Octanal, 7-hydroxy-3,7-dimethyl-, reaction products with 1H-indole

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

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

η-1H-indol-3-yl-α,α,ε-trimethyl-1H-indole-3-heptanol

EC Number:

267-434-2

EC Name:

η-1H-indol-3-yl-α,α,ε-trimethyl-1H-indole-3-heptanol

Cas Number:

67860-00-8

Molecular formula:

C26H32N2O

IUPAC Name:

8,8-di(1H-indol-3-yl)-2,6-dimethyloctan-2-ol

Constituent 2

Reference substance name:

Indole

EC Number:

204-420-7

EC Name:

Indole

Cas Number:

120-72-9

Molecular formula:

C8H7N

IUPAC Name:

1H-indole

Constituent 3

Reference substance name:

7-hydroxycitronellal

EC Number:

203-518-7

EC Name:

7-hydroxycitronellal

Cas Number:

107-75-5

Molecular formula:

C10H20O2

IUPAC Name:

7-hydroxy-3,7-dimethyloctanal

Constituent 4

Reference substance name:

1-(1H-indol-1-yl)-3,7-dimethyloctane-1,7-diol

Cas Number:

1642782-49-7

Molecular formula:

C18H27NO2

IUPAC Name:

1-(1H-indol-1-yl)-3,7-dimethyloctane-1,7-diol

Constituent 5

Reference substance name:

Unknown constituents

IUPAC Name:

Unknown constituents

Specific details on test material used for the study:

Test Item Name: Indolene
Givaudan Product Code: 1490963
Batch Number: VE00434647
Composition: Reaction products from Octanal, 7-hydroxy-3,7-dimethyl with 1H-indole
Appearance: Green yellow liquid
Density: 1017.5 kg/m3 at 20 °C
Expiration Date: June 24, 2018
Storage Conditions (as provided by the Sponsor): Dry, well ventilated, hermetically sealed. Ambient temperature / 10-30 °C. Protect against light.
Storage Conditions (as handled at IES Ltd): At room temperature at approximately 20 °C. Protect against light.
IES Code: 10438

Sampling and analysis

Details on sampling:

Indolene consists of 1H-indole, 7-hydroxy-3,7-dimethyl- and their reaction products. The chromatographic profile of the test item consisted of several peaks. Therefore, the characterization of the WAFs was based on the sum of peaks of the different constituents.
For this duplicate samples were taken from each treatment at the start and at the end of the test (after 48 hours). For the 48-hour stability samples, the contents of the respective replicates were combined prior to sampling.
All samples were stored deep-frozen (at about -20 °C) immediately after sampling. Based on pre-experiments for investigation of the storage stability, the analyzed compounds were found to be stable in the test water under these storage conditions.
The concentrations of the analyzed compounds of the test item Indolene were analytically measured in all samples taken. From the control, one of the duplicate samples was analyzed per sampling time.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The study was performed with young daphnids of the species Daphnia magna Straus. A clone of this species (originally from the Daphnia Collection of the University of Basel/Switzerland in 2015) is successfully bred in IES Ltd Laboratories under temperature and light conditions identical to those of the tests.
During breeding, daphnids were generally fed three times a week with an algal suspension of the green algae Desmodesmus subspicatus CHODAT, Strain No. 86.81 SAG, supplied by the Collection of Algal Cultures (SAG, Institute for Plant Physiology, University of Göttingen, 37073 Göttingen / Germany) and cultivated at IES Ltd Laboratories under standardized conditions or a mixture of this algal suspension and a commercial fish diet (Tetra Min® Hauptfutter, supplied by TETRA-Werke, 49324 Melle / Germany).
At the start of the test, the organisms used in the test were 6-24 hours old and were not first brood progeny.
For evaluation of the quality of the daphnia clone and the experimental conditions, potassium dichromate is tested as a positive control twice a year. The result of the latest positive control test in March 2016 (24-hour EC50: 1.6 mg/L, IES Laboratories Study 20160067) showed that the sensitivity of the test organisms was within the range given by the guideline (24-hour EC50: 0.60-2.1 mg/L).

Study design

Test type:

static

Water media type:

other: Reconstituted test water according to ISO 6341

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

250 mg/L as CaCO3.

Test temperature:

The test was performed in a temperature-controlled room with continuous monitoring of the room temperature. The water temperature was in the range of 20-21 °C.

pH:

The pH was in the range of 7.7 to 7.9.

Dissolved oxygen:

The dissolved oxygen was in the range of 8.1 to 8.7 mg/L

Nominal and measured concentrations:

Indolene consists of several constituents with different solubilities. Therefore, Water Accommodated Fractions (WAFs) with the loading rates of 0.32, 1.0, 3.2, 10 and 32 mg/L were tested to assess the toxicity of Indolene to daphnids. Based on the results of a stirring pre-experiment, 48 hours was considered to be an appropriate stirring period to reach a sufficient concentration of dissolved test item in the test media.

Sample analyses was performed using HPLC-UV/VIS.

At the start of the test, the measured test item concentrations in the test media with the loading rates of 0.32, 1.0, 3.2, 10 and 32 mg/L were 0.062, 0.19, 0.58, 0.61 and 1.9 mg/L, respectively.
The concentrations determined at the end of the test were below the limit of quantification (LOQ = 0.0562 mg/L) for the WAFs with the loading rates of 0.32 and 1.0 mg/L. At the three higher loading rates, 69, 66 and 83% of the initially measured values were found, respectively.

Details on test conditions:

A static test was performed since analytics from the 2nd range-finding study demonstrated high relative stability of the test item over the 48 hour exposure period.

A 16-hour light to 8-hour dark cycle with a 30-minute transition period was used. Light intensity during the light period was between 13 and 18 μmol m-2 s-1.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EL50

Remarks:

based on Loading Rate

Effect conc.:

3.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EL0

Remarks:

Based on loading rate

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

NOELR

Remarks:

Based on loading rate

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other:

Remarks:

No sub-lethal effects observed

Details on results:

Since Indolene consists of several constituents with different solubilities and the analytical method is based only on some of these constituents, the absolute amount of test item could not be analytically determined and the measured test item concentrations should be regarded as approximated values. Therefore, all reported biological results were based on the loading rates of the test item. This procedure of evaluation of data of WAFs is based on recommendations of the OECD Guidance Document No. 23 on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000.

A clear dose-response effect was observed during the study.

During the first 24 hours of the test, no immobilized test organisms were determined in the control and up to and including the loading rate of 1.0 mg/L. At the higher loading rates of 3.2, 10 and 32 mg/L, the immobilization was 15, 40 and 55%, respectively.

The 24-hour EL50 of the test item was calculated to be at the loading rate of 22 mg/L with 95% confidence limits of 13 and 38 mg/L. The 24-hour EL0 was at the loading rate of 1.0 mg/L. The 24-hour EL100 was higher than the loading rate of 32 mg/L.

After 48 hours of exposure, no immobilized test organisms were determined in the control and up to and including the loading rate of 1.0 mg/L. At the loading rate of 3.2 mg/L, 35% of the daphnids were found to be immobile. At the two higher loading rates of 10 and 32 mg/L, all test organisms were found to be immobile.

The 48-hour EL50 was calculated to be at the loading of 3.9 mg/L with 95% confidence limits of 3.0 and 5.0 mg/L. The 48-hour EL0 and NOELR of Indolene were both at the loading rate of 1.0 mg/L, since no toxic effect was observed up to and including this loading rate. The 48-hour EL100 was at the loading rate of 10 mg/L.

No remarkable observations were made concerning the appearance of the test media. All test media were clear solutions throughout the entire test duration.

At the beginning and end of the test medium renewal periods, the pH values of the test media were between 7.7 and 7.9. The dissolved oxygen concentrations in the test media and control were at least 8.1 mg/L and water temperature was in the range of 20-21 °C during the test.

Any other information on results incl. tables

The test is considered to be valid, as in the control no daphnids showed immobilization or other signs of disease or stress (e.g., discolouration or unusual behaviour such as trapping at the surface of water). Furthermore, the dissolved oxygen concentration at the end of the test was ≥3 mg/L in the control and test vessels.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test item Indolene had acute toxic effects on Daphnia magna in a 48-hour static test.
The 48-hour EL50 was determined to be at the loading rate of 3.9 mg/L with 95%-confidence limits of 3.0 and 5.0 mg/L (based on loading rates).