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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 01 JUN 1994 to 29 JUN 1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was performed according to the standardised methods and GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report date:
1994

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
α,α,α-trifluoro-o-toluidine
EC Number:
201-806-7
EC Name:
α,α,α-trifluoro-o-toluidine
Cas Number:
88-17-5
Molecular formula:
C7H6F3N
IUPAC Name:
2-(trifluoromethyl)aniline
Test material form:
other: liquid
Details on test material:
Name: orthotrifluoromethylaniline
Batch: 93-52 from 21/04/1994, Rhône-Poulenc Tolochimie, Usine de Toulouse, Chemin de Palayre, Toulouse.
storage condition: at room temperature in aerated cupboard

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, domestic (adaptation not specified)
Details on inoculum:
- Source of inoculum/activated sludge: from influent of a biological water treatment plant of St Germain au Mont d'Or, took of the 31 may 1994
- Laboratory culture: no
- Method of cultivation: no
- Storage conditions: no data
- Storage length: 24 hours
- Preparation of inoculum for exposure: inoculum was prepared by filtration of the influent, on fiberglass pre-filter (to eliminate gross particles), then centrifugation of filtrate. The centrifugation pellet was washed and then maintained in a solution of Ringer 1/4.
- Pretreatment: no
- Concentration of sludge: 2.7*10E7 bacteria/mL
- Initial cell/biomass concentration: the inoculum was used at 1% in the test.
- Water filtered: yes
- Type and size of filter used, if any: glass fibre prefilter then centrifugation of the filtrate
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
20 other: mg/kg
Based on:
other: initial concentration of total carbon (theorical carbon content of the molecule: 52.1% (w/w))
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: KH2PO4 (85 mg), K2HPO4 (217.5 mg), NH4Cl (5 mg), Na2HPO4, 2H2O (334 mg), MgSO4, 7H2O (22.5 mg), CaCl2, 2H2O (36.4 mg), FeCl3, 6H2O (0.25 mg) and bidistilled water (1000 g).
- Additional substrate: no
- Solubilising agent: no
- Test temperature: 20.9°C to 22.7°C (conform to required data for the test: 22 +/-2°C)
- pH: no data
- pH adjusted: no data
- CEC (meq/100 g): no data
- Aeration of dilution water: no data
- Suspended solids concentration: no data
- Continuous darkness: yes
- Other: no

TEST SYSTEM
- Culturing apparatus: glass erlen (5 liters)
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: aerated water
- Method used to create anaerobic conditions: no
- Measuring equipment: carbon dioxide produced is trapped in barium hydroxide and is measured after visual estimation of quantity of formed precipitate.
- Test performed in closed vessels due to significant volatility of test substance: no data
- Test performed in open system: no
- Details of trap for CO2 and volatile organics if used: barium hydroxide
- Other: On the last day of the experiment, all the recipients were acidified with 1 ml of concentrated HCl to decompose all the carbonates and the bicarbonates. Aeration was continued during 24 hours, then a final measurement was carried out on all the barium hydroxy traps.

SAMPLING
- Sampling frequency: 0;1;2;5;7;9;14;21 and 28 days
- Sampling method: no data
- Sterility check if applicable: Preliminary to the test, all the incubation jars and vessels were treated with sulfochromic acid, to destroy any traces of organic matter or toxic substance.
- Sample storage before analysis: no data
- Other: no

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2
- Abiotic sterile control: 1
- Toxicity control: 1
- Other: 1 recipient for procedure control (with reference substance)
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

Test performance:
Remarks: test vessels were not aerated for an unknown duration between day 3 and day 5, because of obstruction of the air treatment column situated upstream. This had no influence on the final conclusion of the assay.
% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
3
Sampling time:
28 d
Parameter:
% degradation (CO2 evolution)
Value:
0
Sampling time:
2 d
Parameter:
% degradation (CO2 evolution)
Value:
1
Sampling time:
14 d
Details on results:
86% after 28 days; 77% after 14 days (validity criteria: >60% at 14 days)

Any other information on results incl. tables

Table of results:

Days

% of biodegradation

 

FE1

FE2

FC

FI

FA

0

0

0

0

0

0

1

0

0

13

6

2

2

0

0

29

15

4

5

0

1

45

23

4

7

1

1

61

30

4

9

0

0

70

30

4

14

1

1

77

37

4

21

2

2

81

41

4

28

3

3

86

46

5

FE1 and FE2: test substance
FC: inoculum control
FA: abiotic control
FI: toxicity control

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
o-TFMA is not readily biodegradable
Executive summary:

In a study (Rhodia, 1994), o-TFMA was tested for its ready biodegradability in a OECD 301B, under GLP conditions.

The biodegradation of o-TFMA was followed during 28 days, at an initial concentration of 20 mg/kg using a sewage domestic (adaptation not specified) inoculum (30 mg/L). After 28 days, the measured percentage of biodegradation was 3%, based on CO2 evolution.

Based on these results, o-TFMA is not readily biodegradable.