3-anilino-5-methyl-5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione;famoxadone (ISO)

Biodegradation in soil

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EU: 95/36/EC, Point 7.1.1.2.1.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: USA: CFR 40, Part 158.290

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: U.S.A.: EPA Pesticide Assessment Guidelines, Subdivision N, Environmental Fate, 162-1.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: European Union: Procedures for Assessing the Environmental Fate and Ecotoxicity of Pesticides; Laboratory Soil Degradation Studies, 1.1. Aerobic Degradation. Society of Environmental Toxicology and Chemistry (Europe). March 1995. ISBN 90-5607-002-9

Deviations:

no

GLP compliance:

yes

Test type:

laboratory

Specific details on test material used for the study:

Substance name: [14C-POP]-DPX-JE874
Lot #: 3048-237
Specific activity: 23.2 µCi/mmole, 61.8 µСі/mg
Radiochemical purity: 99.2%

Radiolabelling:

yes

Oxygen conditions:

aerobic

Year:

1996

Soil no.:

#1

Soil type:

loamy sand

% Clay:

6.8

% Silt:

8

% Sand:

85.2

% Org. C:

1.1

pH:

7.1

CEC:

5.2

Bulk density (g/cm³):

1.4

% Moisture content:

25.7

Soil no.:

#2

Soil type:

sandy loam

% Clay:

12.8

% Silt:

18

% Sand:

69.2

% Org. C:

2.9

pH:

7.4

CEC:

16.6

Bulk density (g/cm³):

1.3

% Moisture content:

35.4

Soil no.:

#3

Soil type:

silt loam

% Clay:

12.8

% Silt:

61.6

% Sand:

25.6

% Org. C:

1.9

pH:

5.3

CEC:

7.7

Bulk density (g/cm³):

1.3

% Moisture content:

36.4

Soil no.:

#4

Soil type:

silt loam

% Clay:

14.8

% Silt:

64

% Sand:

21.2

% Org. C:

1.9

pH:

8

CEC:

12.5

Bulk density (g/cm³):

1.2

% Moisture content:

49.4

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location: France, the United Kingdom, and the United States
- Storage conditions: ~ 4 °C
- Storage length: 1 month
- Soil preparation: 2 mm sieved

Soil No.:

#1

Duration:

118 d

Soil No.:

#2

Duration:

118 d

Soil No.:

#3

Duration:

118 d

Soil No.:

#4

Duration:

118 d

Soil No.:

#1

Initial conc.:

0.3 mg/kg soil d.w.

Based on:

test mat.

Soil No.:

#2

Initial conc.:

0.3 mg/kg soil d.w.

Based on:

test mat.

Soil No.:

#3

Initial conc.:

0.3 mg/kg soil d.w.

Based on:

test mat.

Soil No.:

#4

Initial conc.:

0.3 mg/kg soil d.w.

Based on:

test mat.

Parameter followed for biodegradation estimation:

radiochem. meas.

Soil No.:

#1

Temp.:

20°C

Microbial biomass:

Bacteria: 9.2E6; Fungi: 5.2E4

Soil No.:

#2

Temp.:

20°C

Microbial biomass:

Bacteria: 2.9E6; Fungi: 4.0E4

Soil No.:

#3

Temp.:

20°C

Microbial biomass:

Bacteria: 4.0E7; Fungi: 3.6E4

Soil No.:

#4

Temp.:

10°C

Microbial biomass:

Bacteria: 8.8E6; Fungi: 4.2E4

Details on experimental conditions:

EXPERIMENTAL DESIGN
- Soil condition: Air dried
- Soil (g/replicate): 20
- No. of replication treatments: 3
- Test apparatus: Plastic desiccators equipped with an inlet and an outlet.
- Details of traps for CO2 and organic volatile, if any: The air exiting the vessel passed through an ethylene glycol volatile organic trap (100 mL) and a 1N sodium hydroxide carbon dioxide trap (75 mL).

Test material application
- Volume of test solution used/treatment: 0.3 mg/kg soil
- Application method: Homogeneous mixing

Experimental conditions (in addition to defined fields)
- Moisture maintenance method: By addition of appropriate amounts of HPLC grade water
- Continuous darkness: Yes

OXYGEN CONDITIONS (delete elements as appropriate)
- Methods used to create the aerobic conditions: Ambient air was allowed to flow at approximately 10 mL/minute through a water saturator jar.

SAMPLING DETAILS
- Sampling intervals: Duplicate nominal rate soil samples were taken on Day 0 from each soil set. Random soil samples (duplicates at each time point) from the test systems taken at 2, 4, 6, 8, 15, 30, 61, 90 and 118 days.

Soil No.:

#1

% Total extractable:

33

% Non extractable:

34

% CO2:

23

% Recovery:

95

Remarks on result:

other: No other volatiles detected

Soil No.:

#2

% Total extractable:

49

% Non extractable:

30

% CO2:

15

% Recovery:

97

Remarks on result:

other: No other volatiles detected

Soil No.:

#3

% Total extractable:

25

% Non extractable:

45

% CO2:

31

% Recovery:

97

Remarks on result:

other: No other volatiles detected

Soil No.:

#4

% Total extractable:

7

% Non extractable:

50

% CO2:

29

% Recovery:

89

Remarks on result:

other: No other volatiles detected

Key result

Soil No.:

#1

DT50:

9 d

Type:

other: Bi-exponential model

Temp.:

20 °C

Key result

Soil No.:

#2

DT50:

11 d

Type:

other: Bi-exponential model

Temp.:

20 °C

Key result

Soil No.:

#3

DT50:

3 d

Type:

other: Bi-exponential model

Temp.:

20 °C

Key result

Soil No.:

#4

DT50:

2 d

Type:

other: Bi-exponential model

Temp.:

10 °C

Transformation products:

yes

Remarks:

IN-KZ007, IN-JS940, and IN-MN467

No.:

#3

No.:

#2

No.:

#1

Details on transformation products:

Madison Loamy Sand (#1): Three minor products in addition to test substance were observed including IN-KZ007, IN-JS940, and IN-MN467. Each of these products was <10% of the applied radiolabel at each time point.

Milton Sandy Loam (#2): Three other components in addition to test substance were observed including IN-KZ007, IN-JS940, and IN-MN467. IN-KZ007 exceeded 10% of the applied radiolabel at several time points. All other products were <10% of the applied radiolabel at each time point.

Matapeake Silt Loam (#3): Three other components in addition to the test substance were observed including IN-KZ007, IN-JS940, and IN-MN467. None of these components exceeded 10% of the applied mass of parent. [IN-JS940 exceeded 10% of the radiolabel but only reached 7% of the applied mass of test substance].

Nambsheim Silt Loam (#4): Four other components in addition to test substance were observed including IN-KZ007, IN-JS940, and IN-MN467. None of these components exceeded 10% of the applied radiolabel.

Volatile metabolites:

yes

Remarks:

CO2 (15-31%); No other volatiles detected

Conclusions:

The DT50 and DT90 values for the test substance (time at which 50% and 90%, respectively of the applied material has degraded) ranged from 2 to 11 days for 50% degradation and from 56 to 248 days for 90% degradation. These values were determined using a bi-phasic kinetic model and nonlinear regression analyses.

Executive summary:

The rate of degradation of the test substance in four aerobic soils was examined. The soils were from representative agricultural regions of France, the United Kingdom and the United States. The pH of the soils ranged from 5.3 to 8.0, and the organic matter content ranged from 1.1 to 2.9%. This study was conducted using the test substance labeled with carbon-14 in the phenoxyphenyl ring ([HC-POP] label). The rate of application was 0.3 mg/kg soil. Samples of each treated soil type were incubated at 50% maximum water-holding capacity at 20°C in darkness for 118 days. An additional set of French soil samples was also treated as above but incubated at 10°C.

Material balance over the course of the study for the five soil sets ranged from 84 to 103%. Extractable radiolabel decreased to less than 50% at Day 120 in all soils. Unextractable residue ranged from 30 to 53% after four months. Mineralization of the carbon to give 14СО2 accounted for up to 31% of the radiolabel after four months.

The DT50 and DT90 values for the test substance (time at which 50% and 90%, respectively of the applied material has degraded) ranged from 2 to 11 days for 50% degradation and from 56 to 248 days for 90% degradation. These values were determined using a bi-phasic kinetic model and nonlinear regression analyses.

Three transformation/degradation routes for the test substance were observed in all soils. The major degradation pathway was hydroxylation to give IN-KZ007, (5-[4-(4-hydroxyphenoxy)phenyl]-5-methyl-3-(phenylamino)-2,4-oxazolidinedione) which reached maximum levels in the four soils of 4 to 16% on Day 4. The estimated DT50 of this compound was 0.6 to 3.4 days. A minor pathway involved cleavage of the oxazolindinedione ring to give IN-JS940, (alpha-hydroxy-alpha-methyl-4-phenoxybenzene-acetic acid) which reached maximum levels of up to 3% of the mass of parent (4.7% of the radiolabel) in three soils. In one acidic soil (pH 5.3) IN-JS940 reached 8% of the mass of parent (11% of the radiolabel). The third transformation route involved nitration of the phenylamino ring to give ortho- and para-substituted isomers of the test substance. These two compounds, IN-MN467 (5-methyl-3-[(2-nitrophenyl)amino]-5-(4-phenoxyphenyl)-2,4-oxazolidinedione) and IN-MN468 (5-methyl-3-[(4-nitrophenyl)amino]-5-(4-phenoxyphenyl)-2,4-охаzolidinedione), reached maximum levels of 1 to 9%. Mineralization of the radiocarbon was significant in all soils.

Reference 2

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 307 (Aerobic and Anaerobic Transformation in Soil)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.4200 (Anaerobic Soil Metabolism)

Deviations:

no

GLP compliance:

yes

Test type:

laboratory

Specific details on test material used for the study:

Substance name: [Oxazolidinedione-5-14C]-DPX-JE874
Lot #: 81022-1-5-1
Radiochemical purity: 98.2%

Radiolabelling:

yes

Oxygen conditions:

aerobic/anaerobic

Soil classification:

USDA (US Department of Agriculture)

Year:

2017

Soil no.:

#1

Soil type:

sandy loam

% Clay:

7.7

% Silt:

24.5

% Sand:

67.8

% Org. C:

1

pH:

5.1

CEC:

4.1

% Moisture content:

8.131

Soil no.:

#2

Soil type:

sandy loam

% Clay:

18.4

% Silt:

6.7

% Sand:

74.9

% Org. C:

2.1

pH:

6.6

CEC:

12.8

% Moisture content:

24.623

Soil no.:

#3

Soil type:

silty clay loam

% Clay:

32.5

% Silt:

55.8

% Sand:

11.7

% Org. C:

4.7

pH:

7.6

CEC:

23.2

% Moisture content:

39.246

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location: Greensboro, Maryland; Grand Forks, North Dakota; Grand Forks, North Dakota
- Pesticide use history at the collection site: None
- Collection procedures: Shovel
- Sampling depth (cm): 0-20
- Storage conditions: ca + 4 °C
- Storage length: Until use
- Soil preparation: 2 mm sieved

PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture content: The moisture content of each soil was adjusted as close as possible to pF 2 (0.1 bar moisture content) by addition of reagent (reverse osmosis (RO)) water at the time of test vessel preparation.

Soil No.:

#1

Duration:

136 d

Soil No.:

#2

Duration:

136 d

Soil No.:

#3

Duration:

136 d

Soil No.:

#1

Initial conc.:

0.5 mg/kg soil d.w.

Based on:

act. ingr.

Soil No.:

#2

Initial conc.:

0.5 mg/kg soil d.w.

Based on:

act. ingr.

Soil No.:

#3

Initial conc.:

0.5 mg/kg soil d.w.

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

radiochem. meas.

Soil No.:

#1

Temp.:

20 ± 2°C

Microbial biomass:

Pre-study: 108.6 µg/g dry soil
Initial: 69.7 µg/g dry soil
Final sampling interval: 17.4 µg/g dry soil

Soil No.:

#2

Temp.:

20 ± 2°C

Microbial biomass:

Pre-study: 232.3 µg/g dry soil
Initial: 150.8 µg/g dry soil
Final sampling interval: 69.9 µg/g dry soil

Soil No.:

#3

Temp.:

20 ± 2°C

Microbial biomass:

Pre-study: 661.1 µg/g dry soil
Initial: 617.5 µg/g dry soil
Final sampling interval: 97.9 µg/g dry soil

Details on experimental conditions:

EXPERIMENTAL DESIGN
- Soil condition: Fresh
- Soil (g/replicate): 50
- No. of replication treatments: Two per sacrifice interval
- Test apparatus: Glass bottle, moist air (aerobic) or nitrogen (anaerobic) flow through system, connections made with PTFE and ETFE tubing.
- Details of traps for CO2 and organic volatile, if any: One ethylene glycol (organic volatiles) and one 1.5N KOH (CO2), per vessel.
- Identity and concentration of co-solvent: Water:acetonitrile (50/50; v/v)

Test material application
- Volume of test solution used/treatment: 515 μL
- Application method: Glass syringe
- Is the co-solvent evaporated: No

Any indication of the test material adsorbing to the walls of the test apparatus: No

Experimental conditions (in addition to defined fields)
- Moisture maintenance method: Vessels weighed periodically and any weight loss relative to the target weight was attributed to water loss. Water added to restore target weight.
- Continuous darkness: Yes

OXYGEN CONDITIONS
- Methods used to create the aerobic conditions: During the aerobic incubation phase, the intake end of the tubing entering the first vial in the trap train was open to room air, drawing air into the first vial, and through the test vessel and trapping vials.
- Methods used to create the anaerobic conditions: During the anaerobic phase, the intake end of the tubing entering the first vial was connected to a pressure manifold supplying laboratory-generated nitrogen. Individual valves for each test vessel were adjusted to maintain a gentle positive pressure matched as closely as possible to the negative pressure from the vacuum manifold, providing a nitrogen flow-through to each test vessel.

SAMPLING DETAILS
- Sampling intervals: Two vessels were removed for analysis at 0 (immediately after treatment), 7, and 14 days (pre-anaerobic), 46, 78, 105, and 136 days after treatment (32, 64, 91, and 122 days after initiation of anaerobic conditions).
- Sampling method for soil samples: Soil and overlying water (anaerobic phase only) were transferred into extraction vessels and extracted two times with acetonitrile:water 80:20 (100 mL). An additional extraction with acetonitrile:methanol 75:25 (100 mL) was performed during the anaerobic phase only. Extraction vessels were placed on an orbital platform shaker table for ca 30 minutes, followed by centrifugation (ca 3000 rpm; 20 minutes). The volume of each extract was recorded and the individual extracts analysed by LSC. All three extracts were combined for processing and HPLC/β-RAM analysis. Triplicate aliquots (1 mL) of soil extracts were submitted for LSC.
- Method of collection of CO2 and volatile organic compounds: No trapping media were collected with the zero-time samples. Ethylene glycol and potassium hydroxide traps were removed from all test vessels at each subsequent sampling interval. Traps were replenished for non-sacrificed vessels.
- Sample storage before analysis: Extraction of samples commenced on the day of sampling. All samples were stored at ca -20 °C following processing and/or analysis.
Extracts were analyzed for total radioactivity on the day of extraction, and analyzed by 21 days of sampling when possible, except for the last two intervals, Day 105 and Day 136, which were stored for 109 and 82 days. Trapping solutions were stored at ambient laboratory temperature.

Soil No.:

#1

% Total extractable:

90.1

% Non extractable:

13.3

% CO2:

3.8

% Recovery:

100.8

Soil No.:

#2

% Total extractable:

36.7

% Non extractable:

51

% CO2:

17.2

% Recovery:

99.1

Soil No.:

#3

% Total extractable:

19.9

% Non extractable:

71.1

% CO2:

30.7

% Recovery:

101.3

Key result

Soil No.:

#1

DT50:

> 365 d

Type:

other: Hockey Stick model

Temp.:

20 °C

Key result

Soil No.:

#2

DT50:

7.91 d

Type:

other: Hockey Stick model

Temp.:

20 °C

Key result

Soil No.:

#3

DT50:

3.54 d

Type:

other: Hockey Stick model

Temp.:

20 °C

Transformation products:

yes

Remarks:

CO2, IN-KZ007, IN-JS940, IN-H3310

No.:

#4

No.:

#3

No.:

#2

No.:

#1

Details on transformation products:

In the Greensboro sandy loam soil, the test substance disappeared steadily over the course of the study, declining from a maximum of 100.1% AR on Day 0 to a maximum of 84.9% AR by Day 136. Transformation products included IN-KZ007, IN-JS940, and IN-H3310. The largest single unassigned peak occurred in one replicate at Day 14 reaching 5.8% AR.

In the RMN-LS-PF sandy loam soil, the test substance disappeared over the course of the study, declining from a maximum of 99.7% AR on Day 0 to a maximum of 9.4% AR by Day 136. Transformation products included IN-KZ007, IN-JS940, and IN-H3310. No single unassigned peak was observed above 5% AR at any interval.

In the HCB-SL-PF silty clay loam soil, the test substance disappeared over the course of the study, declining from a maximum of 90.1% AR on Day 0 to a maximum of 9.7% AR by Day 136. Transformation products included IN-KZ007, IN-JS940, and IN-H3310. No single unassigned peak was observed above 5% AR at any interval.

IN-MN467 and IN-MN468 were not observed in any of the samples.

Volatile metabolites:

yes

Remarks:

CO2 (3.8-30.7%); Volatile 14C gases accounted for negligible radioactivity.

Residues:

yes

Remarks:

Extractability declined over the course of the study. At Day 136 (study termination), maximum non-extractable residues reached 12.5, 47.0, and 63.8% AR for the Greensboro, RMN-LS-PF, and HCB-SL-PF soils, respectively.

Extractability of Residues:

Soil	Greensboro (#1)	RMN-LS-PF (#2)	HCB-SL-PF (#3)
Maximum Radioactivity Extracted at Zero Time	100.1% AR	99.7% AR	93.0% AR
Maximum Radioactivity Extracted at Day 136	90.1% AR	36.7% AR	19.9% AR
Maximum Non-Extractable Residues (Timepoint)	13.3 % AR (Day 105)	51.0 % AR (Day 105)	71.1 % AR (Day 105)

Supplemental extractions were performed using dichlomethane, toluene, and ethyl acetate on selected samples from the RMN-LS-PF and the HCB-SL-PF soils. Each extraction step yielded less than 1% AR.

Soil	Interval	Replicate 1	Replicate 2
RMN-LS-PF	Day 78	1.5 %AR	1.6 %AR
	Day 136	1.4 %AR	2.5% AR
HCB-SL-PF	Day 14	0.9 %AR	1.0 %AR
	Day 136	1.1 %AR	1.5 %AR

A summary of the mean maximum amount of the metabolite observed throughout the study is presented below.

Component	Maximum of metabolite observed expressed as %AR in soil (time point)
	Greensboro	RMN-LS-PF	HCB-SL-PF
IN-KZ007	3.8 (Day 78)	7.2 (Day 46)	8.8 (Day 7)
IN-JS940	8.9 (Day 46)	14.6 (Day 46)	10.1 (Day 78)
IN-H3310	1.1 (Day 136)	14.4 (Day 136)	4.7 (Day 78)

Conclusions:

The test substance would dissipate slowly from an acidic soil (DT50 >365 days) and more rapidly in slightly acidic to alkaline soil with DT50 values ranging from 3.5 to 7.9 days.

Executive summary:

The anaerobic soil rate of degradation of [14C]test substance was studied in three soils, following OECD Guideline 307 and US EPA OPPTS 835.4200. The soils used were Greensboro (sandy loam, 1.0% OC, pH in water of 5.1); RMN-LS-PF (sandy loam, 2.1% OC, pH in water 6.6), and HCB-SL-PF (silty clay loam, 4.7% OC, pH in water 7.6).

The test system was acclimatized for 12 days prior to treatment. [14C]test substance labelled in oxazolidinedione-5-14C position was used on this study. The test substance was applied to the soil at a nominal rate of 0.5 μg a.i./g dry soil weight. Treated vessels were incubated for 14 days under aerobic conditions at ca pF 2 moisture content. After 14 days under aerobic conditions, vessels were flooded with deaerated water to a depth of ca 2 cm, and were thereafter incubated under anaerobic conditions. A 14 day aerobic degradation was chosen in anticipation of aerobic half life of about 14 days. Vessels were incubated in the dark at a nominal temperature of 20 ± 2°C.

The test systems consisted of glass incubation vessels connected to flow-through systems. Test vessels were connected to traps for the collection of 14CO2 and non-specific 14C volatile organic compounds. Samples were analyzed immediately following test substance application (zero time) and after the following periods of aerobic incubation: 7, and 14 days. Following removal of the Day 14 samples, test systems were flooded with dearated water. Sampling during the anaerobic phase occurred on study days 46, 78, 105, and 136 (32, 64, 91, and 122 days after flooding).

Soil samples were extracted with acetonitrile:water (80:20) and acetonitrile:methanol (75:25). Extractable soil radioactivity was quantified by LSC and the radioactive components were quantified by reversed phase HPLC with on-line radiodetection.

Due to substantial non-extractable residue with the initial solvents, extractions with additional array of solvents of varying polarity were attempted. These extractions were performed on the non-extractable residues of selected samples from the RMN-LS-PF and HCB-SL-PF soils. The solvents used and the maximum amounts of extractable radioactivity were toluene (0.9% AR), dichloromethane (0.8% AR), and ethyl acetate (0.7% AR). After attempted extractions with all of these solvents, the residue was considered unextractable. Non-extractable 14C-residues were quantified by combustion analysis.

The material balance was quantitative for all samples and was in the range of 88.2 to 113.6% of the applied radioactivity (% AR) throughout the study.

The extractable radioactivity was quantitative at time 0 in all soils (>92.8% AR). All three soils showed similar degradation, with the silty clay loam soil (HCB-LS-PF) displaying the most extensive degradation.

In the sandy loam soil (Greensboro), extractable radioactivity decreased progressively with study duration to a maximum of 90.1% AR by the final time point, while non-extractable residue increased to maximum of 12.5% AR. The amount of 14CO2 increased over the study duration reaching a maximum of 4.5% AR. Volatile organics traps had insignificant levels of radioactivity.

In the second sandy loam soil (RMN-LS-PF), extractable radioactivity decreased progressively with study duration to maximum of 36.7% AR by the final time point, while non-extractable residue increased to maximum of 47.0% AR. The amount of 14CO2 increased over the study duration reaching a maximum of maximum of 20.0% AR. Volatile organics traps had insignificant levels of radioactivity.

In the silty clay loam soil (HCB-SL-PF), extractable radioactivity decreased progressively with study duration to maximum of 19.9% AR by the final time point, while non-extractable residue increased to maximum of 63.8% AR. The amount of 14CO2 increased over the study duration reaching a maximum of maximum of 35.3% AR. Volatile organics traps had insignificant levels of radioactivity.

The percentages of parent test substance were plotted against time, and representative degradation rates (DT50 and DT90) were determined using a Hockey Stick (HS) kinetic model, which adequately represented the data. In this model, K1 represented the aerobic decline followed by the anaerobic phase represented by K2. The anaerobic DT50 was calculated based on K2. Aerobic degradation, through the first 14 days, showed a rapid decline in two of the three soils. Once the system was turned anaerobic, the rate of degradation of the test substance changed and the degradation was either halted or became very slow. Therefore, the rate of degradation under anaerobic conditions is much slower than the aerobic rate of degradation. It appears that two of the three soils used [HCB-SL-PF and Greensboro] showed no decline during the anaerobic phase of the study. Therefore, a DT50 under strictly anaerobic conditions was not possible.

The test substance undergoes microbial degradation in soil via opening of the oxazolidinedione ring to form IN-JS940. Decarboxylation of IN-JS940 to form IN-H3310 is then followed by further degradation of these metabolites to fragments that are incorporated into the soil matrix, and the formation of CO2. Hydroxylation of the phenoxy ring to form IN-KZ007 was also observed. Further degradation of these metabolites to fragments that are incorporated into the soil matrix and the formation of CO2 indicated that DPX-JE874 would be expected to dissipate from the environment from anaerobic soils.

Description of key information

Study Type	Study Details	Value	Guideline	Reliability
Aerobic metabolism	Milton sandy loam, Trevino loam, Matapeake silt loam and Madison sandy loam	DT50 = 9, 11, 3 and 2 days	EPA 162 -1	1
Anerobic metabolism	Greensboro (sandy loam, 1.0% OC), RMN-LS-PF (sandy loam, 2.1% OC), and HCB-SL-PF (silty clay loam, 4.7% OC) for	DT50 values are >365 days, 7.91 days, and 3.54 days	OECD 307 OPPTS 835.4200	1