2,2'-[ethylenebis(oxymethylene)]bisoxirane

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-[ethylenebis(oxymethylene)]bisoxirane

EC Number:

218-746-2

EC Name:

2,2'-[ethylenebis(oxymethylene)]bisoxirane

Cas Number:

2224-15-9

Molecular formula:

C8H14O4

IUPAC Name:

2,2'-[ethylenebis(oxymethylene)]bisoxirane

Test material form:

liquid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

other: secondary effluent of public sewage treatment facility

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): The secondary effluent of Jinju Munsan public sewage treatment facility
- Storage conditions: After transportation of the inoculum, it was aerated for 6 days at 22.0±2.0˚C before use.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 22 ± 2.0°C
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: test bottle
- Number of culture flasks/concentration: 2
- Measuring equipment: BOD meter: WTW, Oxitop® IS12, Germany ; WTW, Oxitop® OC100, Germany

SAMPLING
- Sampling frequency: The oxygen uptake for all bottles was measured automatically by BOD meter and recorded daily over a period of 28 days

CONTROL AND BLANK SYSTEM
- Inoculum blank: mineral medium + inoculum
- Procedure control: reference item + mineral medium + inoculum
- Abiotic sterile control: test item + mineral medium + sterilising agent (HgCl2)
- Toxicity control: test item + reference item + mineral medium + inoculum

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

1.6

Sampling time:

28 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The coefficients of variation of the test suspensions (Bottle 1, 2) were more than 20% at the end of the test due to low BOD concentration. Though this value was higher than guideline specifications, it did not affect the interpretation of results.

Interpretation of results:

not readily biodegradable

Conclusions:

The percentage microbial degradation of the reference item, sodium benzoate was 86.2% at 14 days. These value was within the acceptable range (60% of ThOD within 14 days) specified by the OECD Guidelines and the National Institute of Environmental Research Guidelines.
The oxygen uptake of the inoculum blank (mean of Bottle 3, 4) for 28 days ranged from 0.0 to 12.7 mg O2/L. The pH value of the test suspensions (Bottle 1, 2) were 7.6 at the end of the test. All values met the criteria of test guidelines. Toxicity control (Bottle 7) showed test item had obviously no inhibitory effect on the activity of the inoculum.
The percentage microbial degradation of the test item based on the theoretical oxygen demand (ThOD) was 1.6±1.1% at 28 days. Therefore 2,2’-[ethylenebis(oxymethylene)]bisoxiranecould not be regarded as readily biodegradable in the aquatic environment based on the pass level of biodegradability (60%).

Executive summary:

The purpose of the study was to evaluate the biodegradability of the test item, 2,2’-[ethylenebis(oxymethylene)]bisoxirane, in the aquatic environment. Microbial degradation test was performed for 28 days in compliance with the OECD Guidelines and the National Institute of Environmental Research Guidelines.

The results are as follows:

1) The test temperature during the test period was maintained at 22.3±0.3˚C and the pH values of test suspensions were 7.6 at 28 days. These values met specifications of the test guidelines (22.0±2.0˚C, pH 6.0~8.5).

2) The percentage microbial degradation of the reference item (sodium benzoate) based on the theoretical oxygen demand (ThOD) was 86.2% at 14 days, indicating that the activity of the inoculum was suitable for this test.

3) The percentage microbial degradation of the toxicity control based on ThOD was 46.0% at 14 days, indicating that the test item had obviously no inhibitory effect on the activity of the inoculum.

4) The percentage microbial degradation of the test item based on the ThOD was 1.6±1.1% at 28 days.