3,7-dimethyloctanal

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:

2017-10-17 to 2017-12-11

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,7-dimethyloctanal

EC Number:

227-810-9

EC Name:

3,7-dimethyloctanal

Cas Number:

5988-91-0

Molecular formula:

C10H20O

IUPAC Name:

3,7-dimethyloctanal

Specific details on test material used for the study:

TEST MATERIAL
Name ( stated on the report) : TETRAHYDRO CITRAL
Appearance: Colourless to pale yellow liquid
Batch: SC00019145
Expiry date: 2018-03-18

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

At the start of the exposure and at the renewal (0 and 24 hours), samples were taken from the freshly prepared test item concentrations and analyzed.
At the renewal and at the end of the exposure (24 and 48 hours), samples of the 24-hour old media were taken directly from the test vessels and analyzed.

Test solutions

Vehicle:

no

Details on test solutions:

The study was conducted in a closed system (sealed glass flasks) without headspace, due to the volatility of the test item to reduce contact with air and losses of the test item by evaporation. A stock solution of 30 mg/L was freshly prepared with dilution water.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Test system: Daphnia magna STRAUS (Clone 5)
- Origin: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu), 14195 Berlin, Germany
- Breeder: Noack Laboratorien GmbH, Käthe-Paulus-Str. 1, 31157 Sarstedt, Germany
- Culture: In glass vessels (2 - 3 L capacity) with approximately 1.8 L culture medium, at 20 ± 2 °C, in an incubator, 16 hours illumination, light intensity of max. 1500 lx
- Culture medium: Elendt M4, according to OECD 202, Annex 3 (2004), modified to a total hardness of 160 to 180 mg CaC03/L, is used.
- Feeding of the culture stocks : The daphnids are fed at least 5 times per week ad libitum with a mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata and Desmodesmus subspicatus, with a cell density of > 106cells/mL. The algae are cultured at the test facility.
- Origin of the food algae: Sammlung von Algenkulturen (SAG),

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg CaCQ3/L

Test temperature:

18 - 22 °C, constant within ± 1 °C

pH:

7.58 to 8.26

Dissolved oxygen:

7.87 to 9.16 mg/L

Conductivity:

410 to 420 microS/cm

Nominal and measured concentrations:

Nominal concentration: 0.582 - 1.28 - 2.82 - 6.20 - 13.6 - 30.0 mg/L
Geometric mean measured concentrations: 0.114 - 0.660 - 1.73 - 3.89 - 7.44 - 18.0 mg/L

Details on test conditions:

- Condition: The study was performed over a period of 48 hours under semi-static conditions with renewal of test solutions after 24 hours. All concentration levels were visually clear throughout the exposure period.
- Daphnids: Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration and the control.
- Application: The test vessels were filled up to the top with the test solutions. The daphnids were inserted with a small amount of dilution water (start of the exposure) or test solution (water renewal) by pipette. Thereafter, the test vessels were closed immediately with screw caps. There was no headspace in the test vessels.
- Renewal of the test solutions: The test solutions were renewed after 24 hours. For this purpose, a second set of test vessels were filled up to the top with the freshly prepared test solutions and the daphnids were transferred by pipette.
- Illumination (target) : Diffuse light, light intensity of max. 1500 lx
- Photoperiod (target) : 16/8 hours light/dark cycle
- Feeding: The daphnids were not fed during the study.

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.17 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Since the measured test item concentrations were not within the range of ± 20% of the nominal or initially measured concentrations, the effect concentrations are based on the geometric mean measured concentrations of the test item TETRAHYDRO CITRAL

Any other information on results incl. tables

   

 

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on the geometric mean measured concentrations of the test item TETRAHYDRO CITRAL, the 48 hour-ECso for Daphnia magna was 1.17 mg/L (95% confidence limits: 0.666 - 1.71 mg/L).

Executive summary:

In the acute immobilization test with Daphnia magna (STRAUS), the effects of the test item TETRAHYDRO CITRAL (batch number: SC00019145) were determined at the test facility according to OECD 202 (2004) from 2017-10-25 to 2017-11-02, with the definitive exposure phase from 2017-10-25 to 2017-10-27.

The study was conducted in a closed system (sealed glass flasks) without headspace, due to the volatility of the test item to reduce contact with air and losses of the test item by evaporation. A stock solution of 30 mg/L was freshly prepared with dilution water. Six concentration levels of 0.582 - 1.28 - 2.82 - 6.20 - 13.6 and 30.0 mg/L, corresponding to the geometric mean measured concentrations 0.114 - 0.660 - 1.73 - 3.89 - 7.44 - 18.0 mg/L were tested. The study was performed over a period of 48 hours under semi-static conditions with renewal of test solutions after 24 hours. All concentration levels were visually clear throughout the exposure period.

Twenty daphnids (divided into 4 replicates with 5 daphnids each) were exposed to each concentration and the control.

The concentrations of the test item were analytically verified via GC-MS in the fresh media at the start of the exposure and at the renewal of the test solutions (0 and 24 hours) and in the old media at the renewal and at the end of the test (24 and 48 hours) in all concentration levels and the control.

The measured concentrations of the test item in the fresh media at the start of the exposure (0 hours) were 0.633 - 1.28 - 2.53 - 4.81 - 8.31 - 22.2 mg/L and 0.331 - 0.804 - 1.88 mg/L at the renewal (24 hours). The measured concentrations in the old media at the renewal and at the end of the test (24 and 48 hours) were in the range of 5 to 80% of the initially measured concentrations.

Since the measured test item concentrations were not within the range of ± 20% of the nominal or initially measured concentrations, the effect concentrations are based on the geometric mean measured concentrations of the test item TETRAHYDRO CITRAL.

The validity criteria of the test guideline were fulfilled. The 48 hour-ECso for Daphnia magna was 1.17 mg/L (95% confidence limits: 0.666 - 1.71 mg/L).