Terpene Dimers

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 2018- November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

The temperature during exp. 2 ranged from 22.4 to 23.1 °C and was therefore higher than stated in the guideline. As no immobility occurred in the blank control during the test and all validity criteria were met this deviation was stated as uncritical.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Terpene Dimers

EC Number:

948-032-2

IUPAC Name:

Terpene Dimers

Test material form:

liquid

Details on test material:

Batch no. DF1710011

Sampling and analysis

Analytical monitoring:

yes

Remarks:

The content of the test item in the test solutions was estimated by calculation based on the carbon content of the test item and DOC measurement following SOP 118 009 02 in the current edition

Test solutions

Vehicle:

no

Details on test solutions:

For both experiments the water-accommodated fractions (WAFs) were prepared for the test. This was done by mixing the nominal loads of 46 / 100 / 220 / 460 / 1000 mg/L resp. 48 / 105 / 231 / 483 / 1050 µL/L test item (based on a density of 0.9526 g/mL given by the sponsor) with the corresponding amount of dilution water in a settling bottle and stirring moderately at 130 rpm on a magnetic stirrer for 7 days. After a settling phase of 24 hours the lower phases were used for the test.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Species Daphnia magna
Authority STRAUS
Strain Berlin
Sex female
Age between 0 and 24 hours
Origin Umweltbundesamt Berlin
In-house breeding since 27. September 2007
Selection of the test system was made following the proposal of the guidelines.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

After 24 and 48 hours, the immobilised daphnia were counted

Post exposure observation period:

After 24 and 48 hours, the immobilised daphnia were counted

Test conditions

Hardness:

Parameter Concentration in mg/L
CaCl2*2H2O 293.80

Test temperature:

Experiment 1 20.9 – 21.9°C
Experiment 2 22.4 – 23.1°C

pH:

7.7- 7.8

Dissolved oxygen:

7.7 - 9.0 mg/L

Nominal and measured concentrations:

Nominal concentration in mg/L Real load in mg/L Experiment 1 Real load in mg/L Experiment 2
46 46.3 46.3
100 100.7 100.7
220 220.4 220.4
460 460.0 460.0
1000 1000.2 1000.2

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 5.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 5.9 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Any other information on results incl. tables

For experiment 1 the immobilisation in the highest tested concentration was 10% and still within the acceptable immobilisation range for the blank control. Therefore, no relevant difference compared to the control could be evidenced, a statistical evaluation was not necessary and results are given as a range based on the geometric mean of the measured concentrations.

For experiment 2 the estimation of the biological results was accomplished using the software ToxRat® Professional, version 3.2.1. The details of calculation are stated in the annex 4, page 28. ToxRat® extrapolated the EC₅₀values to be 15.4 mg/L, however the maximum found solubility of the test item in this study was found to be 8.5 mg/L in the highest tested concentration, therefore the EC₅₀value is given as a range being higher than the highest tested concentration.

 

9.2 Biological Results Test Item

The biological results are presented in the following table:

Table 9.3-a       Biological Results Test Item

Parameter		Experiment 2
48h-NOEC	≥ 5.9 mg/L	3.4 mg/L
48h-LOEC	> 5.9 mg/L	4.9 mg/L
24h-EC50	> 5.9 mg/L	> 8.5 mg/L
48h-EC50	> 5.9 mg/L	> 8.5 mg/L

           

10 VALIDITY

¨         Immobilisation in the controls may not exceed 10 %.

Immobilisation in the controls in experiment 1 and 2 was 0 %.

¨         The concentration of dissolved oxygen at the end of the test must be at least 3 mg/L. The lowest concentration of dissolved oxygen at the end of experiment 1 was 7.9 mg/L. 

The lowest concentration of dissolved oxygen at the end of experiment 2 was 8.4 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Two valid experiments were performed.
The studies were performed using 5 concentrations ranging from 46 to 1000 mg/L (nominal). For each test concentration and the blank control, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.
Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable.

Experiment 1:
The highest concentration led to 10% immobilisation, which is still in the acceptable range in the blank control immobility. None of the animals was immobilised in the blank control.
At the start and at the end of the test, the content of the test item in the test solutions was determined using measurement of dissolved organic carbon (DOC). Solubility of the test item was very low. The measured DOC concentration in the highest concentration 1000 mg/L was 5.50 mg/L at the beginning and 5.51 mg/L at the end of the test.
Therefore, the determination of the results was based on the geometric mean of the measured concentrations based on measured DOC concentration and the carbon content of the test item.
A second experiment was conducted for verification (same test design) because toxicity and measured DOC content were not in accordance with the non-GLP pre-tests (see chapter
7.3).

Experiment 2:
The two highest concentrations showed between 15 and 20% immobilisation. None of the animals was immobilised in the blank control.
The measured DOC concentration in the highest concentration 1000 mg/L was 6.97 mg/L at the beginning and 8.12 mg/L at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured test item concentrations based on measured DOC concentration and the carbon content of the test item.
The slightly higher measured DOC concentrations in the second experiment are coincidental with the slightly higher toxicity in the second experiment.
The higher DOC concentration in the non GLP pre-test was very likely caused by a carryover of undissolved test item.
No observations were made which might cause doubts concerning the validity of the study outcome. All validity criteria were met in experiment 1 and 2.

Executive summary:

Findings and Results:

Two valid experiments were performed.

The studies were performed using 5 concentrations Terpene Dimers ranging from 46 to 1000 mg/L (nominal). For each test concentration and the blank control, 20 Daphnia were exposed to the test item for 48 hours in a static test system. After 24 and 48 hours, the immobilised Daphnia were counted.

Potassium dichromate K₂Cr₂O₇(CAS No. 7778-50-9) was used as positive control in a current reference study to assure that the test conditions are reliable. 

 

Experiment 1:

The highest concentration of Terpene Dimers led to 10% immobilisation, which is still in the acceptable range in the blank control immobility. None of the animals was immobilised in the blank control.

At the start and at the end of the test, the content of the test item in the test solutions was determined using measurement of dissolved organic carbon (DOC). Solubility of the test item was very low. The measured DOC concentration in the highest concentration 1000 mg/L was 5.50 mg/L at the beginning and 5.51 mg/L at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured test item concentrations based on measured DOC concentration and the carbon content of the test item.

A second experiment was conducted for verification (same test design) because toxicity and measured DOC content were not in accordance with the non-GLP pre-tests (see chapter

7.3).

 

Experiment 2:

The two highest concentrations showed between 15 and 20% immobilisation. None of the animals was immobilised in the blank control.

At the start and at the end of the test, the content of the test item in the test solutions was determined using measurement of dissolved organic carbon (DOC). The measured DOC concentration in the highest concentration 1000 mg/L was 6.97 mg/L at the beginning and 8.12 mg/L at the end of the test. Therefore, the determination of the results was based on the geometric mean of the measured test item concentrations based on measured DOC concentration and the carbon content of the test item.

The slightly higher concentrations measured DOC concentrations are in accordance with the slightly higher toxicity in the second experiment.

 

The clearly higher DOC concentration in the non GLP pre-test was very likely caused by a carryover of undissolved test item, (see chapter 7.3).

The following results were determined for the test item Terpene Dimers (species: Daphnia magna).

	Experiment 1	Experiment 2
48h-NOEC	≥ 5.9 mg/L	3.4 mg/L
48h-LOEC	> 5.9 mg/L	4.9 mg/L
24h-EC50	> 5.9 mg/L	> 8.5 mg/L
48h-EC50	> 5.9 mg/L	> 8.5 mg/L