Document ID: EPA-HQ-OPP-2007-1161-0006
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-11-14T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

	OFFICE OF

	PREVENTION, PESTICIDES, AND

	TOXIC SUBSTANCES

MEMORANDUM

Date:		26-June-2008

Subject:	Tetraconazole.  Residue Chemistry Summary for Application of
Tetraconazole to Grape.  

PC Code:  120603	DP Barcode:  353020

Decision No.:  385790	Registration No.:  not applicable

Petition No.:  7E7273	Regulatory Action:  Section 3

Risk Assessment Type:  not applicable	Case No.:  none

TXR No.:  not applicable	CAS No.:  112281-77-3

MRID Nos:  47270101and 47435201	40 CFR:  180.557

From:		Tom Bloem, Chemist

Registration Action Branch 1, Health Effects Division (RAB1/HED); 7509P

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

RAB1/HED (7509P)

To:			Mary Waller/Lisa Jones (RM 21)

Registration Division (7505P) 

The Interregional Research Project No. 4 (IR-4) proposed application of
tetraconazole
(1-[2-(2,4-dichlorophenyl)-3-(1,1,2,2-tetrafluoroethoxy)propyl]-1H-1,2,4
-triazole) to grape.  In conjunction with this request, the petitioner
proposed the establishment of a 0.15 ppm permanent tolerance for
tetraconazole per se residues in/on grape. 

The subsequent text refers to the “free triazole metabolites” and
the “non-free triazole metabolites.” These terms refer to the
following compounds:  (1) free triazole metabolites:  1,2,4-triazole (T;
PC Code 600074)), triazolyl alanine (TA; PC Code 600011), triazolyl
acetic acid (TAA; PC Code 600082), triazolyl hydroxypropionic acid
(THP), and/or all labile conjugates of these compounds and (2) non-free
triazole metabolites:  tetraconazole metabolites of concern for risk
assessment other than T, TA, TAA, THP and/or all labile conjugates of
these compounds.  

Executive Summary

Background:  Tetraconazole is a systemic fungicide and is a member of
the conazole/triazole class of pesticides.  Tetraconazole acts by
inhibiting the metabolic pathway leading to fungal sterol production
(sterol-demethylation inhibitor (DMI)).  Tetraconazole is currently
registered for application to sugar beet, peanut, pecan, and soybean
with tolerances ranging from 0.05-0.80 ppm (40 CFR 180.557).  Tolerances
as a result of secondary residues are also established in/on poultry and
ruminant commodities (0.01-0.25 ppm).  

Based on the revisions made to the livestock feedstuff portion of Table
1 (communication from J. Stokes), there are no grape feed commodities. 
In addition, grape vines are not rotated.  Therefore, the
nature/magnitude of the residue in livestock and rotational crops are
not relevant to the current petition and will not be discussed.  

Direction for Use:  The petitioner is requesting registration for
application of Mettle( 125ME Fungicide (emulsifiable concentrate (EC); 1
lb ai/gallon; EPA Reg. No. 80289-8) to grape for control of numerous
diseases including powdery mildew and black rot.  Table 3 is a summary
of the proposed grape application scenario.  The proposed label does not
indicate a minimum spray volume for ground applications.  Based on the
submitted magnitude of the residue data, HED requests that the label
indicate a minimum spray volume of 20 gallons per acre (GPA) for ground
applications.  A revised Section B is requested.  

Nature of the Residue - Plants:  The HED Metabolism Assessment Review
Committee (MARC) reviewed the sugar beet (triazole ring labeled study),
grape (triazole and phenyl ring labeled studies), and wheat (triazole
and phenyl ring labeled studies) metabolism studies (D264157, W.
Donovan, 19-Apr-2000).  The MARC tentatively concluded that the residue
of concern in banana, peanut, and sugar beet was tetraconazole per se. 
This decision was not finalized due to uncertainty concerning the
toxicity of the free triazole metabolites, incomplete identification of
residues in wheat straw, and the lack of a phenyl-labeled sugar beet
metabolism study.  HED has subsequently determined that the free
triazole metabolites are of toxicological concern (TXR No. 0052011) and
received/reviewed the requested metabolism studies.  Since the MARC was
disbanded prior to the submission/review of the requested data and prior
to the submission of the triazole-labeled soybean study, a final
conclusion pertaining to the residues of concern in plants was not made
by the MARC.  

Based on the tentative conclusions made by the MARC, the results of the
metabolism studies, and toxicological considerations, HED concludes that
the residue of concern for tolerance enforcement in all crops is
tetraconazole per se and the residues of concern for risk assessment are
as follows:  (1) shelled pea and bean (succulent and dried): 
tetraconazole and T, TA, TAA, and all labile conjugates of these
compounds and (2) all remaining crops:  tetraconazole, M14360-alcohol
(free and conjugated), M14360-acid, M14360-DFA,
M14360-hydroxydetriazolyl-O-malonyldiglucoside, and T, TA, TAA and all
labile conjugates of these compounds.  HED notes that Syngenta developed
a common moiety method for propiconazole which employs base hydrolysis
followed by oxidation and that a similar method would be appropriate for
determination of the non-free triazole metabolites (non-free-triazole
metabolites hydrolyzed/oxidized to 2,4-dichlorobenzoic acid).  For a
full discussion pertaining to the residues of concern in plants see the
HED risk assessment document D331476 (M. Clock-Rust et al.,
26-Jan-2007).

Magnitude of the Residue - Grape:  IR-4 submitted field trial and
processing residue data for tetraconazole, T, TA, and TAA in/on grape. 
Twelve field trials were established during 2006 in the North American
Free Trade Agreement (NAFTA) Zones 1 (n=2), 10 (n=8), and 11 (n=2). 
Each field trial consisted of a single control plot and two treated
plots (plots A and B).  Treatment plots A and B received two airblast
applications (retreatment interval (RTI) = 14-16 days) of the 125 g/L
liquid tetraconazole formulation (1.04 lb ai/gal; emulsifiable
concentrate (EC)) at ~0.040 lb ai/acre (1x; 77-104 gallons per acre
(GPA)).  Treatment plot A received the first application 43-47 days
prior to harvest and the samples were harvested 28-31 days after the
last application (DALA).  Treatment plot B received the first
application 28-32 days prior to harvest and samples were harvested from
14-16 DALA.  At two of the trials, a third treated plot received two
airblast applications (RTI = 14-15 days) of the 125 g/L liquid
tetraconazole formulation using the application scenario employed for
plot B but at rates of ~0.200 lb ai/acre (5x).  These samples were
harvested 15 DALA and were processed into juice (cold press) and raisin
(<14% moisture) using simulated commercial practices.  

The samples were analyzed for residues of tetraconazole, T, TA, and TAA
using an adequately validated method (limit of quantitation (LOQ) = 0.01
ppm for all analyte/matrices).  However, data demonstrating the
stability of tetraconazole per se residues in/on grape (236 days) and T,
TA, and TAA residues in/on grape (236 days), grape juice (64 days), and
raisin (68 days) samples should be submitted.  Following two broadcast
foliar applications of tetraconazole totaling ~0.080 lb ai/acre (1x),
tetraconazole per se residues ranged as follows:  plot A - <0.01-0.091
ppm (average = 0.022 ppm) and plot B <0.01-0.096 ppm (average = 0.031
ppm).  Only samples from plot B were analyzed for T, TA, and TAA with
the following residues:  T:  <0.01 ppm in/on all samples; TA: 
<0.01-0.053 ppm (average = 0.016 ppm); and TAA:  <0.01-0.017 ppm
(average = 0.011 ppm).  The processing residue data yielded the
following processing factors:  tetraconazole:  juice - 0.01-0.06x and
raisin - 0.71-0.91x; T:  a processing factor could not be determined for
grape juice and raisin as residues were <LOQ in/on all the samples; TA: 
a processing factor for grape juice could not be determined as residues
were <LOQ in the RAC and processed commodity; processing factor for
raisin was determined to be >2.0x; TAA:  a processing factor could not
be determined for grape juice and raisin as residues were <LOQ in/on all
the samples.  

Since the samples from plot B employed the requested preharvest interval
(PHI) and resulted in higher tetraconazole per se residues, only these
data were used for calculation of the appropriate tolerance.  Based on
these data and the maximum residue limit (MRL) tolerance calculator (see
attachment 2), HED concludes that a grape tolerance of 0.20 ppm
tetraconazole per se residues is appropriate.  A revised Section F is
requested. 

Analytical Methods:  Adequate analytical methods are available to
enforce the currently established tetraconazole per se plant tolerances
(D259205, W. Donovan, 8-May-2000 and D280006, W. Donovan, 10-Jan-2002). 
The method employed in the field trial/processing study for
determination of tetraconazole per se employed the same extraction
solvent as that used for the enforcement method (acetone) but differed
from the current enforcement method in that the residues were quantified
via liquid chromatograph/mass spectrometry/mass spectrometry (LC/MS/MS;
enforcement method employed quantification via gas
chromatograph/electron-capture detection (GC/ECD)).  The data-collection
method also eliminated the dichloromethane partition and alumina column
purification employed in the enforcement method.  HED notes that the
independent laboratory validation (ILV) data submitted for the current
enforcement method employed grape as a sample matrix and resulted in
acceptable recoveries (D264681, W. Donovan, 7-Apr-2000).  Therefore, HED
concludes that the current enforcement method is acceptable for
enforcement of the recommended grape tolerance.  

Multiresidue Methods (MRMs) Testing:  HED has previously reviewed
information concerning the MRMs testing of tetraconazole and forwarded
these data to the Food and Drug Administration (FDA; D278236, W.
Donovan, 22-Oct-2001; D332231, T. Bloem, 13-Sep-2006).  The following
paragraph is a summary of these data.  

Tetraconazole was evaluated by GC on a ZB-1 (100% methyl siloxane)
column with ECD.  The tetraconazole retention time relative to
chlorpyrifos was 1.017.  50% full-scale deflection (FSD) was obtained
using 0.15 and 0.21 ng of chlorpyrifos and tetraconazole, respectively. 
Sugar beets were fortified at 0.05 and 0.10 ppm.  The procedural
recoveries at 0.05 ppm were 83 and 84%, and at 0.10 ppm were 81 and 85%.
 However, an interfering peak was present.  As required by Protocol D, a
florisil clean up is necessary for compounds analyzed by ECD and
matrices that produce an interfering peak at the characteristic
retention time of the analyte.  Low recovery of tetraconazole through
florisil (<10%) precluded the possibility of a cleanup for sugar beet
samples.  Peanuts were fortified at 0.03 and 0.05 ppm.  The fat content
of the peanuts and the inability for a cleanup made it impossible for
sample analysis.  It is suggested that another solid support system,
such as alumina, may be more amenable to recovery of tetraconazole from
all matrices.  However, this method is currently not encompassed by
Pesticide Analytical Methods (PAM) Volume I. 

Recommendation:  Provided revised Sections B and F are submitted, HED
concludes that the residue chemistry database supports a conditional
registration for application of the proposed tetraconazole formulation
to grape and supports establishment of a permanent tolerance in/on grape
of 0.20 ppm for tetraconazole per se residues.  The residue chemistry
database may support an unconditional registration upon submission of
storage stability data demonstrating the stability of tetraconazole per
se residues in/on grape (236 days) and T, TA, and TAA residues in/on
grape (236 days), grape juice (64 days), and raisin (68 days).  Storage
stability data for T, TA, and TAA has been requested as part of a
previous human-health aggregate risk assessment (D322215, M. Doherty, et
al., 7-Feb-2006).  Submission of the data requested in the 7-Feb-2006
document will satisfy storage stability data requirements for T, TA, and
TAA of the subject petition.  A human-health risk assessment will be
prepared as a separate document.

Detailed Considerations

Background

Tetraconazole is a systemic fungicide and is a member of the
conazole/triazole class of pesticides. Tetraconazole acts by inhibiting
the metabolic pathway leading to fungal sterol production (sterol
demethylation inhibitor (DMI)).   

 

Common name	Tetraconazole

Company experimental name	None Specified in Submission

IUPAC name	  SEQ CHAPTER \h \r 1
(±)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl-1,1,2,2-tetr
afluoroethyl ether

CAS name	  SEQ CHAPTER \h \r 1
1-[2-(2,4-dichlorophenyl)-3-(1,1,2,2-tetrafluoroethoxy)
propyl]-1H-1,2,4-triazole

CAS #	112281-77-3

Table 2:  Physicochemical Properties of the Technical Grade
Tetraconazole.

Melting point/range	Not applicable - test is a viscous liquid 	MRID
44268104; D259842, B. Kitchens, 11-Apr-2000.

pH	5.48 in DI H2O

5.47 for saturated solution at 20°C

	Density	1.4382 g/ml at 20°C

1.4252 g/ml at 30°C 

	Water solubility (PAI >94.16%)	159.31 mg/L at 25°C

	Solvent solubility	not available

Vapor pressure (PAI >99.65%)	0.13 x 102 Pa at 35.5°C

0.58 x 102 Pa at 46.5°C

2.985 x 102 Pa at 60°C	MRID 44305301; D259842, B. Kitchens,
11-Apr-2000.

Dissociation constant (Ka)	0.158 - 0.316	MRID 46055603; D294198, B.
Kitchens, 26-Jan-2004.

Octanol/water partition coefficient (PAI >99.65%)	log Pow = 3.53 at
25°C	MRID 44305301; D259842, B. Kitchens, 11-Apr-2000.

UV/visible absorption spectrum	not available

OPPTS GLN 860.1200  Directions for Use

The petitioner is requesting registration for application of Mettle(
125ME Fungicide (EC; 1 lb ai/gallon; EPA Reg. No. 80289-8) to grape for
control of numerous diseases including powdery mildew and black rot. 
Table 3 is a summary of the proposed grape application scenario.  The
proposed label does not indicate a minimum spray volume for ground
applications.  Based on the submitted magnitude of the residue data, HED
requests that the label indicate a minimum spray volume of 20 GPA for
ground applications.  A revised Section B is requested.  

Table 3:  Proposed Pecan Application Scenario.

Formulation	Rate

(lb ai/acre)	No. Apps.	RTI (days)	PHI (days)	Comments

Mettle( 125Me Fungicide; 

microemulsion; 1 lb ai/gal.; 

EPA Reg. No. 80289-8	0.03-0.04	2	14	14	-Ground (sufficient volume for
through coverage) and aerial (≥10 GPA) applications are permitted;
chemigation is prohibited.

-Do no apply more than 0.08 lb ai/acre/season.

-First application may be made pre bloom (1-3 inches of new shoot).

OPPTS GLN 860.1300  Nature of the Residue

See Executive Summary.  

OPPTS GLN 860.1340  Residue Analytical Method

47270101.der.doc (field trial and processing study); ????.der.doc
(storage stability study

Enforcement Method:  Adequate analytical methods are available to
enforce the currently established tetraconazole per se plant tolerances
(D259205, W. Donovan, 8-May-2000 and D280006, W. Donovan, 10-Jan-2002). 
The method employed in the field trial/processing study for
determination of tetraconazole per se employed the same extraction
solvent as that used for the enforcement method (acetone) but differed
from the current enforcement method in that the residues were quantified
via LC/MS/MS (enforcement method employed quantification via GC/ECD). 
The data collection method also eliminated the dichloromethane partition
and alumina column purification employed in the enforcement method.  HED
notes that the ILV data submitted for the current enforcement method
employed grape as a sample matrix and resulted in acceptable recoveries
(D264681, W. Donovan, 7-Apr-2000).  Therefore, HED concludes that the
current enforcement method is acceptable for enforcement of the
recommended grape tolerance.  

Field Trial, Processing, and Storage Stability Studies:  The field trial
and processing samples were analyzed for residues of tetraconazole, T,
TA, and TAA.  The storage stability study pertained only to
tetraconazole per se residues.  Method validation and concurrent
recovery data for tetraconazole, T, TA, and TAA were acceptable
(tetraconazole:  0.01-1.50 ppm; T, TA, and TAA:  0.01-1.00 ppm).  The
LOQ was set at the lowest limit of method validation (LLMV; 0.01 ppm for
all analyte/matrices).  Residues were <LOQ in/on all the control samples
except for control grape RAC samples collected from the field trial
study which had the following:  tetraconazole <LOQ (n=11), 0.025 ppm
(CA1), and 0.028 ppm (CA7); TA <LOQ (n= 11), 0.066 ppm (NY1), and 0.052
ppm (PA1); and TAA <LOQ (n=12) and 0.014 ppm (PA1).  The method employed
for determination of tetraconazole per se used the same solvent as the
current enforcement method (D280006, W. Donovan, 10-Jan-2002) and the
method employed for determination of T, TA, and TAA is identical to
method previously determined to be acceptable (D329379, T. Bloem,
23-Jan-2007).  HED concludes that these methods are appropriate for
data-collection purposes.  The following paragraphs below are summaries
of the tetraconazole per se and T, TA, and TAA analytical methods.  

Tetraconazole per se (Pyxant Method METH1695.00A):  The grape and grape
juice samples were extracted by homogenizing with acetone and the raisin
samples were extracted by homogenizing with acetone:water (7:3).  The
samples were centrifuged, concentrated to dryness, reconstituted in
methanol:water:formic acid (65:35:0.1), and analyzed via LC/MS/MS.  The
study indicated a LOQ of 0.01 ppm (LLMV) for all matrices.  

T, TA, and TAA (Pyxant Method 1572.02):  Briefly, the grape, grape
juice, and raisin samples were extracted by homogenizing with
methanol:water (8:2).  Aliquots of the extract were then processed
separately as described below for determination of T, TA, and TAA.  For
analysis of T, an aliquot of the sample was derivatized with dansyl
chloride to produce the dansyl derivative, which was partitioned into
ethyl acetate.  The ethyl acetate fraction was evaporated to dryness and
redissolved in ACN:water (30:70, v:v) for analysis via LC/MS/MS.  For
analysis of TA, an aliquot of the extract was passed through a Bond Elut
Certify II solid-phase extraction (SPE) column (eluted with
acetonitrile:water (8:2)).  The eluent was derivatized to the butyl
ester using HCl/butanol and then further derivatized using HFBA
(heptafluorobutyric anhydride).  The derviatized extract was evaporated
to dryness and redissolved in ACN:water (30:70, v:v) for analysis via
LC/MS/MS.  For analysis of TAA, an aliquot of the extract was passed
through a Bond Elut C18 SPE column (eluted with acetonitrile:water
(8:2)).  The eluent was derivatized using HCl/butanol esterification. 
The derviatized extract was evaporated to dryness and redissolved in
ACN:water (30:70, v:v) for analysis via LC/MS/MS.  The study indicated a
LOQ of 0.01 ppm (LLMV) for all analyte/matrix combinations.  

OPPTS 860.1360 - MRMs

HED has previously reviewed information concerning the MRMs testing of
tetraconazole and forwarded these data to FDA (D278236, W. Donovan,
22-Oct-2001; D332231, T. Bloem, 13-Sep-2006).  The following paragraph
is a summary of these data.  

Tetraconazole was evaluated by GC on a ZB-1 (100% methyl siloxane)
column with ECD.  The tetraconazole retention time relative to
chlorpyrifos was 1.017.  50% FSD was obtained using 0.15 and 0.21 ng of
chlorpyrifos and tetraconazole, respectively.  Sugar beets were
fortified at 0.05 and 0.10 ppm.  The procedural recoveries at 0.05 ppm
were 83 and 84%, and at 0.10 ppm were 81 and 85%.  However, an
interfering peak was present.  As required by Protocol D, a florisil
clean up is necessary for compounds analyzed by ECD and matrices that
produce an interfering peak at the characteristic retention time of the
analyte.  Low recovery of tetraconazole through florisil (<10%)
precluded the possibility of a cleanup for sugar beet samples.  Peanuts
were fortified at 0.03 and 0.05 ppm.  The fat content of the peanuts and
the inability for a cleanup made it impossible for sample analysis.  It
is suggested that another solid support system, such as alumina, may be
more amenable to recovery of tetraconazole from all matrices.  However,
this method is currently not encompassed by PAM Volume I. 

OPPTS GLN 860.1380  Storage Stability Data

47435201.der.doc

The grape RAC, grape juice, and raisin samples were stored frozen for
236, 64, and 68 days, respectively, prior to analysis.  No data have
been submitted demonstrating the stability of T, TA, and TAA residues
in/on crops.  Data demonstrating the stability of tetraconazole per se
residues in/on several crop commodities including grape juice (69 days)
and raisin (91 days) have been submitted.  None of the commodities
and/or intervals are appropriate for the grape RAC.  To validate the
current residue data, storage stability data demonstrating the stability
of tetraconazole per se residues in/on grape (236 days) and T, TA, and
TAA residues in/on grape (236 days), grape juice (64 days), and raisin
(68 days) samples should be submitted.  Storage stability data for T,
TA, and TAA has been requested as part of a previous human-health
aggregate risk assessment (D322215, M. Doherty, et al., 7-Feb-2006). 
Submission of the data requested in the 7-Feb-2006 document will satisfy
storage stability data requirements for T, TA, and TAA of the subject
petition.  

OPPTS 860.1500 - Crop Field Trials:  

47270101.der.doc

Twelve grape field trials were established during 2006 in NAFTA Zones 1
(n=2), 10 (n=8), and 11 (n=2).  Each field trial consisted of a single
control plot and two treated plot (plots A and B).  Treatment plots A
and B received two applications (RTI = 14-16 days) of the 125 g/L liquid
tetraconazole formulation (1.04 lb ai/gal; EC) at ~0.040 lb ai/acre
(1x).  Treatment plot A received the first application 43-47 days prior
to harvest and samples were harvested 28-32 DALA.  Treatment plot B
received the first application 28-32 days prior to harvest and samples
were harvested 14-16 DALA.  At one of the field trial sites, additional
samples were harvested from treatment plots A (0, 7, 15, 22, and 37
DALA) and B (0, 5, 10, and 22 DALA).  

The samples were analyzed for residues of tetraconazole, T, TA, and TAA
using adequately validated methods.  Tetraconazole per se residues
ranged as follows (see Table 4 for summary):  plot A - <0.01-0.091 ppm
(average = 0.022 ppm) and plot B <0.01-0.096 ppm (0.031 ppm).  Only
samples from plot B were analyzed for T, TA, and TAA with the following
residues:  T:  <0.01 ppm in/on all samples; TA:  <0.01-0.053 ppm
(average = 0.016 ppm); and TAA:  <0.01-0.017 ppm (average = 0.011 ppm). 
The residue decline data indicated that tetraconazole per se residues
decreased with increasing PHI (T, TA, and TAA residues were <LOQ at all
intervals).  Data demonstrating the stability of tetraconazole, T, TA,
and TAA residues in/on grape (236 days) should be submitted.  

Conclusion:  The field trials were geographically distribution has
suggested in Table 5 of OPPTS 860.1500 for a national grape
registration.  Since the samples from plot B employed the requested
application rate and PHI and resulted in higher tetraconazole per se
residues, only these data were used for calculation of the appropriate
tolerance.  Based on these data and the MRL tolerance calculator (see
attachment 2), HED concludes that a grape tolerance of 0.20 ppm
tetraconazole per se residues is appropriate.  A revised Section F is
requested.  

Table 4:  Summary of Residue Data from Crop Field Trials.

Commodity	Total Rate

(lb ai/acre)1	PHI

(days)	Residue Levels (ppm)2

	n	Min.	Max.	HAFT3	Median	Mean	Std. Dev.

tetraconazole

grape	plot A - ~0.080	28-31	24	<0.01	0.091	0.056	0.013	0.022	0.019

grape	plot B - ~0.080	14-16	24	<0.01	0.096	0.095	0.019	0.031	0.027

T4

grape	plot B - ~0.080	15	24	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01

TA4

grape	plot B - ~0.080	15	24	<0.01	0.053	0.051	0.01	0.016	0.012

TAA4

grape	plot B - ~0.080	15	24	<0.01	0.017	0.016	0.01	0.011	0.002

1  Plots A and B both received two (RTI = 14-16 days) airblast
applications of the 125 g/L tetraconazole formulation (1.04 lb ai/gal;
EC) at ~0.04 lb ai/acre.  Plot A received the first application 43-47
days prior to normal harvest while plot B received the first application
28-32 days prior to normal harvest.  Only samples from plot B were
nalyzed for T, TA, and TAA.

2  If some samples resulted in residues >LOQ, the median, mean, and
standard deviation were calculated assuming LOQ residues for residues
<LOQ.  

3  HAFT = Highest-Average Field Trial.

4  Only samples from plot B were analyzed for T, TA, and TAA residues.

OPPTS 860.1520 - Processed Food/Feed:  

47270101.der.doc

Two field trials were established during 2006 in NAFTA Zones 10 and 11. 
Each trial consisted of a single control plot and two treated plots
(plots C and D).  Since only samples from treatment plot D were
processed, treatment plot C will not be discussed.  Treatment plot D
received two applications (RTI = 14-15 days) of the 125 g/L liquid
tetraconazole formulation at ~0.200 lb ai/acre (5x).  The first
application was made 28-32 days prior to harvest and bulk grape samples
were harvested 14-16 DALA.  

The bulk grape samples (n=2) were processed into grape juice (cold
press) and raisin (<14% moisture) using simulated commercial processing
procedures.  The resulting samples were analyzed for tetraconazole, T,
TA, and TAA residues using adequately validated methods.  The resulting
residue data yielded the following processing factors (see Table 5): 
tetraconazole:  juice - 0.01-0.06x and raisin - 0.71-0.91x; T:  a
processing factor could not be determined for grape juice and raisin as
residues were <LOQ in/on all the samples; TA:  a processing factor for
grape juice could not be determined as residues were <LOQ in the RAC and
processed commodity; processing factor for raisin was determined to be
>2.0x; TAA:  a processing factor could not be determined for grape juice
and raisin as residues were <LOQ in/on all the samples.  Data
demonstrating the stability of tetraconazole per se residues in/on grape
(236 days) and T, TA, and TAA residues in/on grape (236 days), grape
juice (64 days), and raisin (68 days) samples should be submitted.  

Table 5:  Grape processing Residue Data.

Trial ID:  City, State; Year; Trial ID No.; NAFTA Zone	Total Rate 

(lb ai/acre)1	PHI (days)	Commodity	Residues (ppm)	Processing Factor

Tetraconazole

Traver, CA; 2006; CA4; 10	plot D - ~0.396	15	grape	0.077	--

	grape juice	0.008	0.01

	raisin	0.070	0.91

Ephrata, WA; 2006; WA1; 11	plot D - ~0.406	14	grape	0.579	--

	grape juice	0.035	0.06

	raisin	0.411	0.71

T

Traver, CA; 2006; CA4; 10	plot D - ~0.396	15	grape	<0.01	--

	grape juice	<0.01	CNBC2

	raisin	<0.01	CNBC

Ephrata, WA; 2006; WA1; 11	plot D - ~0.406	14	grape	<0.01	--

	grape juice	<0.01	CNBC

	raisin	<0.01	CNBC

TA

Traver, CA; 2006; CA4; 10	plot D - ~0.396	15	grape	<0.01	--

	grape juice	<0.01	CNBC

	raisin	<0.01	CNBC

Ephrata, WA; 2006; WA1; 11	plot D - ~0.406	14	grape	<0.01	--

	grape juice	<0.01	CNBC

	raisin	0.020	>2.0

TAA

Traver, CA; 2006; CA4; 10	plot D - ~0.396	15	grape	<0.01	--

	grape juice	<0.01	CNBC

	raisin	<0.01	CNBC

Ephrata, WA; 2006; WA1; 11	plot D - ~0.406	14	grape	<0.01	--

	grape juice	<0.01	CNBC

	raisin	<0.01	CNBC

1  Plot D received two (RTI = 14-15 days) airblast applications of the
125 g/L tetraconazole formulation (1.04 lb ai/gal; EC) at ~0.200 lb
ai/acre; the first application was made ~30 days prior to normal
harvest.  

2  CNBC = can not be calculated; since residues were <LOQ in the raw and
processed commodity, the processing factor CNBC.  

OPPTS 860.1550 Proposed Tolerances

Table 6 is a summary of the proposed and recommended tolerances for
tetraconazole per se residues.  There are currently no established
Codex, Canadian, or Mexican MRLs for tetraconazole per se residues in/on
grape (see attachment 3); therefore, harmonization is not an issue.  A
revised Section F is requested.  

Table 6:  Tolerance Summary

Proposed	Recommended 

Commodity Definition	Tolerance (ppm)	Commodity Definition	Tolerance
(ppm)

grape	0.15	grape	0.20

RDI: RAB1 chemists (18-Jun-2008)

T. Bloem:S10945:PY1:(703)-605-0217

Attachment 1:  Chemical Structures

Attachment 2:  Tolerance Calculations

Attachment 3:  International Residue Limit Status

Attachment 1: Chemical Structures

Common Name; Chemical Name	Structure

Tetraconazole

CAS:  1-[2-(2,4-dichlorophenyl)-3-(1,1,2,2-tetrafluoroethoxy)

propyl]-1H-1,2,4-triazole

IUPAC:  (±)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propyl
1,1,2,2-tetrafluoroethyl ether	

Triazole (T)

1,2,4-triazole	

Triazolyl alanine (TA)

 

Triazolyl acetic acid (TAA)

Triazolyl hydroxypropionic acid (THP)

M14360-acid

M14360-difluoroacetic acid (M14360-DFA)

M14360-alcohol

Attachment 2:	Tolerance Calculations (MLE spreadsheet and Tolerance
Calculations)



Attachment 3:  International Residue Limit Status

INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: 

1-[2-(2,4-dichlorophenyl)-3-(1,1,2,2-tetrafluoroethoxy)
propyl]-1H-1,2,4-triazole	Common Name:

tetraconazole

	( Proposed tolerance

( Reevaluated tolerance

X Other - HED recommended tolerances	Date: 6/11/08

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:   7E7273

DP Number:  D353020

Other Identifier:

Residue definition:   N/A

	Reviewer/Branch: Tom Bloem/RAB1

	Residue definition:  tetraconazole per se

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

grape	0.20

	Limits for Canada	Limits for Mexico

(  No Limits

( No Limits for the crops requested	(   No Limits

(   No Limits for the crops requested

Residue definition:  N/A

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Tetraconazole (120603)	Residue Chemistry Summary	D353020

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