Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011-07-12
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The reliability is rated 2 because the study followed a standard guideline of reference (OECD 301 B), which describes a procedure designed to evaluate this endpoint. The results were reviewed for reliability and assessed as valid. However the study was not conducted under GLP condition.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report date:
2011

Materials and methods

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

Test material

Constituent 1
Chemical structure
Reference substance name:
tetrakis{9-[2-(ethoxycarbonyl)phenyl]-3,6-bis(ethylamino)-2,7-dimethylxanthylium} C12-(branched and/or linear)-alkyl-(4-sulfonatophenoxy)benzenesulfonate and oxybis[C12-(branched and/or linear)-alkyl-benzenesulfonate]
EC Number:
700-761-5
Molecular formula:
not applicable
IUPAC Name:
tetrakis{9-[2-(ethoxycarbonyl)phenyl]-3,6-bis(ethylamino)-2,7-dimethylxanthylium} C12-(branched and/or linear)-alkyl-(4-sulfonatophenoxy)benzenesulfonate and oxybis[C12-(branched and/or linear)-alkyl-benzenesulfonate]
Details on test material:
- Name of test material (as cited in study report): Sepisol Fast Red SN
- Substance type: Organic salt - UVCB
- Physical state: Red/magenta powder
- Lot/batch No.: 029244
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
- Water solubility: 2 mg/L

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, adapted
Details on inoculum:
- Source of inoculum/activated sludge : Maxéville's (France) wastewater treatment plant, mainly treating domestic wastewater (98%).
- Preparation of inoculum: The sludge was washed by 3 successive centrifugations (1100g for 10 min), after resuspension of the pellet in the mineral medium and filtration with a 100 µm porosity sieve. Then, a measurement of suspended solids is performed.
- Storage conditions: activated sludges are used within 24 hours after sampling
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
14.5 mg/L
Based on:
test mat.
Initial conc.:
10 mg/L
Based on:
other: TOC (total organic carbon)
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Test temperature: 22 +/- 2°C
- Suspended solids concentration: ≤ 30 mg/L in the final mixture

TEST SYSTEM
- Details of trap for CO2 and volatile organics if used: The captured CO2 is measured in a flask containing a solution of barium hydroxide close to the test mixture.

CONTROL AND BLANK SYSTEM
- Inoculum blank: inorganic medium + bacteria, in duplicate.
- Toxicity control: acetic acid (TOC = 10 mg/L) + test item (TOC = 10 mg/L)
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

Test performance:
Study validity:
- The degradation percent of the reference substance = 71% at the 14th day, which is above the 60% threshold.
- The CO2 quantity produced by the "blank control" was 13.7 mg at the end of the study (28thday). This result is below the admitted threshold of 40 mg.
- The toxicity control assay showed a degradation percent of 30% of the reference substance following a 14 days period, so Sepisol Fast Violet Red SN was not considered toxic to the microbial populations in the inoculum.

The study was considered as valid.
% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
27
Sampling time:
28 d

BOD5 / COD results

Results with reference substance:
71% of biodegradation at the 14th day

Any other information on results incl. tables

CO2 produced

CO2 produced in mg

DAYS

1

3

6

8

10

14

15

17

21

24

28

28Bis*

Positive control (Sodium acetate)

9.2

22.4

26.8

32.6

35.6

37.8

37.8

40.9

43.1

46.

46.6

47.7

Sepisol Fast Red SN           Assay 1

2.2

5.3

8.2

12.8

15.

17.9

18.5

18.5

21.2

22.1

22.1

23.2

                                 Assay 2

2.2

4.6

7.0

13.4

15.6

17.8

18.7

19.6

22.2

23.3

23.3

24.2

Toxicity control

4.8

18.0

23.5

27.9

30.1

34.3

37.4

40.0

40.4

41.5

42.2

43.3

Negative control (Mean)

1.0

2.7

3.6

8.2

10.0

12.0

12.0

12.2

12.6

13.0

13.3

13.7

*after adding hydrochloric acid to each test vessel to drive off the carbon dioxide present in the test suspensions (left as carbonates and bicarbonates)

 

CO2 produced following the removal of the blank control values

CO2 produced in mg

DAYS

1

3

6

8

10

14

15

17

21

24

28

28Bis*

Positive control (Sodium acetate)

8.2

19.8

23.2

24.5

25.6

25.8

25.8

28.7

30.6

33.0

33.3

34.1

Sepisol Fast Red SN           Assay 1

1.2

2.7

4.6

4.7

5.0

5.9

6.5

6.3

8.7

9.1

8.8

9.6

                                 Assay 2

1.2

2.0

3.4

5.3

5.6

5.8

6.7

7.4

9.7

10.3

10.0

10.6

Toxicity control

3.8

15.4

19.9

19.8

20.1

22.3

25.4

27.8

27.9

28.5

28.9

29.7

*after adding hydrochloric acid to each test vessel to drive off the carbon dioxide present in the test suspensions (left as carbonates and bicarbonates)

Degradation percentage comparing ThCO2

 

 

DAYS

1

3

6

8

10

14

15

17

21

24

28

28Bis*

Positive control (Sodium acetate)

23%

54%

63%

67%

70%

71%

71%

78%

84%

90%

91%

93%

Sepisol Fast Red SN        Assay 1

3%

7%

12%

13%

14%

16%

18%

17%

24%

25%

24%

26%

                                 Assay 2

3%

5%

9%

14%

15%

16%

18%

20%

26%

28%

27%

29%

                                   Mean

3%

6%

11%

13%

14%

16%

18%

19%

25%

26%

26%

27%

                 Standard Deviation

0%

1%

2%

1%

1%

0%

0%

2%

2%

2%

2%

2%

Toxicity control

3.8

15.4

19.9

19.8

20.1

22.3

25.4

27.8

27.9

28.5

28.9

29.7

*after adding hydrochloric acid to each test vessel to drive off the carbon dioxide present in the test suspensions (left as carbonates and bicarbonates)

 

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not inherently biodegradable
Conclusions:
The test item "Sepisol Fast Red SN" was not considered to be readily biodegradable, with a biodegradation of 27 % after 28 days.
Executive summary:

The test item Sepisol Fast Red SN was tested using the OECD method 301B (CO2 evolution) also named Modified Sturm Test.

Activated sludge from wastewater treatment plant, mainly treating domestic wasterwaters at 98%, was used.

14.5 mg/L of the test material (corresponding to a TOC of 10 mg/L) was added to the mineral medium. The assay was performed in duplicate.

The Theoric CO2 ( ThCO2) quantity was calculated to be 36.6 mg. No organic solvents were used to facilitate the dispersion of the test item.

Each test vessel was connected to a bottle containing 10N of sodium hydroxide solution and to a serie of 2 absorption bottles containing 4g/L of barium hydroxyde solution.

The test was started by bubbling CO2-free air through the suspensions.

CO2 evolution from the test suspensions, inoculum blanks and the reference substance were followed in parallel.

Controls: blank and positive controls (sodium acetate) and toxicity checks were included.

Analytical method: for measurement of evolved C02, the barium hydroxide absorber closely to the test vessel was disconnected and titrated.

Under the test condition, the biodegradation percentage of the test material (10 mg/L of TOC) has been determined as 27% after a 28 days period of incubation. The % of biodegradation of the reference substance, sodium acetate, is greater than 60 % (71%) at the 14thdays. According the guideline OCDE 301, the test item is not considered to be easily biodegradable.