1-bromo-3,4,5-trifluorobenzene

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1995-05-01 to 1995-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Safepharm

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: A mixed population of activated sewage sludge micro-organisms was obtained from the secondary treatment stage of the Severn Trent Water Plc sewage treatment plant at Belper, Derbyshire.
- Preparation of inoculum: The sample of activated sewage sludge was allowed to settle for approximately 1 hour, the supernatant removed and maintained on continuous aeration at a temperature of 21 °C prior to use.

Duration of test (contact time):

28 d

Initial conc.:

4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: According to OECD Guideline
- Test temperature: 21 °C
- Inoculum concentration: 1 drop of inoculum/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 250-300 mL Biological Oxygen Demand (BOD) bottles (darkened glass) with ground glass stoppers.
- Number of culture flasks/concentration: 2
- Measuring equipment: Dissolved oxygen concentrations were determined by means of a Yellow Springs BOD Probe (Model 54) and oxygen meter.

SAMPLING
- Sampling frequency: Dissolved oxygen concentrations for each test media were determined on days 0, 3, 6, 9, 12, 15, 21 and 28

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Toxicity control: yes

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (O2 consumption)

Value:

13

Sampling time:

28 d

Details on results:

Points of degradation plot (test substance):
3 % degradation after 3 d
2 % degradation after 6 d
2 % degradation after 9 d
10 % degradation after 12 d
11 % degradation after 15 d
13 % degradation after 21 d
13 % degradation after 28 d

Toxicity control:
33% degradation after 28 days, thereby confirming that the test material was not toxic to the sewage treatment microorganisms.

Results with reference substance:

Points of degradation plot (reference substance):
29 % degradation after 3 d
52 % degradation after 6 d
71 % degradation after 9 d
74 % degradation after 12 d
75 % degradation after 15 d
77 % degradation after 21 d
77 % degradation after 28 d

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Degradation of the test item was examined in a test according to OECD 301D (Closed Bottle Test). After 28 days, 13% degradation were observed.

Executive summary:

The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days according to OECD TG 301D.The test material was exposed to sewage sludge micro-organisms at a concentration of 4 mg/L with culture medium in sealed culture vessels in the dark at 21°C for 28 days. The degradation of the test material was assessed by the determination of the amount of oxygen consumed. Control solutions with inoculum and the standard material, sodium benzoate, together with a toxicity control were used for validation purposes. The test material attained 13% degradation after 28 days and therefore cannot be considered to be readily biodegradable.

Description of key information

Degradation of the test item was examined in a test according to OECD 301D (Closed Bottle Test). After 28 days, 13% degradation were observed (reference 5.2.1-1).

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The test item was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days according to OECD TG 301D.The test material was exposed to sewage sludge micro-organisms at a concentration of 4 mg/L with culture medium in sealed culture vessels in the dark at 21°C for 28 days. The degradation of the test material was assessed by the determination of the amount of oxygen consumed. Control solutions with inoculum and the standard material, sodium benzoate, together with a toxicity control were used for validation purposes. The test material attained 13% degradation after 28 days and therefore cannot be considered to be readily biodegradable (reference 5.2.1-1).