2,6-dibromo-4-cyanophenyl octanoate

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:

07 Oct - 14 Dec, 2010

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)

Remarks:

From Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westlafen

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

The test item was mixed with quartz sand as homogeneously as possible. The application mixture of the highest test concentration was further diluted with quartz sand to obtain the desired test concentrations.
They were thoroughly mixed into the artificial soil of each replicate by using a laboratory mixer, in the order lowest test concentration to highest test concentration. The control group was treated first in the same way as described above but with untreated quartz sand.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

Two days prior to the start of exposure, the test organisms were acclimated to the artificial soil and test temperature. The body wet weight of the test organisms at the start of the test ranged from 0.25 g to 0.45 g per worm. The worms were adult with a well developed clitellum and approximately 6 months old. The age of the worms from the synchronised culture differed by not more than 4 weeks.
One day after the application (day 1), an amount of approximately 5 g finely ground, air dried animal manure was evenly distributed over the surface of the artificial soil in each test vessel. Then, it was moistened with deionised water (approximately 6 mL per 5 g food). The adult earthworms were fed once per week during the test period with approximately 5 g food / vessel.

Study type:

laboratory study

Substrate type:

artificial soil

Remarks:

5 % peat content

Limit test:

no

Total exposure duration:

56 d

Test temperature:

18 - 22 °C

pH:

6.12 - 6.32

Moisture:

17.6 - 21.6 %

Details on test conditions:

Non-re-usable plastic boxes (length x width x height ca. 16.5 cm x 12 cm x 6 cm,) were used as test vessels. Each test vessel contained an amount of approximately 500 g artificial soil (dry weight) to obtain a depth of approximately 5 cm soil in the test vessels.
The test vessels were covered with transparent lids to prevent earthworms from escaping and to reduce evaporation during the test period. The lids were perforated to allow air exchange.
The vessels were kept in a temperature-controlled room under a 16 h light to 8 h darkness photoperiod and a light intensity at light period between approximately 400 – 800 Lux.
For each test concentration 4 replicates of 10 earthworms (4 x 10) and for the control group 8 replicates of 10 earthworms (8 x 10) were tested.
After 28 days the number of surviving animals and their weight alteration was determined. They were then removed from the artificial soil. After further 28 days, the number of offspring was determined.

Nominal and measured concentrations:

Nominal concentrations: 1.0, 1.78, 3.17, 5.64 and 10.0 mg a.i./kg dws

Reference substance (positive control):

yes

Remarks:

Carbendazim 360 g/L

Key result

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Duration:

56 d

Dose descriptor:

NOEC

Effect conc.:

>= 10 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

growth

Details on results:

No mortality of adult earthworms was observed after 28 days of exposure at the control group and at any test concentration.
The mean changes in body weight of the test concentrations of 1.00, 1.78, 3.17, 5.64 and 10.0 mg a.i./ kg dry weight soil were – 1.9 %, - 4.2 %, - 3.5 %, - 4.6 % and 1.2 %, respectively.
At the treatment groups exposed to test substance up to and including the highest test concentration of 10.0 mg a.i./kg dry weight artificial soil, the mean reproduction rate was in the range of 82.9 % to 111.5 % of the control value.

Results with reference substance (positive control):

No mortality of the adult earthworms was observed 28 days after application.
The number of juveniles per test vessel of the test concentrations of 2.5 and 5.0 mg test item/kg dry weight soil were statistically significant reduced to the control.

Please refer to "overall remark/ attached background material" field for result tables.

Validity criteria for OECD 222 (2016) table

Validity criteria	Recommended	Obtained
Mortality of the adults in the control	≤ 10 %	0 %
Mean rate of reproduction of juveniles in the control	≥ 30 earthworms per control vessel	67.3 earthworms per control vessel
Coefficient of variance of reproduction in the control	≤ 30 %	12.4 %

Validity criteria fulfilled:

yes

Remarks:

According to the report and the current OECD 222 guideline. For further details please refer to “Any other information on results incl. tables”.

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, the NOEC for Eisenia fetida andrei was ≥ 10 mg a.i./kg dry soil, based on mortality, growth and reproduction parameters.

Description of key information

The overall long-term NOEC for the soil macroorganisms except arthropods (Eisenia fetida) is ≥10 mg a.i./kg dry weight soil.

Key value for chemical safety assessment

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

10 mg/kg soil dw

Additional information

A GLP-study is available for toxicity testing to soil macroorganisms except arthropods and was identified as key study.

 

In this study (2011), the chronic toxicity of test susbtance to earthworms (Eisenia fetida) was investigated after 56-day exposure according to OECD 222 guideline. Ten earthworms, in each replicate, were exposed to a concentration of 1.0, 1.78, 3.17, 5.64 and 10.0 mg a.i./kg soil dry weight, alongside with a control. The reproduction NOEC was determined to be≥10 mg a.i./kg dry weight soil, the highest concentration tested.