2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline study, GLP

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

The test item was poorly soluble in water; therefore, mixtures of finely ground quartz sand and the test item were produced for the test item concentrations. All concentrations to be tested were based on the product of the test item.
The test item was mixed in an amount of quartz sand (2% of the quartz sand from the total amount of the artificial soil had been separated) to prepare each test item concentration, respectively. These mixtures were used to prepare the concentrations of the test item in the artificial soil.
The test item was incorporated into the remainder of the artificial soil by thoroughly mixing in the respective test item/quartz sand mixtures for 5 minutes.
Finally, the treated artificial soil was filled into the test vessels. Per test vessel an amount corresponding to 500 g dw (dry weight) was used.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: Earthworm
- Source: The earthworms used in this test, Eisenia fetida (Lumbricidae, Earthworms) are kept at ECT Oekotoxikologie GmbH since February 1994. They were originally delivered by Co. Landenberger (D-72355 Schömberg).
- Age at test initiation (mean and range, SD): at least two months, but not more than one year old, however the age of individuals did not differ by more than four weeks
- Weight at test initiation (mean and range, SD): between 250 and 600 mg

ACCLIMATION
- Acclimation period: at least 24 hours before starting the test
- Acclimation conditions (same as test or not): same as test
- Health during acclimation (any mortality observed): no

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

56 d

Test temperature:

18.0 – 21.0 °C

pH:

soil pH-value (day 0): 5.6 – 5.8
soil pH-value (day 56): 6.2 – 6.3

Moisture:

soil moisture(day 0): 49.6 – 54.0%
soil moisture (day 56): 61.1 – 66.0%

Details on test conditions:

Test vessels were Bellaplast containers (Company Polarcup GmbH, Alf/Mosel) consiting of inert (non-toxic) plastic (Polystyrol). The test vessels had a bottom area of 11 x 15.5 cm (= 170.5 cm²) and a height of 6 cm. The test vessels were covered by a transparent and perforated lid.

The earthworms were tested in an artificial soil. The composition of this artificial soil was based on OECD Guideline No. 222 (2004) (the percentages refer to the dry weight):
- 10% Sphagnum peat (no visible plant remains; finely ground and air-dried)
- 20% Kaolin-Clay (kaolinite content > 30%)
- 69.6% Quartz sand (fine sand content with particles between 50 and 200 μm higher than 50%)
- 0.4% Calcium carbonate (CaCO3)
The air dried peat was shredded in a chaff-cutter. Afterwards, all parts of the artificial soil were mixed homogeneously. The pH value was adjusted to 6 ± 0.5 using calcium carbonate. The moisture content was adjusted to 40-60% of WHCmax using deionised water. The water content of the test substrate was checked weekly by reweighing the test vessels and losses of water were compensated.

The following conditions were adjusted:
- Temperature: 20 +/- 2 ºC
- Light/dark cycle: 16 : 8 h with a constant light intensity at the substrate surface of 400 – 800 lx.

The test item was applied once at the beginning of the test. The duration of the test period (exposure of earthworms to the artificial soil containing the test item) was 56 days. The adult worms were removed from the substrate after 28 days.
The test item was tested at five concentrations. The concentrations of the test item (specified by the sponsor) were as follows:
62.5 mg test item/kg soil (dw)
125 mg test item /kg soil (dw)
250 mg test item /kg soil (dw)
500 mg test item /kg soil (dw)
1000 mg test item /kg soil (dw)
Four replicates per concentration and eight replicates for the control (ten worms per replicate) were tested.

Nominal and measured concentrations:

Nominal: 62.5, 125, 250, 500 and 1000 mg test item/kg artificial soil dry weight (dw)

Reference substance (positive control):

yes

Remarks:

Carbendazim

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: biomass

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

LOEC

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Results with reference substance (positive control):

The NOECReproduction for Carbendazim tested as a reference item in a separate GLP test (ECT study no. IRR1308) was determined as 0.32 mg Carbendazim/kg soil (dw) and accordingly the LOECReproduction was determined as 1.0 mg Carbendazim/kg soil (dw). These observed effects are within the range expected from the guideline (1-5 mg Carbendazim/kg soil (dw)) and hence acceptable sensitivity of the test system is assured.

Validity criteria fulfilled:

yes

Description of key information

No toxic effects have been observed in a chronic study with Eisenia fetida.

Additional information

To assess the toxic potential of the test item a chronic toxicity study towards Eisenia fetida according to OECD guideline 222 was conducted. The earthworms were exposed to the test item at 62.5, 125, 250, 500 and 1000 mg test item/kg soil dw for 56 d. No toxic effects on mortality, biomass and reproduction could be observed. The NOEC was determined to be >= 1000 mg/kg soil dw and the LOEC was determined to be > 1000 mg/kg soil dw.