Oxazolidine, diheptyl~

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:

October 28, 2016 - January, 26 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:

OECD Guideline for Testing of Chemicals No. 202: "Daphnia sp., Acute Immobilisation Test" adopted May 30, 2008

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Duplicate samples from the freshly prepared test media of all test concentrations, the solvent control, and the control were taken at the start of the test and at day 1. 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, duplicate samples from the aged test media of all test concentrations, the solvent control, 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 test beakers of each treatment. The pH value was adjusted to pH 10 with 1 M NaOH directly after sampling. Afterwards the samples were diluted by a factor of two with acetonitrile. Additional samples of the control and the dilution solvent were taken at each sampling time without any sample treatment.
The concentrations of the test item were analysed in the duplicate test media samples from all test concentrations, the solvent control, in the duplicate control samples, and the additional control samples and dilution solvent samples, from all sampling times.

Test solutions

Vehicle:

no

Remarks:

Preliminary tests showed, that biological effects may be significantly influenced by physical effects. These effects could be overcome be the addtion of a small amount of a non-toxic surfactant to break the surface tension.

Details on test solutions:

Pre-Experiments:
Pre-experiments were performed to determine a suitable concentration range and to establish suitable methods to prepare the test solutions. The pre-experiments were not performed in compliance with the GLP-Regulations and will be excluded from the Statement of Compliance in the final report, but the raw data of these tests will be archived under the project number of the present study.

Test Concentrations:
110, 55, 27.5, 13.8 and 6.9 mg test item/L, each containing 100 µL Tween80/L, a solvent control containing 100 µL Tween80/L and a control, Corresponding to geometric mean measured test concentrations of 424, 210, 89.3, 37.8 and 17.4 µg test item/L.

Control:
In the control, test water was used without addition of the solvent or the test item.

Solvent Control:
In the solvent control, test water was used with the solvent (100µL Tween80/L) but without the test item.

Dosage of Test Item:
A water accommodated fraction of the highest test concentration was prepared. The highest test item concentration of 110 mg test item/L was prepared by mixing 110.9 mg test item into 1008 mL test water and 110 mg test item into 1000 mL test water after for test start at 0 hours and water renewal after 24 hours respectively. The solutions were carefully stirred for 24 hours in the dark to dissolve as much of the test item as possible. After cessation of mixing and a following period (1 hour) of settling to allow phase separation, the aqueous phase, i.e. the water accommodated fraction, was drawn off carefully and used as the test medium of the highest test concentration. Serial dilutions of the media were performed to obtain the described test concentrations. In each concentration, 100µL/L Tween80 was introduced. The test media were prepared just before introduction of the daphnids (= start of the test) and test medium renewal on Day 1.

Appearance of the Test Item in Test Medium:
No remarkable observations

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Age at Test Start: From 5 to 21.45 hours old
Sex: Female
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 (see 6.5). 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

Hardness:

2.5 mmol/L (= 250 mg/L) as CaCO3

Test temperature:

Water Temperature in the Test Media during the Test Period

20 to 21 °C in the freshly prepared media;
19 to 20 °C in the aged test media

pH:

8.4 to 8.5 in the freshly prepared media;
7.9 to 8.1 in the aged test media; and thus the pH-value did not vary by more than 1.5 units

Dissolved oxygen:

8.0 to 8.7 mg/L in the freshly prepared media;
8.4 to 8.6 mg/L in the aged test media

Reference substance (positive control):

yes

Remarks:

For the evaluation of the quality of the Daphnia clone and the consistency of the experimental conditions, the reference item potassium dichromate is tested at least twice a year to demonstrate satisfactory test conditions.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 424 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EC10

Effect conc.:

> 424 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 3

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

> 424 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 424 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 5

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

> 424 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 6

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 424 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Effect concentrations 7

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

Effect concentrations 8

Key result

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 110 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The toxic effect of the test item to Daphnia magna was assessed in a semi-static concentration-response test. The 48-hour NOEC was determined to be at least the WAF of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L. The NOEC might even be higher than this concentration, but concentrations in excess of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L or the limit of solubility have not been tested according to the recommendations of the test guidelines. The 48-hour LOEC and the 48-hour EC50 were clearly higher than WAF of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L. These values could not be quantified due to the absence of toxicity of the tested substance up to the WAF of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L, the concentration representing the limit of solubility.
The substance is not toxic at the limit of solubility.

Executive summary:

The toxic effect of the test item toDaphnia magnawas assessed in a semi-static concentration-response test. The 48-hour NOEC was determined to be at least the WAF of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L. The NOEC might even be higher than this concentration, but concentrations in excess of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L or the limit of solubility have not been tested according to the recommendations of the test guidelines. The 48-hour LOEC and the 48-hour EC₅₀were clearly higher than WAF of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L. These values could not be quantified due to the absence of toxicity of teh Substance up to the WAF of nominal 110 mg test item/L, corresponding to a geometric mean measured concentration of 424 µg test item/L, the concentration representing the limit of solubility.