2-[2-(3,4-dihydro-6-methoxy-1(2H)-naphthylidene)ethyl]-2-ethylcyclopentane-1,3-dione

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:

other: Well documented study according to international accepted guidelines and GLP compliant.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

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:

2-[2-(3,4-dihydro-6-methoxy-1(2H)-naphthylidene)ethyl]-2-ethylcyclopentane-1,3-dione

EC Number:

212-705-2

EC Name:

2-[2-(3,4-dihydro-6-methoxy-1(2H)-naphthylidene)ethyl]-2-ethylcyclopentane-1,3-dione

Cas Number:

850-92-0

Molecular formula:

C20H24O3

IUPAC Name:

2-ethyl-2-[2-(6-methoxy-3,4-dihydronaphthalen-1(2H)-ylidene)ethyl]cyclopentane-1,3-dione

Test material form:

solid: crystalline

Details on test material:

Test item: Ethyl-secodion
CAS No.: 850-92-0
Batch No.: L49030N
Physical state: Solid, crystalline powder
Colour: Beige
Storage: At room temperature, dry place

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

At the start of the test: 21.1 °C
After 24 hours: 21.5 °C
At the end of the test: 21.2 °C

pH:

The pH was measured at each concentration level at the following time points:
- At the start (day 0, test solution I) from the rest test solution.
- At 24h (day 1/a, test solution I) from each test vessels.
- At 24h (day 1/b, test solution II) from the rest test solution.
- At 48h (day 2, test solution II) from each test vessels.
The measured mean values varied in the range of 7.51 - 7.60.

Dissolved oxygen:

The oxygen concentration was measured at each concentration level at the
following time points:
- At the start (day 0, test solution I) from the rest test solution.
- At 24h (day 1/a, test solution I) from each test vessels.
- At 24h (day 1/b, test solution II) from the rest test solution.
- At 48h (day 2, test solution II) from each test vessels.
The measured mean values varied in the range of 5.71 - 5.90 mg/L.

Nominal and measured concentrations:

In the test the following nominal concentrations of test solutions were applied:
test solution I.: 6.22; 5.18; 4.15; 2.07; 1.04; 0.52; and 0.31 mg/L.
test solution II.: 4.71; 3.93; 3.14; 1.57; 0.79; 0.39; and 0.24 mg/L.
The evaluation of toxic effect was based on the average measured concentrations of 4.38; 3.65; 2.93; 1.47; 0.75, 0.38 and 0.24 mg test item/L.

Details on test conditions:

At each concentration level four replicate test vessels were prepared. Each test vessel contained 5 daphnids in 50 ml test solution. The test vessels were covered with plastic lids and were kept in thermostat at 21 ± 1 °C with a 16/8 hours light/dark cycle.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

2.74 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.5 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The NOEC and LOEC were also determined but the results were not conclusive.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this Daphnia magna, Acute Immobilisation Test for Ethyl-secodion (CAS No. 850-92-0) the results indicated that the test item is hazardous to the aquatic environment [GHS Acute aquatic hazard Category Acute II. – 48 hr EC50 (for Crustacea) > 1 mg/L but ≤ 10 mg/L].