7-(4-ethyl-1-methyloctyl)quinolin-8-ol

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:

21 October - 24 October 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13 April 2004

Deviations:

yes

Remarks:

no acclimation period of 48hrs was performed. Deviation considered uncritical

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

7-(4-ethyl-1-methyloctyl)quinolin-8-ol

EC Number:

277-531-1

EC Name:

7-(4-ethyl-1-methyloctyl)quinolin-8-ol

Cas Number:

73545-11-6

Molecular formula:

C20H29NO

IUPAC Name:

7-(5-ethylnonan-2-yl)quinolin-8-ol

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sponsor / 1702-18-01/O
- Expiration date of the lot/batch: 25 March 2021
- Purity test date: 26 March 2018

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room Temperature (20 ± 5 °C); Keep away from light. The test item was stored in a closed vessel dark and dry at room temperature (16.2 – 23.7 °C).
- Solubility and stability of the test substance in the solvent/vehicle:
Stability: H2O: unknown; Ethanol: unknown; acetone; unknown; CH3CN: unknown; DMSO: unknown
Solubility: H2O: < 0.1 g/L; Ethanol: unknown; acetone: > 1 g/L; CH3CN: unknown; DMSO: unknown


TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
A saturated solution was prepared for the test. This was done by mixing the real load of 99.3 mg/L resp. 100.0 µL/L test item (based on a density of 0.9926 g/mL determined in LAUS study 18081404G912) with the corresponding amount of dilution water and stirring for 24 hours on a magnetic stirrer. The test item was pipetted directly onto the surface of the test dilution water. The lower phase of the resulting solution was used unfiltrated.
The lower treatments (4.6 / 10 / 22 / 46 mg/L nominal) were prepared by dilution of this solution with dilution water.

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A saturated solution was prepared for the test. This was done by mixing the real load of 99.3 mg/L resp. 100.0 µL/L test item (based on a density of 0.9926 g/mL determined in LAUS study 18081404G912) with the corresponding amount of dilution water and stirring for 24 hours on a magnetic stirrer. The test item was pipetted directly onto the surface of the test dilution water. The lower phase of the resulting solution was used unfiltrated.
The lower treatments (4.6 / 10 / 22 / 46 mg/L nominal) were prepared by dilution of this solution with dilution water.
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): No

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: STRAUS
- Age at study initiation (mean and range, SD): 0-24 hours
- Method of breeding: In-house breeding since 2007
- Source: Origin: Umweltbundesamt Berlin
- Age of parental stock (mean and range, SD):
- Feeding during test
- Food type: green algae (Desmodesmus subspicatus)

Animal Husbandry
Daphnia magna is bred in the LAUS GmbH throughout the year. The animals are kept for the use in toxicity tests. They multiply by parthenogenesis, thus being genetically identi-cal. The keeping is performed similar to the method described in the OECD guideline, fol-lowing SOP 115 002 01 („Zucht und Hälterung von Daphnia magna STRAUS“), version 12 from 02. Feb. 2015.
Vessels preserving glasses, nominal volume 2 L
Medium M4-Medium (recipe of ELENDT)
Food green algae (Desmodesmus subspicatus)
Medium renewal twice a week
Photo period 16/8 hours, using neon tubes
Temperature 20 +/- 2 °C

ACCLIMATISATION:
22 hours and 40 minutes before the start of the test, the adult animals were separated from the young. 40 minutes before test start, the adults were caught with the help of a glass tube, and the newborn daphnia (age < 24 h) were sieved from the medium and im-mediately placed into a beaker containing dilution water. After the settling-in period, ani-mals which showed no apparent damage were used for the test.
Switching from M4-medium (husbandry) to Dilution water (test) has been shown not to cause any detrimental effects for test daphnia, therefore no acclimation period of 48 h was performed. This is a deviation from OECD Guideline No. 202 and EU-Method C.2, which can be considered uncritical

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

No

Test conditions

Test temperature:

19.1 – 20.3 °C

pH:

Reported in the table below .

Dissolved oxygen:

Reported in the table below.

Salinity:

N/A

Nominal and measured concentrations:

4.6 / 10 / 22 / 46 / 100 mg/L (nominal concentration)
The concentrations to be tested are based on the result of a non-GLP pre-test.

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers, nominal volume 50 mL, tall shape
- Type (delete if not applicable): open
- Renewal rate of test solution (frequency/flow rate): No renewal
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4 vessels, each containing 20 ± 5 mL test solution and 5 daphnia
- No. of vessels per vehicle control (replicates): 4 vessels, each containing 20 ± 5 mL dilution water and 5 daphnia

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dilution water (Daphnia medium) with the following specification was used (stated in SOP 11800201)
Parameter Concentration in mg/L
CaCl2*2H2O 293.80
MgSO4*7H2O 123.30
NaHCO3 64.80
KCl 5.80

Deviations from the nominal weighted loads were less than 5 %. Exact values are record-ed in the raw data. After preparation, the dilution water was aerated and the pH was measured. The pH was 7.7.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod:
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

VEHICLE CONTROL PERFORMED: yes/no

RANGE-FINDING STUDY
- Test concentrations:
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

yes

Remarks:

Potassium dichromate K2Cr2O7 (CAS No. 7778-50-9) was used as positive control in a current reference study (201902R201).

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

92.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

46 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

The 24h-EC50 value was determined as 1.98 mg/L. The value was within the requested range for the 24h-EC50 between 0.6 - 2.1 mg/L of potassium dichromate K2Cr2O7 as speci-fied in the OECD guideline.

Reported statistics and error estimates:

The estimation of the biological results was accomplished using the software ToxRat® Professional, version 3.3.0. The details of calculation are stated in the Annex 4: Statistical calculation using ToxRat® Professional 3.3.0.

Any other information on results incl. tables

Findings

Immobility

In the blank control and the lower treatments (4.6 – 46 mg/L), none of the daphnia was immobilised (see table below).

Table 1.           Immobility

Nominal Concentration in mg/L	Immobility 24 hours					Immobility 48 hours
	absolute				in %	absolute				in %
Blank control	0	0	0	0	0	0	0	0	0	0
4.6	0	0	0	0	0	0	0	0	0	0
10	0	0	0	0	0	0	0	0	0	0
22	0	0	0	0	0	0	0	0	0	0
46	0	0	0	0	0	0	0	0	0	0
100	2	3	2	1	40	3	5	3	3	70

 

pH and O₂

The pH values and the concentration of dissolved oxygen in the test media and the blank control are given in the following table:

Table 2.pH and O₂-values

Nominal Concentration in mg/L	pH		O2-Concentration in mg/L
	0 h	48 h	0 h	48 h
Blank control	7.7	7.8	8.2	8.0
4.6	7.8	7.8	8.2	8.1
10	7.7	7.7	8.3	8.1
22	7.8	7.7	8.2	8.0
46	7.7	7.7	8.2	8.1
100	7.8	7.7	8.0	8.2

 

Analytical Determinations

At the start and at the end of the test, the content of the test item in the test solutions was estimated by determination of the total organic carbon (TOC) content in the test solutions using a carbon analyser.

Because of the very low solubility of the test item, the measured concentrations in the test solutions were in a similar low range as in the control.

The details are given in the following tables:

Table3.Measured Concentrations IC and TC

Nominal Concentration Test Item	Measured TC  t = 0 h	Measured TC  t = 48 h	Measured IC  t = 0 h	Measured IC  t = 48 h
mg/L	mg/L	mg/L	mg/L	mg/L
Blank control	10.43	11.25	9.90	9.47
4.6	10.55	10.89	9.85	9.59
10	10.50	11.73	9.58	9.53
22	9.76	11.07	9.73	9.31
46	10.15	11.18	9.90	9.38
100	10.89	11.61	9.52	9.39

LOQ (Limit of quantification) TC = 0.90 mg/L

LOQ (Limit of quantification) IC = 1.59 mg/L

Table 4. Calculated Concentrations TOC

Nominal Concentration Test Item	Calculated TOC (TC-IC)  t = 0 h	Calculated TOC (TC-IC)  t = 48 h
mg/L	mg/L	mg/L
Blank control	0.52	1.78
4.6	0.71	1.30
10	0.92	2.20
22	0.03	1.76
46	0.25	1.80
100	1.37	2.21

 

 

Biological Results Test Item

The biological results are presented in the following table:

Table 5. Biological Results Test Item

Parameter	Value	95%-confidence interval
24h EC50	> 100 mg/L	not determinable
48h EC50	92.2 mg/L	not determinable
48h NOEC	46 mg/L	--
48h LOEC	100 mg/L	--

 

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

One valid experiment was performed.
20 Daphnia were exposed to the test item for the treatment for 48 hours in a static test system.
Only the highest concentrated treatment showed toxicity of 70 % immobilisation. None of the animals were immobilised in the blank control and the lower treatments.
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.
At the start and at the end of the test, the content of the test item in the test solutions was estimated by determination of the total organic carbon (TOC) content in the test solutions using a carbon analyser.
Because of the very low solubility of the test item, the measured concentrations in the test solutions were in a similar low range as in the control.
Therefore, calculation of a mean exposure concentration of dissolved test item was not possible, and the determination of the biological results was based on the nominal concentration (OECD Guidance Doc. No.23, §176).
However strong toxicity (70% immobility) in the highest concentrated treatment 100 mg/L showed the presence of dissolved test item in the test solution.
No observations were made which might cause doubts concerning the validity of the study outcome. All validity criteria were met.
The result of the test is considered valid.

Executive summary:

One valid experiment was performed.

The study was performed using 5 concentrations ranging from 4.6 to 100 mg/L nominal concentration. 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.

Only the highest concentrated treatment (100 mg/L nominal concentration) showed toxicity of 70 % immobilisation. None of the animals was immobilised in the blank control and the lower treatments.

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

At the start and at the end of the test, the content of the test item in the test solutions was estimated by determination of the total organic carbon (TOC) content in the test solutions using a carbon analyser.

Because of the very low solubility of the test item, the measured concentrations in the test solutions were in a similar low range as in the control.

Therefore, calculation of a mean exposure concentration of dissolved test item was not possible, and the determination of the biological results was based on the nominal concentration (OECD Guidance Doc. No.23, §176).

However strong toxicity (70% immobility) in the highest concentrated treatment 100 mg/L showed the presence of dissolved test item in the test solution.

The following results were determined for the test item7-(4-ethyl-1-methyloctyl)quinolin-8-ol (species:Daphnia magna).

 

48h-NOEC=46 mg/L (nominal)
48h-LOEC =100mg/L (nominal)
24h-EC₅₀> 100 mg/L(nominal)
48h-EC₅₀= 92.2 mg/L(nominal)