Ethyl 3-hydroxypropanoate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Remarks:

Microbial degradation test (ready) of Ethyl 3-hydroxypropanoate

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2022.03.08 ~ 2022-05-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD guidelines for the testing of chemicals 301 C “MODIFIED MITI TEST(I)” (Adopted : 17 July 1992)

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 301 C (Ready Biodegradability: Modified MITI Test (I))

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

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

mixture of sewage, soil and natural water

Remarks:

Cultured samples which is selected and taken water from ten sites such as river, lake, sewage treatment work and industrial waste-water treatment work in February, May, August and November (four times a year) were used in the test and the collected.

Details on inoculum:

Inoculum samples which were collected from various sites were mixed and then they were filtered through filter paper after removing floating matter. Filtered supernatant was put into 2 L glass bottle, moved into the incubation chamber and provided oxygen for about 23.5 hours. After that, they were stopped to provide oxygen for thirty minutes. One-third of the whole volume supernatant was removed and the supernatant was provided oxygen again after the equal volume of a solution containing 0.1 % each of glucose, peptone and potassium orthophosphate was put into 2 L glass bottle. After checking that more than of 107 cells/mL lived in Nutrient Agar medium, the cultured inoculum was used in the test.

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

ca. 100 mg/L

Based on:

not specified

Initial test substance concentration 2

Initial conc.:

ca. 162.53 other: mg O2/L

Based on:

ThOD

Details on study design:

# Incubation of Inoculum
- Incubation room : Biodegradability test room
- Incubator : HB-103M, Hanbaek scientific technology, Korea
- Temperature : (23 - 27)℃
- Vessel : 2 L glass bottle
- Photoperiod : Dark condition
- pH : 7 ± 1
- Dissolved oxygen : ＞5 mg/L
- Culture medium : 0.1 % each of glucose, peptone and potassium orthophosphate
- {mixture (inoculum) was adjusted to pH 7 ± 1 with sodium hydroxide}
- Medium renewal : Every 24 h

# Test room : Biodegradability test room
- Incubator : HB-103M, Hanbaek scientific technology, Korea
- BOD meter : Automatic recording BOD meter with stirring (OxiTopⓇ-C)
- Inoculum : Cultured inoculum for more than 1 month
- Temperature : (24 - 26) ℃
- Test period : 28 day
- Light : Dark condition

Reference substance

Reference substance:

other: Sodium benzoate

Results and discussion

% Degradation

% Degradation 1

Key result

Parameter:

% degradation (O2 consumption)

Remarks:

Based on these results, the percentage degradation of test substance [Ethyl 3-hydroxypropanoate] by BOD meter were 81.3, 77.6 and 81.3 % (mean : 80.0 %), respectively.

Value:

ca. 77.6 - 81.3

St. dev.:

2.1

Sampling time:

28 d

% Degradation 2

Parameter:

% degradation (test mat. analysis)

Remarks:

A result of the analysis after 28 days, abiotic control and test substance treatment group were 93.3, 0.0, 0.0 and 0.0 mg/L, respectively. Based on these results, the percentage degradation of test substance by analysis were 100.0 %.

Value:

ca. 100

Sampling time:

28 d

Details on results:

It is considered that there will be ready biodegradation by microorganism in aquatic environment in that the degradation percentage measured by BOD meter was more than 60 % according to the OECD guidelines.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The test substance could be concluded to be readily degradable by microorganism in the aquatic environment based on the OECD pass level of biodegradability (60 %).

Interpretation of results:

readily biodegradable

Conclusions:

The microbial degradation rate of the reference substance, sodium benzoate, was met OECD specification which the microbial degradation rate was more than 40 % after 7 days and more than 65 % after 14 days. Therefore, the activity of the inoculum used in the test was suit.
The BOD value (0 - 16.9 mg O2/L) of the inoculum blank used in the microbial degradation test for 28 days was suit for the OECD specification (less than 60 mg O2/L).
The pH range (test bottle 2, 3, 4, 6) was suit for 6.0-8.5.
The temperature of the incubator was suit for OECD specification which its range is 24 ℃ - 26 ℃.
The deviation of the microbial degradation rate of the test bottle 2, 3 and 4 was suit for OECD specification (less than 20 %)