Ethyl 3-hydroxypropanoate

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:

2021-11-12 ~ 2022-01-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD Guideline for Testing of Chemicals, Test No. 202: Daphnia sp., Acute Immobilisation Test (Apr 13, 2004)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2022

Report date:

2022

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-hydroxypropanoate

Cas Number:

623-72-3

Molecular formula:

C5H10O3

IUPAC Name:

ethyl 3-hydroxypropanoate

Test material form:

liquid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

1. Solubility test
Solubility test was conducted using the test solution of 100.000 mg/L prepared by stirring (150 ± 30 RPM, 20.0 ± 1.0 ˚C for 0.5, 24, and 48 hours) and ultrasonication (20 kHz, 0.5 hours). The test solution was filtered using a 0.2 μm PVDF syringe filters. Then the 100.000 mg/L nominal concentration test solution was analyzed using the HPLC analyzer.

2. Limit and range finding test (stability test)
Stability tests were conducted using the test solutions of 10.000 and 100.000 mg/L prepared by stirring (150 ± 30 RPM, 20.0 ± 1.0 ˚C, 0.5 hours). The test solutions were collected at 0 and 48 hr and filtered using 0.2 μm PVDF syringe filters. Then the test solutions were analyzed using the HPLC analyzer.

3. Definitive test
Test solutions of the control and 100.000 mg/L were collected at 0 hour and 48 hours and filtered using 0.2 μm PVDF syringe filters. Then the test solutions were analyzed using the HPLC analyzer.

Test solutions

Vehicle:

no

Details on test solutions:

1. Solubility test
Prior to the limit and range finding test, a solubility test was conducted to identify the solubility of the test substance in the dilution water in compliance with ‘Guidance document on aqueous-phase aquatic toxicity testing of difficult test chemicals (OECD Environmental Health and Safety Publications Series on Testing and Assessment No. 23)’.
A test solution of 100.000 mg/L was prepared by adding 0.1025 g of the test substance (purity 97.55 %) to a 1 L volumetric flask and the volume was filled up to the mark with dilution water. Then the test solution was dissolved using a stirrer (150 ± 30 RPM, 20.0 ± 1.0 ˚C for 0.5, 24 and 48 hours) and a ultrasonication (20 kHz, 0.5 hours), and filtered with a 0.2 μm PVDF membrane filter (Lot No. 5402236, Hyundai Micro, Korea) and a vacuum pump (GAST, DOA-P704-AC, IDEX Corporation USA).
In results of the solubility test, the solubility of the test substance prepared after 0.5, 24, and 48 hours stirring were 103.270, 102.856, and 98.961 mg/L, respectively, and the solubility at 0.5 hours of ultrasonication was 106.762 mg/L. Based on the solubility test, stirring (150 ± 30 RPM, 20.0 ± 1.0 ˚C, 0.5 hours) was selected as the preparation method.

2. Limit and range finding test (stability test)
A stock solution of 100.000 mg/L was prepared by adding 0.1025 g of the test substance to a 1 L volumetric flask and dilution water was added to the mark to make the total volume. Then the test substance was dissolved using a stirrer (150 ± 30 RPM, 20.0 ± 1.0 ℃, 0.5 h) and filtered with a 0.2 μm PVDF membrane filter (Lot No. 5402236, Hyundai Micro, Korea) before use. Limit and range finding tests were conducted at the nominal concentrations of 0.500, 1.000, 10.000, 50.000, and 100.000 mg/L. Each test solution was prepared by diluting the stock solution on the initiation of exposure date.

3. Definitive test
A stock solution of 100.000 mg/L was prepared by adding 0.1025 g of the test substance to a 1 L volumetric flask and dilution water was added to the mark to make the total volume. Then the test substance was dissolved using a stirrer (150 ± 30 RPM, 20.0 ± 1.0 ℃, 0.5 h) and filtered with a 0.2 μm PVDF membrane filter (Lot No. 5402236, Hyundai Micro, Korea) before use. The definitive test was conducted at the nominal concentrations of 100.000 mg/L as a limit test. Each test solution was prepared by diluting the stock solution on the initiation of exposure date.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

# Test species information
- Test species : Daphnia magna
- Supplier: Risk Assessment Division, NIER (42, Hwangyeong-ro, Seo-gu, Incheon, 22689, Republic of Korea)
- Justification of selection : Daphnia magna is a suitable animal model for toxicity studies and have been widely used. Abundant data for this species are available for use in the interpretation and evaluation for this type of study.
- Selection of test animal : Young daphnids for the test were derived from healthy brood stock of Daphnia magna emerged more than three times. At the start of exposure, they were aged less than 24 hours.
- Number of animals :
Limit and range finding test Selection: 80 Exposure : 60
Definitive test Selection: 140 Exposure : 40

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

Observations
Each test vessel was checked for immobilities and any abnormalities at 24 and 48 hr after the beginning of exposure. Those animals that were not able to swim within 15 seconds after gentle agitation of the test vessel were regarded as immobility. In addition to immobility, observations were made to identify any abnormal behavior or appearance.

Test conditions

Hardness:

244 mg/L, as CaCO3

Test temperature:

19.9-20.2 ˚C

pH:

7.57-8.01

Dissolved oxygen:

7.25-8.55

Details on test conditions:

- Photo cycle : 16-hr light (08:00-24:00), 8-hr dark cycle (00:00-08:00)
- TOC (mg C/L) < 2.000 1.391 0.795
- Light intensity (lux) 1000-1500 1083-1457 1176-1424
- Rearing vessel Glass beaker (2 L) Glass beaker (100 mL)
- Rearing water M4 medium
- Rearing water
- volume 1 daphind/100 mL 1 daphind/20 mL

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 102.507 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Remarks on result:

not determinable

Details on results:

During the exposure period, temperature, pH, and DO of the test solutions were 19.9-20.2 ˚C, 7.57-8.01, and 7.25-8.55 mg/L, respectively. And light intensity was 1176-1424 lux at the water bath.
Before exposure (0 hour), hardness of test solution was 244 mg/L (as CaCO3) and TOC was 0.795 mg C/L. During the exposure period, the geometric mean of measured concentrations was 102.507 mg/L.
In results of the acute toxicity test of Ethyl 3-hydroxypropanoate in Daphnia magna, the 48-hour EC50 based on the nominal concentration was > 100.000 mg/L. The 48-hour EC50 based on the
measured concentration was > 102.507 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In results of the acute toxicity test of Ethyl 3-hydroxypropanoate in Daphnia magna, the 48-hour EC50 based on the nominal concentration was > 100.000 mg/L. The 48-hour EC50 based on the measured concentration was > 102.507 mg/L.