2-{2-chloro-4-mesyl-3-[(tetrahydrofuran-2-ylmethoxy)methyl]benzoyl}cyclohexane-1,3-dione

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

Study period:

10 May 2004 - 27 April 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Japan MAFF Test Guideline, 12-Nousan-No. 8147 Part 2-5-2

Deviations:

no

GLP compliance:

yes

Test type:

laboratory

Radiolabelling:

yes

Oxygen conditions:

aerobic

Soil classification:

other: ISSA Classification: LiC

Year:

2004

Soil no.:

#1

Soil type:

other: LiC

% Clay:

25.7

% Silt:

31.6

% Sand:

42.7

% Org. C:

0.85

pH:

5.8

CEC:

11.9 other: cmolc/kg

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location: Saitama Prefecture Agriculture and Forestry Research Center, Kuboshima 1372 Kumagaya-shi, Saitama 360-0831, Japan
- Storage conditions: Room temperature in the dark
- Storage length:16 April 2004 - 3 Aug 2004
- Soil preparation: 2 mm sieved; air dried

PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture at 1/3 atm (%): 40.2%

Soil No.:

#1

Duration:

120 d

Soil No.:

#1

Initial conc.:

0.3 mg/kg soil d.w.

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

CO2 evolution

radiochem. meas.

Soil No.:

#1

Temp.:

25.0°C

Humidity:

50% of MWHC or 20.1% WHC

Microbial biomass:

24.85 - 25 mg C/g soil @ 5 hours

Details on experimental conditions:

1. PRELIMINARY EXPERIMENTS: A preliminary dosing was performed using A, B, and C radiolabels. A total of three samples were dosed with each test substance for single sampling at T0 and following 7 and 14 days of incubation. At application, aliquots of the corresponding dosing solution (100 µL) were added by glass syringe (100 µL capacity) directly to the soil in each of the sample flasks in a spiral motion, applying as evenly as possible. The flasks were then capped and vortexed to ensure homogeneity of the applied soil. Samples were then connected to the trapping system inside the Hotpack Walk-in constant temperature chamber and maintained at 25 ± 1 °C in the dark. Aliquots of the application solutions (10 µL) were taken prior to and after application via a 10-µL syringe and radioassayed by liquid scintillation counting (LSC). At each sampling time after time 0, the corresponding samples were removed from the constant temperature chamber or incubator along with their respective traps. Total volumes in each trap were measured and aliquoted (3 x 1 mL) for radioassay (LSC). At sampling, the soil samples were transferred to pre-weighed Teflon centrifuge bottles, using 75 mL of acetonitrile:1 N HCl (aq) (4:1, v:v) to aid in the transfer. The samples were shaken for 30 minutes followed by centrifugation at 2500 rpm for 10 minutes. The supernatants were decanted and the extraction procedure was repeated twice more with two 75 mL aliquots of fresh extraction solvent. The extracts were combined, the total volume was measured and aliquots (3 x 0.5 mL) were taken for radioassay. Aliquots (4 x 0.25 g) of the post-extraction solids (PES) were combusted to determine the percent of bound radiocarbon.

2. EXPERIMENTAL DESIGN
- Soil preincubation conditions: Upon arrival, the soil was sieved through a 2 mm sieve and maintained at room temperature in the dark until use in the study. Maintained under dark conditions and at room temperature from May 14, 2004 - August 3, 2004
- Soil condition: air dried
- Soil (g/replicate): 50.5 g dwt
- Control condition: To observe the effect of microorganisms, a portion of the soil was autoclaved (30 minutes at 121°C, 103kPa at daily intervals for a period of 3 days) to provide a sterile set of soils. The control sterile soils used in this study were analyzed for microbial activity prior to the experimental start and at the end of the sterile incubation period. The microbial viability was evaluated enumerating the total colony-forming units (CFU) of (1) aerobic bacteria, (2) actinomycetes, and (3) fungi. Sterile samples were not aerated and were only provided with a cotton plug to maintain sterility during incubation. Sterile sample applications were conducted using aseptic techniques in the laminar flow hood previously sterilized by UV.

- No. of control replicates: A total of 8 samples were developed for the sterile set.
- No. of replication treatments: A total of 36 samples were prepared for the viable sets (12 samples for each radiolabel set).
- Test apparatus: Amber glass bottles (250 ml capacity) provided with Teflon®-lined silicon septum caps.
- Details of traps for CO2 and organic volatile, if any: An aquarium air pump was used to circulate air through a 10% NaOH solution and through deionized water into the sample vessels to provide continuous moist CO2-free air to the soil samples. The viable soil samples were connected to the air source via Teflon® tubing threaded through the septum caps. To trap the headspace volatiles, each soil sample was connected to individual sets of traps containing one ethylene glycol (EG), an empty vial, and two caustic traps (10% aqueous NaOH, 20 ml) for CO2. Trap solutions were housed in glass vials fitted with Teflon®-lined silicon septum caps through which the Teflon® tubing was threaded in the same fashion as the samples. The inlet tubing was placed under the surface of the liquid traps to continuously bubble the headspace through the trap solutions. An empty trap was placed before the NaOH traps to avoid loss of sample due to back flow.
- Identity and concentration of co-solvent: acetonitrile

Test material application
- Volume of test solution used/treatment: 100 µL
- Application method: At application, aliquots of the appropriate dosing solution (100 µL) were added by glass syringe (100 µL capacity) directly to the soil in each of 36 sample flasks (for viable soil) or 8 sample flasks (for sterile soil) in a spiral motion to cover the maximum surface, applying as evenly as possible. The samples were vortexed to ensure homogeneity of the dose through the soil samples.
- Is the co-solvent evaporated: No

Any indication of the test material adsorbing to the walls of the test apparatus: None

Experimental conditions (in addition to defined fields)
- Moisture maintenance method: Approximately once every two weeks the samples were weighed. If necessary, moisture loss was replaced by addition of deionized water to obtain the original sample weight. Humidification and CO2 scrubber solutions were checked and replenished with deionized water or fresh base solutions as needed. Viable samples were continuously trapped and approximately once a month, trapping solutions for the incubating samples were exchanged for fresh ones.
- Continuous darkness: Yes


3. OXYGEN CONDITIONS
- Methods used to create the aerobic conditions: An aquarium air pump was used to circulate air through a 10% NaOH solution and through deionized water into the sample vessels to provide continuous moist CO2-free air to the soil samples.
- Evidence that an/aerobic conditions were maintained during the experiment (e.g. redox potential): The viable soil was shown to be microbially active with a biomass of 25 mg C/g soil.

4. SAMPLING DETAILS
- Sampling intervals: Days -0, -3, -7, -14, -30, -62 and -120.
- Sampling method for soil samples: At each sampling time, single replicates of each label set were removed from the incubator. For viable soil samples their respective traps were disconnected and processed on the same day. The soils were extracted on the same day of collection and radioassayed (3 x 1 mL) immediately upon completion of the extraction process. Initial radiochromatograms of the soil extracts were obtained within 3 days of sample collection. Post-extracted soils were weighed and aliquots were combusted for radioassay of unextracted radiocarbon. Total volumes in each trap were measured and aliquots taken (3 x 1 mL) for radioassay (LSC).
- Method of collection of CO2 and volatile organic compounds: Total volumes in each trap were measured and aliquots taken (3 x 1 mL) for radioassay (LSC).
- Sampling intervals/times for:
> Sterility check, if sterile controls are used: Sterile sampling was conducted at time zero and at termination of the sterility check at 61 days.
> Moisture content: 50% of MWHC; 20% WHC
> Sample storage before analysis: None

Soil No.:

#1

% Recovery:

98.2

St. dev.:

1.8

Remarks on result:

other: A-Label [14C] Test Substance

Soil No.:

#1

% Recovery:

98.7

St. dev.:

3.1

Remarks on result:

other: B-Label [14C] Test Substance

Soil No.:

#1

% Recovery:

99.2

St. dev.:

0.9

Remarks on result:

other: C-Label [14C] Test Substance

Soil No.:

#1

% Degr.:

23.5

Parameter:

CO2 evolution

Sampling time:

120 d

Remarks on result:

other: A-Label [14C] Test Substance

Soil No.:

#1

% Degr.:

11.5

Parameter:

CO2 evolution

Sampling time:

120 d

Remarks on result:

other: B-Label [14C] Test Substance

Soil No.:

#1

% Degr.:

28.5

Parameter:

CO2 evolution

Sampling time:

120 d

Remarks on result:

other: C-Label [14C] Test Substance

Soil No.:

#1

DT50:

18.3 d

Type:

other: Biphasic exponential

Temp.:

25 °C

Remarks on result:

other: A-Label [14C] Test Substance

Remarks:

The principal route of test substance dissipation was soil binding.

Soil No.:

#1

DT50:

60.9 d

Temp.:

12 °C

Remarks on result:

other: A-Label [14C] Test Substance

Remarks:

Calculated DT50 based on results at 25 °C.

Soil No.:

#1

DT50:

15.2 d

Type:

other: Biphasic exponential

Temp.:

25 °C

Remarks on result:

other: B-Label [14C] Test Substance

Remarks:

The principal route of test substance dissipation was soil binding

Soil No.:

#1

DT50:

50.6 d

Temp.:

12 °C

Remarks on result:

other: B-Label [14C] Test Substance

Remarks:

Calculated DT50 based on results at 25 °C.

Soil No.:

#1

DT50:

12.3 d

Type:

other: Biphasic exponential

Temp.:

25 °C

Remarks on result:

other: C-Label [14C] Test Substance

Remarks:

The principal route of test substance dissipation was soil binding.

Soil No.:

#1

DT50:

41 d

Temp.:

12 °C

Remarks on result:

other: C-Label [14C] Test Substance

Remarks:

Calculated DT50 based on results at 25 °C.

Transformation products:

yes

No.:

#1

Evaporation of parent compound:

no

Volatile metabolites:

yes

Remarks:

Carbon dioxide only

Residues:

no

Details on results:

TEST CONDITIONS
- Aerobicity (or anaerobicity), moisture, temperature and other experimental conditions maintained throughout the study: Yes

MAJOR TRANSFORMATION PRODUCTS
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:11.5 - 28.5% of AR as CO2 on day 120
- Range of maximum concentrations in % of the applied amount at end of study period: 11.5 - 28.5% of AR as CO2 on day 120

MINOR TRANSFORMATION PRODUCTS
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:4.4 - 4.5 on day 120
- Range of maximum concentrations in % of the applied amount at end of study period: 4.4 - 4.5 on day 120

EXTRACTABLE RESIDUES
- % of applied amount at day 0: 96.0, 93.8, 94.2
- % of applied amount at end of study period: 34.6, 45.5, 34.0

NON-EXTRACTABLE RESIDUES
- % of applied amount at day 0: 6.0, 5.5, 5.8
- % of applied amount at end of study period: 38.5, 39.9, 34.4

The unextracted radiocarbon remaining following soxhlet extraction was characterized by partitioning the humic and fulvic acid fractions from the soil residues (humin). Thus, the fulvic acid fraction contained an average of 15.4% of the dose, with an average of 2.2% of the dose recovered in the humic acid fractions and 5.1% of the dose associated with the humin.

MINERALISATION
- % of applied radioactivity present as CO2 at end of study: 11.5 - 28.5% of AR as CO2 on day 120

VOLATILIZATION
- % of the applied radioactivity present as volatile organics at end of study: 0

STERILE TREATMENTS (if used)
- Transformation of the parent compound: In the sterile B-labeled soil, the test substance represented 93.3% AR at time 0 and degraded to 61.2% AR by the end of the incubation period.
- Formation of transformation products: No significant transformation products
- Formation of extractable and non-extractable residues: Bound residues increased from 3.1% on day 0 to 30.0% on day 61.
- Volatilization: No.

Temperature correction according to Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7b: Endpoint specific guidance (Echa 2017):

DT50env = DT50test e(Ea/R[1/Tenv - 1/Ttest])

With:

Ea = activation energy (65.4 kJ mol-1)

R = gas constant (8.314.10-3kJ.K-1.mol-1)

 

Result:

The DT50 values of 12.3 – 18.3 days at 25°C correspond to temperature corrected DT50 values of 40.9 – 60.9 days at 12°C (average environmental temperature in Europe).

Reference 2

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 March 2012 - 10 Dec 2012

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 835.4100 (Aerobic Soil Metabolism)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: DRAFT SANCO 11802/2010/rev 1 according to Regulation No. 1107/2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese MAFF New Test Guidelines Annex No. 2-5-2

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

laboratory

Radiolabelling:

yes

Oxygen conditions:

aerobic

Soil classification:

USDA (US Department of Agriculture)

Year:

2012

Soil no.:

#1

Soil type:

loamy sand

% Clay:

9

% Silt:

9

% Sand:

82

% Org. C:

1.6

pH:

6.7

CEC:

8.5 meq/100 g soil d.w.

Bulk density (g/cm³):

1.21

Soil no.:

#2

Soil type:

clay loam

% Clay:

29

% Silt:

33

% Sand:

38

% Org. C:

5

pH:

7.3

CEC:

20 meq/100 g soil d.w.

Bulk density (g/cm³):

0.97

Soil no.:

#3

Soil type:

sandy loam

% Clay:

19

% Silt:

23

% Sand:

58

% Org. C:

1.8

pH:

5.8

CEC:

10.1 meq/100 g soil d.w.

Bulk density (g/cm³):

1.16

Soil no.:

#4

Soil type:

silt loam

% Clay:

19

% Silt:

59

% Sand:

22

% Org. C:

1.7

pH:

6.6

CEC:

10.9 meq/100 g soil d.w.

Bulk density (g/cm³):

1.13

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location:
Soil #1: Monheim/North Rhine-Westphalia/Germany
Soil #2: Blakenheim/North Rhine-Westphalia/Germany
Soil #3: Monheim/North Rhine-Westphalia/Germany
Soil #4: Monheim/North Rhine-Westphalia/Germany
- Pesticide use history at the collection site: None used for previous 5 years.
- Collection procedures: Sample taken with shovel and placed in plastic bag.
- Sampling depth (cm): 0–20
- Storage conditions: Stored after sieving at ambient conditions prior to use, afterwards refrigerated.
- Storage length: 20 days from sieving to application; thereof 4 days preincubation at 20°C.
- Soil preparation: 2 mm sieved; air dried

PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture at 1/3 atm (%):
Soil #1: 11.6 g H2O/100 g DW
Soil #2: 33.8 g H2O/100 g DW
Soil #3: 18.0 g H2O/100 g DW
Soil #4: 19.3 g H2O/100 g DW
- Bulk density (g/cm3):
Soil #1: 1.21
Soil #2: 0.97
Soil #3: 1.16
Soil #4: 1.13

Soil No.:

#1

Duration:

120 d

Soil No.:

#2

Duration:

120 d

Soil No.:

#3

Duration:

120 d

Soil No.:

#4

Duration:

120 d

Soil No.:

#1

Initial conc.:

790 other: µg/kg soil dwt

Based on:

act. ingr.

Soil No.:

#2

Initial conc.:

790 other: µg/kg soil dwt

Based on:

act. ingr.

Soil No.:

#3

Initial conc.:

790 other: µg/kg soil dwt

Based on:

act. ingr.

Soil No.:

#4

Initial conc.:

790 other: µg/kg soil dwt

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

CO2 evolution

radiochem. meas.

Soil No.:

#1

Temp.:

20.3°C

Humidity:

11.6 g H2O ad 100 g soil dwt

Microbial biomass:

330 mg microbial carbon/kg soil dwt

Soil No.:

#2

Temp.:

20.3°C

Humidity:

33.8 g H2O ad 100 g soil dwt

Microbial biomass:

1724 mg microbial carbon/kg soil dwt

Soil No.:

#3

Temp.:

20.3°C

Humidity:

18.0 g H2O ad 100 g soil dwt

Microbial biomass:

433 mg microbial carbon/kg soil dwt

Soil No.:

#4

Temp.:

20.3°C

Humidity:

19.3 g H2O ad 100 g soil dwt

Microbial biomass:

426 mg microbial carbon/kg soil dwt

Details on experimental conditions:

1. EXPERIMENTAL DESIGN
- Soil preincubation conditions: Soil was passed through a 2 mm sieve; 20 days from sieving to application; thereof 4 days preincubation at 20°C; stored after sieving at ambient conditions prior to use, afterwards refrigerated.
- Soil condition: freshly collected
- Soil: 100 g
- No. of replication treatments:Duplicate samplesfor each sampling interval
- Test apparatus: 300 mL Erlenmeyer flasks
- Details of traps for CO2 and organic volatile, if any: The traps were filled with soda lime and polyurethane foam. The system was open to air.
- Identity and concentration of co-solvent: Methanol/water (1/1, v/v)

Test material application
- Volume of test solution used/treatment: 370 µL per 100 g soil (dry weight).
- Application method (e.g. applied on surface, homogeneous mixing etc.): Dropwise application to the soil surface using an adjustable pipette.
- Is the co-solvent evaporated: No

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

Experimental conditions:
- Moisture maintenance method: Re-weighing and addition of lost water.
- Continuous darkness: Yes

Other details, if any:

2. OXYGEN CONDITIONS
- Methods used to create the aerobic conditions:system was open to air and the trap attachments permeable for oxygen
- Evidence that aerobic conditions were maintained during the experiment: viable microbial biomass at DAT 120 based on mg microbial carbon/kg soil dwt compared to non-solvent treated controls.

3. SAMPLING DETAILS
- Sampling intervals: Duplicate samples were removed and processed for analysis at 0, 1, 3, 7, 14, 29, 58, 90 and 120 days after application.
- Sampling method for soil samples: The entire soil in each test vessel was transferred into a centrifuge beaker and extracted using a mechanical shaker. The soil of each flask was extracted completely.
- Method of collection of CO2 and volatile organic compounds: Prior to opening an incubated test vessel for processing of soil and volatiles possibly still present in the vessel the volatiles were transferred into the attached trap by purging with humidified air. In the case of DAT-0 samples the trap attachments for volatiles were not analyzed. At each sampling event, the volatiles traps were separated from their respective incubation flasks.
- Sampling intervals/times for:
> Moisture content: Water loss from evaporation was determined at each sampling interval (except DAT-0) by weighing with the evaporated portion replaced accordingly.
> Sample storage before analysis:
Soil extracts were initially analyzed using HPLC-method within one day. After analysis, the soil extracts were stored in a freezer at ≤ -18 °C protected from light.
The trap attachments containing soda lime and PU foam were stored at room temperature and processed within two days.
Non-extractable residues was determined by combustion followed by LSC latest within 5 weeks after sampling. Further characterization was performed within one week after sampling

Soil No.:

#1

Sampling day(s):

120 d

% Total extractable:

4.6

% Non extractable:

30.2

% CO2:

58

% Other volatiles:

< 0.1

% Recovery:

92.8

Remarks on result:

other:

Remarks:

Soil Laacher Hof AXXa

Soil No.:

#2

Sampling day(s):

120 d

% Total extractable:

2.1

% Non extractable:

28.9

% CO2:

63.2

% Other volatiles:

< 0.1

% Recovery:

94.1

Remarks on result:

other:

Remarks:

Soil Dollendorf II

Soil No.:

#3

Sampling day(s):

120 d

% Total extractable:

15.6

% Non extractable:

32.6

% CO2:

47.2

% Other volatiles:

< 0.1

% Recovery:

95.4

Remarks on result:

other:

Remarks:

Soil Laacher Hof Wurmwiese

Soil No.:

#4

Sampling day(s):

120 d

% Total extractable:

2.7

% Non extractable:

33

% CO2:

56.6

% Other volatiles:

< 0.1

% Recovery:

92.3

Remarks on result:

other:

Remarks:

Soil Hoefchen am Hohenseh 4a

Parent/product:

parent

Soil No.:

#1

% Degr.:

58

St. dev.:

0

Parameter:

radiochem. meas.

Sampling time:

120 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Parent/product:

parent

Soil No.:

#2

% Degr.:

63.2

St. dev.:

0

Parameter:

radiochem. meas.

Sampling time:

120 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Parent/product:

parent

Soil No.:

#3

% Degr.:

47.2

St. dev.:

0.1

Parameter:

radiochem. meas.

Sampling time:

120 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Parent/product:

parent

Soil No.:

#4

% Degr.:

56.6

St. dev.:

0.1

Parameter:

radiochem. meas.

Sampling time:

120 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Soil No.:

#1

DT50:

8 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20.3 °C

Soil No.:

#1

DT50:

17.5 d

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Soil No.:

#2

DT50:

2.7 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20.3 °C

Soil No.:

#2

DT50:

5.9 d

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Soil No.:

#3

DT50:

14.7 d

Type:

other: First Order Multi-Compartment

Temp.:

20.3 °C

Soil No.:

#3

DT50:

32.1 d

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Soil No.:

#4

DT50:

5 d

Type:

(pseudo-)first order (= half-life)

Temp.:

20.3 °C

Soil No.:

#4

DT50:

10.9 d

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Transformation products:

yes

No.:

#1

No.:

#2

No.:

#3

Details on transformation products:

- Formation and decline of each transformation product during test:
For all four soils the formation of benzoic acid was < 10% at all sample time points.
Soil #1 Benzyl Alcohol reached a peak of 38.5% of AR on DAT-14 and declined thereafter to non-detectable residue at DAT-120
Soil #2 Benzyl Alcohol reached a peak of 45.6% of AR on DAT-7 and declined thereafter to non-detectable residue at DAT-120
Soil #3 Benzyl Alcohol reached a peak of 11.9% of AR on DAT-14 and declined thereafter to < LOD at DAT-120
Soil #4 Benzyl Alcohol reached a peak of 61.0% of AR on DAT-14 and declined thereafter to non-detectable residue at DAT-120

- Pathways for transformation: Test substance to Benzoic Acid to Benzyl Alcohol all transforming to CO2 or Non-extractable Residues.

Evaporation of parent compound:

no

Volatile metabolites:

yes

Remarks:

Carbon Dioxide

Residues:

yes

Remarks:

Non-extractable residues: 28.9 - 33.0%

Details on results:

TEST CONDITIONS
- Aerobicity, moisture, temperature and other experimental conditions maintained throughout the study: Yes

MAJOR TRANSFORMATION PRODUCTS
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
Soil #1 Benzyl Alcohol reached a peak of 17.2, 38.5 and 34.8% of AR on DAT-7, -14 and 29 and declined thereafter to non-detectable residue at DAT-120
Soil #2 Benzyl Alcohol reached a peak of 20.3, 45.6 and 33.9% of AR on DAT-3, -7 and -14 and declined thereafter to non-detectable residue at DAT-120
Soil #3 Benzyl Alcohol reached a peak of 11.9% of AR on DAT-14 and declined thereafter to < LOD at DAT-120
Soil #4 Benzyl Alcohol reached a peak of 24.5, 61.0 and 49.3% of AR on DAT-7, -14 and -29 and declined thereafter to non-detectable residue at DAT-120

- Range of maximum concentrations in % of the applied amount at end of study period:
Carbon Dioxide: 58.0, 63.2, 47.2, 56.6% on DAT-120 in soils 1 - 4, respectively

MINOR TRANSFORMATION PRODUCTS
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
Soil #1 Benzoic Acid reached a peak of 6.0, 5.8 and 3.1% of AR on DAT-3, -7 and -14 and declined thereafter to non-detectable residue at DAT-120
Soil #2 Benzoic Acid reached a peak of 4.8, 7.0 and 3.0% of AR on DAT-1, -3 and -7 and declined thereafter to non-detectable residue at DAT-120
Soil #3 Benzoic Acid reached a peak of 2.8, 3.2 and 3.1% of AR on DAT-3, -7 and -14 and declined thereafter to 2.3% of AR at DAT-120
Soil #4 Benzoic Acid reached a peak of 3.8, 7.3 and 4.9% of AR on DAT-1, -3 and -7 and declined thereafter to non-detectable residue at DAT-120

TOTAL UNIDENTIFIED RADIOACTIVITY (RANGE) OF APPLIED AMOUNT:
2.3, 1.7, 6.0 and 1.4% of AR in soils 1 - 4, respectively, on DAT-120

EXTRACTABLE RESIDUES
- % of applied amount at day 0: 94.4, 93.2, 93.8 and 94.3% of AR in soils 1 - 4, respectively
- % of applied amount at end of study period: 4.6, 2.1, 15.6 and 2.7% of AR in soils 1 - 4, respectively

NON-EXTRACTABLE RESIDUES
- % of applied amount at day 0: 2.3, 4.2, 4.7 and 3.5% of AR in soils 1 - 4, respectively
- % of applied amount at end of study period: 30.2, 28.9, 32.6 and 33.0% of AR in soils 1 - 4, respectively

MINERALISATION
- % of applied radioactivity present as CO2 at end of study: 58.0, 63.2, 47.2 and 56.6% of AR in soils 1 - 4, respectively

VOLATILIZATION
- % of the applied radioactivity present as volatile organics at end of study: < 0.1,< 0.1, < 0.1 and < 0.1% of AR in soils 1 - 4, respectively

STERILE TREATMENTS (if used): Not applicable

Temperature correction according to Guidance on Information Requirements and Chemical Safety Assessment Chapter R.7b: Endpoint specific guidance (Echa 2017):

 

DT50env = DT50test e(Ea/R[1/Tenv - 1/Ttest])

With:

Ea = activation energy (65.4 kJ mol-1)

R = gas constant (8.314.10-3kJ.K-1.mol-1)

 

Result:

The DT50 values of 2.7 – 14.7 days at 20,3°C correspond to temperature corrected DT50 values of 5.9 – 32.1 days at 12°C (average environmental temperature in Europe).

Reference 3

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 March 2012 - 19 March 2014

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

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

Japanese MAFF New Test Guidelines Annex No. 2-5-3

Deviations:

no

Principles of method if other than guideline:

Guideline study

GLP compliance:

yes (incl. QA statement)

Test type:

laboratory

Radiolabelling:

yes

Oxygen conditions:

aerobic/anaerobic

Soil classification:

USDA (US Department of Agriculture)

Year:

2012

Soil no.:

#1

Soil type:

loam

% Clay:

23

% Silt:

32

% Sand:

45

% Org. C:

5.1

pH:

7.4

CEC:

20.6 meq/100 g soil d.w.

Bulk density (g/cm³):

0.98

Soil no.:

#2

Soil type:

silt loam

% Clay:

17

% Silt:

60

% Sand:

23

% Org. C:

1.9

pH:

6.6

CEC:

11.8 meq/100 g soil d.w.

Bulk density (g/cm³):

1.11

Soil no.:

#3

Soil type:

sandy loam

% Clay:

15

% Silt:

20

% Sand:

65

% Org. C:

2.1

pH:

5.5

CEC:

10.6 meq/100 g soil d.w.

Bulk density (g/cm³):

1.14

Details on soil characteristics:

SOIL COLLECTION AND STORAGE
- Geographic location:
Soil #1 (Dollendorf II): Blankenheim / North Rhine-Westphalia / Germany
Soil #2 (Hofchen am Hohenseh 4a): Burscheid / North Rhine-Westphalia / Germany
Soil #3 (Wurmwiese): Monheim / North Rhine-Westphalia / Germany
- Pesticide use history at the collection site: No plant protection products used for previous 5 years.
- Collection procedures: Sample taken with shovel and placed in plastic bag.
- Sampling depth: 0 - 20 cm
- Storage conditions: Ambient
- Storage length: 10 days from sampling until start of equilibration, pre-equilibration to study conditions for 8 days
- Soil preparation: 2 mm sieved; air dried

PROPERTIES OF THE SOILS (in addition to defined fields)
- Moisture at 1/3 atm (%):
Soil #1: 41.4% at 1/10 bar
Soil #2: 29.6% at 1/10 bar
Soil #3: 22.1% at 1/10 bar
- Bulk density (g/cm3):
Soil #1: 0.98
Soil #2: 1.11
Soil #3: 1.14

Soil No.:

#1

Duration:

123 d

Soil No.:

#2

Duration:

123 d

Soil No.:

#3

Duration:

127 d

Soil No.:

#1

Initial conc.:

0.8 mg/kg soil d.w.

Based on:

act. ingr.

Soil No.:

#2

Initial conc.:

0.8 mg/kg soil d.w.

Based on:

act. ingr.

Soil No.:

#3

Initial conc.:

0.8 mg/kg soil d.w.

Based on:

act. ingr.

Soil No.:

#1

Temp.:

20.0°C

Humidity:

Aerobic incubation phase: 55% of MWHC Anaerobic incubation phase: soil flooded, ca. 3 cm water depth.

Microbial biomass:

DAT-0 untreated samples: 2498 mg microbial carbone/kg dwt

Soil No.:

#2

Temp.:

20.0 °C

Humidity:

Aerobic incubation phase: 55% of MWHC Anaerobic incubation phase: soil flooded, ca. 3 cm water depth.

Microbial biomass:

DAT-0 untreated samples: 791 mg microbial carbone/kg dwt

Soil No.:

#3

Temp.:

20.0 °C

Humidity:

Aerobic incubation phase: 55% of MWHC Anaerobic incubation phase: soil flooded, ca. 3 cm water depth.

Microbial biomass:

DAT-0 untreated samples: 832 mg microbial carbone/kg dwt

Details on experimental conditions:

1. EXPERIMENTAL DESIGN
- Soil preincubation conditions: Fresh field samples sieved to 2 mm and equilibrated to study conditions of 20.0°C in the dark for 4 (soil WW) - 8 (soil DD and HH) days.
- Soil condition: air dried
- Soil (g/replicate): 100 g dry weight equivalents per replicate
- No. of replication treatments: Duplicate samples for each sampling interval.
- Test apparatus (Type/material/volume): 300 mL glass Erlenmeyer flask, static system.
- Details of traps for CO2 and organic volatile, if any: Aerobic Incubation Phase: trap attachment with soda lime (CO2) and polyurethane foam (organic volatiles), permeable for atmospheric oxygen. Anaerobic Incubation Phase: gas-tight gas sampling bag.
- Identity and concentration of co-solvent: Methanol/water (1/1, v/v).

Test material application
- Volume of test solution used/treatment: 400 μL per flask.
- Application method: Dropwise application to soil surface using a pipette.
- 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: No adjustment needed.
- Continuous darkness: Yes

Other details, if any:

2. OXYGEN CONDITIONS
- Methods used to create the an/aerobic conditions: For the aerobic incubation phase a trap was attached to the culture flask. The trap attachment contained soda lime (CO2) and polyurethane plugs (organic volatiles), permeable for atmospheric oxygen. For the anaerobic incubation phase the trap attachments were replaced by sealable two-valve glass stoppers connected with gas sampling bags for the collection of volatiles. Additionally, the test systems were placed into an inert gas flooded box in a climatic chamber.
- Evidence that an/aerobic conditions were maintained during the experiment: Redox potential, pH and oxygen content of the water and pH and redox potential of soil were determined at each sampling interval of the anaerobic incubation phase. Oxygen contents in the water decreased from maximum concentrations of 3.0, 2.4 and 2.5 mg/L at DASF-0 to ≤ 0.2 mg/L from DASF-7 onwards for soils DD, HH and WW, respectively. This demonstrated the shift from aerobic to anaerobic conditions. Redox potential measurements indicated reducing conditions in water and soil from DASF-7 onwards for soil HH or from DASF-14 onwards for soils DD and WW.

3. SAMPLING DETAILS
- Sampling intervals:
Aerobic Incubation Phase:
-0 and -3 days after treatment (DAT) for soils Dollendorf II (DD) and Höfchen am Hohenseh 4a (HH) DAT-0 and -7 for soil Wurmwiese (WW)
Anaerobic Incubation Phase:
DAT-3, -10, -17, -31, -61, -95 and -123 for soils Dollendorf II and Höfchen am Hohenseh 4a DAT-7, -14, -21, -35, -65, -99 and -127 for soil Wurmwiese.
The sampling intervals of the anaerobic incubation phase correspond to 0, 7, 14, 28, 58, 92 and 120 days after soil flooding (DASF) for all soils
- Sampling method for soil samples: 100 g soil samples were extracted and processed as noted previously. For the water phase during the anaerobic incubation phase water was separated from soil via centrifugation. Direct analysis of the water was performed without extraction.
- Method of collection of CO2 and volatile organic compounds:
Aerobic Incubation Phase: Soda lime for absorption of carbon dioxide and polyurethane foam for adsorption of volatile organic compounds.
Anaerobic Incubation Phase: Gas sampling bag for collection of volatiles.
- Sampling intervals/times for:
Anaerobic Incubation Phase:
DAT-3, -10, -17, -31, -61, -95 and -123 for soils Dollendorf II and Höfchen am Hohenseh 4a DAT-7, -14, -21, -35, -65, -99 and -127 for soil Wurmwiese. The sampling intervals of the anaerobic incubation phase correspond to 0, 7, 14, 28, 58, 92 and 120 days after soil flooding (DASF) for all soils
> Moisture content: Moisture adjustments were deemed unnecessary and therefore were not taken.
> Redox potential/other: In water and soil, at each sampling interval of the anaerobic incubation phase
> Sample storage before analysis: The soils were processed immediately after sampling; the first HPLC/radiodetection analysis of water and soil extracts was performed within two days. Re-analysis of single samples became necessary and was performed max. 15 days after the first analysis (equivalent to 17 days after sampling). The storage stability for this period was successfully demonstrated.
- Other observations, if any: Soil microbial biomass was determined for untreated soil at DAT-0 of the aerobic incubation phase Soil microbial viability was determined for untreated soil as well as for soil treated with application solvent at DASF-120 of the anaerobic incubation phase.

Soil No.:

#1

Sampling day(s):

123 d

% Total extractable:

81.3

% Non extractable:

18.4

% CO2:

1.1

% Other volatiles:

< 0.1

Remarks on result:

other:

Remarks:

Total recovery: 100.8%

Soil No.:

#2

Sampling day(s):

123 d

% Total extractable:

78.4

% Non extractable:

22.2

% CO2:

0.3

% Other volatiles:

< 0.1

Remarks on result:

other:

Remarks:

Total recovery: 100.9%

Soil No.:

#3

Sampling day(s):

123 d

% Total extractable:

73.2

% Non extractable:

25.3

% CO2:

1.6

% Other volatiles:

< 0.1

Remarks on result:

other:

Remarks:

Total recovery: 100.1%

Parent/product:

parent

Soil No.:

#1

% Degr.:

1.1

Parameter:

radiochem. meas.

Sampling time:

123 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Parent/product:

parent

Soil No.:

#2

% Degr.:

0.3

Parameter:

radiochem. meas.

Sampling time:

123 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Parent/product:

parent

Soil No.:

#3

% Degr.:

1.6

Parameter:

radiochem. meas.

Sampling time:

123 d

Remarks on result:

other:

Remarks:

%AR mineralised to 14CO2 after 120 days

Soil No.:

#1

DT50:

> 1 yr

Type:

other: Double First Order in Parallel

Temp.:

20 °C

Soil No.:

#1

DT50:

> 1 yr

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C.

Soil No.:

#2

DT50:

> 1 yr

Type:

other: Double First Order in Parallel

Temp.:

20 °C

Soil No.:

#2

DT50:

> 1 yr

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Soil No.:

#3

DT50:

> 1 yr

Type:

other: Double First Order in Parallel

Temp.:

20 °C

Soil No.:

#3

DT50:

> 1 yr

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Transformation products:

yes

No.:

#1

No.:

#2

No.:

#3

Details on transformation products:

- Formation and decline of each transformation product during test:
Soil #1:
CO2: 1.1% at DAT 123;
Benzoic acid: 7.1, 8.0, 7.4, 7.9, 8.5, 8.9, 8.0, and 8.2 % of AR on DAT-0, -3, -3, -10, -17, -31, -61, -95 and -123
Benzyl alcohol:13.1, 16.4, 16.3, 17.2, 18.3, 18.9, 15.9 and 18.1% of AR on DAT-0, -3, -3, -10, -17, -31, -61, -95 and -123
Soil #2:
CO2: 0.3% at DAT 123;
Benzoic acid: n.d., 3.2, 2.6, 3.4, 3.4, 4.0, 3.6, 4.0 and 3.6% of AR on DAT-0, -3, -3, -10, -17, -31, -61, -95 and -123
Benzyl alcohol: 7.7, 8.3, 8.9, 8.5, 8.8, 10.1, 9.2 and 9.5% of AR on DAT-0, -3, -3, -10, -17, -31, -61, -95 and -123
Soil #3:
CO2: 1.6% at DAT 127;
Benzoic acid: 5.6, 6.3, 6.4, 6.6, 6.7, 7.7, 6.9 and 6.6% of AR on DAT-0, -7, -7, -14, -21, -35, -65,- 99 and -127
Benzyl alcohol: n.d., 7.9, 8.3, 8.1, 9.7, 8.9, 9.0, 9.4 and 8.7% of AR on DAT-0, -7, -7, -14, -21, -35, -65,- 99 and -127

- Pathways for transformation: Test substance to benzoic acid to benzyl alcohol
- Other:

Evaporation of parent compound:

no

Volatile metabolites:

yes

Remarks:

Carbon dioxide 0.3 - 1.6% AR

Residues:

yes

Remarks:

Non extracted residues 18.4 25.3% AR

Details on results:

TEST CONDITIONS
- Aerobicity/anaerobicity conditions maintained throughout the study: Yes

MAJOR TRANSFORMATION PRODUCTS
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
Soil #1 Benzyl Alcohol reached a peak of 17.2, 18.3 and 18.9% of AR on DAT-17, -31 and 61
Soil #2 Benzyl Alcohol reached a peak of 8.9, 8.5, 8.8, 10.1, 9.2 and 9.5% of AR on DAT-10, -17, -31, -61, and -95
Soil #3 Benzyl Alcohol reached a peak of 9.7, 8.9, 9.0 and 9.4% of AR on DAT-21, -35, -65, and -99

- Range of maximum concentrations in % of the applied amount at end of study period:
Soil #1 Benzoyl alcohol: At the end of the study period, on DAT-123 concentrations equaled 18.1% of AR
Soil #2 Benzoyl alcohol: At the end of the study period, on DAT-123 concentrations equaled 9.5% of AR
Soil #3 Benzoyl alcohol: At the end of the study period, on DAT-127 concentrations equaled 8.7% of AR

MINOR TRANSFORMATION PRODUCTS
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
Soil #1 Benzoic Acid reached a peak of 7.4, 7.9, 8.5, and 8.9% of AR on DAT-10, -17, -31, and 61
Soil #2 Benzoic Acid reached a peak of 6.6, 6.7, 7.7 and 6.9% of AR on DAT-17, -31, -61 and 95
Soil #3 Benzoic Acid reached a peak of 4.0, 3.6 and 4.0% of AR on DAT-35, -65, and -99
Soil #1 Carbon Dioxide reached a peak of1.2% of AR on DAT-3
Soil #2 Carbon Dioxide reached a peak of 0.3% of AR on DAT-3 - 123
Soil #3 Carbon Dioxide reached a peak of 1.7% of AR on DAT-7

- Range of maximum concentrations in % of the applied amount at end of study period:
Soil #1 Benzoic Acid: At the end of the study period, on DAT-123 concentrations equaled 8.2% of AR
Soil #2 Benzoic Acid: At the end of the study period, on DAT-123 concentrations equaled 6.6% of AR
Soil #3 Benzoic Acid: At the end of the study period, on DAT-127 concentrations equaled 3.6% of AR
Soil #1 Carbon Dioxide : At the end of the study period, on DAT-123 concentrations equaled 1.1% of AR
Soil #2 Carbon Dioxide: At the end of the study period, on DAT-123 concentrations equaled 0.3% of AR
Soil #3 Carbon Dioxide: At the end of the study period, on DAT-127 concentrations equaled 1.6% of AR

TOTAL UNIDENTIFIED RADIOACTIVITY (RANGE) OF APPLIED AMOUNT:
Soil #1: At the end of the study period, on DAT-123 concentrations equaled 6.4% of AR
Soil #2: At the end of the study period, on DAT-123 concentrations equaled 5.2% of AR
Soil #3: At the end of the study period, on DAT-127 concentrations equaled 6.3% of AR

EXTRACTABLE RESIDUES
- % of applied amount at day 0:
Soil #1: 96.6%
Soil #2: 95.8%
Soil #3: 95.8%

- % of applied amount at end of study period:
Soil #1: 77.3%
Soil #2: 77.7%
Soil #3: 77.7%

NON-EXTRACTABLE RESIDUES
- % of applied amount at day 0:
Soil #1: 5.3%
Soil #2: 4.9%
Soil #3: 4.9%

- % of applied amount at end of study period:
Soil #1: 18.4%
Soil #2: 22.2%
Soil #3: 22.2%

MINERALISATION
- % of applied radioactivity present as CO2 at end of study:
Soil #1: 1.1%
Soil #2: 0.3%
Soil #3: 1.6%

VOLATILIZATION
- % of the applied radioactivity present as volatile organics at end of study:
Soil #1: < 0.1%
Soil #2: < 0.1%
Soil #3: < 0.1%

Reference 4

Endpoint:

biodegradation in soil: simulation testing

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

19 Aug 2003 – 28 Jul 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Japanese MAFF New Test Guidelines 12 Nousan 8147 Annex No. 2-5-1

GLP compliance:

yes (incl. QA statement)

Test type:

laboratory

Radiolabelling:

yes

Oxygen conditions:

aerobic

Soil classification:

other: ISSA method

Year:

2003

Soil no.:

#1

Soil type:

clay loam

% Clay:

24.5

% Silt:

29.2

% Sand:

46.3

% Org. C:

0.86

pH:

5.5

CEC:

11.3 meq/100 g soil d.w.

Soil No.:

#1

Duration:

196 d

Soil No.:

#1

Initial conc.:

0.3 mg/kg soil d.w.

Based on:

act. ingr.

Soil No.:

#1

Temp.:

25 ± 2 °C

Soil No.:

#1

Sampling day(s):

196 d

% Total extractable:

>= 36.8 - <= 42.4

% Non extractable:

>= 54 - <= 55.9

% CO2:

>= 0.21 - <= 6.64

Remarks on result:

other:

Remarks:

The total recovery of radioactivity after 196 days was 97.6 - 98.5%

Parent/product:

parent

% Degr.:

>= 0.21 - <= 6.6

Parameter:

radiochem. meas.

Sampling time:

196 d

Soil No.:

#1

DT50:

>= 13.8 - <= 18.4 d

Temp.:

25 °C

Soil No.:

#2

DT50:

>= 45.9 - <= 61.3 d

Temp.:

12 °C

Remarks on result:

other:

Remarks:

Calculated DT50, based on results at 20 °C

Transformation products:

yes

No.:

#1

No.:

#2

Description of key information

Aerobic Biodegradation in soil ( Japan MAFF Test Guideline, 12-Nousan-No. 8147 Part 2-5-2):

DT50 soil: 12.3 – 18.3 days at 25 °C

temperature corrected values DT50 soil: 40.9 – 60.9 days at 12 °C

Aerobic Biodegradation in soil (OECD 307):

DT50 soil: 2.7 - 14.7 days at 20.3 °C

temperature corrected values DT50 soil: 5.9 – 32.1 days at 12 °C

Anaerobic Biodegradation in soil (OECD 307):

DT50 soil: > 1000 days at 20 °C

Key value for chemical safety assessment

Half-life in soil:

60.9 d

at the temperature of:

12 °C

Additional information

In a simulation study, the degradation of the [14C-A ([cyclohexane-UL-14C]), -B ([phenyl-UL-14C]) and –C ([tetrahydrofuranyl-2-14C]) ring labeled test substance was investigated according to Japan MAFF Test Guideline, 12-Nousan-No. 8147 Part 2-5-2 in freshly collected Japanese paddy soil under aerobic conditions in the dark in the laboratory for 120 days at 25 ± 1 °C and at 50% of the maximum water holding capacity. The study application rate was 0.3 mg/kg soil (dry weight). In viable soils, 14CO2 recovered in the NaOH traps represented an average of 23.5%, 11.5% and 28.5% of the applied dose in A-label, B-label and C-label sets, respectively, at the end of the 120 days of incubation. The calculated half-lives were 18.3 days in the [14C-A ([cyclohexane-UL-14C]) labeled, 15.2 days in the-B ([phenyl-UL-14C]) labeled and 12.3 days in the –C ([tetrahydrofuranyl-2-14C]) ring labeled test substance. The mean DT50 equalled 14.6 days (48.6 days, recalculated to 12 °C).

 

In a second simulation study, the biotransformation of [Phenyl-UL-14C]test substance was studied in four different soils (loamy sand, clay loam, sandy loam, silt loam) for 120 days under laboratory aerobic conditions at 20 ± 2 °C and 55 ± 5% maximum water holding capacity. The experiments were conducted in accordance to the OECD Guideline No. 307. The maximum amount of 14CO2 ranged from 47.2 to 63.2% AR after 120 days. The half-lives for the test substance under laboratory aerobic conditions ranged from approximately 3 to 15 days (5.9 to 32.1 days, recalculated to 12 °C).

 

The route and rate of degradation of [phenyl-UL-14C]test substance were studied in three soils (loam, silt loam, sandy loam) under anaerobic conditions for 120 days, after an aerobic incubation phase of up to 7 days, in the dark in the laboratory at 20.0 °C (total study duration of up to 127 days). The study followed the OECD Guideline No. 307. The half-life of the test substance under anaerobic conditions was > 1000 days in all soils. After 123 days 0.3 – 1.6% of the applied radioactivity were mineralized to 14CO2.

 

In a supporting GLP study, the degradation of tefuryltrione in soil was investigated using three radiolabel positions (cyclohexane, phenyl or tetrahydrofuran) of [14C]AE-0173473. The test substance was applied to a Japanese paddy soil (Kumagaya soil) under aerobic flooded condition at a rate of 0.3 mg/kg-dry soil. Treated soil samples were incubated at 25 ± 2°C in the dark for a maximum of 196 days and were periodically sampled and extracted. Radioactivity assigned to radioactive carbon dioxide accounted for 6.6% AR and 3.8% AR during 196 days. The half-life was estimated to be ca. 13.8 - 18.4 days.