2-heptadecyl-1H-imidazole

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:

27 Nov 2017 - 31 Jan 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

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg, Karlsruhe, Germany

Test material

Test material information

1

Reference substance name:

2-heptadecyl-1H-imidazole

EC Number:

245-589-7

EC Name:

2-heptadecyl-1H-imidazole

Cas Number:

23328-87-2

Molecular formula:

C20H38N2

IUPAC Name:

2-heptadecyl-1H-imidazole

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Analytical samples were taken from the highest test item concentration and control at test start and after 24 hours from fresh and aged solutions and after 48 hours from aged solutions. For each sampling also a retain sample was taken.
- Sample storage conditions before analysis: All samples were stored deep frozen until they were transferred to the analytical laboratory.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution was prepared by directly weighing 100 mg in 1000 mL test medium. This stock solution was stirred in the dark at room temperature for 24 h (based on OECD Series on Testing and Assessment No. 23). Afterwards the test item had not gone into solution completely. Small, evenly distributed particles were visible within the solution and particles were observed at the bottom of the vessel and on the surface of the solution. Insoluble particles of the test item were separated from the liquid phase by filtration through a filter with 0.22 µm mean pore size which was saturated beforehand. The test item solutions were made by diluting the stock solution with test medium to give the required nominal test item concentrations. The preparation procedure was repeated after 24 hours. Around 50 mL of the prepared solutions were transferred to each test vessel.
- Controls: blank control without the test item
- Eluate: no
- Differential loading: no
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): The filtrated solution was clear and transparent.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Continuously bred in the laboratory and originally purchased in a healthy condition from the Federal Environment Agency in Berlin/Germany.
- Age: Freshly hatched daphnids less than 24 hours old were used for the test.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

13°dH (232 mg/L CaCO3)

Test temperature:

19.1 ± 0.4 °C

pH:

7.89 ± 0.13

Dissolved oxygen:

8.9 ± 0.4 mg O2/L

Nominal and measured concentrations:

nominal: control, 0.0100, 0.100, 1.00, 10.0, 100 mg/L
measured: < LOD for all treatment solutions

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass vessel (100 mL), were filled up with ~ 50 mL test solution. The test units were covered with a glass plate.
- Renewal rate of test solution: The test solutions were freshly prepared at 0 and 24 h.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
Elendt M4 standard medium was used as test medium. At test initiation the pH-value of the control (untreated test medium) was 7.91, the dissolved oxygen concentration was 9.0 mg/L and the total hardness was 13°dH (232 mg/L as CaCO3).
- Intervals of water quality measurement: The test temperature and the pH-value as well as the oxygen concentration of the test solutions were measured at all loading rates and control at t = 0 h fresh and t = 24 h from fresh test solutions and after t = 24 h and t = 48 h from aged test solutions in one separate replicate per test item loading rate without test organisms.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours photoperiod /8 hours darkness daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Immobility after 24 and 48 h
- Behavioural changes of daphnids were recorded at 24 and 48 hours after starting the test.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

filtered

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

filtered

Basis for effect:

mobility

Details on results:

- Mortality of control: 0%
- Behavioural changes: No behavioural changes were observed.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No; Test solutions were clear and colorless

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50 (24 h) = 1.00 - 2.00 mg/L

Any other information on results incl. tables

Table 1: Determined concentration of the test substance

Test item nominal [mg/L]	Sampling [h]	Test substance
		[mg/L]	% of nominal
Control	0 fresh	< LOD	-
	24 aged	< LOD	-
	24 fresh	< LOD	-
	48 aged	< LOD	-
100	0 fresh	< LOD	-
	24 aged	< LOD	-
	24 fresh	< LOD	-
	48 aged	< LOD	-

- = not calculated; LOD = 0.00150 mg/L test substance; LOQ = 0.00500 mg/L test substance

Table 2: Validity criteria

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	Control: 0%	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	≥ 7.7 mg/L	yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

For further details please refer to “Any other information on results incl. tables”.