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Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:
biodegradation in water: sewage treatment simulation testing
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD 301 B/CO2 Development test
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report):CAS-No 68512-53-8
- Molecular formula (if other than submission substance):
- Molecular weight (if other than submission substance):
- Smiles notation (if other than submission substance):
- InChl (if other than submission substance):
- Structural formula attached as image file (if other than submission substance): see Fig.
- Substance type:
- Physical state:liquid
- Analytical purity:not specified
- Impurities (identity and concentrations):
- Composition of test material, percentage of components:
- Isomers composition:
- Purity test date:
- Lot/batch No.:ESD801441
- Expiration date of the lot/batch:2003-07-12
- Radiochemical purity (if radiolabelling):
- Specific activity (if radiolabelling):
- Locations of the label (if radiolabelling):
- Expiration date of radiochemical substance (if radiolabelling):
- Stability under test conditions:stable (ca. 0.1% aqueous solution)
- Storage condition of test material:
- Other:
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
none
Radiolabelling:
not specified

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on source and properties of surface water:
none given
Details on source and properties of sediment:
- Details on collection (e.g. location, sampling depth, contamination history, procedure):Municipal sewage treatment plant, 0-31 137 Hildesheim
- Storage conditions:
- Storage length:
- Textural classification (i.e. %sand/silt/clay):
- pH at time of collection:
- Organic carbon (%):
- Redox potential (mv) initial/final:
- CEC (meq/100 g):
- Bulk density (g/cm³):
- Biomass (e.g. in mg microbial C/100 mg, CFU or other):Colony forming units of the inoculum 10 to the 7th- 1O to the 8th CFU/L
Colony forming units in the test vessels 1O to the 5th - IO to the 6th CFU/L
- Sediment samples sieved: yes filtered
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):Municipal sewage treatment plant, 0-31 137 Hildesheim
- Laboratory culture:Colony forming units in the test vessels 1O to the 5th - IO to the 6th CFU/L
- Method of cultivation:The necessary amounts of aqua bidest., nutrient media and inoculum
were placed in each of the incubation vessel.
- Storage conditions:20-24 deg C
- Storage length:
- Preparation of inoculum for exposure:
- Pretreatment:The activated sludge was maintained in an aerobic condition by aeration for four hours and then homogenized with a mixer. The
sludge was filtered and the filtrate (30 mL) was subsequently used to initiate inoculation.
- Concentration of sludge:
- Initial cell/biomass concentration:
Initial test substance concentration
Initial conc.:
30 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

Test performance:
PERFORMANCE OF
THE TEST
The theoretical C02 production (ThCOz) was calculated based on
the carbon content (TOC) of the test item.
The following test solutions were prepared in 5 L brown glass
bottles as incubation vessels:
two incubation vessels for the test item concentration (PI, P2)
e one incubation vessel for the reference item (R1)
0 three incubation vessels for the inoculum control ((21, C2, C3)
e one incubation vessel for the toxicity control (TI)
% Degradation
% Degr.:
ca. 78
Parameter:
CO2 evolution
Sampling time:
3 wk
Transformation products:
not specified

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test item must be regarded to be
in the 10-d-window, but after 16 days the level of a biodegradation of more than 60 % was
passed.
not readily biodegradable
The validity criteria according to the guideline are fulfilled.
Executive summary:

The ready biodegradability was determined with a non adapted activated sludge for the test item CAS-NO. 68512-53-8 (batch no.: ESDB01441) over a test period of 28 days in the Modified Sturm Test. The study was conducted from 2002-03-14 to 2002-04-12 according to OECD 301 B/COz evolution test in the DR.U.NOACK-LABORATORFIUOMR A NGEWANDTE BIOLOGIE. The test item was tested in a concentration of 30 mg/L in duplicates, corresponding to a carbon content (TOC) of 11.1 mgC/L in the test vessels. The biodegradation of the test item was followed by titrimetric analyses of the quantity of Cop, which was produced by the respiration of bacteria. The degradation was finished on day 28 by acidification, the last titration was made on day 29, after the soluble C02 was turned out over a period of 24 h. The C02 production was calculated as the percentage of total COZ that the test item could have theoretically produced based on carbon content. Biodegradation is therefore expressed as percentage ThC02 and was calculated for each titration of COZ. , In order to check the activity of the test system sodium acetate was used as functional control. The percentage degradation of the functional control reached the pass level of > 60 % after 7 days. After 14 days a degradation rate of 78 % was reached. The validity criterion of the guideline is fulfilled. In the toxicity control containing both test and reference item a biodegradation rate of 50 % occurred within 14 days and came to a maximum of 68 % after 28 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control. The biodegradation of the test item is shown graphically in Figure 1 in comparison to the readily degradable functional control and the toxicity control. The 10 % level (beginning of biodegradation) was reached after an adaptation phase of 3 days. In the 10-d-window a mean biodegradation rate of 52 % was reached. After 14 days the biodegradation came to 56 % and after 16 days the level of 60 % was passed. The mean biodegradation came to a maximum of 82 % after 28 days. The test item must be regarded to be in the 10-d-window, but after 16 days the level of a biodegradation of more than 60 % was passed. not readily biodegradable The validity criteria according to the guideline are fulfilled.