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

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

MEMORANDUM

Date: 31

- JUL

- 2013

SUBJECT: Prometryn in/ on Snap Beans and Dill. Su mmary of Analyti cal Chemistry and
Residue Data.

PC Code: 080805 DP Barcode: D 408525 Decision No.: 467531 Registration No. : 100

- 620 Petition No.: 2E8052 Regulatory Action: Amended Section 3 Risk Assessment Type: NA Case No.: 0467
T XR No.: NA CAS No.: 7287

- 19

- 6 MRID No s .: 48834201

, 48834202 40 CFR: § 180.222

From: Sarah J. Levy , Chemist Risk Assessment Branch 1 (RAB1) Health Effects Division (HED, 7509P)

Through : George F. Kramer, Ph.D., Senior Chemist RAB1/HED (7509P)

To: Barbara Madden , RM 0 5 Registration Division (RD; 7505P)

Executive Summary

Prometryn [2,4

- bis(isopropylamino)

- 6

- methylthio

- s

- triazine] is a substituted thiomethyl triazine herbicide (Group 5) registered in the U.S. for the control of weeds in a number of commoditie s [40 CFR §180.222(a)]. There is also a tolerance with regional registration in/on dill as well as
tolerances for indirect or inadvertent residues in/on barley, oat, rye, triticale, and wheat
commodities. The Prometryn Reregistration Eligibility Decision (RED) document was issued
FEB

- 1996. The Product and Residue Chemistry Chapters for the Prometryn RED were issued
0 8

- DEC

- 19 94.

The Interregional Research Project No. 4 (IR

- 4), on behalf of the Agricultural Experiment Stations of ID, MI, NC, NJ, NY, OK, OR, TX, and WA has submitted a tolerance petition for new uses of prometryn on snap beans and dill. A Section 3 lab el amendment for an end

- use product is not being submitted with t his action due to indemnification concerns and the intent of the company is to allow this use via a 24 ( c ) in the future. The end

- use product relevant to this registration request is Indemnif ied Caparol ® 4L (EPA Reg. No. 100

- 620). Th i s product is
formulated as a flowable

- concentrate (FlC) and contain s 44.0

- 44.4% prometryn (equivalent to 4.0 pound active ingredient per gallon (lb ai/gal)). It is proposed for preemergence (post

Page 1 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 planting) or po stemergence broadcast application using ground equipment with maximum seasonal rates of 1.5 lb ai per acre (A) for dill and 1.5 lb ai/A for snap beans. The pre

- harvest intervals (PHIs) are 30 days for dill and 52 days for snap beans . In conjunction with these uses,
IR

- 4 proposes the establishment of permanent tolerances for residues of prometryn per se in/on the following:

Bean, snap, succulent

.. ... ..... 0.05 ppm Bean, forage ............

...... 0.09 ppm Dill, leaves ...............

.... 0.3 ppm Dill, dried leaves .........

..... 1.1 ppm Dill, oil ..................

...... 1.3 ppm

It should be noted that prometryn is already registered for use on dill; however, the current registration is limited to regional registration. The Registrant has submitted additional data to expand the regional registration to a national registration. T he proposed national use pattern is identical to the currently registered regional use pattern.

HED previously determined that the residue of concern in plants consists of the parent, prometryn per se , which is the currently regulated residue. HED conc luded that if other major uses were registered in the future, additional metabolism studies would be required. The petitioner recently submitted a metabolism study in rice which was reviewed as part of the following memorandum: S. Levy, 13

- MAR

- 2013; D 398 563. Although the rice metabolism study was deemed adequate, it presents a qualitatively different metabolic profile than the celery and cotton profiles (Memo, C. Swartz, 05

- DEC

- 1994; D208880 and 09

- DEC

- 1995; D207139, respectively). In the celery and cot ton metabolism studies, parent was the major residue and in the rice metabolism study metabolite GS

- 17794 was the major residue. Therefore, HED is still requesting a root crop metabolism study. This deficiency remains outstanding. Depending
results of t he root crop metabolism study, additional field trial data could be required.

The nature of the residue in livestock is adequately understood based on acceptable poultry and ruminant metabolism studies. The residue of concern (and that which should be re gulated) in livestock is the parent, prometryn per se . As in plants, the metabolism of prometryn in livestock
involves N

- dealkylation along with hydrolysis and/or amino acid conjugation.

Adequate enforcement methodology is available to enforce the propos ed tolerances. Prometryn is completely recovered (>80% recovery) using the Food and Drug Administration’s ( FDA’s ) Multiresidue Section 302. In addition, an acceptable gas chromatography (GC) method with
flame

- photometric detection in the sulfur mode (FPD /S), Ciba

- Geigy Method AG

- 559, is available for use as a single

- analyte confirmatory method.

Samples of snap beans and dill commodities were analyzed for residues of prometryn and the triazine impurities GS

- 11354 and GS

- 26831 using methods derived from Method AG

- 559. Samples of snap beans were analyzed using a GC/FPD/S version of the method, and samples of
dill commodities were analyzed using a version with high

- performance liquid chromatography
and tandem mass spectrometry detection ( HP LC/MS/MS). For both methods, the l owest limit of method validation (LLMV) was 0.05 ppm for each analyte in all matrices

. The methods were adequate for data collection based on method verification and concurrent method validation
recoveries.

Page 2 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 The 1994 Residue Chemistry Chapter concluded that residues of prometryn per se in meat and milk can be classified under Category 3 of 40 CFR § 180.6(a). That is, there is no reasonable expectation of finite residues in meat and milk. No tolerances were re quired in the Residue Chapter; therefore , l ivestock feeding studies were not required . Pending submission of an additional plant metabolism study, HED tentatively concludes that the Category 3 situation remains valid for this registration request.

The submitted snap bean and dill crop field trial and dill processing data are supported by adequate storage stability data. The se data show that corrections for storage degradation of
residues are not required for the submitted studies.

The nature of the re sidue in rotational crop is adequately understood. The metabolism of prometryn in rotational crops is similar to that in celery and cotton

. HED previously determined that the minimum plantback restrictions for crops not listed on prometryn labels should be as follows (with these PBIs and the proposed application rates, that currently established rotational crop tolerances are adequate): (1) following maximum application to any primary crop at up to
3.2 lb ai/A: a 5

- month plantback interval (PBI) for leafy vegetables, an 8

- month PBI for root crops, and a 9

- month PBI for small grains and all other crops. (2) Following application at rates higher than 3.2 lb ai/A and up to 6.0 lb ai/A: an 8

- month PBI for root crops; rotation to all other crops is prohi bited. The PBI restrictions listed on the EPA

- registered Caparol ® 4L Label remain appropriate for the proposed crops.

There are currently no established Codex MRLs for prometryn; therefore, harmonization is not
an issue.

Analytical standards for promet ryn are currently available in the EPA National Pesticide Standards Repository.

Regulatory Recommendations and Residue Chemistry Deficiencies

P ending submission of a revised Section F

, there are no residue chemistry issues that would preclude granting registration for the requested uses or establishment of tolerances for residues of prometryn . Furthermore, in accordance with the most recent guidance concerning tolerance expressions, HED recommends that the tolerance expression for 40 CFR § 180.222 be changed as
indicated below.

“(a) General. Tolerances are established for residues of the herbicide prometryn , including its metabolites and degradates, in or on the commodities in the tabl e below. Compliance with the tolerance levels specified below is to be determined by measuring only prometryn [2,4

- bis(isopropylamino)

- 6

- methylthio

- s

- triazine] in or on the following raw agricultural
commodities:”

Snap, bean, succulent

................................ ........................... 0.05 ppm Dillweed, fresh leaves

................................ .......................... 0.30 ppm Dill, dried leaves

................................ ................................ .. 1.1 ppm

and

Page 3 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 (d) Indirect or inadvertent residues

. T olerances are established for indirect or inadvertent residues of the herbicide prometryn , 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 prometryn ([2,4

- bis(isopropylamino)

- 6

- methylthio

- s

- triazine] in or on the following raw agricultural commodities:”

The following data gap has bee n identified:

* Nature of the Residue Study in a Root crop; OCSPP 860.1300 (d epending on results of the root crop metabolism study, additional field trial data could be required ).

Note to PM: Concurrent with the establishment of the HED

- recommended tolerance s for
residues in/on dillweed, fresh leaves and dill, dried leaves, the established tolerance of 0.3 ppm in/on dill with regional restriction should be removed in 40 CFR §180.222 (c)

.

A human

- health risk assessment is forthcoming (DP# 403975 )

.

Background

The chemical structure and nomenclature of prometryn and the triazine impurities GS

- 11354 and
GS

- 26831 are presented in Table 1. The physicochemical properties of the technical grade of prometryn are presented in Table 2.

Table 1. Prometryn Nomenclature.

Chemical structure

Common name Prometryn Company experimental name G

- 34161

IUPAC name N,N'

- diisopropyl

- 6

- (methylthio)

- 1,3,5

- triazine

- 2,4

- diamine

CAS name N,N'

- bis(1

- methylethyl)

- 6

- (methylthio)

- 1,3,5

- triazine

- 2,4

- diamine
CAS registry number 7287

- 19

- 6

End

- use product (EP) Caparol ® 4L (4 lb/gal FlC; EPA Reg. No. 100

- 620) Prometryn 4L Herbicide (4 lb/gal FlC; EPA Reg. No. 66222

- 15) Triazine Impurity
GS

- 11354

N

N N N H 2

N H S C H 3 C H 3 C H 3

2

- amino

- 4

- iospropylamino

- 6

- methylthio

- s

- triazine N

N N N H

N H S C H 3 C H 3 C H 3 C H 3

C H 3

Page 4 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525

Table 1. Prometryn Nomenclature. Triazine impurity
GS

- 26831

N

N N N H 2

N H 2 S C H 3

2,4

- bis

- amino

- 6

- methylthio

- s

- triazine

Table 2. Physicochemical Properties of Prometryn.

Parameter Value Reference
Melting range 118

- 120 ° C Memo, C. Swartz, 08

- DEC

- 1994; D207139
pH 6.7 at 20oC (saturated solution) Density 1.16 g/mL at 20oC Water solubility 33 ppm at 20oC Solvent solubility 10

- 30 g/100 mL in acetone, dichloromethane, methanol, octanol, and toluene at 20oC
Vapor pressure 8.54 x 10 - 7 mm Hg at 25oC
Dissociation constant, pK
a 4.09 at 20oC Octanol/water partition
coefficient K OW = 2140 at 25oC

UV/visible absorption spectrum Not available.

860.1200 Directions for Use

The end

- use product relevant to this registration action is Caparol ® 4L (EPA Reg. No. 100

- 620) registered to Syngenta. Th i s product is formulated as a FlC and contain s 44.0

- 44.4% prometryn (equivalent to 4.0 lb ai/gal). A summary of the proposed use directions for prometryn on the requested crops is presented in Table 3. The petitioner submitted a Section B and draft labeling. On the labeling

, it says to follow all applicable directions, restrictions, requirements, and precautions on the EPA

- registered Caparol ® 4L label.

Table 3. Summary of Directions for Use of Prometryn.

Applic. Timing, Type, and

Equip. Formulation [EPA Reg. No.] Max. Applic. Rate (lb

ai/A) Max. No. Applic. per

Season Max. Seasonal Applic. Rate

(lb ai/A) PHI (days) Use Directions and
Limitations

Snap Bean

Groundboom Chemigation Caparol ® 4L,
44 % prometryn (ai), 4 lb ai/gal liquid
formulation [100

- 620] 1.5 1 1.5 lb ai/A

per crop

cycle 52 days Can be applied preemergence (post planting). Do not use on sand or loamy sand soil.

Dill

Groundboom Chemigation Caparol ® 4L,
44 % prometryn (ai), 4 lb ai/gal liquid
formulation 1.6 1 1.6 lb ai/A

per crop

cycle 30 days Can be applied either pre

emergence (post planting) or post

- emergence. Do not use on sand or loamy
sand soil.

Page 5 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525
Table 3. Summary of Directions for Use of Prometryn.

Applic. Timing, Type, and

Equip. Formulation [EPA Reg. No.] Max. Applic. Rate (lb

ai/A) Max. No. Applic. per

Season Max. Seasonal Applic. Rate

(lb ai/A) PHI (days) Use Directions and
Limitations

[100

- 620]

Conclusions : The proposed use directions are adequate to allow evaluation of the residue data relative to the proposed use s.

860.1300 Nature of the Residue

- Plants

Residue Chemistry Chapter of the Prometryn RED, C. Swartz 08

- DEC

- 1994; D207139 Memo, W. Wassell, 22

- DEC

- 2010; D382622

Acceptable cotton and celery metabolism studies were previously reviewed. The 1994 Residue Chemistry Chapter concluded that the qualitative nature of the residue in plants was adequately
understood for the registered/proposed uses at that time ( including registered uses on celery, cotton, and pigeon peas, and proposed uses on parsley, dill, and sesame) . The results of the
metabolism studies showed metabolic pathways involving N

- dealkylation and hydrolysis of prometryn. HED determined that the residue of concern in plants consists of the parent, prometryn per se , which is the currently regulated residue. HED concluded that if other major uses were registered in the future, additional metabolism studies would be required.

The petitioner recently submitted a metabolism study in rice which was reviewed as part of the following memorandum: S. Levy, 13

- MAR

- 2013; D 398563. Although the rice metabolism study was deemed adequate, it presents a qualitatively different metabolic profile than the celery
and cotton profiles (Memo, C. Swartz, 05

- DEC

- 1994; D208880 and 09

- DEC

- 1995; D207139, respectively). In the celery and cotton metabolism studies, parent was the major residue and in the rice metabolism study metabolite GS

- 17794 was the major residue.

Conclusions : The available cotton

, celery , and rice metabolism data are adequate to support the proposed uses ; however, no data are available reflecting metabolism in a root crop to support the proposed use s on carrot and celeriac

. OCSPP 860.1300 specifies that a me tabolism study should be submitted for each type of plant for which use is proposed or metabolism studies on three dissimilar crops must be provided which indicate a similar metabolic route. Note that IR

- 4 and Syngenta submitted a letter stating that they were working together to plan and conduct a nature of the residue study of prometryn on carrots or another root crop and asked for additional time to conduct this study (with a deadline of January 5, 2012). HED responded that this request was reasonable, considering the length of the study. HED ha s not received this root crop metabolism study and therefore t his deficiency remains outstanding

. Depending on results of the root crop metabolism study, additional field trial data could be required.

860.1300 Nature of the Residue

- Livestock

Residue Chemistry Chapter of the Prometryn RED, C. Swartz 08

- DEC

- 1994; D207139

The nature of the residue in livestock is adequately understood based on acceptable poultry and ruminant metabolism studies. The residue of concern (and that which should be regulated) in
livestock is the parent, prometryn per se . As in plants, the metabolism of prometryn in livestock
involve s N

- dealkylation along with hydrolysis and/or amino acid conjugation.

Page 6 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 860.1340 Residue Analytical Methods

Residue Chemistry Chapter of the Prometryn RED, C. Swartz 08

- DEC

- 1994; D207139 DER References: 48834201.der.doc, 48834202.de2.doc, and 48834202.de 2.doc

Enforcement methods : Adequate enforcement methodology is available to enforce the proposed
tolerances. The FDA PESTDATA database (dated JUN

- 2005) indicates that prometryn is completely recovered (>80% recovery) using the mul tiresidue method (MRM) in the Pesticide Analytical Manual, Volume I (PAM, Vol. I) Section 302 and partially recovered (22

- 87% recovery) using Sections 303 and 304, with the recovery varying depending upon the choice of Florisil system used.

In addition, a n acceptable GC/FPD/S method, Ciba

- Geigy Method AG

- 559, is available for use as a single analyte confirmatory method. Method AG

- 559 has undergone a successful independent laboratory validation (ILV) and was radiovalidated using samples from the celery

met abolism study; however, these samples contained no detectable residues of prometryn. HED previously concluded that Method AG

- 559 is acceptable for enforcement purposes, pending completion of a successful Agency method validation trial. The Residue Chemis try Chapter of the Prometryn RED also required radiovalidation of the method using samples from the cotton metabolism study.

In response to the radiovalidation data requirements, Syn genta submitted a method description and validation data for a GC/NPD method, Method No. AG

- 673, for the determination of prometryn residues in/on cotton matrices . The method determines residues of prometryn and its
metabolites GS

- 11354 and GS

- 26831 in cotton s eed and gin byproducts.

Briefly, samples of homogenized cotton seed and gin byproducts are extracted with methanol/water at reflux, and the extract is concentrated and acidified prior to cleanup by C

- 18
solid

- phase e xtraction (SPE) and then strong

- catio n exchange SPE. The extract is then basified, partitioned into dichloromethane/ethyl acetate, and dissolved in toluene/methanol for analysis by
GC/NPD. The validated limit of quantitation (LOQ) is 0.05 ppm for each analyte in each commodity.

The metho d was adequately validated using samples of cotton seed and gin byproducts fortified with a mixed standard of prometryn and metabolites at 0.05, 0.1, and 1.0 ppm . Recoveries were in the respectable range. Method AG

- 673 specifies that analyte residues may be confirmed by equipping the GC system with a flame photometric detector (FPD) , as described for Method AG

559. The extraction procedures of Method AG

- 673 are similar to those of AG

- 559.

Adequate radiovalidation data were submitted demonstrating that M ethod AG

- 673 adequately extracts aged residues of prometryn and GS

- 11364 from samples of cotton gin byproducts. Although no residues of prometryn, GS

- 11364, or GS

- 26831 were detected in the cotton seed samples, and no residues of GS

- 26831 were detected in the cotton gin byproducts samples used for radiovalidation, no residues of these compounds were found in cotton seed samples in the cotton metabolism study, and the levels of GS

- 26831 found in cotton stalk samples in the cotton metabolism study were below the LOQ of Method AG

- 673.

Method AG

- 673 was previously proposed for enforcement purposes for cotton seed and gin byproducts. No independent laboratory validation (ILV) data were submitted for Method AG

673; however, adequate ILV data have been submitt ed previously for Method AG

- 559 ( Memo,

Page 7 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 E. Zager, 24

- MAY

- 1991; DP# 160100). HED will not require ILV data for Method AG

- 673. Methods AG

- 673 and Method AG

- 559 are both considered adequate for enforcement purposes.

Data

- collection methods : Samples of snap beans and dill from the magnitude of the residue and processing studies were analyzed for residues of prometryn and the triazine impurities GS

- 11354 and GS

- 26831 using methods derived from Method AG

- 559. Modifications to Method AG

- 559 were implemented to improve method performance.

Snap Beans: Briefly, homogenized samples were extracted with methanol:water (90:10, v:v) at reflux for one hour, and filtered. Half of the extract was acidified with 1 N hydrochloric acid, and it was concentrated by rotary evaporation. The aqueous phase was made basic (pH 9.5

- 10 using 50% sodium hydroxide) and partitioned with ethyl acetate. The ethyl acetate phase was concentrated to near dryness and brought to volume with ethyl acetate for analysis by
GC/FPD /S . Extract s were stored refrigerated (1

- 11°C) if not analyzed immediately after
extraction.

Dill: Briefly, samples of homogenized fresh or dried dill leaves/stems, and seed were extracted with methanol:water (90:10, v:v) at reflux for one hour, and filtered. An aliquot of the extract was concentrated, acidified with 1 N hydrochloric acid, and partitioned twice with hexane. The aqueous phase was made basic (pH >9 using 50% sodium hydroxide), diluted with pH 9 water, and cleaned up by Strata

- X (weak cation exchang e) solid

- phase extraction; residues were eluted
with methanol. The eluate was then diluted with methanol and 10 mM ammonium acetate for analysis by LC/MS/MS.

The method s w ere validated prior to and in conjunction with the analysis of field trial samples. The LLMV was 0.05 ppm for each analyte in each matrix. Individual LOQ s and limits of detection (LODs) were calculated statistically for each analyte in each matrix using the
validation data at the LLMV.

The methods were adequately validated prior to an d concurrent ly with the analysis of treated samples. The fortification levels were adequate to bracket residues found in treated samples. Method verification and concurrent method recoveries were generally within the acceptable range of 70

- 120% for snap beans, snap bean plants, dill fresh, dill dried, and dill seed fo rtified with each analyte at 0.05

- 0.5 ppm.

Conclusions : The submitted residue analytical methods data are adequate to satisfy data requirements for the subject action. Acceptable enforcement methodology is available for tolerance enforcement purposes for t he proposed uses, and adequate data

- collection methods
were used in the submitted field trial and processing studies.

860.1360 Multiresidue Methods

The FDA PESTDATA database (dated JUN

- 20 05) indicates that prometryn is completely recovered (>80% recovery ) using the multiresidue method (MRM) in the Pesticide Analytical Manual, V olume I ( PAM, Vol. I ) Section 302 and partially recovered (22

- 87% recovery ) using Sections 303 and 304, with the recovery varying depending upon the choice of Florisil system
used.

Page 8 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 860.1380 Storage Stability

Residue Chemistry Chapter of the Prometryn RED, C. Swartz 08

- DEC

- 1994; D207139 DER References: 48834201.der.doc, 488342 02.de2.doc, and 48834202.de2.doc

Storage stability data are available for fortified samples of celery, cotton seed , fresh and dried parsley, pigeon peas, and sesame seed. Residues of prometryn and the impurities/ metabolites
GS

- 11354 and GS

- 26831 were found to be stable in /on cotton seed and celery samples stored
frozen at

- 20 ° C for up to 37 months, in /on fresh and dried parsley samples stored frozen for up to 21.7 months, and in /on sesame seed stored frozen for up to 14 months. Residues of prometryn

p er se were found to be stable in pigeon peas stored at

- 12 ° C for up to 42 days.

Concurrent storage stability data were generated with snap bean s, snap bean plants, fresh and dried dill and seed matrices, as well as dill oil

. For all matrices, u ntreated s amples were fortified
with prometryn, GS

- 11354

, and GS

- 26831 at 0.5 ppm for each analyte and stored frozen under
conditions similar to those of the field samples. The data demonstrate that residues of prometryn, GS

- 11354, and GS

- 26831 were stable in/on snap beans and snap bean plants stored frozen for up to 401

- 402 days (13.2 months)

, up to 841 days (27.6 months) in/on fresh dill leaves/stems, up to 842 days (27.7 months) in/on dried dill leaves/stems, up to 836 days (27.5 months) in/on dill seed and up to 843 days (27.7 months) in/on dill, oil.

The storage duration s and conditions of samples from the crop field trials submitted to support this petition are presented in Table 4

.

Table 4

. Summary of Storage Conditions and Duration s of Samples from Crop Field Trial Studies.

Matrix Storage Temperature (°C) Actual Storage
Duration 1 Interval of Demonstrated Storage Stability

Snap beans ≤

− 2 269

- 338 days (8.8

- 11.1 months) 402 days (13.2 months); concurrent storage stability data. Snap bean plants ≤

− 2 267

- 337 days (8.8

- 11.1 months) 401 days (13.2 months); concurrent storage stability data.

Dill, fresh leaves/stems

− 20 538

- 933 days (17.7

- 30.7 months) 841 days (27.6 months); concurrent storage stability data.

Dill, dried leaves/stems

− 20 932 days (30.6 months) 842 days (27.7 months ); concurrent storage stability data.

Dill, seed

− 20 501

- 900 days (16.5

- 29.6 months) 836 days (27.5 months ); concurrent storage stability data.

Dill, oil

− 20 918 days (30.2 months) 843 days (27.7 months );

concurrent storage stability data.

1 From harvest to extraction for analysis. Snap bean matrices: samples were analyzed within 1

- 9 days of extraction; D ill
matrices: sam ples were analyzed within 0

- 1 days of extraction.

Conclusions: The storage conditions and durations of s amples from the magnitude of the residue and processing studies on snap beans and dill are supported by adequate storage stability data

. These data show that corrections for storage degradation of residues are not required for the
submitted studies. Although the storage intervals tested in the concurrent storage stability study are less than the maximum storage intervals of dill field trial samples, each interval is ≥ 90% as long as the longest storage duration. These data are adequate to support the storage conditions and durations of samples from the submitted dill field trials.

Zero

- day data were not provided with the concurrent storage stability studies for the snap bean or dill matrices ; IR

- 4 is reminded that storage stability studies should always include a 0

- day

Page 9 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 sampling interval to establish the residue levels present at the time samples are placed into storage [see OCSPP 860.1380(d)(6)(i)].

860.1480 Meat, Milk, Poultry, and Eggs

Residue Chemistry Chapter of the Prometryn RED, C. Swartz 08

- DEC

- 1994; D207139

The 1994 Residue Chemistry Chapter concluded that residues of prometryn per se in meat and milk can be classified under Category 3 of 40 CFR § 180.6(a). “That it is not possible to establish with certainty whether finite residues will be incurred, but there is no reasonable expectation of finite residues

. ” No tolerances were required, and therefore

, livestock feeding
stud ies w ere not needed. In the curr ent petition, there are no significant livestock feed items; therefore, a newly constructed dietary burden was not warranted for this petition. Pending
submission of an additional plant metabolism study , HED tentatively concludes that the Category 3 situation remains valid for this registration request.

860.1500 Crop Field Trials

Dill

DER Reference: 4 8834202 .de 1 .doc

Two dill field trials were conducted in the United States during the 2008 and 200 9 growing season in North American Free Trade Agreement (NAFTA) Growing Zones 5 (OH) and 11 (WA). Each trial site consisted of one untreated plot and one treated plot. The treated plots received a single foliar broadcast application of a 4 lb ai/gal susp ension

- concentrate (SC) formulation of prometryn (Caparol ® 4L ) at 1.62 or 1.70 lb ai/A (~1X) when plants were at the vegetative growth stage. Applications were made using ground equipment in 34 or 38 gal/A spray volumes; no adjuvants were added to the spr ay mixture. Fresh dill leaves with stems were harvested at commercial maturity (pre

- bloom) at PHIs of 27 (untreated only) or 29 days, and dill seed was harvested at seed maturity at PHIs of 62 or 68 days. At one trial, additional fresh dill
leaves with s tems were harvested and dried to generate dried dill leaves with stems. Residue
decline was not evaluated.

Following a single foliar broadcast application of the 4 lb ai/gal SC formulation of prometryn to
dill at 1.6

- 1.7 lb ai/A, prometryn residues (and per

- trial averages) were <0.05

- 0.10 (<0.05

- 0.077) ppm in/on fresh dill leaves/stems. For dried dill, a single foliar broadcast application of the 4 lb ai/gal SC formulation of prometryn was applied to one dill trial at 1.6 lb ai/A; prometryn residues (and per

- trial average) were 0.26

- 0.29 (0.28) ppm in/on dried dill leaves/stems. Prometryn residues were below the LLMV (<0.05 ppm) in/on dill seed (2 trials) harvested 62 or
68 days after treatment ( DAT ) . Residues of the triazine metabolites (GS

- 11354 and G S

- 26831) were each less than the LLMV (<0.05 ppm) in/on all samples of dill fresh leaves/stems, dried leaves/stem, and seeds. There was no residue

- decline study.

Page 10 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525

Table 5 . Summary of Residue Data from Dill Field Trials with Prometryn.

Commodity Total Applic. Rate

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

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

Prometryn
Dill, fresh
leaves/stems 1.62, 1.70 29 2 <0.05 0.10 <0.05 0.077 <0.063 <0.063 N/A

Dill, dried
leaves/stems 1.62 29 1 0.26 0.29 0.28 0.28 0.28 0.28 N/A

Dill, seed 1.62, 1.70 62, 68 2 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 N/A

1 Only the residue of concern (prometryn) is summarized. Except for sample min/max, values reflect per

- trial averages; n = no. of field trials. NA = not applicable. For calculation of median, mean, and standard deviation, the LLMV (0.05 ppm) was used for any results reported as <LLMV.

2 LAFT = lowest

- averag e field trial; HAFT = highest

- average field trial

.

Conclusions : Adequate documentation was provided for the field and laboratory portions of the submitted field trials for dill. An acceptable method was used for residue quantitation, and the study is su pported by adequate storage stability data. The number and locations of the crop field trials are in accordance with OPPTS Guideline 860.1500 (Table 6 ). The available data will support the proposed use pattern.

Table 6 . Trial Numbers and Geographical Locations.

NAFTA Growing Zones Dill

Submitted Requested

Canada U.S. 1

5 1

-- -- 11 1

-- -- Total 2

-- 2

1 As per OCSPP 860.1500, Table 1 for dill.

Currently there is a prometryn tolerance established in/on dill, leaves at 0.3 ppm with regional restriction. This tolerance level is adequate and HED agrees with the petitioner to remove the regional restriction for this crop. However, the tolerance def inition should be changed to Dillweed, fresh leaves

. A revised Section F should be submitted. The data show that residues concentrate by a factor of 3.6 in/on dill dried leaves; therefore

, HED agrees with the petitioner’s requested tolerance of 1.1 ppm i n/on dill, dried leaves.

Snap Beans

DER Reference: 48834201.der.doc

Seven snap bean field trials were conducted in the United States during the 2007 growing season in NAFTA Growing Zones 1 (NY), 2 (MD), 3 (FL), 5 (MI, OH, and WI; 1 trial each)

, and 11 (WA). Each trial site consisted of one untreated plot and two treated plots. The treated plots received a single preemergence (1

- 2 days after planting) broadcast application of a 4 lb ai/gal SC formulation of prometryn (Caparol ® 4L ) to the soil a t 0.74

- 0.76 lb (0.5X) ai/A or 1.46

- 1.56 lb
ai/A (~1X) . Applications were made using ground equipment in 25

- 34 gal/A spray volumes; no adjuvants were added to the spray mixture. Snap beans (pods with seed) and snap bean plants (foliage with pods and seed) were harvested at commercial maturity at PHIs of 52

- 68 days.
Residue decline was not evaluated.

Following a single preemergence broadcast application of the 4 lb ai/gal SC formulation of

Page 11 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 prometryn to the soil at 0.74

- 0.76 lb ai/A (0.5X) , prometryn resi dues were below the LLMV (<0.05 ppm) in/on all samples of snap beans harvested 52

- 68 days after treatment. Residues of prometryn (and per

- trial averages) were <0.05

- 0.077 (<0.05

- <0.064) ppm in/on snap bean plants; quantifiable residues of prometryn were o bserved in/on only one snap bean plant sample. Residues of the triazine metabolites (GS

- 11354 and GS

- 26831) were each less than the LLMV (<0.05 ppm) in/on all samples of snap beans and snap bean plants.

Following a single preemergence broadcast applica tion of the 4 lb ai/gal SC formulation of prometryn to the soil at 1.46

- 1.56 lb ai/A (~1X) , prometryn residues were below the LLMV (<0.05 ppm) in/on all samples of snap beans harvested 52

- 68 days after treatment. Residues of prometryn (and per

- trial avera ges) were <0.05

- 0.061 (<0.05

- <0.055) ppm in/on snap bean plants; quantifiable residues of prometryn were observed in/on only one snap bean plant sample. Residues of the triazine metabolites (GS

- 11354 and GS

- 26831) were each less than the LLMV (<0.05 ppm) in/on all samples of snap beans and snap bean plants. There was no residue

- decline study.

Table 6 . Summary of Residue Data from Snap Bean Field Trials with Prometryn.

Commodity Total Applic. Rate

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

n Sample
Min. Sample
Max. LAFT 2 HAFT 2 Median Mean Std.
Dev.
Prometryn Snap beans 0.74

- 0.76 52

- 68 7 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 N/A
Snap bean plants 7 <0.05 0.077 <0.05 <0.064 <0.05 <0.052 0.005
Snap beans 1.46

- 1.56 52

- 68 7 <0.05 <0.05 <0.05 <0.05 < 0.05 <0.05 N/A
Snap bean plants 7 <0.05 0.061 <0.05 <0.055 <0.05 <0.051 0.002

1 Only the residue of concern (prometryn) is summarized. Except for sample min/max, values reflect per

- trial averages; n = no. of field trials. NA = not applicable. For calculation of median, mean, and standard deviation, the LLMV (0.05 ppm) was used for any results reported as <LLMV.

2 LAFT = lowest

- averag e field trial; HAFT = highest

- average field trial.

Conclusions : Adequate documentation was provided for the field and laboratory portions of the
submitted field trials for snap beans . An acceptable method was used for residue quantitation, and the study is supported by adequate storage stability data. The number and locations of the crop field trials are in accordance with OPPTS Guideline 860.1500 (Table 7 ). The available data will support the proposed use pattern.

Table 7 . Trial Numbers and Geograph ical Locations

.

NAFTA Growing Regions Snap Bean

Submitted Requested 1

Canada U.S.

1 1

-- 1/1

2 1 1/1

3 1 1/1

5 3 3/2

10

-- 1/0

11 1 1/1

Total 7

-- 8/6

1 As per OCSPP 860.1500, Table 5 for snap bean. The second number reflects a 25% reduction in the number of trials allowed for the crop as a representative commodity in support of a crop group/subgroup tolerance or when application results in no quantifiable residues.

Page 12 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 The submitted prometryn data for snap beans are adequate and will support a tolerance of 0.05 ppm for bean, snap, succulent. The Organization for Economic Co

- operation and Development (OECD) tolerance

- calculation procedures were not used to d etermine an appropriate tolerance level for bean, snap, succulent because all of residues values were below the LOQ. The petitioner proposed a tolerance for residues of prometryn in/on bean, forage; however, a tolerance is not necessary for this commodity as it is an insignificant livestock feed item. A revised Section F should be submitted.

860.1520 Processed Food and Feed

DER Reference: 48834202 .d e2 .doc

Note: Dried leaves/stems, which were previously considered a processed commodity of herbs,

are now considered to be a raw agricultural commodity [based on the minutes of the Chemistry Science Advisory Council (ChemSAC) meeting of 14

- JAN

- 2009]; refer to the 860.1500 DER for MRID 48834202 (48834202.der1) for the fresh and dried dill residue data.

Th e IR

- 4 submitted a processing study for prometryn on dill. In a dill field trial conducted in NAFTA Growing Zone 11 (WA) during the 2008 growing season, a single foliar broadcast application of a 4 lb ai/gal SC formulation of prometryn (Caparol ® 4L ) was m ade at 1.62 lb ai/A (~1X) when plants were at the vegetative growth stage. Applications were made using ground equipment in a 34 gal/A spray volume; no adjuvants were added to the spray mixture. Dill leaves with stems were harvested 49 days after applica tion and processed on the day of harvest into oil using simulated commercial procedures.

Residues of prometryn, GS

- 11354

, and GS

- 26831 were each less than the LLMV (< 0.05 ppm) in/on dill fresh leaves/stems harvested 49 days following a foliar broadcast application at 1.6 lb ai/A. Residues of prometryn in dill oil processed from treated dill were 0.33 ppm, for a processing factor of >6.6x. Residues of GS

- 11354 and GS

- 26831 were each below the LLMV (0.05 ppm) in both dill fresh leaves/stems and processed oil.

The processing factor (>6.6x) for dill oil indicates that residues of prometryn concentrate with processing. HED does not require residue data for dill oil (OCSP P 860.1000) and therefore, a maximum theoretical concentration factor is not provided under OCSPP 860.1520.

Table 8

. Residue Data from Dill Seed Processing Study with Prometryn.

Trial: City, State; Year ( Trial ID No.) Applic.
Rate (lb ai/A) PHI (day s) Dill Commodity Residues (ppm) 1 Prometryn Processing

Factor 2 Prometryn GS

- 11354 GS

- 26831

Moxee, WA; 2008 (A3040.08

- WA*25) 1.62 49 Fresh leaves/stems <0.05 <0.05 <0.05

-- Oil 3 0.33, 0.32 [0.33] <0.05, <0.05 [<0.05] <0.05, <0.05 [<0.05] >6.6x

1 All residues are the mean of duplicate analyses (injections). The LLMV (0.05 ppm) was used as the reporting limit for each analyte.

2 Processing factors were calculated using only the prometryn residues and were calculated by the study reviewer, usin g the LOQ for residues reported <LOQ.

3 The oil sample was extracted and analyzed in duplicate (each replicate was also injected twice). The average of the duplicat e analyses is presented in brackets.

Conclusions: The submitted dill seed processing study is adequate. Dill fresh leaves/stems bore

non

- quantifiable residues of prometryn, GS

- 11354, and GS

- 26831 following application of the 4 lb ai/gal SC formulation of prometryn at 1.62 lb ai/A. Although the guidelines require that

Page 13 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 processing studies b e conducted at an exaggerated rate to obtain quantifiable residues in the unprocessed commodity, quantifiable residues were observed in the processed commodity. An acceptable method was used for quantitation of prometryn residues and the sample storage

co nditions and durations are supported by adequate storage stability data.

The processing factor (>6.6x) for prometryn in dill oil indicates that residues of prometryn concentrate with processing. Residues of GS

- 11354 and GS

- 26831 were each below the LLMV (0.05 ppm) in dill oil. The petitioner recommended a tolerance for residues of prometryn in/on dill, oil; however, a tolerance is not necessary for this commodity. A revised Section F should
be submitted.

860.1650 Submittal of Anal ytical Reference Standards

Analytical standards for prometryn are currently available [ expiration 01

- APR

- 20 1 6 ] in the EPA National Pesticide Standards Repository (personal communication with Theresa Cole , ACB, 03

- APR

- 2013 ).

860.1850 Confined Accumulation in Rotational Crops

Residue Chemistry Chapter of the Prometryn RED, C. Swartz , 08

- DEC

- 1994; D207139

The nature of the residue in rotational crops is adequately understood. The metabolism of prometryn in rotational crops is similar to that o f celery and cotton and involves dealkylation, oxidation, hydroxylation, deamination, and conjugation.

Ring

- labeled [ 14 C]prometryn was applied to trial sites containing sandy loam soil in MS and CA. At the MS site, prometryn was applied at 2.8 lb ai/A at the time of planting to a primary crop of cotton. Further applications were made when the plants were 3

- 6" tall (0.65 lb ai/A) and 12

- 18" tall (1.6 lb ai/A) for a total application rate of 5.0 lb ai/A. At the CA site, a single application of prometryn w as made at 3.2 lb ai/A when the primary crop, celery, was immature. After harvesting the primary crop, the rotational crops were planted: lettuce was planted 111 and 229 (MS) and 193 (CA) days after the final prometryn treatment (DAT), wheat was planted 111 (MS) and 350 DAT (CA), soybeans were planted 193 (CA) and 328 DAT (MS), and table beets were planted 193 (CA) and 249 DAT (MS).

The total radioactive residues ( TRR ) in all raw agricultural commodities ( RACs ) from all PBIs at both sites exceeded 0.01 p pm. The TRR values ranged 0.030

- 0.447 ppm. Prometryn and t he following metabolites were identified in the rotational crops: GS

- 11957, GS

- 17794, MCO

- III

25, MCO

- IV

- 34, GS

- 11526 and its side chain alcohol, along with unidentified acetyl and sugar conjugat es of triazines. Although 14 C

- residues were not quantified, greater than 50% of the TRR appeared to consist of triazine

- containing metabolites. Based on these data, the registrant conducted limited field rotational crop studies.

Page 14 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 860.1900 Field Accumulation in Rotational Crops

Memo, C. Swartz, 05

- DEC

- 1994; D207717 DP#s 315763 & 357098

No new field accumulation data in rotational crops were submitted with this petition. Previously reviewed studies include a limited rotational crop study ( Memo, G. Kramer, 03

- SEP

- 1993;
DP#19111 8 ) reflecting application to a primary crop or bare soil at 5

- 12 lb ai/A, with rotational

crops planted at PBIs of 3

- 4 and 7

- 9 months, and an extensive rotational crop study ( Memo, C. Swartz, 05

- DEC

- 1994; D207717 ) on s mall grains reflecting application at 5

- 6 lb ai/A and a 3

- to 6

- month PBI. Based on these studies, HED previously recommended a rotational crop restriction of 8 months for root crops, required additional rotational crop data for leafy vegetables, and reco mmended a 3

- month PBI with establishment of rotational crop tolerances for small grain forage, hay, and straw. The requested tolerances have been established.

Additional data reflecting application to a primary crop or bare soil at 3.2 lb ai/A (

~ 0.5X

max imum proposed seasonal rate for carrot) and PBIs of 5 and 9 months were submitted ( DP#s 315763 & 357098 )

. These data show that residues of prometryn are non

- quantifiable in leafy vegetables at both PBIs, and in root crops and small grains at the 9

- month PBI.

Conclusion s: HED previously determined that the minimum plantback restrictions for crops not listed on prometryn labels should be as follows : (1) f ollowing maximum application to any primary crop at up to 3.2 lb ai/A: a 5

- month PBI for leafy veget ables, an 8

- month PBI for root crops, and a 9

- month PBI for small grains and all other crops. (2) Following application at rates higher than 3.2 lb ai/A and up to 6.0 lb ai/A: an 8

- month PBI for root crops; rotation to all other crops is prohibited. The PBI restrictions listed on the EPA

- registered Caparol ® 4L Label remain appropriate for the proposed crops.

860.1550 Proposed Tolerances

HED has determined that the residue of concern for tolerance enforcement in the subject and rotated crops is prometr yn per se

. In accordance with the most recent guidance concerning tolerance expressions, HED recommends that the tolerance expression for 40 CFR § 180.222 be changed as indicated :

“(a) General. Tolerances are established for residues of the herbicide prometryn , 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 prometryn ([2,4

- bis(isopropylamino)

- 6

- methylthio

- s

- triazine] in or on the followin g raw agricultural
commodities:

Snap, bean, succulent

................................ ........................... 0.05 ppm Dillweed, fresh leaves

................................ .......................... 0.30 ppm Dill, dried leaves

................................ ................................ .. 1.1 ppm
and

(d) Indirect or inadvertent residues

. T olerances are established for indirect or inadvertent
residues of the he rbicide prometryn , including its metabolites and degradates, in or on the
commodities in the table below. Compliance with the tolerance levels specified below is to be

Page 15 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 determined by measuring only prometryn ([2,4

- bis(isopropylamino)

- 6

- methylthio

- s

- triazin e] in or on the following raw agricultural commodities:”

The proposed tolerances and the HED ’s recommendations are presented in Table 9

. The submitted prometryn data for snap beans are adequate and will support a tolerance of 0.05 ppm for bean, snap, succulent. The OECD tolerance

- calculation procedures were not used to determine an appropriate tolerance level for bean, snap, succulent because all of the residues values were below the LOQ. The petitioner propos ed a tolerance for residues of prometryn in/on bean, forage; however, a tolerance is not necessary for this commodity as it is an insignificant
livestock feed item.

Currently there is a prometryn tolerance established in/on dill, leaves at 0.3 ppm with regional restriction. This tolerance level is adequa te and HED agrees with the petitioner to remove the regional restriction for this crop. The data show that residues concentrate by a factor of 3.6 in/on dill dried leaves; therefore HED recommends a tolerance of 1.1 ppm in/on dill, dried leaves. The peti tioner recommended a tolerance for residues of prometryn in/on d ill, oil; however, a
tolerance is not ne cessary for this commodity.

The proposed tolerances should be revised to reflect the HED

- recommended tolerance levels and correct commodity definition s as specified in Table 9

. A revised Section F is requested.

There are currently no establishe d Codex MRLs for prometryn.

Table 9

. Tolerance Summary for Prometryn.

Commodity Proposed Tolerance (ppm) HED

- Recommended Tolerance (ppm) Comments
C orrect Commodity D efinition Bean, snap, succulent 0. 05 0.05 Bean, forage 0.0 9

-- A tolerance is not necessary for this commodity.
Dill, leaves 0. 3 0.30 Concurrent with granting a national registration, the removal of the regional restrictions on dill should be removed.
Dillwee d, f resh leaves
Dill, dried leaves 1.1 1.1
Dill, oil 1.3

-- A tolerance is not necessary for this commodity.

Attachments

Attachment 1: International Residue Limits Sheet

RDI: RAB1 ( 17

- APR

- 2013 ) Petition Number: PP# 2 E 8052
DP Number: 4 08525
PC Code: 080805 S. Levy :S10 953 :Potomac Yard 1 :703

- 305

- 0783 :7509P:RAB1

Template Version September 2005

Page 16 of 17Prometryn Summary of Analytical Chemistry and Residue Data DP# 408525 International Residue Limits



### Prometryn (PC Code 080805; 15

- MAR

- 2013) Summary of US and International Tolerances and Maximum Residue Limits Residue Definition : prometryn (2,4

- bis(isopropylamino

- 6

- methylthio

- s

- triazine)

US Canada Mexico 2 Codex
40 CFR 180. 222
Plants: prometryn (2,4

- bis(isopropylamino

- 6

- methylthio

- s

triazine) None None

Commodity 1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico 2 Codex Bean, snap, succulent 0.05 Dillweed, fresh leaves 0.30 Dill, dried leaves 1.1

Completed: M. Negussie; 22

- MAR

- 2013

1 Includes only commodities of interest for this action. Tolerance values should be the HED recommendations and not those proposed by the applicant.

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.

Page 17 of 17