UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

Date:		21-MAY-2008

Subject:	Spiromesifen:  Requests to Change Use Patterns for Field Corn
and Tomatoes.

PC Code:  024875	DP Barcodes:  342763 and 348427

Decision Nos.:  385369 and 387631	Registration Nos.:  264-719 and
264-850

Petition No.:  7F7274	Regulatory Action:  Section 3 Registration

Risk Assessment Type:  NA	Case No.:  NA

TXR No.:  NA	CAS No.:  283594-90-1

MRID No.:  47262401 and 47303601	40 CFR:  180.607



From:		Jennifer R. Tyler, Chemist

Registration Action Branch 1 (RAB 1)

Health Effects Division (HED) (7509P)

Through:	George F. Kramer, Ph.D., Branch Senior Chemist

RAB1/HED (7509P)

To:		Amer Al-Mudallal/John Hebert (RM Team 07)

Insecticide Branch/Registration Division (RD) (7505P)

Executive Summary

Bayer CropScience has submitted the following:

1)  A petition to increase the individual application rate of
spiromesifen
(2-oxo-3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl
3,3-dimethylbutanoate) on field corn from 0.13 pounds (lb) active
ingredient (ai)/acre (A) to 0.25 lb ai/A.  The maximum seasonal
application rate will remain the same (0.27 lb ai/A).  Subsequently, the
company has proposed an increased tolerance for residues of spiromesifen
and its enol metabolite
(4-hydroxy-3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]non-3-en-2-one),
calculated as the parent compound equivalents, in/on field corn forage
from 3.0 ppm to 6 ppm.  The company submitted revised labels for
Oberon® 2 Soluble Concentrate (SC) Insecticide/Miticide [2 lb ai/gallon
(gal); EPA Reg. No. 264-719] and Oberon® 4 SC Insecticide/Miticide (4
lb ai/gal; EPA Reg. No. 264-850), and the results of a magnitude of the
residue study on field corn (MRID# 47262401).

2)  A request to amend the Oberon® 2 SC label to decrease the
preharvest interval (PHI) on tomato from 7 days to 1 day.  The company
submitted a revised label for Oberon® 2 SC, and the results of a
magnitude of the residues study on tomatoes (MRID# 47303601).

Permanent tolerances are currently established for the combined residues
of spiromesifen and its enol metabolite, calculated as the parent
compound equivalents, in/on corn, field, grain at 0.02 ppm; corn, field,
forage at 3.0 ppm; corn, field, stover at 5.0 ppm; vegetable, fruiting,
group 8 at 0.45 ppm; and tomato, paste at 0.60 ppm (40 CFR §180.607).

Residue Chemistry Deficiencies

Field Corn

Revised Section F to include tolerances of 5.0 ppm for residues in/on
corn, field, forage and 8.0 ppm for corn, field, stover.

Tomato

Revised Section F to include a tolerance of 0.80 ppm for residues in/on
tomato, paste.

  SEQ CHAPTER \h \r 1 RECOMMENDATIONS

Field Corn

The residue chemistry database supports the request to increase the
individual application rate of spiromesifen on field corn from 0.13 lb
ai/A to 0.25 lb ai/A.  Provided a revised Section F is submitted, there
are no residue chemistry issues that would preclude granting permanent
tolerances for residues of spiromesifen and its enol metabolite,
calculated as the parent compound equivalents, in/on corn, field, forage
at 5.0 ppm and corn, field, stover at 8.0 ppm.  The currently
established tolerance of 0.02 ppm for residues in/on corn, field, grain
is adequate.

Tomato

The residue chemistry database supports the request to amend the
Oberon® 2 SC label to decrease the PHI on tomato from 7 days to 1 day. 
Provided a revised Section F is submitted, there are no residue
chemistry issues that would preclude granting the permanent tolerance
for residues of spiromesifen and its enol metabolite, calculated as the
parent compound equivalents, in/on tomato, paste at 0.80 ppm.  The
currently established tolerance of 0.45 ppm for residues in/on
vegetable, fruiting, group 8 is adequate.

Background

Spiromesifen is an insecticide/miticide that is highly active on a broad
spectrum of mite pests, whiteflies, and other insects.  It is a member
of the tetronic acid class and the mode of action is via lipid
biosynthesis inhibition.  The test compound nomenclature and its
physiochemical properties are presented in Tables 1 and 2, respectively.



Table 1.  Test Compound Nomenclature.

Compound	Chemical Structure



Common name	Spiromesifen

Company experimental name	BSN 2060

IUPAC name	3-mesityl-2-oxo-1-oxaspiro[4.4]non-3-en-4-yl
3,3-dimethylbutyrate

CAS name	2-oxo-3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl
3,3-dimethylbutanoate

CAS #	283594-90-1

End-use product	Oberon® 2 SC, Oberon® 4 SC



Table 2.  Physicochemical Properties of the Technical Grade Test
Compound.

Parameter	Value	Reference

Melting point	Crystal modification 1:  98.7°C 

Crystal modification 2:  96.7°C	Memo S. Malak, 4/29/04, DP #298191;
MRID 45854501

pH	5.19 (2% suspension in 0.1% NaCl)

	Density	1.13 g/mL

	Water solubility ( 20°C)	0.13 mg/L (constant from pH 4 to pH 9)

	Solvent solubility (mg/L at 20°C)	Acetone: >250 g/L 

Acetonitrile: >250 g/L 

Ethyl Acetate: >250 g/L 

Dichloromethane: >250 g/L 

n-Heptane: 23 g/L

1-Octanol: 60 g/L

2-Propanol: 110 g/L

Xylene: >250 g/L

	Vapor pressure at 25°C	1 x 10-5 Pa

	Dissociation constant (pKa)	No acid or base properties between pH 2 and
pH 12

	Octanol/water partition coefficient Log(KOW)	4.55 at 20°C

	UV/visible absorption spectrum	Molar absorption coefficient 23,360
L/mol cm at 214 nm (neutral)

	

860.1200  Directions for Use

Field Corn

Bayer submitted proposed labels for Oberon® 2 SC Insecticide/Miticide
(2 lb ai/gal; EPA Reg. No. 264-719) and Oberon® 4 SC
Insecticide/Miticide (4 lb ai/gal; EPA Reg. No. 264-850) to include an
increased application rate on field corn.  The maximum seasonal
application rate will remain the same (0.27 lb ai/A).  It should be
noted that in an email to RD dated 3/13/08, the company submitted
revised proposed labels to correct an error on the Directions of Use
table (email from S. Movassaghi to T. Harris).  The registered and
proposed use patterns are detailed in Table 3.

Table 3.	Summary of Registered and Proposed Directions for Use of
Spiromesifen on Field Corn.

Trade Name	Application Timing, Type, Equipment	Application Rate 

(lb ai/A)	Maximum Number Applications 

Per Season	Maximum Seasonal Application Rate 

(lb ai/A) 	PHI1 

(days)	Use Directions and Limitations1

Registered use pattern

Oberon® 2 SC	Ground & aerial	0.13	2	0.27	30 (grain, stover);

5 (forage)	Minimum RTI:  14 days

Minimum spray volume:  10 GPA ground, 5 GPA aerial

Proposed use pattern

Oberon® 2 SC	Ground & aerial	0.089-0.25	2	0.27	30 (grain, stover);

5 (forage)	Minimum RTI:  14 days

Minimum spray volume:  10 GPA ground, 5 GPA aerial

Oberon® 4 SC







1.  RTI = retreatment interval.  PHI = preharvest interval.  NA = not
applicable.  NS = not specified.  GPA = gallons per acre.



Tomato

The registrant submitted a request to decrease the PHI for tomatoes on
the Oberon® 2 SC label from 7 days to 1 day.  It should be noted that
the current PHI for the remainder of the fruiting vegetables, except
cucurbits (crop group 8) crops will remain at 7 days, and the PHI for
greenhouse grown tomatoes will remain at 3 days.  The proposed use
patterns are detailed in Table 4.



Table 4.  Summary of Registered and Proposed Directions for Use of
Spiromesifen on Fruiting Vegetables, Except Cucurbits, Crop Group 8.

Trade Name	Crop	Application Timing, Type, Equipment	Application Rate 

(lb ai/A)	Maximum Number Application (lb ai/A)	Maximum Seasonal
Application Rate 

(lb ai/A)	PHI1 (days)	Use Directions and Limitations1

Registered use pattern

Oberon® 2 SC	Fruiting vegetables (except cucurbits)	Ground & aerial
0.13	3	0.40	7	Minimum RTI:  7 days

Minimum spray volume:  10.0 GPA ground, 5.0 GPA aerial.

Proposed use pattern

Oberon® 2 SC	Fruiting vegetables (except cucurbits and tomato)	Ground &
aerial	0.13	3	0.40	7	Minimum RTI:  7 days

Minimum spray volume:  10.0 GPA ground, 5.0 GPA aerial.

	Tomato



	1

	1.  RTI = retreatment interval.  PHI = preharvest interval.  NA = not
applicable.  NS = not specified.  GPA = gallons per acre.



Additional Restrictions for all Crops:

RESTRICTED ENTRY INTERVAL:

Do not enter or allow worker entry into treated areas during the
restricted entry interval (REI) of 12 hours following application.  

ROTATIONAL PLANT-BACK INTERVALS:

Immediate plant-back:  Cotton, Field Corn, Fruiting Vegetables, Leafy
Vegetables, Cucurbits, Tuber Vegetables (Potatoes) Strawberry

30-day plant-back:  Alfalfa, Barley, Sugarbeets, Wheat

12-month plant-back:  All other crops



HED Conclusions:  The proposed use directions for field corn and tomato
are adequate and supported by the available residue chemistry data.

860.1300 Nature of the Residue - Plants and Livestock

The nature of the residue in plants and livestock is adequately
understood based on acceptable metabolism studies conducted on lactating
goats, laying hens, lettuce, cotton, tomato, and confined rotational
crops.  Based on these studies, the residues of concern in plants
(primary and rotational) and livestock commodities are as follows (Memo,
K. Martin, et al., 2/17/05; DP# 300469):  

Primary crops:  spiromesifen and its enol metabolite (for risk
assessment only, BSN 2060-4-hydroxymethyl (free and conjugated) is a
residue of concern in leafy vegetables)

Rotational crops:  spiromesifen, its enol metabolite, and its
metabolites containing the 4-hydroxymethyl moiety

Livestock commodities:  spiromesifen and its metabolites containing the
enol and 4-hydroxymethyl moieties

860.1340 Residue Analytical Methods

Adequate methods are available for enforcing the current plant and
livestock tolerances.  The methods used to analyze spiromesifen and
spiromesifen-enol residues in/on field corn and tomato samples in the
crop field trial studies are slightly modified versions of the current
plant enforcement method (Method 00631).  In both studies, residues of
spiromesifen and spiromesifen-enol were quantitated by high-performance
liquid chromatography (HPLC)/triple stage quadruple mass spectrometry
(MS/MS) using deuterated internal standards.  The LOQs for both
spiromesifen and spiromesifen-enol were 0.010 ppm for corn forage,
stover and grain, and tomato.

HED Conclusions:  The HPLC/MS/MS methods used in the submitted field
trials are adequate for determining residues of spiromesifen in/on field
corn and tomatoes.  The current tolerance enforcement method is also
adequate for enforcing the proposed tolerances.  Method 00631 was
forwarded to the Analytical Chemistry Branch (ACB) for Agency petition
method validation (PMVs; memos, J. Tyler, 6/17/03; D290912 and D290914).
 ACB reviewed the proposed enforcement method data without a laboratory
validation (Memo, E. Kolbe, 11/15/07; DP# 305721).  The ACB determined
that Method 00631 appears to meet the guidelines for an acceptable
enforcement method, provided it is modified as detailed in the 11/17/07
memo.  Once the method has been modified, the results of the PMV will be
forwarded to the Food and Drug Administration’s (FDA) for inclusion in
Pesticide Analytical Methods (PAM) Volume II.

860.1360 Multiresidue Methods

Spiromesifen, BSN 2060-enol, and BSN 2060 4-hydroxymethyl were analyzed
according to the Food and Drug Administration’s (FDA) Multiresidue
Method (MRM) Testing guidelines in Pesticide Analytical Methods (PAM)
Volume I, Appendix II (January 1994) by ABC Laboratories, Inc. (MRID
45819420).  Based on the results of this study, the MRMs tested under
Protocols D, E, and F may be suitable for the analysis of spiromesifen
in nonoily (cucumber) and fatty (ground beef) commodities.  These
methods are not suitable for BSN 2060-enol or BSN 2060 4-hydroxymethyl. 
The report has been forwarded to FDA for inclusion in PAM I (Memo, J.
Tyler, 4/16/08; D351116).

860.1380 Storage Stability

Freezer storage stability data are available for a wide variety of crop
matrices for 10.5 to 14.5 months with no indication of residue decline
(Memo, G. Kramer et al., 2/18/05; DP# 308837).  These data validate the
storage intervals for all commodities in the magnitude of the residue
studies (13.6 months in the field corn study and 12 months in the tomato
study).

860.1480 Meat, Milk, Poultry, and Eggs

Livestock feed commodities associated with the current actions are field
corn forage, stover, and grain.  Tolerances on meat, milk, poultry and
egg commodities have been established (40 CFR 180.607).  However, in a
memo dated 12/5/07, the Alternate Risk Integration and Assessment (ARIA)
Team recommended for the following tolerances for residues of
spiromesifen (Memo, D. Rate; DP# 345985):  milk (0.01 ppm); milk, fat
(0.20); and meat (0.02 ppm), meat, byproducts (0.15 ppm), and fat (0.10
ppm) of cattle, goats, horses, and sheep.  These tolerances are based on
an estimate dietary burden of 22 ppm for beef cattle (based on a diet of
20% cowpea, hay; 15% corn, forage; 5% cotton gin byproducts; 35% corn,
grain; 10% beet, sugar, molasses/pulp; and 15% cottonseed, meal) and 22
ppm for dairy cattle (based on a diet of 25% corn, forage; 20% cowpea,
hay; 30% corn, grain; 10% beet, sugar, molasses/pulp; and 15%
cottonseed, meal).  An updated calculation of the dietary burden was
made using the newly proposed tolerance for field corn forage (see Table
5).

In the memo dated 12/5/07, a dietary burden of 0.3 ppm was calculated
for poultry based on 70% cotton, grain; 5% wheat/barley/oat, grain; 5%
alfalfa, meal; and 20% cottonseed, meal;  A dietary burden of 0.04 ppm
was calculated for hog based on 80% corn, grain; 5% wheat/barley/oat
grain; and 10% cowpea see.  As the current action does not affect these
dietary burdens, they were not recalculated.

Table 5.   Calculation of Dietary Burdens of Spiromesifen Residues to
Livestock. a, b

Feedstuff	Type1	% Dry Matter	% Diet2	Recommended Tolerance (ppm)	Dietary
Contribution3 (ppm)

Beef Cattle

cowpea, hay	R	86	20	86	20

corn, forage	R	40	15	5.0	1.9

cotton gin byproducts	R	90	5	15	0.83

corn, grain	CC	88	35	0.02	0.0008

beet, sugar, molasses/pulp	CC	75	10	0.03	0.004

cottonseed, meal	PC	89	15	0.50	0.084

Total	--	--	100	--	23

Dairy Cattle

corn, forage	R	40	25	5.0	3.1

cowpea, hay	R	86	20	86.0	20.0

corn, grain	CC	88	30	0.020	0.007

beet, sugar, molasses/pulp	CC	75	10	0.030	0.004

cottonseed, meal	PC	89	15	0.50	0.084

Total	--	--	100	--	23

1  R = Roughage, CC = Carbohydrate concentrate.  Cattle are typically
given diets with 30-60% R, 20-50% CC, and 10-15% PC.

2  Table 1 Feedstuffs (April, 2008).

3  Contribution = (tolerance /% DM x % in diet) for beef and dairy
cattle.

The   SEQ CHAPTER \h \r 1 updated dietary burden for beef and dairy
cattle is slightly higher than the previous dietary burden; however,
this increase is not expected to have an affect on the expected
secondary residues on dairy and beef cattle.  Therefore, the currently
established tolerances for livestock commodities are adequate.  No new
tolerances are needed.

  SEQ CHAPTER \h \r 1 

Poultry

The petitioner did not submit a poultry feeding study with this
petition, but previously submitted a waiver request for magnitude of the
residues in poultry and eggs.  Based on the results of a hen metabolism
study, HED previously concluded that there is no reasonable expectation
of finite residues (180.6(a)(3)) and that the requested waiver is
appropriate (Memo, G. Kramer, 2/18/05; D308837).  As the current action
does not affect the MTDB for poultry, the waiver is appropriate for the
proposed uses.  However, should additional uses which increase the
poultry MTDB be proposed in the future, this conclusion will be
reevaluated.

860.1500 Crop Field Trials

Field Corn

47262401.der

Table 7.  Summary of Residue Data from Crop Field Trials with
Spiromesifen.

Commodity	Total Application Rate	PHI (days)	Residue Levels (ppm)2



	N	Minimum	Maximum	HAFT1	Median	Mean	Standard Deviation

Spiromesifen (parent)

Corn forage	0.242-0.260

(0.89x-0.96x)	5	40	0.15	3.97	3.61	1.89	1.87	0.96



10	40	0.01	3.63	2.93	1.22	1.18	0.70

Corn stover

30	40	<LOD	3.73	2.54	0.64	0.81	0.70

Corn grain

30	40	<LOD	<LOD	<LOD	<LOD	<LOD	NA

Spiromesifen-enol (metabolite)

Corn forage	0.242-0.260

(0.89x-0.96x)	5	40	0.03	1.56	1.34	0.17	0.30	0.32



10	40	<LOD	0.75	0.68	0.14	0.24	0.20

Corn stover

30	40	<LOD	<LOD	<LOD	<LOD	<LOD	NA

Corn grain

30	40	<LOD	1.94	1.54	0.40	0.48	0.39

Combined Residues

Corn forage	0.242-0.260

(0.89x-0.96x)	5	40	0.18

(0.18)	4.70

(3.87)	4.43

(2.96)	2.07

(1.93)	2.12

(1.97)	1.10

(0.96)



10	40	0.01

(<LOD)	4.05

(4.05)	3.34

(3.34)	1.54

(1.27)	1.46

(1.36)	0.81

(0.81)

Corn stover

30	40	<LOD

(0.01)	5.68

(6.59)	4.09

(6.56)	1.17

(1.75)	1.30

(2.23)	1.00

(1.68)

Corn grain

30	40	<LOD	<LOD	<LOD	<LOD	<LOD	NA

1.  HAFT=Highest-Average Field Trial.

2.  Values in parenthesis were adjusted for average % DM (40% for forage
and 83% for stover).



Bayer CropScience submitted field trial data for spiromesifen on field
corn.  A total of twenty field trials (18 harvest and 2 residue decline)
were conducted in Region 1 (1 trial), Region 2 (1 trial), Region 5 (17
trials) and Region 6 (1 trial).  For each trial, one broadcast foliar
spray application of Oberon®  240 SC (a SC formulation containing 2 lb
ai/gal) was made to the field corn at a target rate of 0.250 lb ai/A
(~0.92x the maximum proposed application rate).  The applications were
made when the corn plants were between the growth stages of ‘early
dough’ (BBCH Crop Stage 83) and ‘fully ripe’ (BBCH Crop Stage 89).
 In each trial, a control and a treated plot were established.  All
applications were made using ground-based equipment and did not include
tank mixes or adjuvants. 

From the 18 trials, duplicate composite samples of corn forage were
collected at PHIs of 5 (±2) and 10 (±2) days, and duplicate composite
samples of corn stover and grain were collected at PHIs of 30 (±2) days
(crop maturity) from the treated plots.  In the two decline trials,
duplicate samples of corn forage were collected at 0 (±2)-, 5 (±2)-,
10 (±2)-, 15 (±2)-, and 20 (±2)-day PHIs; and duplicate treated
samples of stover and grain were collected at 20 (±2)-, 25 (±2)-, 30
(±2)-, 35 (±2)-, and 42-day PHIs.  A single composite sample of each
matrix was collected from the control plot for each trial.

The highest-average field trial (HAFT) total spiromesifen residues on
corn forage was 4.43 ppm (5-day PHI) and 3.34 ppm (10-day PHI). 
However, when adjusted for percent dry matter, the HAFT total
spiromesifen residue in corn forage (5-day PHI) was 2.96 ppm (4.43 ppm
adjusted from 66% dry matter to 40% dry matter).  The HAFT total
spiromesifen residue on corn stover was 4.09 ppm.  However, in another
sample adjusted for percent dry matter, the HAFT total spiromesifen
residue in corn stover was 6.56 ppm (2.61 ppm adjusted from 33% dry
matter to 83% dry matter).  The total spiromesifen residue was less than
the limit of detection (<LOD) in corn grain.  The results of the residue
decline trials indicate that, in general, the total spiromesifen residue
on corn forage and stover declined with time.

Because the total BSN 2060 residue was less than the LOQ of 0.01 ppm in
grain, data for corn aspirated grain fractions are not required.

HED Conclusions:  The results of previously submitted crop field trial
data on field corn were reviewed by HED in a memorandum dated 2/18/05
(Memo, G. Kramer et al.; D308837).  Following two broadcast foliar spray
applications of Oberon 2 SC Insecticide/ Miticide at rate of 0.134 lb
ai/A/application (total application rate of 0.27 lb ai/A), the HAFT
total spiromesifen and residues in corn forage, corn stover and corn
grain were 2.43 ppm (6-day PHI; 1.94 ppm adjusted from 32% DM to 40%
DM), 1.82 ppm (31-day PHI; 36% DM; equivalent to 4.20 ppm when adjusted
to 83% DM), and <LOQ (0.01 ppm), respectively.  These data supported
tolerances of 0.02 ppm (sum of LOQs for each analyte) in/on corn, field,
grain; 3.0 ppm in/on corn, field, forage; and 5.0 ppm in/on corn, field,
stover.

The newly submitted field corn field trial residue data are classified
as scientifically acceptable.  The data support a maximum single and
seasonal application rate of 0.25 lb ai/A (~0.92x the maximum proposed
application rate; 0.27 lb ai/A) on field corn (PHI of 5 days for forage
and 30 days for stover and grain).  Although the maximum application
rate used in the study is slightly lower than the proposed application
rate, HED does not expect total residues of spiromesifen to exceed 2.96
ppm in/on forage (4.43 ppm adjusted from 66% dry matter to 40% dry
matter; 5-day PHI), 6.56 ppm in/on stover (2.61 ppm adjusted from 33%
dry matter to 83% dry matter; 30-day PHI), and <LOD in/on grain.  Using
the North American Free Trade Agreement (NAFTA) Maximum Residue Limit
(MRL)/Tolerance Harmonization Workgroup methodology for forage and
stover, the available crop field trial data indicate that the
appropriate tolerances for total residues of spiromesifen in/on field
corn commodities are 5.0 ppm in/on corn, field, forage; and 8.0 ppm
in/on corn, field stover (see Section 860.1550 Proposed Tolerances). 
The currently established tolerance of 0.20 ppm (sum of LOQs for each
analyte) for residues in/on corn, field, grain is adequate to support
the proposed application rate.  However, a revised Section F to include
the new tolerances for residues in/on corn, field, forage (5.0 ppm) and
corn, field, stover (8.0 ppm) should be submitted.

Tomato

47303601.der

Table 8.  Summary of Residue Data from Crop Field Trials with
Spiromesifen.

Commodity	Total Application Rate	PHI (days)	Residue Levels (ppm)2



	N	Minimum	Maximum	HAFT1	Median	Mean	Standard Deviation

Spiromesifen (parent)

Tomato	0.396-0.409	1	24	0.028	0.437	0.334	0.096	0.110	0.085



3	24	0.0026	0.168	0.165	0.076	0.083	0.049

Spiromesifen-enol (metabolite)

Tomato	0.396-0.409	1	24	<LOD	0.015	0.012	<LOD	0.006	0.004



3	24	<LOD	0.019	0.016	0.006	0.006	0.004

Combined Residues

Tomato	0.396-0.409	1	24	0.033	0.451	0.346	0.099	0.116	0.087



3	24	0.031	0.182	0.181	0.085	0.092	0.046

1  HAFT=Highest-Average Field Trial.



Bayer CropScience submitted field trial data for spiromesifen on tomato.
 A total of twelve field trials were conducted in Region 1 (1 trial),
Region 2 (1 trial), Region 3 (2 trials), Region 5 (1 trial), and Region
10 (7 trials).  For each trial, a total of 3 broadcast foliar spray
applications of Oberon®  240 SC (a SC formulation containing 2 lb
ai/gal) were made to tomatoes at actual rates of 0.130-0.140 lb
ai/A/application at retreatment intervals (RTIs) of 5-7 days, for a
total application rate of 0.396-0.409 lb ai/A.  All applications were
made using ground-based equipment and did not include tank mixes or
adjuvants.

From the 12 trials, duplicate composite samples of tomatoes were
collected at PHIs of 1 and 3 days.  A single composite sample of each
matrix was collected from the control plot for each trial.

The combined residues (parent spiromesifen plus the enol metabolite)
in/on tomato were 0.033-0.451 ppm (1-day PHI) and 0.031-0.182 ppm (3-day
PHI).  The HAFT total spiromesifen residues on tomato were 0.346 ppm
(1-day PHI) and 0.181 ppm (3-day PHI).  No residue decline data were
provided.  

HED Conclusions:  The newly submitted tomato field trial residue data
are classified as scientifically acceptable.  The data support a maximum
single and seasonal application rate of 0.40 lb ai/A (1x the maximum
proposed application rate) on tomato.  HED does not expect total
residues of spiromesifen to exceed 0.346 ppm in/on tomatoes when
harvested 1 day following the last application (1-day PHI is proposed). 
Using the NAFTA MRL/Tolerance Harmonization Workgroup methodology, the
available crop field trial data indicate that the appropriate tolerance
for total residues of spiromesifen in/on tomato is 0.40 ppm (see Section
860.1550 Proposed Tolerances).  The currently established tolerance of
0.45 ppm for residues in/on fruiting vegetables is adequate to support
the proposed 1-day PHI for tomatoes.

860.1520 Processed Food and Feed

Field Corn

The results of previously submitted processing study in field corn
indicate that the total spiromesifen and spiromesifen-enol residues were
<LOQ (0.01 ppm) in corn grain when harvested 31 days following the last
of two applications of spiromesifen at a rate of 0.67 lb
ai/A/application, with a 13-day RTI, for a total rate of 1.34 lb ai/A
(5X).  Since the total spiromesifen residues on corn grain treated at 5X
was <LOQ, no further processing data were provided.  Separate tolerances
are thus not required for field corn processed commodities.

Tomato

™ 2 SC at approximately 0.41 lb ai/A/application with a 7-day RTI, for
a total rate of 1.24 lb ai/A (3.1X).  The tomatoes, bearing spiromesifen
and BSN 2060-enol total residues of 0.26 ppm, were processed using
simulated commercial procedures into the required processed commodities
of paste and puree as well as additional commodities of canned tomatoes,
tomato juice, hot crushed tomatoes, and dried tomatoes.  A comparison of
the residues in the raw agricultural commodity (RAC) with those in each
processed fraction resulted in processing factors of 2.3 for paste, 0.69
for tomato puree, 0.15 for canned tomatoes, 0.54 for tomato juice, 0.85
for hot crushed tomatoes, and 4.8 for dried tomatoes.  These
concentration factors conform with the theoretical concentration factors
for tomato paste, tomato puree, and tomato juice.    SEQ CHAPTER \h \r 1
Based on a processing factor of 2.3X for tomato paste and a HAFT residue
of 0.346 ppm, for tomato, a revised tolerance of 0.80 ppm for tomato
paste is appropriate.  The petitioner should submit a Section F to
include this tolerance.

860.1550 Proposed Tolerances

The residue chemistry database supports the establishment of the
permanent tolerances for the combined residues of spiromesifen and its
enol metabolite, calculated as the parent compound equivalents, in/on
the RACs listed in Table 9.

For purposes of determining appropriate tolerance levels for field corn,
individual spiromesifen and spiromesifen-enol were summed to yield a
total residue value.  The appropriate tolerances for field corn forage
and stover were determined using the methodology formulated by the NAFTA
MRL/Tolerance Harmonization Workgroup for calculating statistically
based pesticide tolerances for plant commodities based on field trial
residue data (see Attachment 2).  For field corn grain, the appropriate
tolerance level was calculated by summing the LOQ (0.01 ppm) for each
analyte.  The available crop field trial data indicate that the
appropriate tolerances for total residues of spiromesifen in/on field
corn commodities are 0.02 ppm in/on corn, field, grain; 5.0 ppm in/on
corn, field, forage; and 8.0 ppm in/on corn, field stover (see Section
860.1550 Proposed Tolerances).  The currently established tolerance of
0.20 ppm for corn, field, grain is adequate to support the proposed
application rate.  However, a revised Section F to include the new
tolerances for corn, field, forage (5.0 ppm) and corn, field, stover
(8.0 ppm) should be submitted.

The appropriate tolerances for tomato were determined using the NAFTA
MRL/Tolerance Harmonization Workgroup methodology.  The available crop
field trial data indicate that the appropriate tolerance for total
residues of spiromesifen in/on tomato is 0.40 ppm (see Section 860.1550
Proposed Tolerances).  The currently established tolerance of 0.45 ppm
for fruiting vegetables is adequate to support the proposed 1-day PHI
for tomatoes.

The results of previously submitted processing study in field corn and
tomatoes indicate that separate tolerances are not required for field
corn or tomato processed commodities, except tomato paste.    SEQ
CHAPTER \h \r 1 Based on a processing factor of 2.3X for tomato paste
and a HAFT residue of 0.346 ppm, for tomato, a revised tolerance of 0.80
ppm for tomato paste is appropriate.  The petitioner should submit a
Section F to include this tolerance.

Livestock feed commodities associated with the current actions are field
corn forage, stover, and grain.  The following meat, milk, poultry and
egg tolerances have been established (40 CFR 180.607):  0.05 ppm for fat
and meat byproducts for cattle, goats, sheep and horse; and 0.10 ppm for
milk, fat.    SEQ CHAPTER \h \r 1 Based on the results of the new
dietary burden and the previously-submitted cattle feeding study, the
currently established tolerances for livestock commodities are adequate.
 No new tolerances are needed.

The petitioner did not submit a poultry feeding study with this
petition, but previously submitted a waiver request for magnitude of the
residues in poultry and eggs.  Based on the results of a hen metabolism
study, HED previously concluded that there is no reasonable expectation
of finite residues (180.6(a)(3)) and that the requested waiver is
appropriate (Memo, G. Kramer, 2/18/05; D308837).  As the current action
does not affect the dietary burden for poultry, the waiver is
appropriate for the proposed uses.  However, should additional uses
which increase the poultry dietary burden be proposed in the future,
this conclusion will be reevaluated.

Table 9.  Tolerance Summary for Spiromesifen.

Commodity	Proposed Tolerance (ppm)	Registered Tolerance (ppm)	HED
Recommended Tolerance (ppm)	Comments

(correct commodity definition)

Corn, field, forage	6	3.0	5.0

	Corn, field, stover	-	5.0	8.0

	Corn, field, grain	-	0.02	-	Currently established tolerance is
adequate.

Tomato, paste	-	0.60	0.80

	Vegetable, fruiting, group 8	-	0.45	-	Currently established tolerance
is adequate.



The International Residue Limit Status (IRLS) Sheet is attached as
Attachment 1.  There are no established Mexican or Codex MRLs for the
proposed uses.  There are established Canadian MRLs for tomato paste
(0.6 ppm); fruiting vegetables (crop group 8), except cherry tomatoes
(0.45 ppm); field corn (0.02 ppm); and cherry tomato (0.6 ppm).  As the
available residue data on tomato and field corn support the tolerances
listed in Table 9, harmonization is not possible at this time.

Attachments

Attachment 1:  IRLS Sheet.

Attachment 2:  Inputs for calculating statistically based pesticide
tolerances.

cc: J. Tyler

RDI: RAB1 Chemists (4/30/08); G. Kramer (5/21/08)

J. Tyler: S-10943: Potomac Yard 1 (PY1): (703) 305-5564: 7509P: RAB1

Attachment 1.  IRLS Sheet.

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name:

2-oxo-3-(2,4,6-trimethylphenyl)-1-oxaspiro[4.4]non-3-en-4-yl
3,3-dimethylbutanoate	Common Name:

Spiromesifen	x Proposed tolerance

( Reevaluated tolerance

( Other	Date: 5/1/08

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

X No Codex proposal step 6 or above

( No Codex proposal step 6 or above for the crops requested	Petition
Number:  7F7274

DP#s: 342763 and 348427

No Limits

( No Limits for the crops requested	X No Limits

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thylphenyl)- 1-

oxaspiro[4.4]non-3-en-2-one.

Livestock:  2-oxo-3-(2,4,6-trimethylphenyl)-1-

oxaspiro[4.4]non-3-en-4-yl 3,3-dimethylbutanoate, including the

metabolites 4-hydroxy-3-(2,4,6-trimethylphenyl)-
1-oxaspiro[4.4]non-3-en-2-one and

4-hydroxy-3-[4-(hydroxymethyl)-2,6-

dimethylphenyl]-1-oxaspiro[4.4]non-3-en-2-one

	Residue definition:  N/A

Crop(s)	MRL (mg/kg)1	Crop(s)	MRL (mg/kg)

Tomato paste	0.6



Fruiting vegetables (Crop Group 8), except cherry tomatoes	0.45



Field corn	0.02



Cherry tomato	0.6



Notes/Special Instructions:  S.Funk, 05/02/2008. 1 Per PMRL2007-15

Attachment 2.  Inputs for calculating statistically based pesticide
tolerances.

Field Corn Forage

Field Corn Stover

Tomato

Spiromesifen	Summary of Analytical Chemistry and Residue Data	DP#: 
342763 and 348427

Page  PAGE  19  of   NUMPAGES  19 

