4-(5-(3,5-dichloro-4-fluorophenyl)-5-(trifluoromethyl)-4,5-dihydro-1,2-oxazol-3-yl)-N-(2-ethyl-3-oxo-1,2-oxazolidin-4-yl)-2-methylbenzamide

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29th January to 28th May 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

Version / remarks:

2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

yes

Details on preparation and application of test substrate:

Stock solutions of the substance in acetone were prepared to dose 10 mL of solution at 10 mL/kg dry soil to quartz sand. The acetone was allowed to evaporate off from dose sand for about three hours in a fumehood. The treated sand was then added to artificial soil along with a volume of deionised water required to target the test moisture of 46& of the maximum water holding capacity.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Source: Bias Labs Limited, Fife, United Kingdom
Age: 6 months old, with a clitellum
Weight range at test start: 250 to 600 mg
Feeding: 5 g of air-dried, finely ground untreated rabbit/horse manure, one day after addition of worms and once per week thereafter

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

19.2 to 22.7 °C

pH:

Test start: 6.1 to 6.2
Test end: 6.3 to 6.4

Moisture:

Test start: 58.3% of maximum water holding capacity
Test end: 49% of maximum water holding capacity

Details on test conditions:

Vessels: plastic boxes of 1L capacity (18 cm x 13 cm x 8 cm deep = 234 cm2 surface area) filled with 500 g dry weight of test soil substrate
Substrate: Artificial soil comprising 10% sphagnum peat, 20% kaolinite clay, 70% industrial quartz sand (>50% of the particles between 0.05 mm and 0.2 mm)
Replicates: 8 per control, 4 per test concentration
Number of worms per arena: 10
Photoperiod: 16 hours light at 613 to 777 lux to 8 hours darkness

Nominal and measured concentrations:

Nominal: 0.625, 1.25, 2.5, 5 and 10 mg/kg dry soil

Reference substance (positive control):

yes

Remarks:

Carbendazim

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: adult live weight

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Results with reference substance (positive control):

In a study using the reference item carbendazim, an EC50 was determined as 3.08 mg carbendazim/kg dry soil (with 95% confidence limits of 1.89 to 3.76 mg carbendazim/kg dry soil).
The OECD Guideline indicates significant effects should be observed between 1 and 5 mg carbendazim/kg dry soil. Therefore, the data demonstrate that the worms used in the study were within the recommended range for sensitivity.

Validity criteria fulfilled:

yes

Conclusions:

The 56-day NOEC for reproduction of earthworm was 10 mg/kg soil dry weight.

Executive summary:

The effects of the substance on the growth and reproduction of earthworms were studied under GLP to OECD TG 222 over a period of 56 days. The test substance was dissolved in acetone to treat quartz sand, which was then mixed with artificial soil (comprising 10% sphagnum peat, 20% kaolinite clay and 70% industrial quartz sand) to achieve nominal test concentrations of 0.625, 1.25, 2.5, 5 and 10 mg/kg dry soil. Four replicates were tested for each test concentration alongside 8 negative controls (untreated substrate), solvent controls (soil treated with acetone) and positive controls (soil treated with carbendazim). Ten adult earthworms (6 months old with a clitellum, weighing between 250 and 600 mg) were added to each test vessel filled with appropriate substrate. These were fed with 5 g of air-dried, finely ground untreated rabbit/horse manure on the day after addition and weekly thereafter. The artificial soil was kept at a moisture of about 40 to 60% of the maximum water holding capacity. After four weeks, the adult worms were removed from the test vessels, and mortality and the body weight of the surviving worms were determined. After all of the adult worms had been removed, the soil in each vessel was mixed with a 5 g mix of horse and rabbit manure. Four weeks later, the number of surviving juveniles and any morphological alterations were recorded. Observations of behavioural and pathological symptoms were observed weekly. The NOEC for mortality of adults and adult live weight after 28 days and reproduction after 56 days was 10 mg/kg soil dry weight. All validity criteria specified in the test guideline for the controls were met.

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 November 2016 to 22 November 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

Approximately 24 hours prior to test start, the artificial soil was prepared and deionised water was added to the dry components. The test item was introduced by mixing the quantity of the test item with a small quantity of finely ground quartz sand, such that the required test concentrations were achieved once mixed with the artificial soil (10 g treated sand per replicate). The control substrate contained the corresponding amount of quartz sand only. The test vessels were then filled with the treated soil.

Test organisms (species):

Eisenia andrei

Animal group:

annelids

Details on test organisms:

Source: W. Neudorff GmbH KG”, An der Mühle 3, 31860 Emmerthal, Germany then reared in the test facility
Age and weight range: Adult worms approximately 3 months old with clitellum, 300 – 451 mg/worm
Feeding: none during test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Test temperature:

18.7 to 21.9 °C

pH:

Test start: 6.07 to 6.12
Test end: 5.83 to 5.93

Moisture:

Test start: 34.9 – 35.0 g/100 g dry soil (equivalent to 55.3 – 55.5% of water holding capacity)
Test end: 34.3 – 34.8 g/100 g dry soil (equivalent to 54.4 – 55.2% of water holding capacity)

Details on test conditions:

Vessels: 1 L glass containers with glass lids
Substrate: Artificial soil comprising 10 % sphagnum peat, 20 % kaolin clay, 69.5 % industrial quartz sand (> 50 % of the particles between 0.05 mm and 0.2 mm) and 0.5 % calcium carbonate. 751 g wet weight soil, corresponding to approximately 556 g dry weight, of artificial soil was added to each test vessel
Replication: 4 per test concentration or control
Number of worms per arena: 10
Photoperiod: continuous illumination at 590 lux

Nominal and measured concentrations:

Nominal: 62.5, 125, 250, 500 and 1000 mg/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

2-chloroacetamide at concentrations of 14.1, 18.3, 23.8, 31.0 and 40.3 mg/kg soil dry weight

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Results with reference substance (positive control):

The 14-day LC50 was calculated as 22.2 mg/kg soil dry weight with 95% confidence limits ranging from 21.2 to 23.2 mg/kg soil dry weight. The test results indicated that the laboratory conditions were adequate and have not changed over time.

Validity criteria fulfilled:

yes

Conclusions:

The 14-day LC50 in the acute toxicity study with earthworms (Eisenia andrei) was >1000 mg/kg soil dry weight.

Executive summary:

The study was conducted under GLP to OECD TG 207 to determine the acute toxicity of the substance to earthworms (Eisenia andrei) over a period of 14 days. Artificial soil (comprising 10% sphagnum peat, 20R kaolin clay, 69.5% quartz sand and 0.5% calcium carbonate) was treated with the test substance to achieve nominal test concentrations of 62.5, 125, 250, 500 and 1000 mg/kg soil dry weight. Four replicates were tested per concentration alongside negative controls using untreated substrate and positive controls with the reference substance 2-chloroacetamide. Ten adult worms were placed in each test vessel (1-L glass containers with glass lids), which were filled with the untreated or treated artificial soil. The 14-day LC50 was >1000 mg/kg soil dry weight, and the NOEC based on mortality was 1000 mg/kg soil dry weight. The 14-day NOEC based on biomass was 500 mg/kg soil dry weight.

Description of key information

Short-term toxicity: 14-day LC50 >1000 mg/kg soil dry weight, Eisenia andrei, Friedrich 2016

Long-term toxicity: 28-day NOEC = 10 mg/kg soil dry weight (mortality, adult live weight), Eisenia foetida, Hucheson 2015

Long-term toxicity: 56-day NOEC = 10 mg/kg soil dry weight (reproduction), Eisenia foetida, Hucheson 2015

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

10 mg/kg soil dw

Additional information

In an acute toxicity test in which earthworms (Eisenia andrei) were exposed to the substance, the 14-day LC50 was found to be >1000 mg/kg soil dry weight, the highest concentration tested. The NOEC based on mortality was 1000 mg/kg soil dry weight. The NOEC based on biomass was determined to be 500 mg/kg soil dry weight.

In a chronic toxicity test in which earthworms (Eisenia foetida) were exposed to the substance, the 56-day NOEC (based on reproduction) was determined to be 10 mg /kg soil dry weight, as was the 28-day NOEC based on adult mortality and live body weight.