[(2,4-dibromophenoxy)methyl]oxirane

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:

January - May 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

[(2,4-dibromophenoxy)methyl]oxirane

EC Number:

243-606-2

EC Name:

[(2,4-dibromophenoxy)methyl]oxirane

Cas Number:

20217-01-0

Molecular formula:

C9H8Br2O2

IUPAC Name:

2-[(2,4-dibromophenoxy)methyl]oxirane

impurity 1

Reference substance name:

2,4-dibromophenol

EC Number:

210-436-5

EC Name:

2,4-dibromophenol

Cas Number:

615-58-7

Molecular formula:

C6H4Br2O

IUPAC Name:

2,4-dibromophenol

impurity 2

Reference substance name:

[(p-bromophenoxy)methyl]oxirane

EC Number:

218-656-3

EC Name:

[(p-bromophenoxy)methyl]oxirane

Cas Number:

2212-06-8

Molecular formula:

C9H9BrO2

IUPAC Name:

2-[(4-bromophenoxy)methyl]oxirane

impurity 3

Reference substance name:

[(2,4,6-tribromophenoxy)methyl]oxirane

EC Number:

226-140-4

EC Name:

[(2,4,6-tribromophenoxy)methyl]oxirane

Cas Number:

5296-40-2

Molecular formula:

C9H7Br3O2

IUPAC Name:

2-[(2,4,6-tribromophenoxy)methyl]oxirane

Test material form:

liquid

Details on test material:

sample used for testing,
no further details

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: CG272
- Expiration date of the lot/batch: 11. July 2018
- Purity test date: not stated

RADIOLABELLING INFORMATION (if applicable)
not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature
- Stability under test conditions: assumed stable
- Solubility and stability of the test substance in the solvent/vehicle: solubility in water: 68.3 mg/L in water, stability to be tested
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: assumed not reactive

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
none

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly domestic sewage.
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt)
sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf.
Date of collection: 20. Jan. 2017, batch no: 20170120.
- Laboratory culture: not applicable
- Method of cultivation: not applicable
- Storage conditions: re-suspended in test medium. It was then aerated until use.
- Storage length: few days
- Preparation of inoculum for exposure:
- Pretreatment: The sludge was filtrated, washed with tap water (2x), then washed with and re-suspended in test medium. It was then aerated until use.
- Concentration of sludge: The dry matter was determined as 5000 mg suspended solids/L.
- Initial cell/biomass concentration:
- Water filtered: yes
- Type and size of filter used, if any:not stated

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

>= 56.8 - <= 58.5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to Guideline
- Additional substrate: none
- Solubilising agent (type and concentration if used): none
- Test temperature: 19.1 - 21.6 °C
- pH: 6.7 - 7.2
- pH adjusted: no
- CEC (meq/100 g): not stated
- Aeration of dilution water: not stated
- Suspended solids concentration: not stated
- Continuous darkness: not stated
- Other:

TEST SYSTEM
- Culturing apparatus: 2000 mL Schott flasks
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: The test vessels were aerated with purified (by activated charcoal), CO2-scrubbed, moistened
air. The scrubbing of carbon dioxide was achieved by bubbling the purified air
through a flask containing 1.5 M NaOH. To control the absence of CO2, the air was then
led through a flask containing a solution of Ba(OH)2 before reaching the test vessels.
- Method used to create anaerobic conditions: not applicable
- Measuring equipment:
- Test performed in closed vessels due to significant volatility of test substance: closed to maintain CO2 free aeration
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: The emitted CO2 was trapped in 0.25 M NaOH. Two scrubbers containing 100 mL each
were connected in series to the test vessels. The initial IC value of the 0.25 M NaOH was
separately determined in each flask.
- Other:

SAMPLING
- Sampling frequency:
- Sampling method:
- Sterility check if applicable:
- Sample storage before analysis:
- Other:

CONTROL AND BLANK SYSTEM
- Inoculum blank:
- Abiotic sterile control:
- Toxicity control:
- Other:

STATISTICAL METHODS:

Reference substance

Reference substance:

aniline

Results and discussion

Preliminary study:

not performed

Test performance:

Validity criteria:
Parameter Criterion Found Assessment
IC content of test item solution in medium <= 5% of TC > 5% *see below
CO2 emitted by the controls < 70 mg/L 13.2 mg/L valid
Difference within replicates <= 20% 1.2 % valid
Degradation of positive control > 60% ≤ 14 days 7 days valid
Degradation in the toxicity flask on day 14 > 25% 26 % valid
*The IC content of test item in medium was more than 5 % of TC as demanded in the
guideline. This is due to the fact that the test item is very poorly soluble in water. Therefore,
this validity criterion is not applicable for the test item.

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

28 d

Details on results:

 The test item DENACOL EX-147 is considered as “not readily biodegradable“.
 For the test item DENACOL EX-147 no biodegradation was observed after 28 days.
 The 10-day window could not be determined. The criterion of reaching 60% of degradation
after 28 days was not met.
 Abiotic degradation was not observed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

DENACOL EX-147 is considered as “not readily biodegradable”.

Executive summary:

The test item DENACOL EX-147 was tested using a concentration of nominally 20 mg organic

carbon/L (corresponding to 56.9 mg/L test item) in test medium following OECD

301B and EU-Method C.4-C.

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 25.0 mg dry matter/L).

The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 62 % after 7 days.

The following data were determined for the test item DENACOL EX-147:

10-day-window: not detected

degradation at the end of 10-day-window none

degradation at the end of the test 0 %

pass level following guideline: 60% at the end of 10-day-window for pure substances

respective 60 % at the end of the test for mixtures

For the test item DENACOL EX-147 no biodegradation was observed after 28 days. The

10-day window could not be determined. The criterion of reaching 60% of degradation after

28 days was not met. DENACOL EX-147 is therefore considered as “not readily biodegradable”.