Registration Dossier

Diss Factsheets

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

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:
2017-06-15 to 2017-08-15
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
1992-07-17
Deviations:
no
GLP compliance:
yes (incl. QA statement)
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):
Municipal sewage treatment plant, 31137 Hildesheim, Germany
Receipt: 2017-06-08

The activated sludge was washed twice with chlorine free tap water. After the second washing the settled sludge was resuspended in mineral salts medium and was maintained in an aerobic condition by aeration for 2 hours. Thereafter the sludge was homogenized with a blender. After sedimentation the supernatant was decanted and maintained in an aerobic condition by aeration with CO2 free air until test start (6 days). 15 mL/L of this mixture were used to initiate inoculation.

- Concentration of sludge:
15 mL/L of the mixture above were used to initiate inoculation.

- Initial cell/biomass concentration:
Approx. 10E7 - 10E8 CFU/L

Duration of test (contact time):
60 d
Initial conc.:
17 mg/L
Based on:
test mat.
Initial conc.:
10.2 mg/L
Based on:
other: Carbon content in test vessel
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: Mineral salts medium acc. to OECD 301 B / CO2 Evolution Test
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 22±2 °C
- pH: 7.77 and 7.71 on day 60
- pH adjusted: yes/no
- CEC (meq/100 g):
- Aeration of dilution water: 24h
- Suspended solids concentration: not mentioned
- Continuous darkness: Low light conditions (brown glass bottles)
- Other:

TEST SYSTEM
- Culturing apparatus: 5000ml brown glas
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: vessels were aerated for 24 h with CO2 free air
- Measuring equipment:
pH-Meter, Multi 350i, WTW
Thermohygrograph, LUFFT
Ultrasonic bath, SONOREX, BANDELIN
Flow meter, Typ DK 800 PV, KROHNE DUISBURG
Analytical balance, SARTORIUS
Balance, KERN
Dispensette, BRAND
Digital Buret continuous RS, VITLAB
Medo Compressor, REBIE
Magnetic stirrer Mono, VARIOMAG
Multipette X-Stream, EPPENDORF
Various Pipettes

- Test performed in closed vessels due to significant volatility of test substance: -
- Test performed in open system: no: CO2 evolution test
- Details of trap for CO2 and volatile organics if used: according to guideline

SAMPLING
- Sampling frequency:
Determination of CO2 was carried out by titration subsequent to complete adsorption of the released CO2 in an alkaline solution (0.0125 mol/L Ba(OH)2).
For each titration the first gas wash bottle was removed and a new bottle was connected to the last one.
Back titration of the residual Ba(OH)2 with 0.05 N HCl was carried out three times a week during the first ten days and thereafter twice weekly.

- Sampling method: no sampling

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 vessels for inocculum control
- Functional control: one vessel
- Toxicity control: one vessel

Reference substance:
benzoic acid, sodium salt
Key result
Parameter:
% degradation (CO2 evolution)
Remarks:
replicate 1
Value:
18
Sampling time:
28 d
Key result
Parameter:
% degradation (CO2 evolution)
Remarks:
replicate 1
Value:
29
Sampling time:
60 d
Key result
Parameter:
% degradation (CO2 evolution)
Remarks:
replicate 2
Value:
19
Sampling time:
28 d
Key result
Parameter:
% degradation (CO2 evolution)
Remarks:
replicate 2
Value:
23
Sampling time:
60 d

Biodegradation of the Test Item Octadecanoic Acid, reaction products with triethylenetetraminein

Comparison to the Functional Control and Toxicity Control

 

Biodegradation [%]

Study Day [d]

 

 

6

14

21

28

42

53

60

Test Item, 1stReplicate

5

12

15

18

26

26

29

Test Item, 2ndReplicate

8

11

18

19

21

22

23

Functional Control

53

72

76

83

-

-

-

Toxicity Control
test item + reference item

35

49

53

55

59

60

62

CO2-Production and Biodegradation after 60 Days

CO2-Production

Functional

Test Item

Toxicity Control

 

Control

 

test item +
reference item

1

2

Net      [mg/3 L]

107.5

32.6

26.2

149.7

           [mg/L]

35.8

10.9

8.7

49.9

Theor. [mg/3 L]

127.8

112.2

240.0

           [mg/L]

42.6

37.4

80.0

Degradation [%] after 60 d*

83

29

23

62

* For the functional control the last measurement was on day 28.

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
The test item Octadecanoic Acid, reaction products with triethylenetetramine is not readily biodegradable.
The test item did not inhibit the biodegradation of the reference item in the toxicity control.
Executive summary:

The ready biodegradability of Octadecanoic Acid, reaction products with triethylenetetramine was determined with non-adapted activated sludge in a CO2 Evolution Test according to OECD guideline 301 B for a period of 60 days. The test item concentration selected as appropriate was 17 mg/L, corresponding to a carbon content (TOC) of 10.2 mgC/L in the test vessels.

The biodegradation of the test item was followed by titrimetric analysis of the quantity of CO2 produced by the respiration of bacteria. The degradation was stopped on day 60 by acidification of the test solutions. The percentage CO2 production was calculation in relation the theoretical CO2 production of the test item.

In order to check the activity of the test system sodium benzoate was used as functional control. The pass level > 60% was reached within 8 days.

The biodegradation reached a maximum of 84% degradation on day 28.

In the toxicity control containing both test and reference item 49% degradation occurred within 14 days and 62 % after 60 days.

The biodegradation of the reference substance was not inhibited by the test item in the toxicity control.

Both replicates of the test item reached the 10% level (beginning of biodegradation) within 8 days. Both test item replicates did not reach the 60% pass level within the 60-day-period of the study.

The mean biodegradation on day 60 was 26 % (23 and 29 % for the replicates).

The test substance Octadecanoic Acid, reaction products with triethylenetetramine is classified as not readily biodegradable within the 60 day period of the study.

Description of key information

For the test item Octadecanoic Acid, reaction products with triethylenetetramine a test for ready biodegradability was performed according to Guideline OECD301B (17 July 1992).

The duration of the test was extended to 60 days.

Degradation rates of 18% and 19% after 28 days and 29% and 23% after 60 days were observed.

The test item Octadecanoic Acid, reaction products with triethylenetetramine is not readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

The ready biodegradability of Octadecanoic Acid, reaction products with triethylenetetramine was determined with non-adapted activated sludge in a CO2 Evolution Test according to OECD guideline 301 B for a period of 60 days. The test item concentration selected as appropriate was 17 mg/L, corresponding to a carbon content (TOC) of 10.2 mgC/L in the test vessels.

The biodegradation of the test item was followed by titrimetric analysis of the quantity of CO2 produced by the respiration of bacteria. The degradation was stopped on day 60 by acidification of the test solutions. The percentage CO2 production was calculation in relation the theoretical CO2 production of the test item.

In order to check the activity of the test system sodium benzoate was used as functional control. The pass level > 60% was reached within 8 days.

The biodegradation reached a maximum of 84% degradation on day 28.

In the toxicity control containing both test and reference item 49% degradation occurred within 14 days and 62 % after 60 days.

The biodegradation of the reference substance was not inhibited by the test item in the toxicity control.

Both replicates of the test item reached the 10% level (beginning of biodegradation) within 8 days. Both test item replicates did not reach the 60% pass level within the 60-day-period of the study.

The mean biodegradation on day 60 was 26 % (23 and 29 % for the replicates).

The test substance Octadecanoic Acid, reaction products with triethylenetetramine is classified as not readily biodegradable within the 60 day period of the study.