Methanesulfonamide, N-[2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)carbonyl]-6-fluorophenyl]-1,1-difluoro-N-methyl-

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water and sediment: simulation testing, other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 308 (Aerobic and Anaerobic Transformation in Aquatic Sediment Systems)

Version / remarks:

2002

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.4400 (Anaerobic Aquatic Metabolism)

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westfalen

Radiolabelling:

yes

Oxygen conditions:

anaerobic

Inoculum or test system:

natural water / sediment

Details on source and properties of surface water:

WATER SAMPLES:
The systems were freshly sampled and waters and sediments sieved to ≤ 2 mm:
1. Lawrence, Kansas, USA: GPS Coordinates: N 39° 03.0’ W 095° 11.6’; Research farm pond
2. Pikeville, North Carolina, USA: GPS Coordinates: N 35° 29.1’ W 078° 02.6’; Farm pond

PHYSICO-CHEMICAL CHARACTERIZATION:
pH water at time of collection
1. Lawrence, Kansas, USA: 8.1
2. Pikeville, North Carolina, USA: 7.1

TOC water [mg/L]
1. Lawrence, Kansas, USA: 5.3
2. Pikeville, North Carolina, USA: 10.3

Total nitrogen water [mg/L]
1. Lawrence, Kansas, USA: 0.4
2. Pikeville, North Carolina, USA: 1.1

Total phosphorous water [mg/L]
1. Lawrence, Kansas, USA: 1.2
2. Pikeville, North Carolina, USA: 1.2

Water hardness [mg/L]
1. Lawrence, Kansas, USA: 95 mg/L
2. Pikeville, North Carolina, USA: 21 mg/L

Details on source and properties of sediment:

SEDIMENT SAMPLES:
The systems were freshly sampled and waters and sediments sieved to ≤ 2 mm:
1. Lawrence, Kansas, USA: GPS Coordinates: N 39° 03.0’ W 095° 11.6’; Research farm pond
2. Pikeville, North Carolina, USA: GPS Coordinates: N 35° 29.1’ W 078° 02.6’; Farm pond


PHYSICO-CHEMICAL CHARACTERIZATION:
Textural classification:
1. Lawrence, Kansas, USA: silty clay loam
Sand [50 μm – 2 mm] = 15%
Silt [2 μm – 50 μm] = 45%
Clay [< 2 μm] = 20%
2. Pikeville, North Carolina, USA: silt loam
Sand [50 μm – 2 mm] = 29%
Silt [2 μm – 50 μm] = 71%
Clay [< 2 μm] = 0%

pH at time of collection
1. Lawrence, Kansas, USA: 7.7
2. Pikeville, North Carolina, USA: 5.5

Organic matter [%]
1. Lawrence, Kansas, USA: 2.2
2. Pikeville, North Carolina, USA: 0.8

Organic carbon [%]
1. Lawrence, Kansas, USA: 1.3
2. Pikeville, North Carolina, USA: 0.4

Total nitrogen [mg/kg]
1. Lawrence, Kansas, USA: 900
2. Pikeville, North Carolina, USA: 100

Total phosphorous [mg/kg]
1. Lawrence, Kansas, USA: 104
2. Pikeville, North Carolina, USA: 42

CEC [meq/100 g]
1. Lawrence, Kansas, USA: 23.3
2. Pikeville, North Carolina, USA: 2.9

Moisture [%]
1. Lawrence, Kansas, USA: 138
2. Pikeville, North Carolina, USA: 23

Bulk densitiy [g/cm3]
1. Lawrence, Kansas, USA: 1.0
2. Pikeville, North Carolina, USA: 1.46

Duration of test (contact time):

> 100 d

Initial conc.:

75 µg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

radiochem. meas.

Details on study design:

EXPERIMENTAL DESIGN
The test systems consisted of Erlenmeyer flasks each containing a water-to-sediment weight ratio of 3:1, corresponding to 150 or 180 mL water and 50 or 60 g sediment dry weight, repectively. For equilibration to anaerobic conditions, the test vessels were equipped with mineral oil traps, flushed with nitrogen and the test systems were set under an atmosphere of nitrogen. During the incubation under anaerobic conditions, the test vessels were quipped with double-valved tops, which were connected at each sampling interval to trapping solutions for the collection of volatiles.
- Oxygen conditions: Anaerobic
- Light conditions: Dark
- Temperature: mean 19.9 ± 0.2 °C
- Stock solution: Prepared by obtaining 0.100 mL of the [14C]triafamone standard (47.1 μCi, 460 μg) in acetonitrile, evaporating solvent just to dryn ss under nitrogen, and re-dissolving to 8.0 mL with methanol. The concentration was determined by radioassay to be 62.8 μg/mL (test sytem Lawrence) and 60.6 µg/mL (test system Pikeville).
- The application solution was uniformly applied to the surface of the water (conc.water = 0.075 μg/mL). The final concentration of methanol was <0.1% in the test systems.
- Duplicate samples were analyzed 0, 1, 2, 4, 7, 14, 30, 60 and 100 days after treatment.
- The water was separated from the sediment by decantation and centrifugation and the sediment was extracted three times by shaking at ambient temperature and once by microwave-accelerated extraction at 70 °C using acetonitrile / water 4/1 (v/v).
- The amounts of test item and its degradation products in water and sediment extracts were determined by liquid scintillation counting (LSC) and HPLC/radiodetection. Test item and degradation products were identified by HPLC-MS(/MS) including accurate mass determination.

Compartment:

other: water / sediment, material (mass) balance

Remarks on result:

other: The complete material balances (95.1 - 101.6%) found at all sampling intervals demonstrated that there was no significant loss of radioactivity from the test systems or during sample processing.

% Degr.:

100

Parameter:

radiochem. meas.

Sampling time:

60 d

Remarks on result:

other: < LOD

Compartment:

entire system

DT50:

>= 4.2 - <= 10.4 d

Type:

other: Single first order

Temp.:

12 °C

Remarks on result:

other: recalculated half-life to 12°C with Arrhenius equation

Compartment:

water

DT50:

>= 3.6 - <= 9.8 d

Type:

other: Single first order

Temp.:

12 °C

Remarks on result:

other: recalculated half-life to 12°C with Arrhenius equation

Compartment:

entire system

DT50:

>= 2 - <= 4.9 d

Type:

other: Single first order

Temp.:

20 °C

Remarks on result:

other: 6.6 - 16.3 days DT90

Compartment:

water

DT50:

>= 1.7 - <= 4.6 d

Type:

other: Single first order

Temp.:

20 °C

Remarks on result:

other: 5.8 - 15.2 days DT90

Transformation products:

yes

No.:

#1

No.:

#2

No.:

#3

Details on transformation products:

Three degradation products ≥ 10% were identified (see above).

Details on results:

TEST CONDITIONS
-The pH values in Lawrence samples ranged from 6.7 to 7.1 in water and from 6.6 to 6.9 in sediment. In Pikeville samples, the pH values ranged from 5.2 to 6.8 in water and from 5.1 to 6.8 in sediment.
- The oxygen content (dissolved oxygen) in waters ranged from 0.1 to 0.3 mg/L in Lawrence samples and from 0 to 0.5 mg/L in Pikeville samples.
- The redox potentials in waters and sediments remained at negative to low positive EH-values. In Lawrence samples, the EH-values ranged from -23 to +133 mV in water and from -4 to +139 mV in sediment. In Pikeville samples, the EH-values ranged from -203 to -17 mV in water and from -12 to +172 mV in sediment.
- The negative to low positive values for the redox potentials and the oxygen contents indicate anaerobic conditions over the duration of the laboratory study.

EXTRACTABLE RESIDUES
In water:
Extractable residues in Lawrence system decreased in the water from 95.0% at study start to a minimum of 37.7% AR at DAT-30 and then slightly increased to 41.0% at study end. In Pikeville system, the extractable residues in water decreased from start to end from 99.4 to 56.4%.

In sediment:
In the sediment, the extractable residues in Lawrence system increased from 2.8% at study start to a maximum of 45.6% after 14 days and then slightly decreased to 41.1% at study end. The sediment extractable residues in Pikeville system increased from 1.9% AR at study start to a maximum of 38.6% at day 60 and then slightly decreased to 34.9% at day 100.

Entire system:
The total extractable residues in the entire system (water and sediment) decreased in Lawrence system from 95.0% at start to 82.0% at day 30 and remained constant until the test end. In Pikeville system, the total extractable residues in the entire system decreased from start to end from 101.3 to 91.3%.

NON-EXTRACTABLE RESIDUES
Non-extractable residues increased from start to test end from < 0.1 to 14.0% in Lawrence system and from 0.1 to 12.4% in Pikeville system.

VOLATILIZATION
Formation of volatiles was insignificant as demonstrated by values of ≤ 0.2%.

The route and rate of degradation of the test item was studied in two water / sediment systems under anaerobic conditions in the dark in the laboratory for 100 days at 19.9 °C. A study application rate of nominal 75 μg per liter was applied. The results show rapid degradation of triafamone in water / sediment systems under anaerobic conditions. The DT50 value in water ranges (recalculated to 12°C) from 3.6 to 9.8 days and in the entire system from 4.2 to 10.4 days. Three degradation products ≥ 10% were detected in the entire system and identified as AE 1887196-dihydro, AE 1887196-dihydro-O-desmethyl and AE 1887196-oxazolidine-dione. The main degradation product AE 1887196-dihydro was also degraded under anaerobic condtions.

Reference 2

Endpoint:

biodegradation in water and sediment: simulation testing, other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 308 (Aerobic and Anaerobic Transformation in Aquatic Sediment Systems)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.4300 (Aerobic Aquatic Metabolism)

Qualifier:

according to guideline

Guideline:

other: Commission Directive 95/36/EC amending Council Directive 91/414/EEC

Qualifier:

according to guideline

Guideline:

other: Regulation (EC) No 1107/2009 of the European Parliament and of the Council

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westfalen

Radiolabelling:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

natural water / sediment

Details on source and properties of surface water:

WATER SAMPLES:

- The waters were freshly sampled prior to the start of the study at two sites (No pesticides used for previous 5 years):
1. Artificially damned pond: Hoenniger Weiher, Close to Wipperfürth , North Rhine-Westphalia, Germany
GPS Coordinates: N 51° 08.2’ E 007° 27.1’
2. Small, reclaimed gravel pit: Anglersee / Leverkusen / North Rhine- Westphalia / Germany
GPS Coordinates: N 51° 01.3’ E 007° 00.7’


PHYSICO-CHEMICAL CHARACTERIZATION:

- pH at time of collection:
1. Artificially pond: 7.7
2. Small, reclaimed gravel pit: 7.6

- Oxygen saturation:
1. Artificially pond: 95.5%
2. Small, reclaimed gravel pit: 100%

- Dissolved Organic Carbon:
1. Artificially pond: <2 mg/L at start of equilibration
2. Small, reclaimed gravel pit: <2 mg/L at start of equilibration

- Water Hardness:
1. Artificially pond: 0.6 mmol/L
2. Small, reclaimed gravel pit: 1.8 mmol/L

Details on source and properties of sediment:

SEDIMENT SAMPLES:

- The sediments were freshly sampled prior to the start of the study at two sites (No pesticides used for previous 5 years):
1. Artificially pond: Hoenniger Weiher, Close to Wipperfürth , North Rhine-Westphalia, Germany
GPS Coordinates: N 51° 08.2’ E 007° 27.1’
2. Small, reclaimed gravel pit: Anglersee / Leverkusen / North Rhine- Westphalia / Germany
GPS Coordinates: N 51° 01.3’ E 007° 00.7’
- Sampling depth (cm): The upper sediment layer was collected (0-10 cm)
- Sediment preparation prior to use: Sieved to 2 mm mesh-size
- Storage length: 1-2 days until start of equilibration


PHYSICO-CHEMICAL CHARACTERIZATION:

- Textural classification:
1. Artificially pond:
Sand [50 μm – 2 mm] = 60%
Silt [2 μm – 50 μm] = 34%
Clay [< 2 μm] = 6%
2. Small, reclaimed gravel pit:
Sand [50 μm – 2 mm] = 83%
Silt [2 μm – 50 μm] = 11%
Clay [< 2 μm] = 6%

- pH at time of collection:
1. Artificially pond: 5.3
2. Small, reclaimed gravel pit: 7.1

- Organic Matter:
1. Artificially pond: 7.8% at start of equilibrium
2. Small, reclaimed gravel pit: 2.8% at start of equilibrium

- Organic Carbon:
1. Artificially pond: 4.5% at start of equilibrium
2. Small, reclaimed gravel pit: 1.6% at start of equilibrium

- Total Nitrogen:
1. Artificially pond: 3100 mg/kg
2. Small, reclaimed gravel pit: 1400 mg/kg

- Total Phosphorus:
1. Artificially pond: 650 mg/kg
2. Small, reclaimed gravel pit: 440 mg/kg

- Redox Potential:
1. Artificially pond: +224 mV
2. Small, reclaimed gravel pit: +361 mV

- Moisture:
1. Artificially pond: 142.1 g H2O / 100 g dry weight
2. Small, reclaimed gravel pit: 34.1 g H2O / 100 g dry weight

Duration of test (contact time):

> 100 d

Initial conc.:

75 µg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

radiochem. meas.

Details on study design:

EXPERIMENTAL DESIGN
The test systems consisted of cylindrical glass containers each containing a water-to-sediment volume ratio of 3:1, corresponding to 520 mL water (approx. 6 cm in height) and 175 mL wet sediment (approx. 2 cm in height), and equipped with traps for the collection of carbon dioxide and volatile organic compounds but permeable for oxygen.
- Oxygen conditions: Aerobic
- Light conditions: Dark
- Temperature: mean 20 ± 2 °C (mean: 20.0 °C, min: 19.8 °C, max. 20.4 °C)
- Stock solution:
[Phenyl-UL-14C]Triafamone was dissolved in 5.369 mL acetonitrile by sonication, resulting in a stock solution with a nominal concentration of 3.79 MBq/mL (1 mg/mL) and [Triazine-UL-14C]Triafamone was dissolved in 4.563 mL acetonitrile by sonication, resulting in a stock solution with a nominal concentration of 4.46 MBq/mL (1 mg/mL)
- The stock solution was stored frozen protected from light
- The test item was applied dropwise onto the water surface in 500 μl methanol / water 1/1 (v/v).
- Duplicate samples were analyzed 0, 1, 2, 4, 7, 14, 30, 60 and 100 days after treatment for Hoenniger Weiher systems and 0, 1, 2, 4, 7, 14, 30, 63 and 102 days after treatment for Anglersee test systems.
- At each sampling interval, the redox potentials and the pH values of the water and sediment as well as the oxygen content of the water were determ ned in the unprocessed samples after removal of the trap attachments.
- The water was separated from the sediment by decantation and centrifugation and the sediment was extracted three times by shaking at ambient temperature and once by microwave-accelerated extraction at 70 °C using acetonitrile / water 4/1 (v/v).
- The water of Anglersee samples was stabilized with 0.1 M TRIS buffer solution (pH 7) prior to HPLC/radiodetection analysis to prevent further hydrolytic degradation after sampling.
- The amounts of test item and its degradation products in water and sediment extracts were determined by liquid scintillation counting (LSC) and HPLC/radiodetection. The amounts of volatiles and nonextractable residues were determined by LSC and combustion/LSC, respectively. Test item and degradation products were identified by HPLC-MS(/MS) including accurate mass determination.

Compartment:

other: water / sediment, material (mass) balance

Remarks on result:

other: The complete material balances found at all sampling intervals demonstrated that there was no significant loss of radioactivity from the test systems or during sample processing.

% Degr.:

100

Parameter:

radiochem. meas.

Sampling time:

30 d

Remarks on result:

other: < LOD

Compartment:

entire system

DT50:

>= 6.2 - <= 8.9 d

Type:

other: Single first order

Temp.:

12 °C

Remarks on result:

other: recalculated half-life to 12°C with Arrhenius equation

Compartment:

water

DT50:

>= 5.3 - <= 7.2 d

Type:

other: Double first order in parallel

Temp.:

12 °C

Remarks on result:

other: recalculated half-life to 12°C with Arrhenius equation

Compartment:

entire system

DT50:

>= 2.9 - <= 4.2 d

Type:

other: Single first order

Temp.:

20 °C

Remarks on result:

other: 9.7-13.8 days DT90

Compartment:

water

DT50:

>= 2.5 - <= 3.4 d

Type:

other: Double first order in parallel

Temp.:

20 °C

Remarks on result:

other: 9.3-11.5 days DT90

Transformation products:

yes

No.:

#1

No.:

#2

No.:

#3

Details on transformation products:

Three degradation products ≥ 10% were identified (see above). Small amounts of extractable and charaterisable by chromatography residues were observed with no one component exceeding 4.2% at any sampling interval.

Volatile metabolites:

yes

Residues:

yes

Details on results:

TEST CONDITIONS
- The pH values in waters and sediments remained stable except for the day 60 and day 100 samples of Hoenniger Weiher where a decrease of pH values was observed. In Hoenniger Weiher samples, the pH values ranged from 4.8 to 7.6 in water and from 5.8 to 6.8 in sediment. In Anglersee samples, the pH values ranged from 7.9 to 8.5 in water and from 7.2 to 7.4 in sediment.
- The oxygen content (dissolved oxygen) in waters ranged from 6.5 to 9.2 mg/L in Hoenniger Weiher samples and from 4.2 to 8.7 mg/L in Anglersee samples.
- The redox potentials in waters and sediments remained at highly positive EH-values. In Hoenniger Weiher samples, the EH-values ranged from 374 to 428 mV in water and from 115 to 390 mV in sediment. In Anglersee samples, the EH-values ranged from 341 to 424 mV in water and from 94 to
406 mV in sediment.
- The clearly positive values for the redox potentials and the oxygen contents indicate aerobic conditions over the duration of the laboratory study.

EXTRACTABLE RESIDUES
In water:
Extractable residues decreased in the water from study start (day 0) to study end (day 100 / say 102) from 98.9 to 34.9% AR in phenyl-label Hoenniger Weiher system, from 98.8 to 29.0% AR in triazine-label Hoenniger Weiher system, from 95.5 to 51.1% AR in phenyl-label Anglersee system and from 95.9 to 46.6% AR in triazine-label Anglersee system.
In sediment:
In the sediment, the extractable residues in phenyl- and triazine-label Hoenniger Weiher systems increased from 5.4 and 4.9% AR at DAT-0 to a maximum of 52.3 and 52.4% AR at day-60 and then decreased to 44.6 and 42.8% AR at day 100, respectively. The sediment extractable residues in phenyl- and triazine-label Anglersee systems increased from 4.9 and 4.5% AR at day 0 to a maximum of 39.0 and 37.9% AR at day 30 and then decreased to 34.5 and 34.9% AR at day 102, respectively.
Entire system:
The total extractable residues in the entire system (water and sediment) decreased from day 0 to day 100 / day 102 from 104.3 to 79.5% AR in phenyl-label Hoenniger Weiher system, from 103.7 to 71.8% AR in triazine-label Hoenniger Weiher system, from 100.4 to 85.6% AR in phenyl-label Anglersee system and from 100.4 to 81.5% AR in triazine-label Anglersee system.

NON-EXTRACTABLE RESIDUES
Non-extractable residues (NER) increased from day 0 to day 100 / day 102 from 0.3 to 21.2% AR in phenyl-label Hoenniger Weiher system, from 0.3 to 20.5% AR in triazine-label Hoenniger Weiher system, from 0.2 to 11.7% AR in phenyl-label Anglersee system and from 0.2 to 10.7% AR in triazine-label Anglersee system.

VOLATILIZATION
The maximum amount of carbon dioxide at day 100 / day 102 was 3.0 and 9.1% AR in phenyl- and triazine-label Hoenniger Weiher systems, respectively, and 3.0 and 6.2% AR in phenyl- and triazinelabel Anglersee systems, respectively. Formation of other volatile organic compounds was insignificant as demonstrated by values of ≤ 0.1% AR.

The route and rate of degradation of the test item was studied in two water / sediment systems under aerobic conditions in the dark in the laboratory for a maximum of 102 days at 20.0 °C. A study application rate of nominal 75 μg per liter was applied. The results show rapid degradation of the test item in water / sediment systems under aerobic conditions. The DT50 value in water ranges (recalculated to 12°C) from 5.3 to 7.2 days and in the entire system from 6.2 to 9.0 days. Three degradation products ≥ 10% AR were detected in the entire system and identified as AE 1887196-dihydro, AE 1887196-dihydro-O-desmethyl and AE 1887196-oxazolidine-dione. Formation of carbon dioxide from both phenyl and triazine rings demonstrates mineralization of the test item.

Description of key information

DT50 = 3.6 – 10.4 days (OECD 308, aerob and anaerob conditions, recalculated to 12 °C)

In water / sediment systems the substance will be degraded within a short time period.

Additional information

The route and rate of degradation of triafamone (CAS No. 874195-61-6) was studied under aerobic conditions and anaerobic conditions in two water / sediment systems. The studies conducted according to OECD guideline 308 and GLP in the dark at approximately 20.0 °C. A study application rate of nominal 75 μg per liter was applied. The results show that triafamone degrades fast in water / sediment systems under aerobic and anaerobic conditions. All results were recalculated to 12 °C with Arrhenius equation. Under aerobic conditions the DT50 value in water ranges from 5.3 - 7.2 days and in the entire system from 6.2 to 8.9 days. Under anaerobic conditions the DT50 value in water ranges from 3.6 to 9.8 days and in the entire system from 4.2 to 10.4 days. Aerobic and anaerobic degradation resulted in equal degradation products, which have been identified as AE 1887196-dihydro, AE 1887196-dihydro-O-desmethyl and AE 1887196-oxazolidine-dione.