Methyl 1,2,3,4-tetrahydro-6-naphthyl ether

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

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:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Methyl 1,2,3,4-tetrahydro-6-naphthyl ether

EC Number:

217-049-0

EC Name:

Methyl 1,2,3,4-tetrahydro-6-naphthyl ether

Cas Number:

1730-48-9

Molecular formula:

C11H14O

IUPAC Name:

6-methoxy-1,2,3,4-tetrahydronaphthalene

Test material form:

other: liquid

Details on test material:

Test item: Methoxy-tetraline
CAS number: 1730-48-9
Physical state: Liquid
Coluor: Brown
Storage: At a temperature of 15 to 30 °C

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

Preparation of stock solution:
The preparation of stock and test solutions was based on the preliminary non GLP range finding test. As the Range Finding Test was not performed in compliance withthe GLP-Regulations it is excluded from the Statement of Compliance in the final report, but the raw data of this test are archived under the study code of present study. The stock solution was prepared by measuring 15.36 mg of test item into 1 000 ml OECD growth medium. The suspension was stirred till complete dilution of test item. The stock solution was clear and colourless. The nominal concentration of stock solution was 15 mg/L.

Preparation of test solutions:
Seven test solutions of different concentration were prepared by mixing appropriate volume of OECD medium and stock solution of the test item. The maximum separation factor between of test vessels was 2. Two additional replicates were prepared for controlling the abiotic degradation of the test substance. These test vessels were not inoculated with alga inoculum culture. The following table shows the preparation of test solutions. The volume of the prepared dilution levels was 300 ml except the control solution which was 600 ml.

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

Test species: Pseudokirchneriella subcapitata (Korshikov) F. Hindák (formerly known as Selenastrum capricornutum)
Source: UTEX The Culture Collection of Algae (USA)
Batch: UTEX ID. number: 1648
Date of arriving: 28 November 2014

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Hardness:

At the beginning of the test the pH values were measured in the remaining test solution of the concurrent test vessels at each dilution level. At the end of the test the pH values were measured in each test vessel. The pH of test solutions was not adjusted at the beginning of the test.

Test temperature:

The temperature inside the incubator at the test vessels was measured and registered continuously by Extech SD200 thermometer and datalogger. Throughout the test the temperature was nearly constant.

Nominal and measured concentrations:

In the test the following nominal concentrations were applied: 0.75; 1; 1.5; 3; 4; 5 and 10 mg/L. The following concentrations were calculated from the measured values and were applied for the statistical evaluation in the test: 0.24; 0.33; 0.52; 1.10; 1.52; 1.83 and 3.80 mg test item/L. The test item concentrations of the abiotic controls were 3.84 (in light) and 4.27 (in darkness) mg/L.

Details on test conditions:

The test organism was grown and hold in OECD medium which was used also for preparing test item solutions. The stock solution was prepared by measuring 15.36 mg of test item into 1 000 ml OECD growth medium. The suspension was stirred till complete dilution of test item. The stock solution was clear and colourless. The nominal concentration of stock solution was 15 mg/L.
As parts of the reported results are based on analytically measured concentration data which are not included in validation range, the toxicity results must be interpreted by precaution!

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.35 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

0.23 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.19 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

LOEC

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

not determinable

Effect concentrations 5

Duration:

72 h

Dose descriptor:

NOEC

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

not determinable

Details on results:

The No Observed Effect Concentration and Lowest Observed Effect Concentration for the test item were calculated by ToxRat® software with Fisher’s exact binominal test with Bonferroni correction for specific growth rate and yield. The results were not conclusive or not determinable.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the Council Regulation (EC) 440/2008 Methoxy-tetraline is hazardous to the aquatic environment and classified into the first acute toxic hazardous category [GHS Acute aquatic hazard Category Acute I. – 72 h EC50 (for algae or other aquatic plants) < 1 mg/].