Reaction mass of 3-(difluoromethyl)-1-methyl-N-[(1RS,4SR,9RS)-1,2,3,4-tetrahydro-9-isopropyl-1,4-methanonaphthalen-5-yl]pyrazole-4-carboxamide and of 3-(difluoromethyl)-1-methyl-N-[(1RS,4SR,9SR)-1,2,3,4-tetrahydro-9-isopropyl-1,4-methanonaphthalen-5-yl]pyrazole-4-carboxamide; isopyrazam

Other distribution data

Administrative data

Endpoint:

column leaching studies

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

25 Jun 2008 to 20 Apr 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 312 (Leaching in Soil Columns)

Version / remarks:

adopted April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

soil leaching

Media:

water - soil

Test material

Test material information

Constituent 1

Reference substance name:

632-619-2

EC Number:

632-619-2

Cas Number:

881685-58-1

Molecular formula:

C20 H23 F2 N3 O

IUPAC Name:

632-619-2

Results and discussion

Any other information on results incl. tables

- Total Radioactivity Balance: The total mean recovery for both columns per soil was 98.3% (Argissolo), 91.8% (Latossolo) and 99.1% (Neossolo) of the applied radioactivity.

- Distribution of the Radioactivity in the Leachates: Radioactivity levels in the leachates were at or below the limit of quantitation for all soils.

- Distribution of the Radioactivity and Atrazine in the Soil Profile:  In soils I & III essentially all the applied activity was recovered from the first layer of the columns, with all of the remaining layers containing less than 0.5% of the applied activity. In Soil II a mean amount of 93.6% of the applied activity was found in the top layer with only 2% of applied being found in the second layer and with the remaining layers containing less than 0.5% of the applied activity or less. In soils I-III analyses of the top layer`s extracted radioactivity (over 88% of applied) showed only the parent compound. The HPLC results were confirmed by TLC. Essentially all the extracted radioactivity consisted of the test item. The non-extractable radioactivity remained very low and did not exceed 6.5% of the initially applied radioactivity. TLC analysis of the extractable activity from the second layer in soil II (total 1.2% of applied) showed that 86% of it was the test item, giving a total test item content in the layer of 1% of applied (i.e. 0.86×1.2%). Atrazine was used as a reference compound and showed leaching up to 20-25 cm in soil I (layer 5) and up to 25 - 30 cm in soils II and III (layer 6). Some atrazine probably eluted from the base of columns in soils II and III however no analysis of the leachate for atrazine was performed. This is shown by the lower atrazine recoveries in soils II and III relative to soil I.
The relative mobilities of atrazine and the test item are defined based on the leaching distances of the two compounds in the column systems. The leaching distance of a compound is defined as (the depth of) the deepest soil segment in which ≥ 0.5% of the applied test (or reference) substance was found after the leaching process.
Given the leaching distances of the test item and reference compound atrazine a relative mobility factor (RMF) can be calculated. The precise lengths of the individual column sections were calculated based on the mass of soil in each fraction, the mass of the six fractions added together and the total length of the soil pack. 

Table 3 Radioactivity in the Leachates of Soil I Argissolo (Top) and Soil II Latossolo (Bottom) Treated with the 14C-labelled test item

Soil I Argissolo Piracicaba	Column 1			Column 2			Mean
Period of collection [hours]	Volume of leachate [mL]	Amount of radioactivity		Volume of leachate [mL]	Amount of radioactivity		Volume of leachate [mL]	Amount of radioactivity
		% applied	ppb		% applied	ppb		% applied	ppb
0-14	130	n.d.	n.d.	130	n.d.	n.d.	130	n.d.	n.d.
14-24	74	n.d.	n.d.	82	n.d.	n.d.	78	n.d.	n.d.
24-48	202	n.d.	n.d.	208	<LOQ	<LOQ	205	n.d.	n.d.
Total	406	n.d.	n.d.	420	<LOQ	n.d.	413	<LOQ	n.d.

 

Soil II Latossolo Veranopolis	Column 3			Column 4			Mean
Period of collection [hours]	Volume of leachate [mL]	Amount of radioactivity		Volume of leachate [mL]	Amount of radioactivity		Volume of leachate [mL]	Amount of radioactivity
		% applied	ppb		% applied	ppb		% applied	ppb
0-14	120	n.d.	n.d.	120	n.d.	n.d.	120	n.d.	n.d.
14-24	72	n.d.	n.d.	84	n.d.	n.d.	78	n.d.	n.d.
24-48	214	0.1	0.1	204	0.1	0.1	209	0.1	0.1
Total	406	0.1	<LOQ	408	0.1	<LOQ	407	0.1	<LOQ

ppb.: µg parent equivalents/L

n.d.: not detected (below the limit of detection (0.05% of applied radioactivity or 0.06 µg parent equivalents/L)

<LOQ Concentration lies below the limit of quantitation (0.08% of applied activity or 0.10 µg parent equivalents/L)

Table 4 Radioactivity in the Leachates of Soil III Neossolo Treated with the 14C-labelled test item

Soil III Neossolo Osòrio	Column 7			Column 8			Mean
Period of collection [hours]	Volume of leachate [mL]	Amount of radioactivity		Volume of leachate [mL]	Amount of radioactivity		Volume of leachate [mL]	Amount of radioactivity
		% applied	ppb		% applied	ppb		% applied	ppb
0-14	96	n.d.	n.d.	96	n.d.	n.d.	96	n.d.	n.d.
14-24	80	n.d.	n.d.	76	n.d.	n.d.	78	n.d.	n.d.
24-48	208	0.1	0.1	208	0.1	0.1	208	0.1	0.1
Total	384	0.1	<LOQ	380	0.1	<LOQ	382	0.1	<LOQ

ppb.: µg parent equivalents/L

n.d.: not detected (below the limit of detection (0.05% of applied radioactivity or 0.06 µg parent equivalents/L)

<LOQ Concentration lies below the limit of quantitation (0.08% of applied activity or 0.10 µg parent equivalents/L)

Table 5 Distribution of the Radioactivity in Soil I Argissolo (Columns 1 and 2) Treated with the 14C-labelled test item

Soil I, Column 1
Soil Layers		Extractables and non-extractables from soil segments						Parent	Atrazine
Layer	soil dry weight	Extractables		Non-extractables		Total
no.	(kg)	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied
1 (top)	0.126	90.9	182.1	6.1	12.2	97.0	194.2	90.9	1835.8	72.3
2	0.108	N.D.	N.D.	N.D.	N.D..	N.D.	N.D.	N.A.	<0.1	<0.1
3	0.109	N.D.	N.D.	N.D.	N.D..	N.D.	N.D.	N.A.	<0.1	<0.1
4	0.111	N.D.	N.D.	N.D.	N.D..	N.D.	N.D.	N.A.	25.5	0.9
5	0.118	0.2	0.4	<LOQ	<LOQ	0.2	0.4	N.A.	281.5	10.4
6	0.128	N.D.	N.D.	N.D.	N.D..	N.D.	N.D.	N.A.	<0.1	<0.1
Total soil layers		91.1	---	6.1	---	97.2	---	90.9	---	83.6
Total leachates						N.D..	---	N.A.	---	N.A.
Total						97.2	---	90.9	---	83.6

 

Soil I, Column 2
Soil Layers		Extractables and non-extractables from soil segments						Parent	Atrazine
Layer	soil dry weight	Extractables		Non-extractables1		Total
no.	(kg)	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied
1 (top)	0.135	92.8	173.7	6.5	12.3	99.4	185.9	92.8	1499.3	63.3
2	0.105	N.A.	N.A.	N.D.	N.D.	N.D.	N.D.	N.A.	N.A.	N.A.
3	0.115	N.A.	N.A.	N.D.	N.D.	N.D.	N.D.	N.A.	N.A.	N.A.
4	0.108	N.A.	N.A.	N.D.	N.D.	N.D.	N.D.	N.A.	N.A.	N.A.
5	0.120	N.A.	N.A.	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	N.A.	N.A.
6	0.099	N.A.	N.A.	N.D.	N.D.	N.D.	N.D.	N.A.	N.A.	N.A.
Total soil layers		92.8	---	6.5	---	99.4	---	92.8	---	---
Total leachates						<LOQ	---	N.A.	---	N.A.
Total						99.4	---	92.8	---	---
Mean radioactivity recovered from Columns 1 and 2						98.3

N.A.: Not Analysed

N.D.: Not Detected

<LOQ Detected, but the value is below the limit of quantitation.

1 Corresponds to non-extractable activity in layer 1, but to total activity in the remaining layers as no extraction was performed in layers 2 - 6 of column 2

Table 6 Distribution of the Radioactivity in Soil II Latossolo (Columns 3 and 4) Treated with the 14C-labelled test item

Soil II, Column 3
Soil Layers		Extractables and non-extractables from soil segments						Parent	Atrazine
Layer	soil dry weight	Extractables		Non-extractables		Total
no.	(kg)	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied
1 (top)	0.085	85.0	251.3	3.8	11.1	88.8	262.5	85.0	662.0	17.7
2	0.120	1.2	2.5	0.8	1.7	2.0	4.2	1.0	241.0	9.1
3	0.100	0.1	0.3	0.1	0.4	0.3	0.7	N.D.	336.6	10.5
4	0.107	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	N.D.	393.8	13.1
5	0.104	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	N.D.	378.3	12.3
6	0.102	N.D.	N.D.	N.D.	N.D.	N.D.	N.D.	N.D.	97.6	5.2
Total soil layers		86.3	---	4.7	---	91.0	---	86.0	---	67.8
Total leachates						0.1	---	N.A.	---	N.A.
Total						91.1	---	86.0	---	67.8

 

Soil II, Column 4
Soil Layers		Extractables and non-extractables from soil segments						Parent	Atrazine
Layer	soil dry weight	Extractables		Non-extractables1		Total			detected
no.	(kg)	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied	μg/kg	% applied
1 (top)	0.102	87.1	215.0	4.3	10.7	91.4	225.7	87.1	521.7	16.7
2	0.115	N.A..	N.A..	0.8	1.7	0.8	1.7	N.A.	N.A.	N.A.
3	0.105	N.A.	N.A..	0.1	0.3	0.1	0.3	N.A.	N.A.	N.A.
4	0.110	N.A.	N.A.	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	N.A.	N.A.
5	0.105	N.A.	N.A.	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	N.A.	N.A.
6	0.088	N.A.	N.A.	N.D.	N.D.	N.D.	N.D.	N.A.	N.A.	N.A.
Total soil layers		87.1	---	5.3	---	92.3	---	87.1	---	---
Total leachates						0.1	---	N.A.	---	N.A.
Total						92.5	---	87.1	---	---
Mean radioactivity recovered from Columns 3 and 4						91.8

N.A.: Not Analysed

N.D.: Not Detected 

<LOQ Detected, but the value is below the limit of quantitation

1 Corresponds to non-extractable activity in layer 1, but to total activity in the remaining layers as no extraction was performed in layers 2 - 6 of column 4

Table 7 Distribution of the Radioactivity in Soil III Neossolo (Columns 7 and 8); Treated with the 14C-labelled test item

Soil III, Column 7
Soil Layers		Extractables and non-extractables from soil segments						Parent	Atrazine
Layer	soil dry weight	Extractables		Non-extractables		Total
no.	(kg)	% applied	µg/kg	% applied	µg/kg	% applied	µg/kg	% applied	µg/kg	% applied
1 (top)	0.138	93.8	172.2	3.3	6.1	97.1	178.3	93.8	675.8	29.0
2	0.147	0.1	0.2	0.2	0.3	0.3	0.6	N.A.	210.3	9.6
3	0.133	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	293.1	12.2
4	0.140	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	319.6	14.0
5	0.136	N.D.	N.D.	N.D.	N.D.	N.D.	N.D.	N.A.	173.1	7.3
6	0.151	N.D.	N.D.	N.D.	N.D.	N.D.	N.D.	N.A.	32.6	2.2
		93.9	---	3.5	---	97.4	---	93.8	---	74.4
Total soil layers
Total leachates						0.1	---	N.A.	---	N.A.
Total						97.5	---	93.8	---	74.4

 

Soil III, Column 8
Soil Layers		Extractables and non-extractables from soil segments						Parent	Atrazine
Layer	soil dry weight	Extractables		Non-extractables1		Total
no.	(kg)	% applied	µg/kg	% applied	µg/kg	% applied	µg/kg	% applied	µg/kg	% applied
1 (top)	0.140	96.7	174.8	3.7	6.7	100.4	181.5	96.7	638.8	27.9
2	0.136	N.A.	N.A.	0.2	0.4	0.2	0.4	N.A.	N.A.	N.A.
3	0.140	N.A.	N.A.	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	N.A.	N.A.
4	0.139	N.A.	N.A.	<LOQ	<LOQ	<LOQ	<LOQ	N.A.	N.A.	N.A.
5	0.131	N.A.	N.A.	N.D..	N.D..	N.D.	N.D..	N.A.	N.A.	N.A.
6	0.140	N.A.	N.A.	N.D..	N.D..	N.D.	N.D..	N.A.	N.A.	N.A.
Total soil layers		96.7	---	3.9	---	100.6	---	96.7	---	---
Total leachates						0.1	---	N.A.	---	N.A.
Total						100.7	---	96.7	---	---
Mean radioactivity recovered from Columns 7 and 8						99.1

N.A.: Not Analysed

N.D.: Not Detected

<LOQ Detected, but the value is below the limit of quantitation

1 Corresponds to non-extractable activity in layer 1, but to total activity in the remaining layers as no extraction was performed in layers 2-6 of column 8

The table below shows the deepest soil layers in which at least 0.5% of the applied test item and atrazine were found, the depths of the mid-points of these layers in cm, and the calculated relative mobility factors.

	Test item Front2 in Layer No.	Leaching Distrance test item (cm)1	Atrazine Front2 in Layer No.	Leaching Distance Atrazine (cm)1	Relative Mobility Factor (RMF)
Soil I (Column 1)	1	2.5	5	20.1	0.12
Soil II (Column 3)	2	6.4	6	26.33	0.24
Soil III (Column 7)	1	2.3	6	26.43	0.09

1 The 30cm soils columns were divided into 6 sections for extraction, for the calculation of the leaching distance the centre point of each layer, is taken as representative for the corresponding layer, the precise layer thicknesses were calculated based on the weights of the individual layers relative to the total weight of the soil pack and from the total length of the column pack.

2 The front corresponds to the definition of the migration distance, i.e. the front is taken as being located in the deepest layer containing at least 0.5% of the applied test substance or atrazine.

3 Minimum leaching distances for atrazine (atrazine was found in the last layer of the column, and would probably have migrated further in a longer column; however no analysis of the leachates for atrazine was performed).

Applicant's summary and conclusion

Conclusions:

The leaching behaviour of the 14C-labelled test item in three Brazilian soils, Argissolo from Piracicaba (soil I, clay loam), Latossolo from Veranópolis / RS (soil II, clay) and Neossolo from Osório (soil III, loamy sand) was studied under laboratory conditions according to OECD TG 312. The relative mobility factors were 0.12, 0.24 and 0.09 in soils I, II and III, respectively. Therefore the test item can be considered as immobile in soils I and III and as slightly mobile in soil II.

Executive summary:

The leaching behaviour of the 14C-labelled test item in three Brazilian soils was studied under laboratory conditions according to OECD TG 312 and in compliance with GLP. The three Brazillan soils types used in the study were as follows: Argissolo from Piracicaba (soil I, clay loam), Latossolo from Veranópolis / RS (soil II, clay) and Neossolo from Osório (soil III, loamy sand). A reference item, atrazine, was also used in the study. Two glass columns per soil were filled to a height of 30 cm. After conditioning with 0.01 M CaCl2 solution, the test and reference items were applied onto the surface of the soil column. The application rate of the test item was equivalent to the maximum recommended field rate of 125 g/ha. Following application of the test item, the reference item atrazine was applied at an application rate equivalent to a field rate of 1.6 kg Atrazine/ha, and about 200 mm of 0.01 M CaCl2 “artificial rainfall” was applied continuously to the top of the soil columns over two days. Leachates were collected after 14, 24 and 48 hours and analysed by LSC and the quantity and nature of the radioactivity in the soil column layers after the percolation period was determined. Atrazine concentrations were also determined in the soil layers.

The radioactivity levels in the leachates of the three soils were at or below the limit of quantitation. The total mean recovery for both columns per soil was, 98.3% Argissolo, 91.8% Latossolo and 99.1% (Neossolo) of the applied radioactivity. In soils I & III essentially all the applied activity was recovered from the first layer of the columns, with all of the remaining layers containing less than 0.5 % of the applied activity. In Soil II a mean amount of 90.1% of the applied activity was found in the top layer with on average only 1.4% of applied being found in the second layer and with the remaining layers containing less than 0.5% of the applied activity. All of the activity in the first layer of soil II consisted of the test item whereas in the second layer only 86% of the extractable activity present was the test item. The total amount of the test item in the second layer of soil II amounted to 1% of applied. Analyses of the extracted radioactivity of the top layer in all three soils showed only the parent compound. The non-extractable radioactivity remained very low and did not exceed 6.5% of the initially applied radioactivity. Atrazine as reference compound showed leaching in soils I-III (down to layer 5 (ca.20-25 cm) in soil I and layer 6 (ca. 25-30 cm) in soils II and III). The table overleaf shows the deepest soil layers in which at least 0.5% of the applied the test item and atrazine were found, the depths of the mid-points of these layers in cm, and the calculated relative mobility factors.

In conclusions, the test item showed leaching distances of 2.5 cm, 6.4 cm and 2.3 cm in soils I, II and III respectively whereas the reference compound atrazine displayed leaching distances of 20.1 cm in soil I, 26.3 cm in soil II and 26.4 cm in soil III. The relative mobility factors for the test item are therefore 0.12, 0.24 and 0.09 in soils I, II and III respectively. Given these relative mobility factors the test item can be considered as immobile in soils I and III and as slightly mobile in soil II.