Diethyl ethylmalonate

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Diethyl ethylmalonate

EC Number:

205-093-3

EC Name:

Diethyl ethylmalonate

Cas Number:

133-13-1

Molecular formula:

C9H16O4

IUPAC Name:

1,3-diethyl 2-ethylpropanedioate

Test material form:

liquid

Details on test material:

Test item: diethyl ethylmalonateCAS No.: 133-13-1Physical state: colourless liquidStorage: in cool, dry, well-ventilated place

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION OF STOCK SOLUTIONThe preparation of stock and test solutions was based on the preliminary non GLP range finding test. As the Range Finding Test was not performed in compliance with the GLP-Regulations it is excluded from the Statement of Compliance in the final report, but the raw data of this test are archived under the study code of present study.For the stock solution 800.04 mg of test item was measured into 2 000 ml OECD medium. The emulsion were stirred and ultrasonicated till complete dilution of test item. The stock solution was clear and colourless. The concentration of stock solutions was determined by validated HPLC method. The measured concentration was 401.939 mg/L.PREPARATION OF TEST SOLUTIONSSeven test solutions of different concentration were prepared by mixing appropriate volume of OECD medium and stock solution of the test item. These concentrations were arranged in a geometric series with a maximum separation factor 1.6. Three additional replicates were prepared for controlling the abiotic degradation of the test substance. These test vessels were not inoculated with alga inoculum culture.The volume of the prepared dilution levels was 300 ml except the control solution which was 600 ml.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

Test species: Pseudokirchneriella subcapitata(Korshikov)F.Hindák(formerly known asSelenastrumcapricornutum)Source: UTEX The Culture Collcetion of Algae (USA)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

The temperature inside the incubator at the test vessels was measured and registered continuously by Extech SD200 thermometer and datalogger. Throughout the test the temperature was nearly constant.

pH:

At the beginning of the test the pH values were measured in the remaining test solution of the concurrent test vessels at each dilution level.At the end of the test the pH values were measured in each test vessel. The pH of test solutions was not adjusted at the beginning of the test.

Nominal and measured concentrations:

The nominal concentration of the stock solution was 400 mg/L. In the test the following nominal concentrations were applied: 400; 300; 260; 200; 160; 100 and 80 mg/L.The following concentrations were calculated from the measured values in the test: 360.690; 272.232; 233.909; 177.906; 139.996; 77.406 and 61.085 mg test item/L.

Details on test conditions:

The test organism was grown and hold in OECD medium which was used also for preparing test item solutions.The toxic property of test item was investigated at seven concentrations which were prepared by different dilutions of stock solution of test item. OECD medium was used for preparation and dilution of stock solution.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

167.28 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

195.59 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

263.77 mg/L

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Conc. based on:

test mat.

Remarks on result:

not determinable

Effect concentrations 5

Duration:

72 h

Dose descriptor:

LOEC

Conc. based on:

test mat.

Remarks on result:

not determinable

Details on results:

The values of LOEC and NOEC were also calculated by ToxRat® statistic software but the results were not conclusive or determinable.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Acute toxic effect of Diethyl ethylmalonate was investigated in Freshwater Alga and Cyanobacteria, Growth Inhibition Test (according to OECD 201 guideline). The ErC50 was 263.77 mg/L. According to the Council Regulation (EC) 440/2008 diethyl ethylmalonate is not hazardous to the aquatic [72 hr EC50 (for algae or other aquatic plants) > 100 mg/L].