 Other	Date: 07/06/2009

Codex Status (Maximum Residue Limits)	U. S. Tolerances

 √ No Codex proposal step 6 or above

 No Codex proposal step 6 or above for the crops requested	Petition
Number:  8F7430, 8F7439

DP Number:  360852

 No Limits

 √ No Limits for the crops requested	 No Limits

 No Limits for the crops requested

Residue definition: N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]
carbonyl]-3-(ethylsulfonyl)-2-pyridinesulfonamide

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Note:  Mexico adopts Codex MRLs or US tolerances.

Crop(s)	MRL (mg/kg)	Crop(s)	MRL (mg/kg)



Corn	0.1











Notes/Special Instructions:  S.Funk, 07/06/2009.



 PAGE   

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Rimsulfuron	Summary of Analytical Chemistry and Residue Data	DP#: 
D360852

 PAGE   28  of   NUMPAGES  28 

