2-ethylhexyl 2-([1,1'-biphenyl]-4-ylcarbonyl)benzoate

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 February 2020 to 17 July 2020

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Version / remarks:

Adopted April 4, 1984

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Physical Description: Colourless to pale yellow liquid (determined by Charles River Den Bosch)
Purity/Composition: 96.27%
Storage Conditions: At room temperature
Purity/Composition correction factor: No correction factor required
Test item handling: No specific handling conditions required

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 1, 10, 100 and 1000 mg/kg d.s.
- Sampling method: not reported
- Sample storage conditions before analysis: room temperature

Vehicle:

yes

Details on preparation and application of test substrate:

- Method of application to filter paper (if used):
- Method of mixing into soil (if used): large-scale laboratory mixer
- Method of application to soil surface (if used):
- Controls: blank control, solvent control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone
- Concentration of vehicle in test medium (stock solution and final test solution): not reported
- Evaporation of vehicle before use: not reported

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Common name: earthworm
- Source: Bias Labs Ltd. United Kingdom
- Age at test initiation (mean and range, SD): approximately 6 months old at test initiation
- Weight at test initiation (mean and range, SD): between 300 and 600 mg

ACCLIMATION
- Acclimation period: 24 hours
- Acclimation conditions (same as test or not): similar conditions as in the test
- Health during acclimation (any mortality observed): not reported

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

20 ± 2 °C

pH:

6.0 ± 0.5 at the start of the test

Moisture:

25-42% of the dry weight

Details on test conditions:

TEST SYSTEM
- Test container (material, size): Glass jars of approximately 1.8 liter, covered with a glass lid
- Amount of soil or substrate: 727.6 g
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4
- No. of replicates per vehicle control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Geographic location: not applicable
- Pesticide use history at the collection site: not applicable
- Collection procedures: not applicable
- Sampling depth (cm): not applicable
- Soil texture (if natural soil): not applicable
- % sand: 70
- % silt: 10
- % clay: 20
- Soil taxonomic classification: not reported
- Soil classification system: not reported
- Composition (if artificial substrate): 10% sphagnum peat (Horticoop, Katwijk, The Netherlands), 20% kaolin clay (Silex Pottenbakkermat, 's-Hertogenbosch, The Netherlands), 70% industrial sand M62 (Sibelco, Nieuwegein, The Netherlands).
- Organic carbon (%): not reported
- Maximum water holding capacity (in % dry weigth): not reported
- CEC: not reported
- Pretreatment of soil: not reported
- Storage (condition, duration): not reported
- Stability and homogeneity of test material in the medium: not reported

OTHER TEST CONDITIONS
- Photoperiod: continuous
- Light intensity: 400 to 800 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): data recorded after 7 and 14 days

VEHICLE CONTROL PERFORMED: yes

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not reported
- Justification for using less concentrations than requested by guideline: not applicable
- Range finding study: yes
- Test concentrations: 1, 10, 100 and 1000 mg/kg d.s.
- Results used to determine the conditions for the definitive study: yes

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:

mortality

Details on results:

- Mortality at end of exposure period: No mortality or other effects were observed in the blank and solvent control and at the limit concentration throughout the test.
- Total mass of adults at beginning of test: 2.915
- Changes in body weight of live adults (% of initial weight) at end of exposure period: -11%
- No. of offspring produced: not reported
- No. of unhatched cocoons: not reported
- Morphological abnormalities: not reported
- Behavioural abnormalities: not reported
- Other biological observations:

Results with reference substance (positive control):

- Results with reference substance valid: yes
- Relevant effect levels: 50 mg/kg d.s.
- Other:

No mortality or other effects were observed in the blank and solvent control and at the limit concentration throughout the test. Hence, lower concentrations were not scored on mortality.

Mortality of Eisenia fetida in the reference control (2-chloroacetamine; 50 mg/kg d.s.) was 78% after seven days and 83% after fourteen days of exposure. The recorded mortality indicates that the batch of earthworms was slightly more sensitive to the reference item than expected (i.e. between 20 and 80% mortality after 14 days). Despite, no toxicity was found at the regulatory limit concentration of 1000 mg/kg d.s. This rather shows the worst-case than the best-case. Therefore, the test was considered valid.

Individual weight of ten earthworms was determined at the start of the test. These earthworms were introduced to replicate 1 of the blank control. The individual weight of these worms varied between 0.32 and 0.44 gram with a mean weight ± standard deviation of 0.38 ± 0.039 gram. The body weights were within the range of 300 to 600 mg as prescribed by the Study Plan.

During the exposure period, the mean reduction in body weight (fresh) was 15% in the blank control and 14% in the solvent control. No statistically significant difference in mean body weight was found between the blank and solvent control. Thus, data of both controls was pooled and used as reference for expression of body weight reduction at the limit concentration and the reference control.

A statistically significant reduction of body weight of 11% was found at the limit concentration when compared to the pooled controls.

Conclusions:

In conclusion, the 14-day LC50 for Eisenia fetida exposed to the test item was beyond the maximum concentration tested, i.e. exceeded the regulatory limit concentration of 1000 mg/kg d.s.

Executive summary:

The objective of the study was to assess the ability of the test item to generate acute toxic effects in the earthworm Eisenia fetida during an exposure period of 14 days and, if possible, to determine the LC50 at the observation times.

The study procedures described in this report were based on the OECD guideline for Testing of Chemicals No. 207 (adopted April 4, 1984).

The batch of the test item tested was a colorless to pale yellow liquid with a purity of 96.27%. Solubility in acetone was sufficient to enable addition of the item by means of pre-dissolved stock solutions.

A combined limit/range-finding test was performed exposing forty earthworms (10 per replicate, 4 replicates) per group to a blank control, solvent control, reference control and nominal concentration of 1000 mg test item/kg d.s. In addition, ten earthworms (1 replicate) per group were exposed to 1.0, 10 and 100 mg/kg d.s. The total test period was 14 days.

No mortality or other effects were observed in the blank and solvent control and at the limit concentration throughout the test. Hence, lower concentrations were not scored on mortality.

No statistically significant difference in mean body weight was found between the blank and solvent control. Hence, data of both controls was pooled. A statistically significant reduction of body weight of 11% was found at the limit concentration when compared to the pooled controls.

The study met the acceptability criteria prescribed by the study plan and was considered valid.

In conclusion, the 14-day LC50 for Eisenia fetida exposed to the test item was beyond the maximum concentration tested, i.e. exceeded the regulatory limit concentration of 1000 mg/kg d.s.

Description of key information

Study conducted to recognised testing guidelines with GLP certification.

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

1 000 mg/kg soil dw