Registration Dossier

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:
2018-06-28 to 2018-07-27
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
1992
GLP compliance:
yes (incl. certificate)
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
- Laboratory culture/ Method of cultivation:
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 with CO2 free air until one day before test start (1 day).
- Pretreatment: no
- Concentration of sludge: 14 mL/L of the mixture above were used to initiate inoculation. () 25.0 mg/L dw)
- Initial cell/biomass concentration: approx. 10E7 - 10E8 CFU/L
- Water filtered: no information
Duration of test (contact time):
28 d
Initial conc.:
10.7 mg/L
Based on:
other: Carbon content (TOC) in test vessel
Initial conc.:
16 mg/L
Based on:
test mat.
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 measured 20.5 - 23 °C
- pH: 7.6
- Aeration of dilution water: 30 - 100 mL/min
- Suspended solids concentration: not mentioned
- Continuous darkness: Low light conditions (brown glass bottles)

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; 30 - 100 mL/min

- 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 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.
On day 28 the pH of all solutions was measured prior to acidification.
- Sampling method: no sampling

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 vessels for inocculum control
- Toxicity control: one vessel
Reference substance:
benzoic acid, sodium salt
Key result
Parameter:
% degradation (CO2 evolution)
Value:
3
Sampling time:
28 d

CO2-Production and Biodegradation in the Inoculum Control and Test Item Samples

Study Day

Date

Inoculum
Control

Test Item

Replicate 1

Replicate 2

 

 

[mg CO2/3 L]

[mg CO2/3 L]

Degr.

[mg CO2/3 L]

Degr.

 

 

mv

Gross

Net Sum

[%]

Gross

Net Sum

[%]

1

2018-06-29

4.4

5.5

1.1

1

5.6

1.2

1

4

2018-07-02

12.8

14.9

3.2

3

14.0

2.4

2

6

2018-07-04

16.1

14.4

3.2

3

15.3

2.4

2

8

2018-07-06

12.5

10.7

3.2

3

11.9

2.4

2

11

2018-07-09

16.0

13.0

3.2

3

15.0

2.4

2

14

2018-07-12

13.8

11.6

3.2

3

12.0

2.4

2

18

2018-07-16

16.2

12.2

3.2

3

15.1

2.4

2

21

2018-07-19

14.7

11.0

3.2

3

11.6

2.4

2

25

2018-07-23

15.5

12.5

3.2

3

11.2

2.4

2

28

2018-07-26

12.4

10.5

3.2

3

8.5

2.4

2

29*

2018-07-27

8.8

7.8

3.2

3

6.2

2.4

2

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
Under the test conditions Octadecanoic acid, reaction products with acetic acid and tetraethylenepentamine is classified as not readily biodegradable within the 28 day period of the study.
Executive summary:

The ready biodegradability ofOctadecanoic acid, reaction products with acetic acid and tetraethylenepentaminewas determined with a non-adapted activated sludge over a test period of 28 days in the Modified Sturm Test. The study was conducted according to OECD 301 B.The test item was tested at a concentration of16 mg/L with 2 replicates corresponding to a carbon content (TOC) of10.7 mg C/L in the test vessels.The test vessels were incubated at low light conditions and at a temperature of 22 ± 2 °C.

The biodegradation of the test item was followed by titrimetric analysis of the quantity of CO2produced by the respiration of bacteria. The degradation was stopped on day 28 by acidification of the test solutions. The last titration was made on day 29 after residual CO2had been purged from the test solutions over a period of 24 hours. The percentage CO2production was calculated in relation to the theoretical CO2production (ThCO2) of the test item. The biodegradation was calculated for each titration time.

 

To check the activity of the test system sodium benzoate was used asfunctional control. The percentage degradation of the functional control reached the pass level of 60% within 8 days and a maximum biodegradation of 86% on day 28. In the toxicity control containing both test and reference item a biodegradation of 42% was determined within 14 days, with 42% after 28 days. The biodegradation of the reference item was not inhibited by the test itemin the toxicity control.

 

Both test item replicates did not reach the 10% level (beginning of biodegradation) within the 28 day period of the study. The mean biodegradation on day 28 was 3%.

Under the test conditions Octadecanoic acid, reaction products with acetic acid and tetraethylenepentamine is classified as not readily biodegradable within the 28 day period of the study.

Description of key information

Under the test conditions Octadecanoic acid, reaction products with acetic acid and tetraethylenepentamine is classified as not readily biodegradable within the 28 day period of the study.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed
Type of water:
freshwater

Additional information

The ready biodegradability ofOctadecanoic acid, reaction products with acetic acid and tetraethylenepentaminewas determined with a non-adapted activated sludge over a test period of 28 days in the Modified Sturm Test. The study was conducted according to OECD 301 B. The test item was tested at a concentration of16 mg/L with 2 replicates corresponding to a carbon content (TOC) of 10.7 mg C/L in the test vessels.The test vessels were incubated at low light conditions and at a temperature of 22 ± 2 °C.

The biodegradation of the test item was followed by titrimetric analysis of the quantity of CO2produced by the respiration of bacteria. The degradation was stopped on day 28 by acidification of the test solutions. The last titration was made on day 29 after residual CO2had been purged from the test solutions over a period of 24 hours. The percentage CO2production was calculated in relation to the theoretical CO2production (ThCO2) of the test item. The biodegradation was calculated for each titration time.

 

To check the activity of the test system sodium benzoate was used asfunctional control. The percentage degradation of the functional control reached the pass level of 60% within 8 days and a maximum biodegradation of 86% on day 28.In the toxicity control containing both test and reference item a biodegradation of 42% was determined within 14 days, with 42% after 28 days. The biodegradation of the reference item was not inhibited by the test itemin the toxicity control.

 

Both test item replicates did not reach the 10% level (beginning of biodegradation) within the 28 day period of the study. The mean biodegradation on day 28 was 3%.

Under the test conditions Octadecanoic acid, reaction products with acetic acid and tetraethylenepentamine is classified as not readily biodegradable within the 28 day period of the study.