Commission Regulation 1107/2009
Triazole Derived Metabolite:
1,2,4-Triazole
Proposed revision to DT50
Summary, Scientific Evaluation and Assessment
July 2011, revised September 2011 (after comments from MS and
EFSA) and further revised January 2013 (minor
clarifications added post-commenting)
2
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
CONTENTS
Page
Background
3
B.8
Environmental fate and behaviour
B.8.1
Route and rate of degradation in soil
B.8.1.1 Aerobic and anaerobic studies
B.8.1.3 Field Dissipation studies
B.8.10 References relied
Appendix 1: List of endpoints June 2011
Appendix 2 : Copy of endpoints agreed at PRAPeR 12 meeting of 15 – 18
January 2007
3
3
3
21
68
70
72
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1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Background and summary
A number of the triazole fungicides that were evaluated in the 2nd and 3rd stages of the review
programme (as referred to in Article 8(2) of Council Directive 91/414/EEC) have metabolites in
common. These metabolites (triazole alanine, triazole acetic acid and 1,2,4-triazole) are
collectively known as the ‘Triazole Derivative Metabolites’. A group of Notifiers of triazole
fungicides have formed a task force called the Triazole Derivative Metabolite Group (TDMG) to
produce a common data package to cover the risk assessment for these metabolites. The UK is
acting as RMS for a number of parent triazole active substances, and also for the evaluation of a
number of metabolite assessments.
This document presents a kinetic re-evaluation of previously submitted laboratory degradation
data on the 1,2,4-triazole metabolite using the principles of the FOCUS Degradation Kinetics
Guidance. In addition, the TDMG has generated field dissipation data to supplement the reassessment of the laboratory data. The endpoints derived are presented in Appendix I.
Fate and behaviour endpoints for 1,2,4-triazole were previously discussed and agreed at the
PRAPeR 12 meeting of 15 – 18 January 2007. The endpoints agreed at PRAPeR 12 are presented
in Appendix II.
CRD proposes that the revised endpoints for metabolite 1,2,4-triazole are agreed by Member
States, and then MS should use these endpoints in the re-registration assessments of the triazole
fungicide group of parent active substances.
Note that the assessment of July 2011 (version 1) was amended in September 2011 (version 2)
after comments from MS and EFSA, and again in January 2013 to provide further clarity of
information (FINAL version 3). These latter amendments do not result in a change in the
assessment or endpoints from those in version 2 and all changes are highlighted in turquoise.
B.8
ENVIRONMENTAL FATE AND BEHAVIOUR
B.8.1
Route and rate of degradation in soil (IIA 7.1.1, IIIA 9.1.1)
B.8.1.1
Aerobic and anaerobic studies (II 7.1.1, IIIA 9.1.1)
B.8.1.1.2 Soil rate of degradation studies - laboratory
The study subject to re-evaluation is that of Slangen 2000 which was presented in the
DARs of a number of triazole fungicide a.s. which have subsequently been listed on
Annex I of Directive 91/414/EEC. For completeness, the previous UK evaluation of
this study has been re-presented below (in italics) to aid the consideration of the reassessment.
i)
The degradation of metabolite 1,2,4-triazole under aerobic conditions was
investigated according to SETAC (1995), CTB (1995), EPA (Subdivision N, part 1621, 1982) and BBA (part IV, 4-1, 1986) guidelines and GLP. The study is acceptable.
[3,5-14C] 1,2,4-triazole (radiochemical purity >98%) was applied to three soils at a
dose of 0.06 mg/kg of dry soil, based on an assumption of 750 g of fungicide active
4
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
substance/ha, incorporation in 5 cm of soil and a bulk density of soil of 1.5 g/ml, crop
interception of 50 %, 50 mol% of the fungicide is converted to 1,2,4-triazole and that
the ratio of the molar mass triazole to parent is 0.25. Portions of 100 g (dry weight) of
treated soil were transferred into incubation vessels and adjusted to 40 % of the water
holding capacity. The test vessels were connected to a humidified air supply (reduced
in CO2 content) and to trapping vessels for volatiles (2-methoxyethanol) and carbon
dioxide (2 x NaOH). Monitoring and adjustment of the water content in the soil was
performed regularly. Temperature for the incubation was maintained at 20 ± 2°C
under dark conditions (incubation vessels were made from brown glass). Details of
the soils are given in Table B.8.1.
Table B.8.1 Soils used in rate of degradation study on 1,2,4-triazole
Identity and Soil type Texture analysis
provenance (USDA)
(%)
Org.
C
(% )
sand silt clay
Laacherhof
pH
holding
capacity
(CaCl2)
1.4
34.4
6.4
78.9 14.4 6.7
2.2
50.0
5.8
Laacherhof silt loam 36.9 51.1 12.0 0.98
36.4
6.7
BBA2.2
Hanhofen,
Microbial
biomass
(mg C/kg
soil)
(g /100 g)
72.4 22.6 5.0
AXXa Germany
sandy
loam
loamy
sand
Water
init.:334
end: 198
init.:294
end: 138
Germany
AIII Germany
init.:252
end: 138
At each sample time, a single metabolism vessel with its traps was removed from the
incubation system for analysis. Soil samples were extracted with methanol,
methanol/water (x2) and finally with methanol under reflux conditions. After each
extraction step residues were separated by centrifugation and volume and
radioactivity of supernatants were determined. Analysis of extracts was performed by
TLC combined with radiography scanning. The identity of metabolites and triazole
was ascertained by co-chromatography with reference substances on selected samples.
Residual radioactivity remaining in soil samples after extraction was determined by
combustion in an oxidizer followed by LSC of the trapped carbon dioxide.
The sodium hydroxide traps were weighed and their radioactivity determined in an
aliquot by LSC. The identity of the radioactivity as 14C-CO2 was confirmed by
precipitation as barium carbonate in the solutions from the first trap of the samples
from day 120. Volatiles others than carbon dioxide were estimated by determining the
weight of the 2-methoxyethanol and measuring its radioactivity in an aliquot.
Results are presented in Tables B.8.2 – 4. Degradation rates calculated according to
non-linear first order kinetics are presented in Table B.8.5. It should be noted that
only data for the first 14 days of the incubation with the BBA 2.2 soil were used in the
calculation. The absence of decline in residues of 1,2,4-triazole from day 30 onwards
was considered by the study authors as being attributable to ‘reduced bioavailability’
and reduced microbial viability of the soil.
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1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.2 Results of aerobic soil incubation of 1,2,4-triazole in Laacherhof AXXa
soil (% AR)
1,2,4triazole
total
extracts
92.79
89.18
61.84
37.39
30.82
25.76
1,2,4triazole
shaking
extracts
83.33
81.53
55.33
30.68
23.83
19.11
TAA
Dihydro- CO2
shaking triazolone
extracts shaking
extracts
Extr
Unextr Mass
balance
*)
day 0
93.72 7.50
101.22
day 0
89.18 9.60
98.78
day 1
2.95
0.04 65.56 31.27 96.87
day 3
4.75
0.39 42.13 58.40 100.92
day 7
6.30
0.89 37.12 56.14 94.15
day
6.93
0.61
7.38 33.31 51.59 92.27
14
day
29.58
22.03
5.58
5.70 35.16 60.82 101.68
14
day
19.83
16.35
1.29
0.52
5.34 22.15 71.86 99.34
30
day
12.49
9.77
0.55
1.03
12.53 14.60 74.64 101.78
61
day120 11.99
7.75
19.63 11.99 63.21 94.83
day120 11.94
8.18
11.10 11.94 66.16 89.20
*)
Additionally one unknown with a maximum amount of 0.93 % found for day 0
Table B.8.3 Results of aerobic soil incubation of 1,2,4-triazole in BBA 2.2 Hanhofen
soil (% AR)
1,2,4triazole
total
extracts
90.45
89.39
76.15
52.44
45.68
39.35
1,2,4triazole
shaking
extracts
80.39
80.25
58.80
43.09
34.47
29.26
TAA
Dihydro- CO2
shaking triazolone
extracts shaking
extracts
Extr
Unextr Mass
balance
**)
day 0
90.45 8.98
99.43
day 0
89.39 11.19 100.58
day 1
0.01 76.15 24.31 100.47
day 3
0.10 52.44 44.01 96.55
day 7
0.13 45.68 49.73 95.55
day
1.31
0.28 40.67 51.53 92.48
14
day
39.86
27.70
1.67
0.31 41.53 53.07 94.92
14
day
31.84
20.50
0.42
0.49 32.59 69.80 102.87
30
day
30.24
21.13
0.91
0.98 31.75 65.45 98.18
61
day120 32.12
21.00
1.42 32.12 54.13 87.67
day120 29.85
21.22
1.58 29.85 65.01 96.44
**)
Additionally one unknown with a maximum amount of 0.63 % found for day 63
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1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.4 Results of aerobic soil incubation of 1,2,4-triazole in Laacherhof AIII soil
(% AR)
1,2,4triazole
total
extracts
85.21
84.70
75.38
50.92
45.24
37.45
1,2,4TAA
triazole shaking
shaking extracts
extracts
75.14
75.56
62.36
46.66
41.85
32.67
Dihydro- CO2
triazolone
shaking
extracts
Extr
Unextr Mass
balance
***)
day 0
85.21 16.87 102.08
day 0
84.70 13.22 97.92
day 1
0.1
75.38 24.72 100.20
day 3
0.57 50.92 44.19 95.68
day 7
1.84 45.24 49.38 96.45
day
2.61
0.28 40.06 47.74 88.07
14
day
38.74
32.40
1.85
1.25 40.59 49.31 91.15
14
day
18.29
16.41
0.27
2.22
19.42 20.99 61.64 102.0
30
day
6.58
5.52
1.50
19.65 8.08 49.90 77.62
61
day
3.74
3.56
24.65 3.74 59.33 87.53
83
day120 1.73
1.32
33.70 1.73 38.47 73.90
day120 2.39
1.61
32.22 2.39 41.79 76.40
***)
Additionally one unknown with a maximum amount of 0.19 % found for day 30
Table B.8.5 Degradation 1,2,4-triazole in three different soils under laboratory
conditions (20˚C, 40% MWHC).
Soil
Soil type
Laacherhof
sandy loam
AXXa
BBA 2.2
loamy sand
Laacherhof A III silt loam
Organic
carbon
1.4 %
DT50 values
1st order, nonlinear
one compartment
6.32 days
2.19 %
9.91 days*)
0.98 %
12.27 days
Arithmetic mean 9.5 days
*) Only 0-14 day data used for calculation.
r2
0.75
0.81
0.95
The degradation rates calculated by the notifier have been confirmed as being
acceptable by the Rapporteur.
(Slangen 2000)
Note that the final sentence relating to the kinetic calculations was in relation to the
evaluation which was originally conducted prior to adoption of the FOCUS
Degradation Kinetics Guidance Document.
7
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
The TDMG have now provided an updated kinetic assessment of the Slangen 2000
study.
ii)
The following assessment relates to re-evaluation of the Slangen 2000 study results
according to FOCUS Degradation Kinetics guidance. As such, there is no requirement
for this evaluation to comply with GLP as it comprises mathematical modelling, but
the study appears to have been conducted appropriately.
The applicant used the KinGUI 1.1 software with MatLab v 7.0.4.365 to perform the
modelling analysis and statistical evaluation of kinetic fits. As the original data (see
tables B.8.2 – 4) only had data from single replicate samples except for days 0 and 14,
the two replicate data points from each of days 0 and 14 were averaged to give a single
data point for each of these two sample times in the kinetic analysis. The fitting
procedure started by free-fitting SFO to each data set. If the free-fitting approach was
considered unacceptable, the fitting procedure was repeated but fixing the initial
concentration. Following the SFO steps (free-fitting and fixed initial concentration),
bi-phasic kinetics were considered. As the establishment of modelling parameters for
1,2,4-triazole was under consideration, HS and DFOP were tested for the Laacher Hof
AXXa and BBA 2.2 datasets as the final concentrations were >10% and FOMC was
used to model the Laacher Hof AIII dataset as final concentration was <10%. The data
used in the fitting procedure is shown in Table B.8 6. It is noted that the FOCUS
Degradation Kinetics guidance indicates that where concentrations do not reach 10%
of the initial concentration at study end then HS or DFOP kinetics should be used. The
study author has used both HS and DFOP for these soils. In addition, as DFOP
appeared to represent the better kinetic for the Laacher Hof AXXa and BBA 2.2 soils,
the Laacher Hof AIII dataset was also subject to analysis using DFOP kinetics to
determine whether the endpoints from the database of three soils could be expressed by
a single consistent kinetic.
Table B.8.6 1,2,4-triazole metabolite data used in fitting (taken from Slangen 2000, %
AR)
Laacher Hof
AXXa
DAA
BBA 2.2
Laacher Hof
AIII
Residues %
0
90.99
89.92
84.96
1
3
7
14
30
61
83
120
61.84
37.39
30.82
27.67
19.83
12.49
76.15
52.44
45.68
39.60
31.84
30.24
Not determined
Not determined
11.96
30.99
75.38
50.92
45.24
38.09
18.29
6.58
3.74
2.06
8
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
In terms of initial concentration used in the fitting procedure, the mass balance at day 0
was used as there were significant unextracted residues (10 – 15% AR) by the time that
the day zero sample was taken after dosing. Radiochemical purity of the test
compound was also >98% indicating that radiolabelled impurities would be
insignificant at this initial sample time; this is confirmed by the information on the
extracted fraction which virtually completely comprised 1,2,4-triazole. Correction of
the day 0 residue to account for unextracted residues etc. is appropriate and in
accordance with FOCUS Kinetics guidance (see section 6.1.6 of the Kinetics
guidance). Fitting was unconstrained except for attempts to achieve an acceptable fit
with SFO kinetics where the initial concentration was constrained. As these attempts
did not result in acceptable fit, results of SFO fit with constrained initial concentration
have not been shown. The results obtained for all three soils are collated below.
DT50 /
DT50-fast
DT90 /
DT50-slow
[d]
Resid. fit
Model
Visual
ranking
Table B.8.7 Statistical results of the Applicant kinetic fits for 1,2,4-triazole in three
laboratory soils: DT50 and DT90 [d], visual ranking and quality of fits, visual
assessment of random-ness of residuals, scaled error ε to pass the 2 test, and T-test for
relevant parameter fit.
χ2 test
error
T-test
k1
T-test
k2
Other
Laacher Hof AXXa
SFO
4.7
15.6
--
--
29.7
0.028
HS
1.9
59.2
++
++
8.5
<0.001
0.03
DFOP
0.9
59.2
++
++
5.1
0.001
0.006
SFO
40.9
136.2
--
--
26.4
0.061
HS
3.2
203.9
+
++
6.2
<0.001
0.047
DFOP
1.5
247.6
++
++
5.1
0.004
0.065
Tb: 3.2447 (Ttest tb: 0.030)
“g”: 0.683 (P=
<0.001)
BBA 2.2
Tb: 4.0139 (Ttest tb: NA)
“g”: 0.580 P=
<0.001)
Laacher Hof AIII
SFO
9.9
33.0
-
-
19.3
FOMC
22.1 (from DT90)
+
+
12.3
DFOP
0.8
++
++
4.5
20.6
0.003
0.003
<0.001
“g”: 0.443 P=
<0.001)
Summary: Geomean all DFOP fits:
DFOP
1.0 d
1
67.1 d
“g”: 0.5691
= arithmetic mean
The Applicants assessments for each individual soil are shown below in Table B.8.8 10 and Figures B.8.1 – 9. Note that for visual and residual assessment, the following
key is used:
++ = Very good; + = Good; - = Marginal; - - = Poor
9
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Laacher Hof AXXa
Table B.8.8 Statistical results of the Applicant kinetic fits for Laacher Hof AXXa soil:
DT50 and DT90 [d], visual ranking and quality of fits, visual assessment of randomness of residuals, scaled error ε to pass the 2 test, and T-test for relevant parameter fit.
Kinetics
DT50
DT90
Visual
ranking
Resids
fit
SFO
Kinetics
4.7
DT50
-fast
1.9
DT50
-fast
0.9
15.6
DT50slow
59.2
DT50slow
59.2
--
--
Visual
ranking
++
Visual
ranking
++
Resids
fit
++
Resids
fit
++
HS
Kinetics
DFOP
Tb
3.2447
g
0.683
χ2 test
error
29.7
χ2 test
error
8.5
2
χ test
error
5.1
T-test k
0.028
T-test
k1
<0.001
T-test
k1
0.001
T-test
k2
0.03
T-test
k2
0.006
T-test
tb
0.030
T-test g
<0.001
10
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.1 Laacher Hof AXXa Applicant SFO visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
20
Parent
15
10
Residuals
5
0
-5
-10
-15
-20
0
20
40
60
Time
80
100
120
11
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.2 Laacher Hof AXXa Applicant HS visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
6
Parent
4
Residuals
2
0
-2
-4
-6
-8
0
20
40
60
Time
80
100
120
12
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.3 Laacher Hof AXXa Applicant DFOP visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
5
Parent
4
3
Residuals
2
1
0
-1
-2
-3
-4
0
20
40
60
Time
80
100
120
13
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
BBA 2.2
Table B.8.9 Statistical results of the Applicant kinetic fits for BBA 2.2 soil: DT50 and
DT90 [d], visual ranking and quality of fits, visual assessment of random-ness of
residuals, scaled error ε to pass the 2 test, and T-test for relevant parameter fit.
Kinetics
DT50
SFO
Kinetics
40.9
DT50
-fast
3.2
DT50
-fast
1.5
HS
Kinetics
DFOP
DT90
136.0
DT50Tb
slow
4.0139
203.9
DT50g
slow
247.6
0.580
a
= not available
Visual
ranking
Resids
fit
--
--
Visual
ranking
+
Visual
ranking
++
Resids
fit
++
Resids
fit
++
χ2 test
error
26.4
χ2 test
error
6.2
2
χ test
error
5.1
T-test k
0.061
T-test
k1
<0.001
T-test
k1
0.004
T-test
k2
0.047
T-test
k2
0.065
T-test
tb
NA a
T-test g
<0.001
14
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.4 BBA 2.2 Applicant SFO visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
40
Parent
30
Residuals
20
10
0
-10
-20
0
20
40
60
Time
80
100
120
15
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.5 BBA 2.2 Applicant HS visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
6
Parent
4
Residuals
2
0
-2
-4
-6
0
20
40
60
Time
80
100
120
16
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.6 BBA 2.2 Applicant DFOP visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
5
Parent
4
3
Residuals
2
1
0
-1
-2
-3
-4
-5
0
20
40
60
Time
80
100
120
17
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Laacher Hof AIII
Table B.8.10 Statistical results of the Applicant kinetic fits for Laacher Hof AIII soil:
DT50 and DT90 [d], visual ranking and quality of fits, visual assessment of randomness of residuals, scaled error ε to pass the 2 test, and T-test for relevant parameter fit.
Kinetics
DT50
DT90
Visual
ranking
Resids
fit
SFO
Kinetics
9.9
DT50
33.0
DT90
-
-
DT50
-fast
0.8
73.4
DT50slow
20.6
Visual
ranking
+
Visual
ranking
++
Resids
fit
+
Resids
fit
++
FOMC
Kinetics
DFOP
g
0.443
χ2 test
error
19.3
χ2 test
error
12.3
χ2 test
error
4.5
T-test k
0.003
T-test
k1
0.003
T-test
k2
<0.001
T-test g
<0.001
18
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.7 Laacher Hof AIII Applicant SFO visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
20
Parent
15
10
Residuals
5
0
-5
-10
-15
-20
0
20
40
60
Time
80
100
120
19
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.8 Laacher Hof AIII Applicant FOMC visual and residual fits
Measured & Predicted vs. Time
100
Parent
90
80
Concentration
70
60
50
40
30
20
10
0
0
20
40
60
Time
80
100
120
Residual Plot
12
Parent
10
8
Residuals
6
4
2
0
-2
-4
-6
-8
0
20
40
60
Time
80
100
120
20
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.9 Laacher Hof AIII Applicant DFOP visual and residual fits
Measured & Predicted vs. Time
120
Parent
100
Concentration
80
60
40
20
0
0
20
40
60
Time
80
100
120
Residual Plot
4
Parent
3
2
Residuals
1
0
-1
-2
-3
-4
0
20
40
60
Time
80
100
120
The Applicant proposed the following DT50 values for use in modelling. It should be
noted that the slow phase DFOP values are significantly longer than those agreed at
PRAPeR 12.
21
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.11 Applicant proposed soil degradation DT50 values of 1,2,4-triazole.
Location
Laacher Hof AXXa
BBA 2.2
Laacher Hof AIII
Model
fitted:
DFOP
DFOP
DFOP
“g”
0.683
0.580
0.443
DT50-fast
[d]
0.9
1.5
0.8
DT50-slow
[d]
59.2
247.6
20.6
1.0
67.1
Geometric mean:
Arithmetic mean:
0.569
Note that no normalisation for moisture content has been performed. This is
considered appropriately conservative for 1,2,4-triazole as a terminal metabolite as
normalisation for moisture content will result in faster degradation. However,
assuming that under conditions of constant moisture status (40% of water holding
capacity) the ‘g’ value will be unchanged and fast and slow phases are equally
affected, the RMS has calculated the following corrected DT50 values. Note that the
values for BBA 2.2 are unchanged as the moisture content in the study was the same as
the FOCUS recommended pF2 value for a loamy sand soil.
Table B.8.11a RMS calculated DT50 values of 1,2,4-triazole corrected for moisture.
Location
Model
fitted:
“g”
Laacher Hof AXXa
BBA 2.2
Laacher Hof AIII
DFOP
DFOP
DFOP
0.683
0.580
0.443
Geometric mean:
Arithmetic mean:
Moisture
correction
factor
0.624
1
0.531
DT50-fast
[d]
DT50-slow
[d]
0.6
1.5
0.4
36.9
247.6
10.9
0.7
46.4
0.569
The Evaluator agrees with the use of the initial concentration of 100% for all three
soils based on the mass balance data from the original study for all three soils. The
Evaluator also considers that whilst DFOP would not be normally be used on data sets
where the applied substance reached at least 10% of the initial dose within the study,
e.g. the data set for the Laacher Hof AIII soil, DFOP is considered the preferred kinetic
for all three soils, this being a pragmatic choice for consistent modelling parameters.
Overall, the Evaluator agrees with this kinetic assessment of 1,2,4-triazole in
laboratory soils.
Chapple 2010a
B.8.1.3
Field studies
Field dissipation
i)
A field dissipation study was conducted on 1,2,4-triazole in accordance with BBA
(Part IV, 4-1, 1986) and SETAC (1995) guidelines and to GLP.
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1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
The field dissipation study was conducted at four different locations, one each in
Germany, UK, Italy and Spain. Details of the sites and soil properties are given in
Table B.8.12 - 15. The study author stated that the sites had not been treated with
chemicals which could influence the dissipation behaviour of 1,2,4-triazole or interfere
with analysis. Site histories were presented, which indicated no apparent application
of triazole fungicides in at least the previous three years at the German and Italian site.
Site history was not actually available for the UK site although it was acknowledged
that the site had been used for field testing of triazole fungicides previously. No
history of previous pesticide use was available for the Spanish site. Untreated control
plots were sampled at each site to determine background levels of 1,2,4-triazole.
Table B.8.12 Soil characteristics of German field dissipation site
23
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.13 Soil characteristics of Italy field dissipation site
Table B.8.14 Soil characteristics of UK field dissipation site
24
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.15 Soil characteristics of Spain field dissipation site
Note: MWHC = maximum water holding capacity; organic matter content calculated
from % organic carbon x 1.724
At all sites, a single application of 100 g 1,2,4-triazole/ha was applied to bare soil plots
which had been pre-prepared to have a fine crumb structure. Following application,
grass seed was sown on the bare soil plots at all sites except the Spanish site. The staff
conducting the Spanish site considered that given the time of year of application, i.e.
June, and the prevailing drought conditions at the time of application, there was no
prospect of grass emergence, and so no grass seed was sown at this site. The study
author noted that the substance was incorporated almost immediately after application
to a depth of 8cm by the grass seed sowing operation. Accuracy of application was
checked using filter papers laid on the soil surface. Control plots were also left
unsprayed to check for any background levels of 1,2,4-triazole.
Meteorological data were available for all four sites. For the German site, a weather
station was available at the test location. For the Italian site, the weather station was
located 200 m away from the site. For the UK, weather data was available for a
weather station 32km away. For the Spanish site, weather data were available from a
site 2.7 km away. Full daily weather data were not presented in the report, but
meteorological data at selected dates and total precipitation and monthly mean
temperature were available. Total precipitation and range of monthly mean
temperature are presented with results of the residues for the individual sites in Tables
B.8.20 – 23. It should be noted that daily resolution weather data were provided in
another report (Chapple 2010b) detailing normalisation of field dissipation data.
Soil sampling was conducted before and immediately after application at all sites. Day
0 samples were taken to a depth of 10cm (50 mm diameter, 40 cores per sample). On
11 subsequent occasions up to 454 days after application, samples were taken down to
a maximum of 50cm depth. Dates and depths of samples are given in the following
25
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
results tables. Note that the Italian study was terminated at day 180 as the site became
no longer available.
Soil samples were deep frozen within 24 hours and stored frozen at -18ºC or below
until preparation for analysis. Prior to analysis, cores were divided into 10cm
segments and the sample from the appropriate segment homogenised. 15 g
subsamples of the homogenised soil were then extracted with acetonitrile/water (6:4
v/v) at 65-70ºC for one hour. Following centrifugation, an aliquot of the extract was
derivitised using dansyl chloride in acetone and aqueous sodium sulphate to form
dansyl triazole; derivitisation was stated to have been performed to enable analysis to
be performed using a non-polar HPLC system and to allow production of more
transitional ions in mass spectrometric analysis, aiding sensitivity and detection.
Following addition of ammonium hydroxide solution, the derivatives were partitioned
into ethyl acetate and dried with anhydrous sodium sulphate. The study author stated
that possible matrix effects on the determination of dansyl triazole were eliminated by
the use of an internal standard solution of a mixture of isotopically labelled reference
items added to an aliquot of the extract. Extracts were concentrated to dryness and
reconstituted in acetonitrile/water (1:1 v/v). Following filtering, the extracts were
analysed by HPLC-MS/MS. The claimed LOQ was 3 µg/kg for each of the four test
sites, and LOD was set at 1 µg/kg. Procedural recovery at the claimed LOQ was in the
range 67 – 118% with a mean of 94%. Filter papers from day 0 application checks
were also extracted and analysed in a similar method. Procedural recovery at a
fortified level of 0.1 µg/cm2 was in the range 75 – 101% with a mean of 89%.
In the context of the day 0 samples, the LOQ of 3 µg/kg represents:
Germany 4.9 – 5.9% of day 0 sample concentrations
Italy 6.0 – 8.6% of day 0 sample concentrations
UK 6.9 – 7.3% of day 0 sample concentrations
Spain 6.6 – 9.7% of day 0 sample concentrations
Representative chromatograms were presented for this study, which demonstrated
good separation of peaks and close agreement of peaks from actual residues and the
internal standard.
Further assessment of methods of analysis data are presented in B.8.1.3 iii); in
summary, the methods of analysis are considered acceptable.
Results of analysis were presented as both 1,2,4-triazole equivalents in both wet and
dry weight of soil, but only dry weight concentrations are presented here, in line with
normal practice. Residues below LOQ were treated in the following manner:



Values between LOD and LOQ were set to measured values
Values <LOD were set 0.5LOD for samples of the next deeper soil layer in
case the detection had been >LOD for the previous soil layer. The curve was
stopped after the first non detect of <LOD if no later value >LOD followed
At day 0, values <LOD in deep horizons were set to 0
This procedure is in line with FOCUS kinetics guidance on treatment of values below
LOQ and LOD.
26
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
The concentrations of 1,2,4-triazole in dry weight soil were also used to calculate g/ha
doses in 10cm of soil at individual time points for the purpose of kinetic calculations.
The bulk density of soil was assumed to be 1.5 g/cm3 for this calculation. The
Evaluator confirms that this conversion is acceptable. The study author used MatLab
with KinGUI to fit SFO, FOMC and DFOP kinetics to the experimental data.
Results of residues in µg/kg (dry weight) are shown in Tables B.8.16 – 19, and results
converted to g/ha in 10cm soil depth are presented in Tables B.8.20 – 23. Results of
filter paper analysis are also shown in Table B.8.15a.
Table B.8.15a Results of filter paper analysis as dose check (1,2,4-triazole)
Germany
Italy
UK
Spain
ng/cm2
mg/m2
g/ha
873.9
901.0
869.9
804.9
8.739
0.010
8.699
8.049
87.4
90.1
87.0
80.5
Amount
recovered %
87
90
87
81
27
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.16 Residues of 1,2,4-triazole in German field dissipation study (µg/kg).
28
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.17 Residues of 1,2,4-triazole in Italian field dissipation study (µg/kg).
29
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.18 Residues of 1,2,4-triazole in UK field dissipation study (µg/kg).
30
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.19 Residues of 1,2,4-triazole in Spanish field dissipation study (µg/kg).
31
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
It is noted that in the Italian, UK and Spanish sites, residues of 1,2,4-triazole were
found at day 0 in untreated plots, this being particularly noticeable at the Italian site.
Subsequent calculation of g/ha residues and kinetic assessments did not correct
residues for the concentrations in the untreated plots. The RMS considers that the noncorrection of residues would not significantly influence DT50 values recorded.
Table B.8.20 Residues of 1,2,4-triazole in German field dissipation study (g/ha)
Total Rainfall 1381mm; Mean monthly air temperature range 0 – 18ºC
Table B.8.21 Residues of 1,2,4-triazole in Italian field dissipation study (g/ha)
Total rainfall 431mm; Mean monthly air temperature range 5 – 23ºC
32
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.22 Residues of 1,2,4-triazole in UK field dissipation study (g/ha)
Total Rainfall 714mm; Mean monthly air temperature range 5 – 18ºC
Table B.8.23 Residues of 1,2,4-triazole in Spanish field dissipation study (g/ha)
Total Rainfall 600mm; Mean monthly air temperature range 3 – 23ºC
Results of the kinetic assessment performed by the applicant are shown in Table
B.8.24. Note this is on the basis of data not normalised to standard temperature and
moisture conditions. The kinetics selected by the study author as the best fit are
highlighted in bold text. Visual and residual fits are shown in Figures B.8.10 – 12 for
the German trial, Figures B.8.13 – 15 for the Italian trial, Figures B.8.16 – 18 for the
UK trial and Figures B.8.19 – 21 for the Spanish site.
33
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.24 Results of kinetic assessment on 1,2,4-triazole un-normalised field
dissipation data
Location
Germany
Kinetic
Model
SFO
FOMC
DFOP
SFO
FOMC
Italy
DFOP
SFO
FOMC
UK
DFOP
SFO
FOMC
Spain
DFOP
DT50
[days]
22.9
7.8
DT90
[days]
75.9
366.7
α 0.4454
β 2.0966
11.3
241.6
k1
0.1149
k2 0.0051
g 0.6602
48.8
16.3
162.2
>1000
α 0.3883
β 3.2894
21.2
207.4
k1
0.3500
k2 0.0086
g 0.4000
21.8
8.1
72.3
188.4
α 0.5728
β 3.4434
6.8
109.3
k1
0.4863
k2 0.0154
g 0.4633
85.6
28.6
284.4
>1000
α 0.3618
β 4.9336
28.1
717.6
k1
0.0632
k2 0.0020
g 0.5732
Visual Chi2
Assess*
24.9
+
15.2
t-test
O
18.5
O
+
17.9
11.3
k1 0.0449
k2 0.1137
g 7.2x10-4
k 0.0026
-
+
10.7
O
+
25.4
20.2
+
17.8
O
+
21.8
12.6
+
13.3
k 0.0037
-
k1 0.0853
k2 0.0060
g 0.0018
k 0.0064
k1 0.0868
k2 0.0178
g 0.0024
k 0.0031
k1 0.0395
k2 0.0903
g 4.5x10-4
*Visual assessment: + = good O = medium -- = bad
t-test: SFO, for rate constant; DFOP, for k1, k2 and g; FOMC, t-test not applicable, no confidence
intervals for α or β parameters given
Note α and β values for FOMC and k values for DFOP fast and slow phases and
associated g values have been added for clarity if these are required for e.g. PECsoil
calculation. The DT50 and DT90 values in each case refer to the whole decline curve.
34
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.10 SFO visual and residual fits for 1,2,4-triazole at German field
dissipation site
35
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.11 FOMC visual and residual fits for 1,2,4-triazole at German field
dissipation site
Figure B.8.12 DFOP visual and residual fits for 1,2,4-triazole at German field
dissipation site
36
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.13 SFO visual and residual fits for 1,2,4-triazole at Italian field dissipation
site
Figure B.8.14 FOMC visual and residual fits for 1,2,4-triazole at Italian field
dissipation site
37
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.15 DFOP visual and residual fits for 1,2,4-triazole at Italian field
dissipation site
Figure B.8.16 SFO visual and residual fits for 1,2,4-triazole at UK field dissipation
site
38
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.17 FOMC visual and residual fits for 1,2,4-triazole at UK field dissipation
site
Figure B.8.18 DFOP visual and residual fits for 1,2,4-triazole at UK field dissipation
site
39
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.19 SFO visual and residual fits for 1,2,4-triazole at Spanish field
dissipation site
Figure B.8.20 FOMC visual and residual fits for 1,2,4-triazole at Spanish field
dissipation site
40
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.21 DFOP visual and residual fits for 1,2,4-triazole at Spanish field
dissipation site
Based on the good visual fits, the RMS accepts the Applicant choice of best fit kinetics
as reported in Table B.8.24 above. However, it should be noted that care should be
exercised in the use of these endpoints as they only represent dissipation/disappearance
of this substance which has been applied as the starting material. In the real
agricultural field situation, formation will be occurring from the parent at the same
time as degradation and other dissipation processes which would lead to a longer
dissipation rate.
Tarara 2010
ii)
A modelling procedure was conducted on the results of the field dissipation studies
described in Tarara 2010 to normalise the field dissipation DT50 and DT90 to standard
temperature and moisture conditions of 20ºC and pF2. As this was a modelling
exercise, GLP is not applicable, but the procedure appeared to have been conducted in
an appropriate manner.
The study author investigated the suitability of the field dissipation study data for
normalisation to standard temperature and moisture conditions. It was noted that
volatilisation may be an important route of loss for 1,2,4-triazole as the substance has a
vapour pressure of 3.4 x 10-1 Pa at 25ºC (reported in the DAR for the substance
difenoconazole; it is also noted from the DAR for difenoconazole that the Henry’s law
constant is calculated to be 3 x 10-5 Pa.m3.mol-1 at 25ºC). In addition, it was noted that
soil photolysis may be a potential route of degradation.
41
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
The study author noted that in three of the four field dissipation sites (i.e. not the
Spanish site), the substance was incorporated almost immediately after application to a
depth of 8cm by the grass seed sowing operation. Reference to sections 3.3. and
Appendix 5 of the Tarara 2010 study demonstrate that whilst grass was not sown at the
Spanish site, an incorporation procedure was included at this site. The study author
stated that in each study, four samples were taken at day 0, two before incorporation
and two after. The study author analysed the day 0 data set for the four sites using
ANOVA (analysis of variance) techniques, and whilst finding that the mean difference
in residue before and after incorporation was small (mean residue before 46.4, mean
residue after 44.9, units not stated but assumed to µg/kg dry weight), the difference
was not statistically significant. Difference between sites was significant. From this,
they concluded that any effect of volatilisation and photolysis would have been only
slight or non-existent. The Evaluator notes that the residues measured at day zero were
relatively scattered at all sites, and only at the Spanish site was there much of a
difference apparent between the first two and the second two day 0 samples (see Table
B.8.20); the magnitude of difference between the pre- and post-incorporation residues
is similar to the magnitude of scatter at other sites, suggesting that differences between
pre- and post-incorporation residues at the Spanish sites may not be a real reduction in
residues over time but a chance arrangement of scattered data. The Evaluator also
notes that there were no volatile substances other than CO2 captured in the Slangen
2000 laboratory study on 1,2,4-triazole which adds additional weight to the hypothesis
that volatilisation would have been minimal. In addition, whilst the vapour pressure is
relatively high, the Henry’s Law constant is relatively low suggesting that
volatilisation from moist soil would be relatively low. Overall, the Evaluator
concludes that significant losses via volatilisation and/or photolysis would have been
minimal.
The study author also noted that plant uptake may also influence the results from this
procedure. However, whilst acknowledging that this normalisation procedure did not
explicitly take plant uptake into consideration, they stated that any subsequent
groundwater modelling should specifically set crop uptake for this metabolite to 0.
The Evaluator notes that grass cropping was implemented in the subsequent PEARL
procedure to simulate soil temperature and soil moisture, but this procedure did not
actually simulate pesticide fate. Thus the study author is correct to make this specific
recommendation to avoid crop uptake being double counted in any exposure
assessment.
Prior to kinetic fitting, the same pre-processing of raw field dissipation residues data
was conducted as performed in the Tarara 2010 study. Consequently the residues data,
expressed in g/ha and assumed to be in the top 10cm, and shown in Tables B.8.21 –
24, were used in the analysis. The Evaluator notes that soil residues from 0-30cm and
on occasion 0-40cm were used to derive the residues in g/ha. It is also noted that
FOCUS leaching models assume that degradation slows at increasing soil depth and
thus if this was not taken into consideration in the normalisation procedure for residues
reaching depth, there could be an over-estimation of speed of degradation. The general
assumption in FOCUS models is that degradation slows by a factor of 0.5 at soil
depths of 30-60cm; there is no depth-related reduction in degradation in the 0-30cm
layer. In the 1,2,4-triazole residues data set, residues were only infrequently analysed
for soil depths of 30-40cm, but these were present below LOD in all instances. On
further questioning from the Evaluator, the Applicant stated that 88-98% of residues
42
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
were found in the 0-10cm layer and considered that any influence of change in
temperature, moisture or depth dependent degradation rate would be relatively small
over this soil depth. They also demonstrated that normalising the timesteps based on
just the top 5cm depth compared to a 30cm depth had a very small impact on the
normalised timesteps in the case of these four soils; this is shown in Table B.8.24a.
The Evaluator considers that whilst the effect of moisture was not considered in this
response, the fact that the majority of the residue was located in the top most layer
means that effectively restricting consideration to the top 10cm in this case has little
impact on the normalisation procedure.
Table B.8.24a Effect of target soil depth (5 cm v. 30 cm) on timestep calculations for
correction of field trial time scale to temperature (20 °C) and soil moisture (pF2)
Days
0
1
3
8
14
28
59
91
121
185
364
451
Germany
5 cm
30 cm
0.0
0.3
0.9
3.3
5.8
12.8
31.5
58.4
76.0
96.3
136.9
190.5
0.0
0.3
0.9
3.1
5.6
12.4
29.7
56.2
73.9
94.5
133.9
186.8
Italy
Days
5 cm
30 cm
0
1
3
7
14
25
60
90
118
180
0.0
0.8
2.9
7.3
11.9
21.9
56.4
76.5
92.9
112.7
0.0
0.9
2.8
7.0
12.0
22.1
57.4
78.4
94.4
114.7
UK
Days
0
1
2
7
14
28
63
91
135
191
364
454
5 cm
30 cm
Days
Spain
5 cm
30 cm
0.0
0.3
0.7
3.4
8.1
14.0
35.1
57.0
78.6
98.3
145.6
189.4
0.0
0.4
0.7
3.2
7.8
14.0
34.3
55.8
77.4
97.1
143.9
186.2
0
1
3
8
16
28
64
93
140
210
330
415
0.0
0.7
1.9
4.8
9.6
17.3
44.7
64.1
81.6
98.9
133.8
192.1
0.0
0.8
2.4
5.8
10.4
18.5
45.0
63.0
80.9
98.1
133.0
191.0
43
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Free-fitting of the data was allowed. The four replicate samples taken at day 0 were
averaged due to the variability of the residue values and because it was considered that
the four replicates at this single time point compared to the single replicate at other
times would inappropriately weight the fit to the day 0 data.
The daily weather data from the local weather stations for the study period were used
to derive the .met files for use in PEARL. Whilst the daily resolution weather data are
not available in the Tarara 2010 field dissipation study report, the study author for the
normalisation procedure has included the daily weather data as an appendix. Soil
descriptions were input into PEARL using the available textural information from the
Tarara 2010 report. Additional hydraulic parameters were then derived using the
ROSETTA software. Soil profiles of 1m depth were described; the profile was
discretised at 2.5cm intervals for the first 60cm and then at 5cm intervals for the
remaining profile. The three sites where grass was sown had grass implemented as the
crop using relevant development stages and leaf area indices taken from the
FOCUSgw report.
Using this information, PEARL was run for each soil to generate daily soil temperature
and soil moisture information for each of the field dissipation sites. The daily values at
1.25, 3.75, 6.25 and 8.75cm were averaged to give a value for the top 10cm. The daily
difference between predicted soil temperature and moisture and the standard
conditions, i.e. 20ºC and pF2 were then calculated and used in a time step
normalisation procedure to amend the sampling times used in kinetic analysis.
Temperature normalisation used a Q10 value of 2.58 as recommended by the EFSA
PPR Panel in their opinion of 2007. Moisture normalisation used a Walker exponent
of 0.7 as recommended in the FOCUSgw report.
The study author stated that volumetric water contents at pF2 were calculated for each
soil. These values (shown below) are different to those quoted in the Tarara 2010
study. However, given that the soil moisture parameters used in PEARL were derived
from ROSETTA, it was appropriate that the pF2 values for the simulated soils be
calculated from ROSETTA parameters for consistency. This seems to be an
acceptable approach in the opinion of the evaluator. In addition, the calculated values
are, in most cases, quite close to the measured values (see Tables B.8.12 – 15 for
measured values).
Table B.8.25 Calculated pF2 values for field soils
44
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.26 Calculated timesteps for use in kinetic evaluation
Following calculation of the timesteps, kinetic analysis was undertaken with these new
values to derive kinetic parameters for use in modelling. The modelling was
undertaken using KinGUI v 1.1 with MatLab v 7.0.4.365. The methodology used
generally agreed with principles outlined in the FOCUS Degradation Kinetics
guidance document. FOMC kinetics was not attempted for the Italian and Spanish
sites because residues at the end of the study were >10% of the day 0 residue
However, it is noted that they considered a t-test value of<0.1 to be acceptable for field
studies. The Evaluator notes that this is not specifically stated in FOCUS Degradation
Kinetics; FOCUS Degradation Kinetics uses a general assumption that t-test values
<0.05 can be considered as indicating the parameter is significantly different from zero
at a 5% significance level and that values between 0.05 and 0.1 can be considered as
acceptable provided that there is further discussion and justification based on fit and
weight of evidence. However, the Evaluator can understand the reasons for using this
assumption given the general observation that field dissipation data can be more
scattered than laboratory data. It is noted that the study author attempted to obtain
DFOP kinetic endpoints for each trials site in order to maintain consistency for
selection of mean input parameters but also to make use of the bi-exponential
approaches for groundwater modelling as detailed in FOCUS Degradation Kinetics
guidance. Results of statistics generated from the kinetic analyses are given in Tables
B.8.27 – 30, and graphical fits in Figures B.8.22 – 35.
45
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.27 Statistical results of the Applicant kinetic fits for SFO model to
normalised field dissipation data: DT50 and DT90 [d], visual ranking and quality of
fits, visual assessment of random-ness of residuals, scaled error ε to pass the 2 test,
and T-test for relevant parameter fit.
Table B.8.28 Statistical results of the Applicant kinetic fits for FOMC model to
normalised field dissipation data: DT90 [d], visual ranking and quality of fits, visual
assessment of random-ness of residuals, scaled error ε to pass the 2 test, and T-test for
relevant parameter fit.
Note: t-test is not directly applicable to the α and β parameters; assessment of confidence intervals for
both FOMC assessments indicates that the ranges include zero for the β parameter for both sites and
therefore may be unreliable
Table B.8.29 Statistical results of the Applicant kinetic fits for Hockey Stick model to
normalised field dissipation data: DT50 and DT90 [d], visual ranking and quality of
fits, visual assessment of random-ness of residuals, scaled error ε to pass the 2 test,
and T-test for relevant parameter fit.
46
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.30 Statistical results of the Applicant kinetic fits for DFOP model to
normalised field dissipation data: DT50 and DT90 [d], visual ranking and quality of
fits, visual assessment of random-ness of residuals, scaled error ε to pass the 2 test,
and T-test for relevant parameter fit.
Errata: Note that the k1 t-test result for the Vilobi, Spain site above is incorrect, it is
actually 0.082.
In every case, the kinetic behaviour observed was bi-phasic rather than SFO. The
Evaluator considers that for the UK site that DFOP is a slightly better fit than FOMC.
In the case of the Italian and Spanish sites, there seems to be no advantage in choosing
DFOP over HS except for the pragmatic choice of consistency and using DFOP in
leaching models.
In the study author’s view, the preferred kinetic at the German site was FOMC. In an
attempt at obtaining consistency of modelling endpoints conforming to DFOP, a
further assessment of the German site was conducted. In this, the initial data point was
removed and the DFOP kinetics re-fitted. This resulted in an improved visual and
residual fit and improved χ2 error test. However, the applicant considered that removal
of the data point could not be justified and thus in a further analysis, the g parameter in
the DFOP assessment was fixed at the value of 0.655, i.e. that achieved when the
initial data point was removed, but the initial data point was re-instated in the dataset.
This improved the visual and residual fits, but resulted in a poorer χ2 error test. The
statistical results of this further assessment are shown below.
Table B.8.31 Statistical results of the Applicant kinetic fits for DFOP model to
normalised field dissipation data for German site: DT50 and DT90 [d], visual ranking
and quality of fits, visual assessment of random-ness of residuals, scaled error ε to pass
the 2 test, and T-test for relevant parameter fit.
It is noted that relying solely on the outcome of the statistical evaluation in Table
B.8.31 above indicates that the procedure fixing g to 0.655 results in a poorer χ2 value
compared to the free fit to the German site dataset but improved t-test for the k1 value.
However, whilst the procedure fixing g results in a poorer χ2 value, the visual fit is
improved for data points 5 onwards, i.e. from a residue of approx 30 g/ha or 35% of
47
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
the initial (contrast Figures B.8.29 for free fit and B.8.31 for fixed g). The Evaluator
postulates that the reason why χ2 becomes higher in value with fixing of g is that the
residuals for the first three data points have become much greater, indicating that the
initial data points are fitted less well (indeed, estimated M0 for free fit is 86.96 g/ha vs.
73.60 g/ha for fit with g fixed; actual M0 was 87.5 g/ha). Thus the Evaluator
considers that the study author conclusion that the overall fit of the curve was better as
a result of fixing ‘g’ to 0.655 is subjective and that the choice of DFOP fits is
marginal. Comparisons of k and g values for the two fits with the German site dataset
and the difference in overall geometric mean parameters for all 4 soils based on DFOP
kinetics are given in Tables B.8.32 and 33.
Table B.8.32 Comparison of DFOP kinetic values for the German field dissipation site
with free fitting of g and fixing g
Fast phase
DT50
0.21 days
2.5 days
Free fit g
Fixed g
1
Slow phase
DT50
30.1 days
70.7 days
g
0.4687
0.6550
Estimated
M01
86.96
73.60
Actual M0 87.5 g/ha
Table B.8.33 Comparison of geomean modelling parameters from all four field
dissipation sites using alternative DFOP parameters from German site
Free fit g
Fixed g2
1
arithmetic mean
Fast phase
DT50
0.91
1.68
2
Slow phase
DT50
48.8
60.5
g1
0.442
0.489
study author proposed values
Overall, the Evaluator considers that there is little to choose between the mean
parameters. Free fitting of ‘g’ at the German site leads to slightly faster degradation
but less substance in the faster degrading compartment, whereas fixed ‘g’ at the
German site leads to slightly slower degradation but a higher proportion of substance
in the faster degrading compartment. Thus, taking all considerations into account, the
Evaluator considers that the study authors choice of parameters based on the fixed g
value for the German site is acceptable, particularly if 1,2,4-triazole is the terminal
metabolite in the leaching assessment. The final presentation of the study author’s
choice of modelling endpoints for 1,2,4-triazole is given below.
48
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.34 Proposed kinetic endpoints for 1,2,4-triazole for modelling (normalised
to 20°C and pF2)
a
The proportion of the substance described by k1. bFixed to 0.655. cArith. mean
49
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Germany
Figure B.8.22 SFO visual and residual fits for 1,2,4-triazole at German field
dissipation site, timestep normalised
50
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.23 FOMC visual and residual fits for 1,2,4-triazole at German field
dissipation site, timestep normalised
51
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.24 DFOP visual and residual fits for 1,2,4-triazole at German field
dissipation site, timestep normalised
52
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.25 DFOP visual and residual fits for 1,2,4-triazole at German field
dissipation site, timestep normalised, initial data point removed
53
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.26 DFOP visual and residual fits for 1,2,4-triazole at German field
dissipation site, timestep normalised, initial data point included, ‘g’ fixed at 0.655
54
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Italy
Figure B.8.27 SFO visual and residual fits for 1,2,4-triazole at Italian field dissipation
site, timestep normalised
55
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.28 HS visual and residual fits for 1,2,4-triazole at Italian field dissipation
site, timestep normalised
56
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.29 DFOP visual and residual fits for 1,2,4-triazole at Italian field
dissipation site, timestep normalised
57
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
UK
Figure B.8.30 SFO visual and residual fits for 1,2,4-triazole at UK field dissipation
site, timestep normalised
58
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.31 FOMC visual and residual fits for 1,2,4-triazole at UK field dissipation
site, timestep normalised
59
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.32 DFOP visual and residual fits for 1,2,4-triazole at UK field dissipation
site, timestep normalised
60
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Spain
Figure B.8.33 SFO visual and residual fits for 1,2,4-triazole at Spanish field
dissipation site, timestep normalised
61
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.34 HS visual and residual fits for 1,2,4-triazole at Spanish field dissipation
site, timestep normalised
62
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Figure B.8.35 DFOP visual and residual fits for 1,2,4-triazole at Spanish field
dissipation site, timestep normalised
Chapple 2010b
Evaluator’s final note: The geomean slow phase DT50 from this evaluation is in
reasonable agreement with that from the kinetic assessment of the laboratory studies.
Overall, it is considered that the laboratory and the field data give strong support for
1,2,4-triazole demonstrating bi-phasic degradation. If 1,2,4-triazole is being
considered as a terminal metabolite in a leaching assessment, it is appropriate to
simulate degradation of this metabolite using two compartments, one for the rapid
degradation phase and the other the slow degradation phase. The separate flows from
63
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
the precursor to the rapid and slow phases should be specified along a similar scheme
as shown in chapter 8.3.3.2.2 and Box 8-2 of the FOCUS Degradation Kinetics
guidance. Specifically, the proportion of flow to the rapid phase of degradation would
be specified by ffM x g (i.e. formation fraction for precursor to 1,2,4-triazole
multiplied by the DFOP ‘g’ parameter) and the proportion of flow from precursor to
the slow phase would be specified by ffM x (1-g) (i.e. formation fraction for precursor
to 1,2,4-triazole multiplied by 1-‘g’). Given that this method divides the formation
fraction for the metabolite between fast and slowly degrading compartments using the
‘g’ parameter as part of the simulation, it is considered unnecessary to run the model
twice as specified in FOCUS degradation kinetics (i.e. it is unnecessary to run the fast
and slow compartments separately and add the results together). However, due to the
1/n value for 1,2,4-triazole being less than 1, the recommendation that the application
rate in the simulation is doubled and the resulting leaching concentrations divided by 2
is supported.
Note that no PEC calculations are considered in this evaluation document as the
concentrations of 1,2,4-triazole will be dependent on the amount of formation from
each separate triazole parent a.s. and the GAP details for the parent.
iii)
An assessment of freezer storage stability and analytical methods in support of these
data is given below.
Freezer Storage Stability of lH-l,2,4-Triazole[3,5-14C] in Soil; (report no. 108303)
Samples of loamy sand soil from a site in Fresno, California, USA were fortified with
[14C]-1, 2, 4-triazole at a concentration of 10.3 mg/kg and stored frozen at -25°C for up
to 42 months. Duplicate samples were removed from the freezer and analysed for
residues of 1, 2, 4-triazole at day 0 and after 1, 3, 6, 12, 21 and 42 months storage. A
“control” sample, freshly fortified was also analysed at each time point
Analysis for residues of 1, 2, 4-triazole was conducted as follows:
Samples were extracted for 1 hour at room temperature (by magnetic stirrer) with
methanol: water 4:1 (v/v) and centrifuged. The supernatant was decanted. The
samples were then extracted for 30 minutes with two aliquots of methanol and
centrifuged. Finally the samples were extracted for 2 hours with methanol: ammonium
hydroxide (aq) 7:3 (v/v) and centrifuged.
Radioactive residues were determined by LSC or LSC following combustion in the
case of the post extraction solids. Aliquots of the extracts were filtered, concentrated
under a stream of oxygen free nitrogen and analysed by TLC against certified
reference standards. Further analyte confirmation was conducted by LC-MS (ESI
mode). The results are shown below:
The Evaluator considers that the results indicate that residues of 1, 2, 4-triazole are
stable in samples of loamy sand soil stored frozen for up to 42 months.
64
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.35: Radioactive residues in samples of soil stored frozen for up to 42
months
65
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.36: Residues of 1,2,4 – triazole samples of soil stored frozen for up to 42
months of soil
Shadrick et al, 1999
66
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Analytical method JA005-W04-01 was used in field dissipation studies. The method
utilises derivation of 1, 2, 4-triaozle with dansyl chloride to give dansyl-1, 2, 4triazole. The following justification for using a derivatisation method was provided:
“Derivatisation allowed triazole to be run in a non-polar HPLC system, similar to other
fungicide metabolites. Also, derivatisation provided larger mass; therefore more
transitional ions within the mass spectrometer environment, which aided sensitivity
and detection.”
This is considered acceptable by the Evaluator.
Analytical Method for the Determination of Triazole in Soil and Sediment; Method
JA005-W04-01
Samples of soil were extracted by ultrasonication for 1 hour with acetonitrile: water
6:4 (v/v) at 65-70°C. Samples of sediment were extracted in the same manner but
using 1% sodium hydroxide: acetonitrile 6:4 (v/v). A 1ml aliquot of the extract was
taken and derivatised with dansyl chloride to give dansyl 1, 2, 4-triazole. The
derivatised extract was partitioned with ethyl acetate, filtered through anhydrous
sodium sulphate, concentrated to dryness and reconstituted in acetonitrile: water 1:1
(v/v). Extracts were analysed by LC/MS/MS in positive ionisation mode; luna C13
column, 100 x 4.6mm, 5 µm i.d. Stable isotope [15N]-1, 2, 4-triazole was used as an
internal standard by addition to the extract prior to derivatisation. Quantitative
analysis was performed using reference standards of dansyl 1, 2, 4-triazole and stable
isotope [15N]-dansyl 1, 2, 4-triazole. The ion transitions monitored were 303→170 for
dansyl 1, 2, 4-triazole and 306→170 for the stable isotope internal standard. Results
were expressed in terms of 1, 2, 4-triazole.
The LOQ was stated to be 10µg/kg. Validation data were provided using soil from
Saskatchewan, Canada as follows:
Linearity: demonstrated in the range 2.5 – 100 ng/ml (equivalent to 5 – 200 µg/kg in
the samples). R2 > 0.99.
Precision: 7 determinations made at 10µg/kg. RSD = 1.84%. 5 determinations made
at 100 ppb. RSD = 2.29%
Accuracy: Mean recovery values at fortification levels of 10µg/kg and 100 µg/kg for
several different soil types were in the range 79-105%. Further details are given in the
table below:
67
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.37 Average recoveries of 1,2,4-traiazole in soils
The Evaluator considers that the method is suitably validated/fit for purpose.
I. M. Murphy, 2004
Determination of the Residues of 1,2,4-Triazole in/on soil after spraying of 1,2,4Triazole (1000 TS) in the field in Germany, Italy, Great Britain and Spain Analytical
Phase; report PF/04/004.
Samples were analysed according to the method JA005-W04-01 above. The filter
paper samples were extracted in the same way as the soil samples but extracts were
diluted by 1:20 with acetonitrile: water 6:4 (v/v) before an aliquot was taken for
derivatisation.
The LOQ was stated to be 3µg/kg for soil and 0.1µg/cm2 for filter papers.
A separate validation study for the method was provided (S Jones 2005. Report
CX/05/035). The results are summarised in the table below
68
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Table B.8.38 Validation of Analytical Method for the Determination of 1,2,4-Triazole
in Soil and Filter Papers.
Matrix
Method
Analyte
Soil
HPLC–
MS/MS
Dansyl
1,2,4triazole
Filter
paper
HPLC–
MS/MS
Dansyl
1,2,4triaozle
LOQ
(µg/kg)
Recovery
fortificati
on level
(µg/kg)
3.0
Recoveries
% range
(mean*)
65-100
(82.6)
Repeatabi
lity
% RSD
(n)
11.7
(12)
64-79
(72.0)
4.7
(12)
Linearity
3.0
30
0.1
µg/cm2
0.1
µg/cm2
1.0
µg/cm2
75-101 (89)
0.75-100
ng/ml
r2 = 0.9996
10.9 (6)
80-89 (83)
Some of the control samples used for fortification had apparent residues at levels
>30% of the LOQ – recoveries were corrected to take these residues into account. The
potential residues in the blank samples may explain the variable recoveries. Whilst
some individual recoveries are outside of the range 70-110%, the mean recoveries are
within the acceptable range and the precision (repeatability) is acceptable. It has been
demonstrated that the derivative is formed reproducibly by the use of an external
standard of the derivate. The method is considered suitably validated.
Further procedural recoveries in the soil at fortification levels of 3µg/kg were in the
range 67-118% with a mean of 94% and for a fortification level of 100µg/kg were in
the range 70-80% with a mean of 75%. These are considered acceptable by the
Evaluator.
S Jones 2005; M Fitzmaurice 2010
69
1,2 4-Triazole– Revision of DT50
B.8.10
July 2011 (revised September 2011)
References relied on
Annex
point
Author
Year
Title
Source (where different from
company)
Company, Report No.
GLP or GEP status (where relevant)
Published or Unpublished
Data
protection
claimed
Y/N
Owner
B.8.1.1.2
Slangen, P.J.
2000
Yes
TDMG
B.8.1.1.2
Chapple, A.
2010a
Yes
TDMG
B.8.1.3
Tarara, G.
2010
Yes
TDMG
B.8.1.3
Chapple, A.
2010b
Yes
TDMG
B.8.1.3
Shadrick, B.A;
Bloomberg, A.M;
Helfrich, K.K.
1999
Yes
TDMG
B.8.1.3
Murphy, I.M.
2004
Degradation of 1,2,4-triazole in
three soils under aerobic
conditions
NOTOX Safety & Environmental
Research B.V., 's-Hertogenbosch,
Netherlands
Bayer CropScience AG,
Report No.: 278336,
Date: 2000-05-08
GLP, unpublished
Kinetic evaluation of the
degradation in soil of 1,2,4triazole under laboratory
conditions
Bayer CropScience AG
Report No. MEF-10/556
Date: 2011-02-09
Non-GLP, unpublished
Determination of the residues of
1,2,4-triazole in/on soil after
spraying of 1,2,4-tiazole (1000 xx)
in the field in Germany, Italy,
Great Britain and Spain
Bayer CropScience AG
Report No.: RA-2145/04
Date: 2010-03-04
GLP, unpublished
Kinetic evaluation of the
dissipation in soil of 1,2,4-triazole
under field conditions
Bayer CropScience AG
Report No.: MEF-10/069
Date: 2010-03-17
Non-GLP, unpublished
Freezer storage stability of 1H1,2,4-triazole [3,5-14C] in soil
Bayer CropScience AG
Report No.: 108303
Date: 1999-12-22
GLP, unpublished
Analytical method for the
determination of triazole in soil
and sediment
Bayer CropScience AG
Report No. 200516
Method No. JA005-W04-01
Date: 2004-02-20
GLP, unpublished
Yes
TDMG
70
1,2 4-Triazole– Revision of DT50
July 2011 (revised September 2011)
Annex
point
Author
Year
Title
Source (where different from
company)
Company, Report No.
GLP or GEP status (where relevant)
Published or Unpublished
Data
protection
claimed
Y/N
Owner
B.8.1.3
Jones, S.
2005
Yes
TDMG
B.8.1.3
Fitzmaurice, M.
2010
Validation of analytical method
for the determination of triazole in
soil and filter papers
Battelle UK Ltd, Ongar, Essex,
UK
Bayer CropScience AG
Date: 2005-06-20
GLP, unpublished
Determination of the residues of
1,2,4-triazole in/on soil after
spraying of 1,2,4-triazole (1000
TS) in the field in Germany, Italy,
Great Britain and Spain, analytical
phase
Battelle UK Ltd, Ongar, Essex,
UK
Bayer CropScience AG
Date: 2010-02-23
GLP, unpublished
Yes
TDMG
1,2 4-Triazole– Revision of DT50 – APPENDIX I
71
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
United Kingdom
July 2011
1,2 4-Triazole
Fate and behaviour in the environment
Appendix I – List of end points July 2011
Rate of degradation in soil (Annex IIA, point 7.1.1.2, Annex IIIA, point 9.1.1)
Laboratory studies – modelling kinetic parameters
1,2,4-triazole
(applied as
parent)
Aerobic conditions
Soil type
X1
pH
t. oC / %
MWHC
DT50 fast DT50 (d)
phase/DT5
20C
0 slow
pF2/10kPa
phase(d)/g
St.
(r2)
Method of
calculation
Sandy loam
6.4
20 oC / 40 %
0.9/59.2/
0.683
DFOP
Loamy sand
5.8
20 oC / 40 %
1.5/247.6/
0.580
DFOP
Silt loam
6.7
20 oC / 40 %
0.8/20.6/
0.443
DFOP
1.0/67.1/
0.569
DFOP
Geometric mean/median
Field studies ‡
1,2,4-triazole
(applied as
parent)
Aerobic conditions, kinetics calculated for ambient conditions. Bare soil
with grass sown immediately after application (with exception of Spain site
where no grass sown).
Soil type
Location
(indicate if bare (country or
or cropped soil USA state).
was used).
1
X1
pH
Dept
h
(cm)
DT50
(d)
actual
DT90( St. DT50 Method
d)
of
(χ2) (d)
actual
Norm. calculati
on
Silt loam
Germany
6.4
0-30
7.8
366.7 15.2
FOMC
Silty clay loam
Italy
7.6
0-40
21.2
207.4 10.7
DFOP
Sandy loam
UK
7.4
0-40
6.8
109.3 17.8
DFOP
Loam
Spain
5.8
0-30
28.1
717.6 13.3
DFOP
X This column is reserved for any other property that is considered to have a particular impact on the degradation rate.
1,2 4-Triazole– Revision of DT50 – APPENDIX I
72
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
United Kingdom
July 2011
1,2 4-Triazole
Fate and behaviour in the environment
Geometric mean/median
1,2,4-triazole
(applied as
parent)
Aerobic conditions, kinetics calculated timestep normalised to 20ºC and
pF2 moisture. Bare soil with grass sown immediately after application
(with exception of Spain site where no grass sown).
Soil type
Location
pH
Dept
h
(cm)
DT50
(d)
DT50
(d)
Fast
phase
Slow
phase
‘g’
St.
(χ2)
Method
of
calculati
on
Silt loam
Germany
6.4
0-30
2.5
70.7
0.65 18.8
5
DFOP
Silty clay loam
Italy
7.6
0-40
1.4
59.8
0.36 10.6
4
DFOP
Sandy loam
UK
7.4
0-40
0.5
25.1
0.45 18.1
8
DFOP
Loam
Spain
5.8
0-30
4.6
126.0 0.48 12.7
9
DFOP
1.68
60.5
DFOP
Geometric mean (‘g’ value is arithmetic mean)
Repeat for as many metabolites as necessary
pH dependence ‡
(yes / no) (if yes type of dependence)
No
0.48
9
73
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Appendix 2 – copy of endpoints agreed at PRAPeR 12 meeting of 15 – 18 January 2007
Route of degradation (aerobic) in soil (Annex IIA, point 7.1.1.1.1)
Mineralization after 100 days ‡
Bitertanol
1,2,4-triazole
1.6-52% after 90-120 days triazole label (n=6)
Epoxiconazole
- Metabolite [3,5-14C] 1,2,4-triazole:
Study duration 360 days, (CO2 % TAR)
soil 1, pre-adapted 24 % after 90 days
39.1 % after 180 days
soil 2, pre-adapted 51.6 % CO2 after 90
days
soil 3, non-adapted: 15/14 % CO2 after 90
days
- Metabolite [3,5-14C] 1,2,4-triazole, rate study:
Sandy loam 20/11 % CO2 after 120 days
(study end)
Loamy sand: 1.4/1.6 % CO2 after 120 days
(study end)
Silt loam: 34/32 % CO2 after 120 days (study
end)
Triadimenol
1,2,4-triazole
1.6-52% after 90-120 days triazole label (n=6)
Agreed End Point (PRAPeR 12)
Non-extractable residues after 100 days ‡
Bitertanol
1,2,4-triazole
38-67% after 90-120 days triazole label (n=6)
Epoxiconazole
- Metabolite [3,5-14C] 1,2,4-triazole (% TAR):
soil 1, pre-adapted - max. 75 % after 28 days,
43 % after 360 d (study end)
soil 2, pre-adapted - max. 53.5 % after 28 days,
74
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
33.7 % after 360 d (study end)
Triadimenol
1,2,4-triazole
38-67% after 90-120 days triazole label (n=6)
Agreed End Point (PRAPeR 12)
Metabolites requiring further consideration
‡
- name and/or code, % of applied (range
and maximum)
Bitertanol
1,2,4-triazole 44% at 62 d (n=1) declining to
36% at study end (120 days)
Cyproconazole
Triazole ( triazole label), 17.36 % at 140 d (n=
1), max
17.36%, day 140
Triazole acetic acid (triazole label), 0-6.7 % at
140 d (n= 1).
Bromuconazole
1,2,4-triazole is no major metabolite in soil, No
end points derived.
Difenoconazole
1, 2, 4-triazole (CGA 71019) max. 20.6-23.4%
after 190/271 d [14C-triazole]-label (n=2)
Epoxiconazole
Investigated: triazole 14C-labelled
epoxiconazole (% TAR): Study duration 343 d,
only study end data:
Loamy sand: 5.0 % (4.6/5.4 %) 1,2,4-triazole
2.4 % others after 343 d
Sandy loam: 1.9 % 1,2,4-triazole after 343 d
3.3 % others after 343 d
Sandy loam: 6,6 % (5.3/7.9 %) 1,2,4-triazole
after 175 d.
(study end, only study end data).
Fenbuconazole
RH-0118 (1,2,4-triazole) peaked at 12.4% AR
after 363 d [14C-TR] label (25°C)
Flunquiconazole
Triazole – 9.0-18.9% after 119-182 d, [14C]Fluquinconazole – triazolyl label (n = 3 soils at
20 C)
Paclobutrazol
75
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
1,2,4-triazole is no major metabolite in soil,
however some end points were derived.
Tetraconazole
Laboratory study (dark):
no metabolite formation
Laboratory study under sunlight:
TAA (Triazolyl acetic acid):
max: 4.55 and 4.89% after 60 and 112 days
(n=1)
Triadimenol
Triazole ring not labelled; in absence of other
information, 1,2,4-triazole assumed to be
formed at 100% for environmental exposure
assessment
Route of degradation in soil - Supplemental studies (Annex IIA, point 7.1.1.1.2)
Anaerobic degradation ‡
Bitertanol
Anaerobic degradation ‡
Triadimenol
Anaerobic degradation ‡
Agreed end point
1,2,4-triazole
Mineralisation 1.3% after 126 d triazole label
(n=1)
Non extractable residues max 21% 64 days
declining to 16% at study end 126d triazole
label (n=1)
Major metabolite Triazole acetic acid 50% at
study end 126 days triazole label (n=1)
1,2,4-triazole
Mineralisation 1.3% after 126 d triazole label
(n=1)
Non extractable residues max 21% 64 days
declining to 16% at study end 126d triazole
label (n=1)
Major metabolite Triazole acetic acid 50% at
study end 126 days triazole label (n=1)
76
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Rate of degradation in soil (Annex IIA, point 7.1.1.2, Annex IIIA, point 9.1.1)
Laboratory studies ‡
Bitertanol
Laboratory studies (range or median, with
n value,
with r2 value) ‡
DT50lab (20C, aerobic): ‡
1,2,4-triazole
20C: 6.3-12.3 d (n=3, r2= 0.75-0.95)
triazole acetic acid
20C: 6-11 d (n=3, r2= 0.76-0.9)
For FOCUS modelling geometric mean first
order 20ºC DT50lab normalised to -10kPa soil
moisture:
1,2,4-triazole:
7.4 d
DT90lab (20C, aerobic): ‡
1,2,4-triazole
20C: 21-41 d (n=3, r2= 0.75-0.95)
triazole acetic acid
20C: 20-37 d (n=3, r2= 0.76-0.9)
Cyproconazole
Triazole
Soil type
pH
©
Sandy loam
f. f. DT50 (d)
kdp/k
20C
f
pF2/10kPa
St.
(r2)
Method of
calculation
20 oC /
34.4 %
6.32
5
0.75
SFO
5.8
20 oC / 50
%
9.91
13
0.81
SFO
6.7
20 oC /
36.4 %
12.27
8
0.95
SFO
9.15/9.91
8.06/8.2
(Hanhofen)
Silt loam
DT50/
DT90
(d)
6.4
(Laacherhof
AXXa)
Loamy sand
t. oC / %
MWHC
(Laacherhof A
III)
Geometric mean/median
77
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Difenoconazole
CGA 71019
Aerobic conditions
1,2,4-triazole
Soil type
pH t. oC / %
MWHC
sandy loam
loamy sand
silt loam
Geometric mean
Median
6.4
5.8
6.7
20 / 40
20 / 40
20 / 40
DT50/
f. f.
DT90
kdp/
(d)
kf
6.3 / 21
9.9 / 33
12 / 41
9.1 / 30.5
9.9 / 33
Epoxiconazole
Laboratory studies (range or median, with
n value, with r2 value) ‡
DT50 (d)
20 C
pF2/10kPa
4.3
7.6
7.5
6.3
7.5
St.
(r2)
Method of
calculation
0.75
0.81
0.95
SFO
SFO
SFO
DT50lab (20C, aerobic): standardised to field capacity
pF2 if test soil moisture < field capacity, -10kPa, with
Q10 2.2, Walker-equation exponent 0.7. r² > 0.7
Metabolite 2 = 1,2,4-triazole
20 °C, moisture
not standardised
Loamy sand
10 d
Sandy loam
6d
Silt loam
12 d
geometric mean DT50lab:
9d
Fenbuconazole
Aerobic conditions
1,2,4triazole
Soil type
pH
t. oC / % MWHC
(USDA)
(CaCl2
)
Sandy loam
6.4
Loamy sand
5.8
Silt loam
6.7
Arithmetic mean
20oC / 40 %
MWHC
20oC / 40 %
MWHC
20oC / 40 %
MWHC
DT50 /DT90
(d)
1st order
20 °C, pF2
10 d
5d
9d
8d
Method of
calculation
6.32 / 21.0
DT50 (d) St.
(r2)
20C
pF2/10kP
a
5.0
0.75
9.91 / 33.0
9.9
0.81
SFO
12.27 / 40.8
8.2
0.95
SFO
7.7
SFO
78
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Fluquinconazole
Laboratory studies (range or median, with
n value, with r2 value)
Aerobic studies:
Triazole DT50lab (20 C, aerobic, sfo non-linear
regression): 6.32, 9.91, 12.27 d, mean = 9.5 d (n
= 3 soils, r2 = 0.75-0.95)
Triazole DT50lab (20 C, aerobic, multicompartment model): 2.34, 9.34, 12.27 d, mean
= 7.98 d (n = 3 soils, r2 = 0.95-0.99)
Triazole DT90lab (20 C, aerobic, sfo non-linear
regression): 21.0, 32.9, 40.8 d, mean =31.6 d (n
= 3 soils, r2 = 0.75-0.95)
For FOCUS gw modelling:
Triazole DT50lab (aerobic, 1st order kinetics):
mean = 7.0 d (normalized to 10kPa, 20 C with
Q10 of 2.2 and B-value of 0.7)
Tetraconazole
Triazolyl acetic Aerobic conditions
acid (TAA)
Soil type
X1 pH
t. oC / %
MWHC
DT50/
DT90
F.F. DT50 (d)
kdp/k
20C pF2/10kPa
2
Method of
calculation
f
(d)
Sand
5.2
(0.01M
CaCl2)
20°C / 60%
(pF=2.5)
9.6/ 31.8
10.9
12.0
SFO
Loamy sand
5.6
(0.01M
CaCl2)
20°C / 60%
(pF=2.5)
8.4/ 27.8
8.6
14.1
SFO
Sandy loam
6.3
(0.01M
CaCl2)
20°C / 60%
(pF=2.5)
18.7/
62.1
16.7
9.5
SFO
DT50:
11.6 / 10.9
Geometric mean/median
11.5/ 9.6
79
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Triadimenol
Laboratory studies (range or median, with
n value,
with r2 value) ‡
Aerobic DT50:
1,2,4-triazole
20C: 6.3-12.3 d (n=3, r2= 0.75-0.95)
triazole acetic acid
20C: 6-11 d (n=3, r2= 0.76-0.9)
Aerobic DT90:
1,2,4-triazole
20C: 21-41 d (n=3, r2= 0.75-0.95)
triazole acetic acid
20C: 20-37 d (n=3, r2= 0.76-0.9)
Agreed end point
1,2,4-triazole
Aerobic conditions
Soil type
(USDA)
pH
Sandy loam
6.4
Loamy sand
5.8
Silt loam
6.7
Geometric mean
(CaCl2
)
t. oC / %
MWHC
DT50/
DT90
(d)
20oC / 40
%
MWHC
20oC / 40
%
MWHC
20oC / 40
%
MWHC
6.32 /
21.0
f. f. DT50 (d)
kdp/
20C
kf
pF2/10kPa
5.0
St.
(r2)
Method of
calculation
0.75
SFO
9.91 /
33.0
9.9
0.81
SFO
12.27 /
40.8
8.2
0.95
SFO
7.4
Agreed End-point for calculating PEC soil for EU assessments 12 days (Not normalised).
80
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Laboratory studies ‡ anaerobic
Bitertanol
DT50lab (20C, anaerobic): ‡
1,2,4-triazole
58 d (n=1, r2= 0.77.)
Cyproconazole
Triazole
Soil type
Silt loam
pH
t. oC / %
MWHC
DT50/
DT90
(d)
81/291
f. f.
kdp/
kf
----
7.31
20/40
(KC
l)
Geometric mean/median
81/291
Difenoconazole
Laboratory studies 1,2,4- Triazole‡
Anaerobic conditions
g/ha pH
t. oC / %
DT50 /
DT50 (d)
1
MWHC
DT90 (d)
20 C
pF2/10kPa
128 7.2
20 / flooded
stable
-
DT50 (d)
20C
pF2/10kPa
------
St.
(r2)
Method of
calculation
0.972 SFO
St.
(r2)
Method of
calculation
-
-
1 Test concentration re-calculated into corresponding g a.s./ha dose for comparison with the
representative uses.
Triadimenol
Anaerobic:
1,2,4-triazole
20˚C: DT50 = 58 d (n=1, r2= 0.77.)
Agreed end point
81
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Soil adsorption/desorption (Annex IIA, point 7.1.2)
Bitertanol
Kf /Koc ‡
Kd ‡
pH dependence (yes / no) (if yes type of
dependence) ‡
1,2,4-triazole
Kfoc:43-120 ml/g, 1/n 0.83-1.016 (n=4)
No evidence of pH dependence
Arithmetic mean values for FOCUS modelling
89ml/g, 1/n 0.91
Cyproconazole
1,2,4-Triazole‡
Soil Type
Alpaugh Silty clay
Hollister Clay loam
Lawrenceville Silty clay
Pachappa Sandy loam
OC %
1.2
3.0
1.2
1.4
Soil pH
8.8
6.9
7.0
6.9
Kd
Arithmetic mean
pH dependence (yes or no)
Difenoconazole
CGA 71019 (1,2,4-Triazole)‡
Soil Type
silty clay
clay loam
silty clay loam
sandy loam
Arithmetic mean
Median
pH dependence (yes or no)
Koc
Kf
Kfoc
0.833
120
0.748
43
0.722
104
0.719
89
0.7555
89
1/n
0.897
0.827
0.922
1.016
0.91
No.
OC %
0.70
1.74
0.70
0.81
Soil
pH
8.8
6.9
7.0
6.9
Kd
Koc
Kf
Kfoc
(mL/g) (mL/g) (mL/g) (mL/g)
0.83
120
0.75
43
0.72
104
0.72
89
0.75
89
0.74
82
No
1/n
0.90
0.83
0.92
1.02
0.91
0.91
82
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Epoxiconazole
metabolite 1,2,4-triazole
Koc: 43-120, arithmetic mean 89 (n=4)
soil
pH
Koc
Kf
1/n
Sandy loam
6.9
89
0.720 1.016
(62 % sand, 21 % silt, 17 % clay, 1.4 % org. matter, Corg 0.812 %.)
Clay loam
6.9
43
0.748 0.827
(26 % sand, 46 % silt, 28 % clay, 3.0 % org. matter, Corg 1.74 %.)
Silty clay
8.8
120
0.833 0.897
(11 % sand, 44 % silt, 45 % clay, 1.2 % org.C matter, Corg 0.696)
Silty clay loam
7.0
104
0.722 0.922
(9 % sand, 62 % silt, 29 % clay, 1.2 % org. matter, Corg 0.696)
Kf /Koc ‡
pH dependence (yes / no) (if yes
type of
dependence) ‡
yes (metabolite), increasing sorption with increasing pH
Fenbuconazole
1,2,4-triazole
Soil Type (USDA)
OC %
Soil pH
(CaCl2)
Silty clay
0.70
8.8
Clay loam
1.74
6.9
Sand
0.12
4.8
Silty clay loam
0.70
7.0
Sandy loam
0.81
6.9
Mean1
1
Results from the sand soil excluded as an outlier
Fluquinconazole
Kf/Koc
Kd
pH dependence (yes/no) (if yes type of
dependence)
Kf
Kfoc
1/n
r2
0.833
0.748
0.234
0.722
0.720
0.756
120
43
202
104
89
89
0.897
0.827
0.885
0.922
1.016
0.916
0.996
0.997
0.997
0.998
0.997
-
Triazole:
Kf: 0.234-0.833 mL/g (mean = 0.651 mL/g, 5
soils)
Kfoc: 43-202 mL/g (mean = 111.6 mL/g, 5 soils)
1/n: 0.827-1.016 (mean = 0.909, 5 soils)
Kd: Not determined
No pH dependence for Fluquinconazole or its
metabolite, dione.
83
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Paclobutrazol
Metabolite 1,2-4 triazole ‡
Soil Type
OC %
Soil pH Kd
Koc
(mL/g)
(CaCl2)
(mL/g)
8.8
0.833
120
6.9
0.748
43
4.8
0.234
202
Kf
Kfoc
1/n
(mL/g) (mL/g)
0.833
120
0.748
43
0.2341 2021
0.897
0.827
0.8851
Lakeland
0.70
1.74
0.12
Lawrenceville
0.70
7.0
0.722
104
0.722
104
0.922
Pachappa
0.81
6.9
0.719
89
0.720
59
1.016
Alpaugh
Hollister
0.7561
Arithmetic mean
pH dependence (yes or no)
891
0.91551
Yes. Positive correlation with organic carbon, pH
and clay content
1
Results from the Lakeland soil were excluded on the basis of being an outlier
Tetraconazole
TAA(Triazole acetic acid)
Soil Type
OC %
Soil pH
Kd
Koc
Loamy sand
14.42
3.38
0.150
1.04
(0.01M CaCl2)
Kf
Kfoc
1/n
adsorb:
0.903;
desorb:
0.786
Clay
0.89
7.55
0.178
20
(0.01M CaCl2)
adsorb:
0.911;
desorb:
0.865
Silt loam
2.13
5.16
0.448
21
(0.01M CaCl2)
adsorb:
0.926;
desorb:
0.820
Geometric mean/median
0.229/
0.178
7.59/
20.0
adsorb:
0.913/
0.911;
desorb:
0.823/
0.820
pH dependence, Yes or No
no
84
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Triadimenol
Kf /Koc ‡
1,2,4-triazole
Kfoc:43-120 ml/g, 1/n 0.83-1.016 (n=4)
No evidence of pH dependence
Kd ‡
pH dependence (yes / no) (if yes type of
dependence) ‡
Agreed end point
Metabolite 1,2-4 triazole ‡
Soil Type(USDA)
Silty clay
Clay loam
OC %
Soil pH Kd
Koc
(mL/g)
(CaCl2)
(mL/g)
8.8
6.9
4.8
Kf
Kfoc
1/n
(mL/g) (mL/g)
0.833
120
0.748
43
0.234
202
0.897
0.827
0.8851
Sand
0.70
1.74
0.12
Silty clay loam
0.70
7.0
0.722
104
0.922
Sandy loam
0.81
6.9
0.720
89
1.016
Arithmetic mean (of 4 values excluding the very low OC sand that 0.756
was considered not representative of agricultural soils)
pH dependence (yes or no)
89
0.9155
No
Mobility in soil (Annex IIA, point 7.1.3, Annex IIIA, point 9.1.2)
Tetraconazole
Column leaching ‡
Tetraconazole metabolites column leaching in
slightly humous sand:
elution: 200 mm
time period : 2 days
Tetraconazole metabolites column leaching in
slightly humous sand:
Triazole: 59.04% (of applied Triazole)
TAA: 95.53% (of applied TAA)
85
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Tetraconazole
Aged residues leaching ‡
Laboratory study (dark):
Aged for (d): 30 d
Time period (d): 2 d
Elution (mm): 200 mm
Laboratory study under sunlight:
Aged for (d): 53 d (samples D2 and D3), 48 d
(sample D1)
Time period (d): 2 d
Elution (mm): 200 mm
Soil residues post ageing
Laboratory study (dark):
% of 14C-Tetraconazole: 96.21%AR
% of bound residues: 2.32%AR
Laboratory study under sunlight:
% of bound residues: 8.50%AR (53 d);
8.38%AR (48d)
Characterization of soil residue before leaching
was performed just for the 53 d aged sample;
Tetraconazole in D2 sample (53 d): 41.80 %AR
M14360-alcohol in D2 sample (53 d):8.07
%AR
Triazole in D2 sample (53 d):1.97 %AR
DFA in D2 sample (53 d):9.97 %AR
M14360-acid in D2 sample (53 d): 2.74 %AR
TAA in D2 sample (53 d): 4.11 %AR
Analysis of leachate
Laboratory study:
tetraconazole equivalents in the leachate:
0.15%AR
bound residues: 2.13%AR
Study under sunlight:
Total residues/radioactivity: 33.15%AR
Active substance: 0.00%AR
Metabolites: 0.45%AR (M14360-alcohol),
1.88%AR (Triazole), 10.01%AR (DFA),
4.12%AR (M14360-acid), 5.69%AR (TAA)
Radioactivity retained in soil segment:
12.93%AR in top 5 cm; 15.29%AR in top 30
cm
86
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
PEC (soil) (Annex IIIA, point 9.1.3)
Cyproconazole
Metabolite I
Method of calculation
Triazole
Molecular weight relative to the parent: 0.236
(69.1 g/mol)
DT50 (d): 12.3 days.
Kinetics: SFO,
Lab worst case
Difenoconazole
CGA 71019 (1,2,4-Triazole)
Method of calculation
Epoxiconazole
Method of calculation
Initial PECs=
Max parent PECs x Max. metabolite in soil x
Mol. Wt fraction.
where:
Max. parent PECs: 0.016 mg/kg (seed
treatment);
0.136 mg/kg (apples); 0.096 mg/kg (carrots)
Max. CGA 71019 in soil: 23%
Molecular weight fraction: 0.170.
PEC: 1st order kinetic, DT50Lab worst case
standardised to 15 °C of 3 studies: 18 d, 5 cm
soil layer, 1.5 kg/L bulk density, with
interception (FOCUS) for cereal scenario f =
0.5 (BBCH 25) and 0.7 (BBCH 61). Interval
between applications 21 d. ModelMaker,
k1_deg = 1st order rate constant BAS 480 F to
metabolite 1 1,2,4-triazole 0.0038/d, , k2_deg
= 1st order rate constant BAS 480 to metabolite
0.039/d, molar mass correction BAS 480 F to
metabolite 1,2,4-triazole 0.211 (69.1
g/mol/329.8g/mol).
Fluquinconazole
Triazole
Method of calculation
Kinetics: first order
DT50: 12.27 d (worst case first order laboratory
value)
Soil depth: 5 cm
87
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
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State
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January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Paclobutrazol
Metabolite II: 1,2,4-triazole (CGA 71019)
Method of calculation
Tetraconazole
TAA
Method of calculation
Peak formation of 1,2,4-triazole from
paclobutrazol of 3% AR from laboratory
studies (correction factor from parent
paclobutrazol = 0.007 taking into account
differences in molecular weights).
Molecular weight relative to the parent: MWM
= 127.1; MWP = 372.16
DT50 (d): 15 days
Kinetics: 1st order, best fit according to Slide
Write Plus software
Field or Lab: representative worst case from
laboratory studies.
Triadimenol
Method of calculation
Application rate
For M04, a conservative approach has been
taken for PECsoil calculation, assuming 100%
formation. The longest laboratory DT50 at
20˚C and pF2 with an r2 value ≥0.85 is 8.2
days. Molecular weight correction factor is
0.234. With multiple application scenarios and
metabolites, there is uncertainty with respect to
peak metabolite formation, and as a worst case,
PECsoil for this metabolite is calculated on the
basis of the maximum total dose of
triadimenol.
The metabolite 1,2-dihydro-triazolone was
formed at maximum of 30.8% AR in a study
on degradation of M04. Therefore the initial
PECsoil has been calculated on the basis of the
maximum total dose of triadimenol, molecular
weight correction factor of 0.288 and 30.8%
AR formation. The initial PECsoil for this
metabolite is 0.009 mg/kg.
88
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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Triazole fungicides and their
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Fate and behaviour in the environment
Agreed end point
Metabolite I
Method of calculation
Molecular weight relative to the parent:
DT50 (d): x days
Kinetics: SFO
Field or Lab: representative worst case from
field studies.
Route and rate of degradation in water (Annex IIA, point 7.2.1)
Hydrolytic degradation of the active
substance and metabolites > 10 % ‡
pH 5: 1,2,4-triazole: stable at 25 °
pH 7: stable at 25 °
Photolytic degradation of active substance
and metabolites above 10 % ‡
pH 9: 1,2,4-triazole: stable at 25 °
Bitertanol
metabolites formed (triazole label, natural
water)
1,2,4-triazole max 86% AR at 6 test system
days
Epoxiconazole
Metabolite: 1,2,4-triazole, 14C-labelled
80 mg/L triazole in distilled water containing
humic acid (Fluka). No photochemical loss
after 30 days (natural sun light).
absorption coefficient < 10 L/mol x cm
Fluquinconazole
[Triazole is not expected to photodegrade in
water under environmental conditions, with
mean molar extinction coefficients for triazole
determined at <0.1 L mol-1 cm-1]
Agreed end point
89
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
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Triazole fungicides and their
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Fate and behaviour in the environment
Degradation in water / sediment
Fluquinconazole
Degradation in
water/sediment
- DT50 water
- DT90 water
Water phase (two different multi-compartment
modelling methods used):
- DT50 whole system
- DT90 whole system
Metabolites:
Triazole (aerobic) DT50 = 41.9-190 d, (1st order
compartmental model TopFit v1, n = 2, r2 =
0.8714-0.9620), DT50 = 11.6-92.5 d, (1st order
5-compartmental model TopFit v2, n = 2, r2 =
0.752-0.936)
Distribution in water / sediment systems
(metabolites)
Whole system:
Metabolites: not determined
Water phase:
Triazole (aerobic) = 0.0-2.3% (day 0), 3.9-5.1%
(day 1), 28.8% and 31.6% (day 14 and 63,
respectively), 4.5-21.4% (day 100) (n = 2
systems)
SN 616368 (aerobic) = max. 2.1% (day 2),
0.6% (day 26), not detected (day 100)
Sediment phase:
Triazole (aerobic) = 0.0-0.9% (day 0), 0.0-0.5%
(day 1), 21.5% and 37.4% (day 26 and 63,
respectively), 26.3-33.7% (day 100) (n = 2
systems)
Triazole: Maximum of 37.4% applied
radioactivity in sediment after 100 d.
Triazole (aerobic) DT50 in sediment = 105.36931.5 d, (1st order 5-compartmental model
TopFit v2, n = 2, r2 = 0.937-0.977)
For FOCUS surface water modelling a DT50
value in sediment of was set to 730 days.
90
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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Triazole fungicides and their
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Fate and behaviour in the environment
Paclobutrazol
1,2-4 triazole Max in water 9.4% A.R. after 84 d.
Water /
sediment
system
pH
pH
water sed
phase
Basing (14C
7.6
triazole label)
t. oC DT50DT90
whole
sys.
N/R 22
N/R
St.
(r2)
DT50DT90
r2
water
N/R N/R
DT50- St.
DT90 (r2)
sed
N/R N/R
N/R
Method
of
calculatio
n
-
Geometric mean/median
Triadimenol
Distribution in water / sediment systems
(metabolites) ‡
No metabolites in water or sediment at >1.7%
at any time.
For environmental exposure assessment, M-04
assumed to form at 100% AR.
Agreed end point
PEC (surface water) and PEC sediment (Annex IIIA, point 9.2.3)
Bitertanol
Method of calculation
FOCUS step 2 ‘STEPS 1-2 in FOCUS’, ‘FOCUS
surface water tool version 1.1’
1,2,4-triazole
Soil DT50
7.4 d
Soil formation fraction
44 % (x69/337)
Whole aquatic system DT50 *999 d
Aquatic system formation
*100% (x69/337)
fraction
89 ml/g
Kfoc
Parameters used in FOCUSsw step 3
Cyproconazole
Metabolite Triazole
Molecular weight:69.1
Parameters used in FOCUSsw step 1 and
Water solubility (mg/L):1,250,000
2
Soil or water metabolite:Soil
Koc/Kom (L/kg): 89
DT50 soil (d): 8.6 days [Average Lab value,
FOCUS normalised]
DT50 water/sediment system (d): 300
DT50 water (d):300
DT50 sediment (d):300
Crop interception (%): For Step 3, the model
performs this calculation
91
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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Triazole fungicides and their
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Fate and behaviour in the environment
Parameters used in FOCUSsw step 3 (if
performed)
Difenoconazole
CGA 71019 (1,2,4-triazole)
Parameters used in FOCUSsw step 1 and
2
Epoxiconazole
Method of calculation
Vapour pressure:2.2 x10-4 Pa
Kom/Koc: 89
1/n: 0.92 (Freundlich exponent general)
Metabolite kinetically generated in simulationyes:
Formation fraction in soil (kdp/kf): (If formation
degradation of metabolite is kinetically
simulated by PRZM)
For FOCUS calculations the maximum
occurrence of triazole with respect to parent
was set at 90 %
Molecular weight (g/mol): 69
Water solubility (mg/L): 730
Soil or water metabolite: Both
KOC (mL/g): 89 (mean value)
DT50 soil (d): 6.45 (arithmetic mean of
normalised lab values)
DT50 water/sediment system (d): 1000 (worst
case assumption)
DT50 water (d): 1000 (worst case assumption)
DT50 sediment (d): 1000 (worst case
assumption)
Simulated together with parent compound:
Crop interception (%): 0 (seed treatment); 70
(apples and carrots)
"No drift" option used for seed treatment
scenario.
Max. occurrence observed (%):
Water/Sediment: 9.6 (worst case assumption
calc. by RMS)
Soil: 23.4
not required, maximum 1.7 % in water phase of
water/sediment study
Fenbuconazole
Parameter
Mol wt. (g/mol)
Water solubility (mg/l)
Max. observed in soil
studies (%)
Max. observed in
water/sediment studies
Kfoc (ml/g)
1,2,4-triazole
69.1
1000*
12.4
0
89
92
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
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State
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Triazole fungicides and their
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Fate and behaviour in the environment
DT50 soil (d)
DT50 water/sediment (d)
DT50 water (d)
DT50 sediment (d)
Application
7.7
999*
999*
999*
Single application of
7.12g/ha based on total
dose of parent of 4 x 70g
a.s./ha used on pome
fruit
*worst case assumptions
Flunquinconazole
Triazole
Parameters used in FOCUSsw step 1 and 2
Parameters used in FOCUSsw step 3 (if
performed)
Tetraconazole
TAA (triazol acetic acid)
Parameters used in FOCUSsw step 1:
calculation of initial PECsw
Molecular weight (g/mol): 69.07
Water solubility (mg/l): 50.0 mg/l
Koc/Kom (ml/g): Koc = 89.0 (mean of 4
values)
1/n: 0.91 (mean of 4 values)
DT50 soil (d): 7 d (geometric mean)
DT50 water/sediment system (d): Not applicable
DT50 water (d): 52.1 d (mean value)
DT50 sediment (d): 730 d (worst-case value)
Maximum occurrence observed (%): 65%
(soil), 59.0% (sediment)
Not applicable
Molecular weight: 372.16
Water solubility (mg/l): not provided
Soil or water metabolite: soil metabolite
Koc (L/kg): 11.7
DT50 soil (d): not used
DT50 water/sediment system (d): not used
DT50 water (d): not used
DT50 sediment (d): not used
Crop interception (%):not used
Maximum occurrence observed (% molar basis
with respect to the parent): 14.11 % in soil
Ratio of field to water body: 10
Effective sediments depth of the surface water:
1cm
Sediment bulk density (kg/L): 0.8
Sediment organic carbon content (%): 5
93
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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Triazole fungicides and their
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Fate and behaviour in the environment
Sediment depth of the surface water: 5 cm
Equations from FOCUS Step 1 were used
Triadimenol
Step 2 – M04 (1,2,4-Triazol)
Summary of chemical property parameters input to FOCUS Step 2 (version 1.1) for
triadimenol and M04 surface water modelling
Input parameter
Unit
M04 (1,2,4 – triazol)
Physico-chemical parameters
Molecular mass
g.mol-1
69.1
Water solubility
mg.l-1
700000
Soil degradation parameters
$
Geometric mean Half-life
days
9.9***
Max. observed formation
%
100%**
Sediment/water degradation parameters
@
Mean Half-life (whole
days
999
system)
Max. observed formation
%
100%**
Sorption parameters
£
Median KfOC
cm3.g-1
89+
@
arbitrary high value as measured data not available, also set for degradation DT50 in water
and sediment compartments $ half lives were from field dissipation studies normalised to
20˚C and field capacity moisture content (-10kPa), as recommended by FOCUS guidance. £
see section B.8.2.4. * also set for degradation DT50 in water and sediment compartments;
value from 22˚C study, NOT normalised to 20˚C. **extreme worst case assumption ***
notifier stated that DT50 soil used was 7 days, geometric mean of temperature and moisture
normalised lab data. In practice, value used was 9.9 days, the median uncorrected DT50. +
mean value
94
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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Month and year
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State
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Triazole fungicides and their
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Fate and behaviour in the environment
Agreed end point
1,2,4-triazole
Parameters used in FOCUSsw step 1 and 2
Parameters used in FOCUSsw step 3 (if
performed)
Molecular weight:
Water solubility (mg/L):
Soil or water metabolite:
Koc/Kom (L/kg): (if necessary, soil
metabolites)
DT50 soil (d): x days (If necessary, Lab or field.
In accordance with FOCUS SFO)
DT50 water/sediment system (d):
(representative worst case from sediment water
studies)
DT50 water (d):
DT50 sediment (d):
Crop interception (%):
Maximum occurrence observed (% molar basis
with respect to the parent)
Water:
Sediment:
Vapour pressure:
Kom/Koc:
1/n: (Freundlich exponent general or for soil
,susp. solids or sediment respectively)
Metabolite kinetically generated in simulation
(yes/no):
Formation fraction in soil (kdp/kf): (If formation
degradation of metabolite is kinetically
simulated by PRZM)
PEC (groundwater) (Annex IIIA, point 9.2.1)
Bitertanol
Method of calculation and
type of study (e.g.
modelling, monitoring,
lysimeter )
FOCUSPELMO 3.2.2 modelling for scenarios pertinent to top
fruit and cereals.
1,2,4-triazole
Geometric mean Soil DT50 (10kPa 20ºC
Soil formation fraction
Kfoc
1/n
7.4 d
100 %
89 ml/g
0.91
95
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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Month and year
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State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
Cyproconazole
Method of calculation and type of study
(e.g. modelling, field leaching, lysimeter)
PECgw were calculated using the FOCUS
PELMO model
Metabolites
Triazole
Data as for parent (cyproconazole) with the
following exceptions:
Median parent DT50 field 8.6 d (normalisation
to 10 kPa or pF2, 20°C with Q10 of 2.2).
Koc: triazole, mean 89, 1/n= 0.92.
Assuming a 90 % transformation rate from
parent to metabolite.
Difenoconazole
Method of calculation and type of study
(e.g. modelling, field leaching, lysimeter )
Model used: FOCUS PEARL 2.2.2
Scenarios: Difenoconazole and the metabolites
CGA71019 and CGA 205375 were simulated
in separate model runs.
CGA 71019 (1,2,4-triazole):
DT50 soil (d): 6.45 (arithmetic mean of
normalised lab values)
Koc (mL/g): 89 (mean value)
1/n: 0.9 (mean value)
Epoxiconazole
Method of calculation and type of study
(e.g.
modelling, monitoring, lysimeter )
Fenbuconazole
Method of calculation and type of study
(e.g. modelling, field leaching, lysimeter )
Fluquinconazole
Method of calculation and type of study
(e.g. modelling, monitoring, lysimeter)
FOCUS-PELMO 2.2.2 and FOCUS-Macro
3.3.1
Metabolite 1,2,4-triazole: DT50 lab 8 (20°C, pF2
standardised). Koc 43, 1/n 0.827, water sol. 700
mg/L,pH independent, TSCF (crop uptake
default 0.5)
Mean 1,2,4-triazole Kfoc: 89 ml/g
Mean 1,2,4-triazole 1/n: 0.9 (default)
Modelling using FOCUS groundwater scenarios
Model used: FOCUS PELMO 3.3.2 including
the FOCUS shell and simulation model.
Triazole: calculations were based on a mean
DT50 value of 7.0 d (determined from a
96
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
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State
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January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment
laboratory study, corrected to pF2 moisture and
20 C where appropriate). Averaged Freundlich
sorption data used were Kfoc 89.0 ml/g and 1/n
= 0.91. A temperature correction exponent
(Q10) of 2.2 and a moisture correction exponent
(B) of 0.7 were used. A transformation rate of
65% (Fluquinconazole to triazole) was used,
based on a calculated formation fraction.
Tetraconazole
TAA
Method of calculation and type of study
(e.g. modelling, field leaching, lysimeter )
For FOCUS gw modelling, values used –
Model(s) used: FOCUS-PELMO 3.3.2
TAA
DT50 lab :9.7 (mean value, not normalized)
Koc: 11.7 (worst case mean value); 1/nads = 0.9
(default value)
Triadimenol
M04
Parameters
Molecular weight
Solubility in water (mg/l at 20˚C)
Vapour pressure (Pa at 20˚C)
First order DT50 (days)
Reference temperature (˚C)
Reference soil moisture (pF)
Activation energy (kJ/mole)
Moisture exponent
Kom-value (ml/g)
Exponent of the Freundlich isotherm
Formation fraction
Agreed end point
Method of calculation and type of study
(e.g. modelling, field leaching, lysimeter )
69.1
7
20
2
54
0.7
51.7
0.92
1
Geometric mean or median DT50lab/field x d
(normalisation to 10kPa or pF2, 20 C with
Q10 of 2.2).
KOC: parent, arithmetic mean or median x, 1/n=
y.
97
1,2 4-Triazole– Revision of DT50 - APPENDIX II
July 2011
List of end points (based on EPCO Manual E4 - rev. 4 (September 2005))
Rapporteur Member
Month and year
Active Substance (Name)
State
EFSA
January 2007
Triazole fungicides and their
metabolites
Fate and behaviour in the environment