Ethyl-(3-hydroxypropyl)propanedioic acid

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:

48 h

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

Reference substance name:

Ethyl-(3-hydroxypropyl)propanedioic acid

EC Number:

610-813-8

Cas Number:

52250-47-2

Molecular formula:

C8H14O5

IUPAC Name:

Ethyl-(3-hydroxypropyl)propanedioic acid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Details on test solutions:

The test organism was bred and held in Elendt M4 medium which was also used for preparing of test item solutions.
The preparation of stock and test solutions was based on the preliminary non GLP range finding test [9]. 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 200.29 mg of test item was measured into 1 000 ml Elendt M4 medium. As the calculated active ingredient content of test item is less than 95%, a correction factor was used for the determination of nominal concentration. The value of correction factor is 1.062. The calculated nominal concentration of the stock solution was 188.60 mg/L.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Test species: Daphnia magna Straus
Age: < 24 hours neonates
Origin: National Institute of Environmental Health
Date of arriving: 16 May 2013
Culture 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 stock, breeding and test cultures were kept at the same conditions in thermostat (temperature: 21 ± 1 °C; light/dark cycle: 16/8 hour). These conditions ensure that the reproduction was by parthenogenesis. The temperature of thermostat was recorded daily and registered continuously by Extech datalogger. The temperature inside the thermostat at the test vessels was measured and registered continuously by Extech SD200 thermometer and datalogger.

pH:

The pH and dissolved oxygen were measured at the beginning and at the end of the test.

Dissolved oxygen:

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

Nominal and measured concentrations:

The stock solution was prepared by measuring 200.29 mg of test item into 1 000 ml Elendt M4 growth medium. As the calculated active ingredient content of test item is less than 95%, a correction factor was used for the determination of nominal concentration. The value of correction factor is 1.062. The calculated nominal
concentration of the stock solution was 188.60 mg/L. The toxic property of test item was investigated at six concentrations which were prepared by different dilutions of stock solution of test item. Elendt M4 medium was used for dilution of stock solution. In the test the following calculated concentrations were applied: 188.60; 125.73; 94.30; 62.87; 47.15 and 31.43 mg/L.

Details on test conditions:

At each concentration level four replicates were prepared. Each test vessel contained 5 daphnids in 50 ml test solution. The test vessels were covered with plastic lids and were kept in thermostat at 21 ± 1 °C and 16/8 hours light/dark cycle. The controls were kept under the same conditions in Elendt M4 medium.
Selection of young daphnids: On the first day of the test, all of juvenile daphnids were removed from the selected breeding cultures by sieving. Juvenile daphnids were disposed. Next day the neonates (which are younger than 24 hours) were separated from the parental culture by filtering and were transferred into test vessels.
Preparation of stock solution: The preparation of stock and test solutions was based on the preliminary non GLP range finding test [9]. 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 200.29 mg of test item was measured into 1 000 ml Elendt M4 medium. As the calculated active ingredient content of test item is less than 95%, a correction factor was used for the determination of nominal concentration. The value of correction factor is 1.062. The calculated nominal concentration of the stock solution was 188.60 mg/L.
Preparation of test solutions: Six 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 1.50. The following table shows the preparation of the different dilution levels. The volume of the prepared test solutions was 300 ml.
Test procedure: 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.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

LC10

Effect conc.:

128.75 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

139.99 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The evaluation of the toxic effects of the test item was based on the following calculated concentrations 188.60; 125.73; 94.30; 62.87; 47.15 and 31.43 mg/L.
The statistical analyses of data were performed by ToxRat® software. The effective concentrations (ECx) were calculated with Probit analysis using linear max. Likelihood regression. The EC10, EC20 and EC50 were calculated for immobility at both 24 h and 48 h period.

Reported statistics and error estimates:

The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) of the test item were determined with Fisher’s exact binominal test with Bonferroni correction by ToxRat® software. The value of NOEC was 125.73 mg/L. The calculated value of LOEC was not conclusive.

Applicant's summary and conclusion

Validity criteria fulfilled:

no

Conclusions:

Acute toxic effect of Ethyl-hydroxypropyl malonic acid was investigated in Daphnia sp. Acute Immobilisation test (according to OECD 202 guideline).
The EC50 was 139.99 mg/L at 48 h. In this Daphnia sp., Acute Immobilisation Test for Ethyl-hydroxypropyl malonic acid the results indicated that the test item is not hazardous to the aquatic environment [48 hr EC50 (for Crustacea) > 100 mg/L] .