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Ecotoxicological information

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:
11 Sept 2017 - 02 Feb 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Specific details on test material used for the study:
- Lot No.: 75518
- Purity: 95.7%
- Expiration date: September 19, 2018

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Samples of stock solution and test solutions were taken to determine the actual test item concentrations in comparison to the nominally applied concentrations. Samples of test solutions were taken at the start (0 hour) and end (48 h) of exposure.

Test solutions

Vehicle:
no
Details on test solutions:
Based on the results of a preliminary non-GLP range finding test, a nominal limit concentration of 100mg/L was tested in the definitive test.
A stock solution was prepared at a nominal loading rate of 100 mg/L by adding 50 mg of the test item to 500 mL of the test medium. This stock solution (S1) was slowly stirred (500 rpm) for 10 minutes at ambient temperature in the dark. Thereafter this stock solution was left to settle for 20 minutes. The stock solution was visually examined for undissolved/particulate matter in the free water column. Visual inspection of the flask showed a clear solution without Tyndall effect.
The stock solution S1 was prepared once to prepare the test solutions. The volume of the stock solution was large enough to prepare the test concentrations and all analytical samples.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Species: Daphnia magna STRAUS (clone M10), cultured at ECT Oekotoxikologie GmbH since December 22, 2011.
Origin: The organisms were originally supplied by KU Leuven, Belgium.
Age of parental daphnids: less than 35 d
Age of exposed daphnids at the beginning of the test: less than 24 h

Study design

Test type:
static
Water media type:
freshwater
Remarks:
Elendt medium M4
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
Water hardness: 254 mg/LCaCO3
Test temperature:
target: 18 to 22°C, constant within a range of 2°C
actual: 19.9 to 20.9°C
pH:
7.7 to 7.8
Dissolved oxygen:
8.3 to 8.6 mg/L
Nominal and measured concentrations:
Nominal: 100 mg/L
Geometric Mean Measured: 96.1 mg/L
Details on test conditions:
- Based on the results of a preliminary non-GLP range finding test, the following nominal limit concentration was tested in the definitive test: 100 mg/L.
- The test period (exposure of test organisms to the test solutions in a static system) was 48 hours.
- Additionally, daphnids were exposed under control conditions (non-treated test medium without solvent).
- Four replicates were used for the test item concentration and the control. Each replicate vessel contained five daphnids.
- Glass beakers (nominal 60 mL), covered with watch glasses, were used as test vessels. The test vessels were filled-up as far as operationally possible as a means of reducing the overall headspace.
- Volume of test solution per test vessel: 57-60 mL
- Test medium: medium M4 (OECD 2004)
- Adjustment of pH in the medium: none
- Application of test item: test item dissolved in Medium M4 applied once at the beginning of the test
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Details on results:
Analytical Findings: The test item concentration was stable during the test period, with 93.5% of the initially measured concentration found in the aged solution.
Biological findings: In this limit test no immobilities were observed in control or in the limit concentration of 100 mg test item/L. It is therefore concluded that the EC50 of the test item is higher than the limit concentration tested (nominal: 100 mg test item/L). This corresponds to a geometric mean measured D-Panthenyltriacetate concentration of 96.1 mg/L
Results with reference substance (positive control):
The most recent reference test with potassium dichromate performed in a separate study (Study No. IDA1705) resulted in an EC50(24 h) of 1.29 mg/L.
According to the OECD guideline No. 202 (OECD, April 2004) EC50(24 h)-values for potassium dichromate obtained from different laboratories should range between 0.6 mg/L and 2.1 mg/L.
The toxicity of the reference item is within this range. Therefore the results of this reference test are acceptable and the test conditions are reliable and the sensitivity of the test system could be demonstrated.
Reported statistics and error estimates:
In this limit test no immobilities were observed in control or in the limit concentration of 100 mg test item/L. A statistical evaluation for differences between treatment and control was therefore not required and was not performed.

Any other information on results incl. tables

Validity of the test - All validity criteria were fulfilled as required by the test guideline:

 Required  Found

 immobilised daphnids in the control: <=10%

 0%

 dissolved oxygen concentration in control and test vessels at the end of the test: => 3mg/L

 => 8.3mg/L

Signs of disease or stress, for example, discoloration or unusual behaviour such as trapping at surface of water, did not exceed 10 per cent of the daphnids in the controls.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
In a study to determine the acute toxicity of D-Panthenyltriacetate to the water flea Daphnia magna, no immobilities were observed in a limit test performed at a concentration of 100 mg test item/L.

It is therefore concluded that the 48h EC50 of the test item is higher than the limit concentration tested (nominal: 100 mg test item/L). This corresponds to a geometric mean measured D-Panthenyltriacetate concentration of 96.1 mg/L