Dodecahydro-3,8,8,11a-tetramethyl-5H-3,5a-epoxynaphth[2,1-c]oxepin

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:

28 June 2017 to 29 November 2017

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)

Version / remarks:

The study was performed according to the guideline, the study plan and its amendment(s).

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

rel-(3S,5aR,7aR,11aR,11bS)-3,8,8,11a-tetramethyldodecahydro-5H-3,5aepoxynaphtho[2,1-c]oxepine

Molecular formula:

C18H30O2

IUPAC Name:

rel-(3S,5aR,7aR,11aR,11bS)-3,8,8,11a-tetramethyldodecahydro-5H-3,5aepoxynaphtho[2,1-c]oxepine

Constituent 2

Reference substance name:

rel-(3R,5aS,7aR,11aR,11bS)-3,8,8,11a-tetramethyldodecahydro-5H-3,5aepoxynaphtho[2,1-c]oxepine

Cas Number:

220432-47-3

Molecular formula:

C18H30O2

IUPAC Name:

rel-(3R,5aS,7aR,11aR,11bS)-3,8,8,11a-tetramethyldodecahydro-5H-3,5aepoxynaphtho[2,1-c]oxepine

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot No.: VE00484383
- Purity: 99.8% (major peak)
- Physical appearance: solid
- Color: whitish to pale yellow
- Water solubility: 0.63 mg/l at 20 °C
- Vapour Pressure: 0.0013 Pa at 20 °C
- Log kow: 5.9; method: OECD Test Guideline 117
- Density: not applicable
- Storage conditions: in a dry, well ventilated location at ambient temperature/10–30 °C, protected from light
- Stability under correct storage conditions (expiry date): August 23, 2017

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples of stock solution and test solutions were taken to determine the actual test item concentrations in comparison to the nominally applied concentrations. The duplicate samples were kept separately as a reserve. The nominal volume per sample was 10 mL. The volume of each sample was recorded. After sampling and before shipment, all samples were stored in amber glass bottles in the dark
at a temperature of ≤ -18°C. A record was kept for each sample. Samples of untreated test medium were provided to the analytical laboratory in order to determine the recovery of the analytical method with the specific test medium. Samples were transferred to the test site for chemical analysis (address see section 1.3 in study report) under the required storage conditions.

The sampling schedule for chemical analysis during the test period was:
- the start of exposure in fresh test solution (hour 0)
- 48 hours, Aged test solution

Test solutions

Vehicle:

no

Details on test solutions:

As the test item is poorly water-soluble, the following approach was used taking into account aspects of OECD 2000, Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures. OECD Series on Testing and Assessment Number 23. ENV/JM/MONO(2000)6.
A saturated stock solution was prepared at a nominal loading rate of 100 mg/L by adding 200 mg of the test item to 2000 mL of the test medium. This stock solution (S1) was slowly stirred (250 rpm) for 139 hours at ambient temperature in the dark. Thereafter this stock solution was left to settle for half an hour. The stock solution was visually examined for undissolved/particulate matter in the free water column. There was still undissolved material visible in the water column.
Thereafter this stock solution was filtered (filter type: Macherey-Nagel MN GF-5; 0.4 μm pore size); the initial 0.5 L of filtrate were discarded. The remaining stock solution was filtered via the same filter. Visual inspection of the flask showed a clear solution without Tyndall effect.
The filtrate of the stock solution was used, immediately and undiluted, as the test concentration (100% of a filtrate of a saturated solution at a loading rate of 100 mg/L).

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

- Species: The test system used in this study was Daphnia magna STRAUS (clone M10), a water flea, cultured at ECT Oekotoxikologie GmbH since December 22, 2011.
- Origin: The organisms were originally supplied by KU Leuven, Belgium
- Food: algae (Desmodesmus subspicatus), instant baker’s yeast suspension, TetraMin® suspension
- Feeding frequency: 4 times per week

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

14.2 °dH

Test temperature:

21.2 °C

pH:

7.9

Dissolved oxygen:

8.7 mg/L

Conductivity:

659 μS/cm

Nominal and measured concentrations:

Nominal concentration: 100% of a saturated solution at a loading rate of 100 mg/L.
Measured concentrations (test period: 0 h) : 1.18 mg test item/L
Measured concentrations (test period: 48 h) : 0.978 mg test item/L

Details on test conditions:

- Test duration: 48 h
- Test units: 60-mL glass beakers, closed by screw-caps
- Volume of test solution per test vessel: 50-60 mL
- Number of daphnids per test vessel: 5
- Target temperature: 18 - 22°C
- Photoperiod: 16 h light / 8 h dark
- Aeration: none
- Feeding during exposure: none
- Test concentrations (nominal): Control; 100% of a saturated solution at a loading rate of 100 mg/L
- Number of replicates per concentration: 4
- Number of replicates in the controls: 4
- Renewal of test solution during exposure: Static, no renewal
- Chemical analysis of test concentrations: At start and at end of exposure

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1.07 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Remarks:

saturated solution at a loading rate of 100 mg test item/L.

Basis for effect:

mobility

Remarks on result:

other: no effects at solubility limit of the test media

Details on results:

In this limit test no immobilities were observed in control or in the undiluted filtrate of a saturated solution at a loading rate of 100 mg test item/L.
It is therefore concluded that the EC50 of the test item at the water saturation level under the conditions of this test is higher than the limit concentration tested (saturated solution at a loading rate of 100 mg test item/L). This corresponds to a geometric mean measured Amberketal concentration of 1.07 mg/L.
The test item concentration was stable during the test period, with 83% of the initially measured concentration found in the aged solution.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this limit test no immobilities were observed in control or in the undiluted filtrate of a saturated solution at a loading rate of 100 mg test item/L.
It is therefore concluded that the test item exhibits no acute toxicity to daphnia at the solubility limit under the conditions of this test (saturated solution at a loading rate of 100 mg test item/L). This corresponds to a geometric mean measured Amberketal concentration of 1.07 mg/L.

Executive summary:

Acute Toxicity Study in Daphnia magna with AMBERKETAL was determined according to OECD guideline No. 202.

The Batch of AMBERKETAL tested was a whitish to pale yellow solid.

As the test item is poorly water-soluble, the following approach was used taking into account aspects of OECD 2000, Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures. OECD Series on Testing and Assessment Number 23. ENV/JM/MONO(2000)6.

A saturated stock solution was prepared at a nominal loading rate of 100 mg/L as described below by adding 200 mg of the test item to 2000 mL of the test medium (section 13.4). This stock solution (S1) was slowly stirred (250 rpm) for 139 hours at ambient temperature in the dark. Thereafter this stock solution was left to settle for half an hour. The stock solution was visually examined for undissolved/particulate matter in the free water column. There was still undissolved material visible in the water column. Thereafter this stock solution was filtered (filter type: Macherey-Nagel MN GF-5; 0.4 μm pore size); the initial 0.5 L of filtrate were discarded. The remaining stock solution was filtered via the same filter. Visual inspection of the flask showed a clear solution without Tyndall effect. The filtrate of the stock solution was used, immediately and undiluted, as the test concentration (100% of a filtrate of a saturated solution at a loading rate of 100 mg/L).

Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to a saturated solution at a loading rate of 100 mg/L. This corresponds to a geometric mean measured Amberketal concentration of 1.07 mg/L. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test ( Day 0 and Day 2).The test item concentration was stable during the test period, with 83% of the initially measured concentration found in the aged solution.The study met the acceptability criteria prescribed by the study plan and was considered valid.

In this limit test no immobilities were observed in control or in the undiluted filtrate of a saturated solution at a loading rate of 100 mg test item/L.

It is therefore concluded that the EC50 of the test item at the water saturation level under the conditions of this test is higher than the limit concentration tested (saturated solution at a loading rate of 100 mg test item/L). This corresponds to a geometric mean measured Amberketal concentration of 1.07 mg/L.