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

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

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:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening 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

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Type of inoculum: aerobic mixed bacterial culture
Source: Municipal wastewater treatment plant, Esztergom-Kertváros
Date of arriving: 03 July 2017

Duration of test (contact time):

28 d

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Preparation of inoculum test culture:
Before the test 300 ml stock culture was filtered through a filter with 0.2 mm pore size to remove the bigger insoluble particles and then the dry substance content of the filtrate was determined. The measured value was 10.90 g/L. For preparing the inoculum culture 181.6 ml mineral medium was added to 18.4 ml filtered stock culture. The calculated dry mass of inoculum culture was 1 g/L.

Preparation of reference solution:
For the reference solution 320.01 mg sodium acetate was diluted in 100 ml mineralmedium.

Preparation of test vessels:
Following test vessels were prepared and analysed for the study:
- Test item (in two replicates)
- Blank control (in two replicates)
- Reference solution (positive control)
- Reference and test item solution (toxicity control)
- Sterilized solution of test item (abiotic control)

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

Test performance:

Aerobic biodegradation of the test item was determined by measuring oxygen consumption in an inoculum containing aerobic mixed bacterial culture originated from a municipal wastewater treatment plant and maintained at laboratory conditions. The bacterial culture was not adapted to the test item. The Biochemical Oxygen Demand for 28 days (BOD28) of test item were determined by the manometric respiratory - OxiTop® system. Blank controls, a positive control (reference item), a toxic control and an abiotic control treatment were also included in the study. The test duration was 28 days. Sodium acetate was used as reference item.

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 3

Sampling time:

28 d

Details on results:

According to OECD guideline the test item should be classified as readily biodegradable if the percentage biodegradation reaches 60% of theoretical oxygen demand within 28 day period in a 10-day window. According to the test results Methoxy-tetraline is not readily biodegradable.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Biodegradability classification of the test item is made according to OECD 301 guideline, which says that chemicals which reach or exceeds the pass level (60%) up to 28-d period are
deemed to be readily biodegradable. According to the test results (3%) Methoxy-tetraline is not readily biodegradable.