3,5-bis(2,4-dimethylcyclohex-3-en-1-yl)polyheterocycle

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:

2019-04-12 to 2019-08-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

The samples were taken from the biological phase of the study.
For the determination of the stability of the test item under the test conditions and of the maintenance of the test item concentrations during the test period, quadruplicate samples from the aged test media of all test concentrations and the control were collected at day 1 (after 24 hours of exposure) and at the end of the test by pouring together the contents of the additional test beakers prepared for the analytical dose verification.
The pH of all samples was adjusted to pH10 using 1 M Sodium hydroxide solution. No further steps were performed until sample preparation.
Samples of the solvent control were not taken since Tween 80 is interfering with the analytical method and would therefore not have been reasonably analysable.

Test solutions

Vehicle:

yes

Details on test solutions:

The test item is not well soluble in test water. To avoid physical effects of undissolved test item on the daphnids, no concentrations far above the solubility limit of the test item in test water was tested. An aqueous solution of the test item in test media with a concentration (nominal: 110 mg/L) as close to saturation as possible (referred to as a ´stock solution´) was obtained first. This stock solution and its dilutions of 1:2, 1:4, 1:8 and 1:16 were prepared for test start and at the renewal period after 24 hours. Samples of the freshly prepared solutions for analytical dose verification were taken before Tween 80 was added to each test concentration at 100 μL/L, after which the
test organisms were introduced for testing.
Additionally, a solvent control (100 μL Tween 80/L) and a control were tested.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Age at Test Start: From 2.00 to 23.00 hours old
Origin: The daphnids introduced in the test were taken from ibacon's in-house laboratory culture.
Breeding Conditions: The daphnids were bred in the laboratories of ibacon under similar temperature and light conditions as used in the test. The cultivation of the parental daphnids was performed in Elendt M4 medium. The test organisms were not first brood progeny. The daphnids in the stock culture were fed at least on all working days with green algae (Desmodesmus subspicatus) freshly grown in the laboratories of ibacon.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

19.6 to 19.8 °C in the freshly prepared media;
19.2 to 20.0°C in the aged test media

pH:

8.0 in the freshly prepared media;
7.9 to 8.0 in the aged test media

Dissolved oxygen:

8.8 to 8.9 mg/L in the freshly prepared media;
8.3 to 9.2 mg/L in the aged test media

Nominal and measured concentrations:

Nominal: 110, 55, 27.5, 13.75 and 6.875 mg test item/L

measured:
The mean measured values in the freshly prepared solutions from test start and the first renewal period after 24 hours are the following: 346 μg test item/L, 200 μg test item/L, 102 μg test item/L, 45.2 μg test item/L, 25.0 μg test item/L
The mean measured values in the 24 hours aged solutions taken after 24 hours and 48 hours are the following: 202 μg test item/L, 70.6 μg test item/L,

Details on test conditions:

photoperiod: 16 h light - 8 h dark; light intensity: 220 to 380 lux

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 110 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

All reported results refer to nominal concentrations (loading rate) since a supersatured stock solution via a water accommodated fraction was prepared.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

After 48 hours of exposure no immobilisation of the test animals was observed in the control and up to and including the highest test item concentration of 110 mg test item/L.

The 48-hour NOEC was determined to be ≥ 110 mg test item/L. The 48-hour LOEC was determined to be > 110 mg test item/L and the 48-hour EC50 value was determined to be > 110 mg test item/L.

Executive summary:

The purpose of this study was to determine the influence of the test item on the mobility of Daphnia magna.
For this purpose, young daphnids (< 24 hours old) were exposed in a semi-static test to various concentrations under defined conditions for 48 hours. The recorded effects were the mobility of the daphnids after 24 and 48 hours.

After 48 hours of exposure no immobilisation of the test animals was observed in the control and up to and including the highest test item concentration of 110 mg test item/L.

The 48-hour NOEC was determined to be ≥ 110 mg test item/L. The 48-hour LOEC was determined to be > 110 mg test item/L and the 48-hour EC50 value was determined to be > 110 mg test item/L.
The initial concentrations and the maintenance of the exposure concentrations during the test were verified in the analytical part. All reported results refer to nominal concentrations (loading rate) since a supersatured stock solution via a water accommodated fraction was prepared.