4-Morpholinepropanal, .alpha.,.alpha.-dimethyl-

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-07-30 to 2013-08-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP and guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

31 May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

13th April 2004

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

April 1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Four replicates samples were taken from the test solutions at the start and at the end of the test. Two samples were taken from the control samples.

Vehicle:

no

Details on test solutions:

- Reconstituted water: ISO medium (according to OECD 202 guideline) was used as dilution water in the experiment.
Separate stock solutions of individual substances were first prepared in deionised water (prepared in the laboratory by MILLIPORE ELIX 3 water purification system). The ISO medium was prepared by adding 25 mL from each of four stock solutions to one litre deionised water.

Test solutions:
A stock solution of 100 mg/L (nominal concentration) was first prepared by dissolving the test item in ISO medium. The test solution of 1 mg/L concentration was prepared by appropriate dilution of this stock solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Species: Daphnia magna (Straus)
- Age at test start: Less than 24 hours old
- Sex: Female
- Origin: Laboratory of Hydrobiology (Central Agricultural Office, Directorate of Plant-, and Soil Protection) 2100 Gödöllő, Kotlán S. u. 3. Hungary
- Breeding conditions: Daphnia were bred in the Laboratory of TOXI-COOP ZRT. under similar temperature and light conditions as in the test, and in reconstituted water of a similar quality regarding to pH, components of the main ions and total hardness as the test water used in the test. The test animals were fed with centrifuged green alga suspension.

ACCLIMATION
Test animals were bred under similar conditions as that used during the exposure period, therefore additional acclimatisation before the test was not necessary.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The reconstituted water (ISO medium) has an approximate theoretical total hardness of 249 mg/L (as CaCO3).

Test temperature:

The test temperature was in the range of 20.1 – 20.7 °C measured in the test and control vessels during the test. The additionally measured ambient temperature within the climate chamber was between 19.7 – 20.8 °C.

pH:

The pH was in the range of 7.73 – 8.11 during the test and not varied by more than 1.5 units in any one test during the test period in the test and control vessels.

Dissolved oxygen:

The dissolved oxygen concentration was in the range of 7.87 – 8.24 mg/L during the test in the test and control vessels.

Nominal and measured concentrations:

Pre-test: 1, 100 mg/L (nominal)
Main-test: 100 mg/L (nominal)
The average measured concentration of the test item in the test solution was 99.06 % of the nominal at the start and 99.51 % of the nominal at the end of the test. There is evidence that the concentration of the tested substance was satisfactorily maintained within ± 20 % of the nominal concentration throughout the test. Therefore the analysis of the results was based on the nominal concentration value.

Details on test conditions:

TEST SYSTEM
- Number of animals: Twenty Daphnia per test group and control, divided into four groups of five animals, each group in approx. 40 mL test medium.
- Test vessel: Glass beakers of approximately 40 mL test medium
- Aeration: no

Pre-Experiments:
In order to select appropriate test concentrations for use in the definitive test, a preliminary range-finding test was conducted to determine the approximate toxicity of the test item. A stock solution of 100 mg/L (nominal concentration) was first prepared by dissolving the test item in ISO medium. The test solution of 1 mg/L concentration was prepared by appropriate dilution of this stock solution. Ten daphnids (divided into two replicates) in each test concentration and control were exposed for 48 hours.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: The light-dark cycle during the test was 16 hours light (artificial illumination) and 8 hours darkness.

TEST CONCENTRATIONS
- Limit test at 100 mg/L (nominal)

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Pre-test:
Significant toxic effects were not observed during the preliminary range-finding test therefore only one test concentration (nominal 100 mg/L) and one control group were applied in a limit test.

Biological Results
- Results after 48 hours: There was no immobilisation observed in twenty daphnids exposed to either test item treated or control group. In addition to immobility, no abnormal behaviour or appearance of test animals was detected. Accordingly, the 48-h NOEC was determined as 100 mg/L.
The 48-h EC50 and LOEC were determined to be higher than 100 mg/L.
The concentration of the test item degradation product was expected to be stable over the test period of 48 hours, therefore the biological results are based on the nominal concentration.

Results with reference substance (positive control):

The date of the last study with reference item Potassium dichromate was: 05 – 06 March 2013.
The 24h EC50 value was determined to be 0.97 mg/L, (95 % confidence limits: 0.81 – 1.14 mg/L).

The measured concentrations of the test item varied between 99 and 100 % of the nominal concentration during the experiment.

Validity criteria fulfilled:

yes

Conclusions:

In a 48-hour acute toxicity test with Daphnia magna the 48 h EC50 value was determined to be higher than 100 mg/L.

Executive summary:

The 48-hour acute toxicity test with Daphnia magna was conducted in accordance with EU method C.2, OECD guideline no. 202 and EPA OPPTS 850.1010 guideline. The 48 h-EC50 value was determined to be higher than 100 mg/L. The 48 h NOEC was determined to be 100 mg/L. The measured concentrations of the test item varied between 99 and 100 % of the nominal concentration during the experiment.Therefore, the results are based on the nominal test item concentrations.

Description of key information

In a 48-hour acute toxicity test with Daphnia magna the 48-h EC50 value was determined to be higher than 100 mg/L.

Additional information

The 48-hour acute toxicity test with Daphnia magna was conducted in accordance with EU method C.2, OECD guideline no. 202 and EPA OPPTS 850.1010 guideline. The 48-h EC50 value was determined to be higher than 100 mg/L. The 48-h NOEC was determined to be 100 mg/L. The measured concentrations of the test item varied between 99 and 100 % of the nominal concentration during the experiment. Therefore, the results are based on the nominal test item concentrations.