Diethyl ethylmalonate

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

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 202 (Daphnia sp. Acute Immobilisation 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. For the stock solution 800.16 mg of test item was measured into 2 000 ml Elendt M4 medium. The emulsion were stirred and ultrasonicated till complete dilution of the test item. The stock solution was clear and colourless. The concentration of stock solutions was determined by validated HPLC method. The measured concentration of the stock solution was 398.98 mg/L.PREPARATION OF TEST SOLUTIONSIn the case of both stock solutions seven dilution levels were prepared by mixing appropriate volume of Elendt M4 medium and stock solution of the test item. The maximum separation factor between of test vessels was 1.6. The following table shows the preparation of the different dilution levels. The volume of the prepared test solutions was 300 ml.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Test species: Daphnia magna StrausAge: < 24 hours neonatesOrigin: National Institute of Environmental HealthCulture conditions: The test species is maintained in Elendt M4 medium with culture conditions at 21±1 °C and a light/dark cycle of 16/8 hours with light intensities of less than 1000 Lux. The cultures are fed with centrifugalized green alga (Pseudokirchneriella subcapitata) cells daily at weekdays.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

The temperature of thermostat was recorded daily and registered continuously by Extech datalogger.- at the start of the test: 21.1 °C- after 24 hours: 21.1 °C- at the end of the test: 21.3 °CThe temperature inside the thermostat at the test vessels was measured and registered continuously by Extech SD200 thermometer and datalogger.

pH:

The pH was measured at the beginning and at the end of the test. At the beginning of the test the pH was measured from the remaining test solutions of the concurrent test vessels at each dilution levels. At the end of the test the pH was measured in each test vessel.

Dissolved oxygen:

The dissolved oxygen was measured at the beginning and at the end of the test. At the beginning of the test the dissolved oxygen was measured from the remaining test solutions of the concurrent test vessels at each dilution levels. At the end of the test the dissolved oxygen was measured in each test vessel.

Nominal and measured concentrations:

The nominal concentration of the stock solutions was 400 mg/L. In the test the following nominal concentrations of test solutions were applied: 400; 300; 260; 200; 160; 100 and 80 mg/L.The following actual concentrations were calculated from the measured values in the test: 381.007; 282.807; 247.809; 189.632; 151.862; 95.205 and 76.974 mg test item/L.

Details on test conditions:

The test was maintained under static conditions for a period of 48 hours.At the start of the study each test vessels contained 50 ml of test solutions and five young daphnids. In the test four replicates total of 20 animals at each test concentration level were investigated. The test vessels were covered with plastic lids and were kept in thermostat at 21 ± 1 °C with a 16/8 hours light/dark cycle. Each control vessels containing five young daphnids in Elendt M4 medium were prepared in four replicates and kept under the same static conditions. The number of immobilised and abnormally behaved daphnids was recorded after 24 and 48h. A daphnia is considered to be immobile if it is not able to swim within 15 seconds after a gentle agitation of the test vessel. The daphnids were not fed during the test.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

182.04 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

223.75 mg/L

Conc. based on:

test mat.

Basis for effect:

mobility

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In this Daphnia sp., Acute Immobilisation Test for diethyl ethylmalonate the results indicated that the test item is not hazardous to the aquatic environment [48 hr EC50 (for Crustacea) > 100 mg/L].