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

Bioaccumulation: terrestrial

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation: terrestrial

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 317 (Bioaccumulation in Terrestrial Oligochaetes)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Substance ID: DPX-JE874-496
Lot #: MAR15MB104
Purity: 98.2%

Vehicle:

yes

Remarks:

Acetone, fine quartz sand

Test organisms (species):

Eisenia andrei

Total exposure / uptake duration:

21 d

Total depuration duration:

21 d

Test temperature:

20 ± 2 °C

pH:

At start of the uptake phase: 5.6 to 6.0
at end of the uptake phase: 5.8 to 6.0
at start of the elimination phase: 5.7 to 5.8
at end of the elimination phase: 5.9 to 6.1

Moisture:

Water content: At start of the uptake phase: 32.6% to 34.4%
(equivalent to 47.2% to 49.9% WHC)
at the end of the uptake phase: 28.6% to 30.6%
(equivalent to 41.4% to 44.3% WHC)
at start of the elimination phase: 36.3% to 36.4%
(equivalent to 52.6% to 52.8% WHC)
at the end of the elimination phase: 31.8% to 33.1%
(equivalent to 46.1% to 48.0% WHC)

Nominal and measured concentrations:

Nominal: 2 mg/kg soil (dry weight)
Measured: 1.69 mg/kg

Type:

BCF

Value:

0.369 dimensionless

Basis:

other: wet weight

Calculation basis:

steady state

Type:

BCF

Value:

1.813 dimensionless

Basis:

other: dry weight

Calculation basis:

steady state

Type:

BCF

Value:

0.756 dimensionless

Basis:

other: Wet weight

Calculation basis:

kinetic

Type:

BCF

Value:

3.364 dimensionless

Basis:

other: dry weight

Calculation basis:

kinetic

Kinetic parameters:

The uptake rate constant (ks) (wet weight) was 0.251 d-1 and the elimination rate constant in worm tissues (ke) was 0.332 d-1. The corresponding kinetic bioaccumulation factor BAFK (wet weight) was calculated to be 0.756. The uptake rate constant (ks) (dry weight) was 1.960 d-1 and the elimination rate constant in worm tissues (ke) was 0.583 d-1. The corresponding kinetic bioaccumulation factor BAFK (dry weight) was calculated to be 3.364.

Conclusions:

During the uptake phase, the concentration of the test substance in worm tissue peaked at Day 2, and then decreased and was 0.394 mg/kg (wet weight) at the end of the uptake phase. Steady state was reached by Day 10. Based on the analysed concentrations, the Steady state BAF was 0.369 (wet weight) and 1.813 (dry weight), and the Kinetic BAF was 0.756 (wet weight) and 3.364 (dry weight).

Executive summary:

The residues of the test substance in earthworms, Eisenia andrei Savigny, were determined at intervals up to 21 days uptake phase in artificial soil in a GLP-compliant laboratory study based on OECD 317 (2010). The elimination of residues was investigated over a further 21-day period (elimination phase). 22 replicates for the control and 54 replicates for the test item groups of five clitellated adult earthworms each were exposed to artificial soil (prepared according to OECD 222 with 10% organic matter) treated with the test item to obtain the nominal concentrations of 2 mg/kg dry artificial soil (1.69 mg/kg analytically) and to an untreated control moistened with deionized water (deionized water only). No reference item is tested.

Adult earthworms were sorted from soil and assessed for mortality, weight loss, and concentration of the test substance (as total radioactivity) after different exposure time. After 21 days exposure, the worms were transferred to untreated soil. For the 21 days elimination phase worms were removed after 4 hours (h), and after 1, 2, 4, 7, 10, 14, 17 and 21 days (d) uptake.

All study validity criteria were met. Mortality was 0% at the end of the uptake and elimination phase and the mean loss of biomass did not exceed 20%. Cumulative mortality and weight loss of adults at sampling time, and food consumption are reported below for each treatment group. No mortality was observed in any treatment group. During the uptake phase, the measured concentration of the test substance in soil was 1.490 mg/kg soil (dry weight) at start of the uptake phase and 1.386 mg/kg soil (dry weight) after 21 days uptake phase.

The concentration of the test substance in worm tissues was in the range of 0.296 to 1.006 mg/kg wet weight during the uptake phase. In the test, the test substance was absorbed by the earthworms. 24 hours after start of exposure, 0.581 mg/kg worm tissue (wet weight, mean value) was found in earthworm tissue. Up to Day 7 of the uptake phase, the test item concentration in worm tissue ranged from 0.926 to 1.006 mg/kg (wet weight). At the following sampling occasions, the test item concentration in worm tissue was almost constant ranging from 0.296 to 0.495 mg/kg (wet weight).

After transferring the worm to untreated soil, the test item concentration in worm tissue decreased rapidly. After Day 1 of the elimination phase, the concentration was 0.189 mg/kg (wet weight) and was below limit of quantification (0.05 mg/kg wet weight) at Day 7 to the end of the elimination phase.

The steady state was reached after 10 days of exposure in the uptake phase. Successive analysis of BAF made on samples taken at following sampling occasions did not vary by more than 24%. The BAFss was calculated to 0.369 (wet weight) and 1.813 (dry weight). The uptake rate constant (ks) (wet weight) was 0.251 d-1 and the elimination rate constant in worm tissues (ke) was 0.332 d-1. The corresponding kinetic bioaccumulation factor BAFK (wet weight) was calculated to be 0.756. The uptake rate constant (ks) (dry weight) was 1.960 d-1 and the elimination rate constant in worm tissues (ke) was 0.583 d-1. The corresponding kinetic bioaccumulation factor BAFK (dry weight) was calculated to be 3.364.

During the uptake phase, the concentration of the test substance in worm tissue peaked at Day 2, and then decreased and was 0.394 mg/kg (wet weight) at the end of the uptake phase. Steady state was reached by Day 10. Based on the analysed concentrations, the BAFSS was 0.369 (wet weight) and 1.813 (dry weight), and the BAFK was 0.756 (wet weight) and 3.364 (dry weight).

Description of key information

Study Type	Study Details	Value	Guideline	Reliability
Bioaccumulation: terrestrial	Accumulation and elimination in earthworms in artificial soil	BCF = 0.369 for wet weight; BCF = 1.813 for dry weight	OECD 317	1

Additional information

The BCF study state was calculated to 0.369 (wet weight) and
1.813 (dry weight)