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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:
2011-12-07 - 2012-02-29
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The GLP study was conducted according to an internationally accepted guideline. All study parameters are given in detail.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
yes
Remarks:
Temperature range was 18.5 - 20.1 °C instead of 20 - 24 °C. As degradation of the positive control was in the normal range, this is considered as uncritical concerning the outcome of the study.
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
semi-solid (amorphous): gel
Details on test material:
Name: Ukanol FR 70
Batch no.: 4251318
Appearance: white solid
Composition: 9,10-Dihydro-9-oxa~10-[2,3-Di-(2-hydroxyethoxy) carbonylpropyl]-10-phosphaphenanthren-10-oxid; Bis(2-hydroxyethyl)-(6H-dibenz[c,e][1,2]oxaphos-phorin-6-yl-methyl)succinat-P-oxide
CAS No.: 63562-34-5
EINECS-No.: 264-313-6
Molecular formula: C21H23O8P
Molecular weight: 434 g/mo
Purity: app. 90% (HPLC)
Homogeneity: homogeneous

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, adapted
Details on inoculum:
Activated sludge from a biologic sewage treatment plant was used. The chosen plant is treating mostly domestic sewage.

Source and Pre-Treatment:
Source:
The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant, Im Altenschemel, NW-Lachen-Speyerdorf.

Date of collection:
13. Jan. 2012, batch no: 20120113.

Pre-Treatment:

The sludge was filtrated, washed with tap water twice, then washed with and re-sus-pended in test medium. It was then aerated for > 12 hours. The dry matter was determined with 4420 mg suspended solids/litre.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
20 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
The test vessels were aerated with purified (by activated charcoal), C02-scrubbed, moistened air. The scrubbing of carbon dioxide was achieved by bubbling the purified air through a flask containing 1.5 m-NaOH. To control the absence of C02, the air was then led through a flask containing a solution of Ba(OH)2 before reaching the test vessels.
Magnetic stirrers were used to prevent deposition of inoculum.
The emitted C02 was trapped in 0.25-m-NaC)H. Two scrubbers containing 100 mL each were connected in series to the test vessels. The initial IC value of the 0.25 m-NaOH was separately determined in each flask.

From each front scrubber flask, ten samples were taken in order to determine the emitted C02. (on days 0, 2, 4, 7, 9, 11, 14, 18, 23 and 29). The sample volume was 1 mL. The resulting change in the volume of the front flask was considered in the calculation of emitted C02 (see also chapter 8.2.1).

On day 28, 5 mL HCI 2-m. were added to each test flask in order to drive off dissolved C02. On day 29, samples from both scrubber flasks were taken.
Reference substance
Reference substance:
aniline

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
0.8
Sampling time:
2 d
Parameter:
% degradation (CO2 evolution)
Value:
1.9
Sampling time:
7 d
Parameter:
% degradation (CO2 evolution)
Value:
0.5
Sampling time:
14 d
Parameter:
% degradation (CO2 evolution)
Value:
1.2
Sampling time:
18 d
Parameter:
% degradation (CO2 evolution)
Value:
4.2
Sampling time:
29 d
Details on results:
see below

BOD5 / COD results

Results with reference substance:
see below

Any other information on results incl. tables

Degradation values:

Day

Positive Control 1

Positive Control 2

Positive

Control

Mean

Test1

Test2

Test Mean

abiotic Control

Toxicity Control

2

0.8

1.5

1.1

0.6

1.0

0.8

0.0

1.4

4

3.0

16.2

9.6

0.8

1.9

1.3

0.0

6.2

7

33.6

52.9

43.3

1.5

2.3

1.9

0.3

20.4

9

53.8

59.5

56.7

2.1

2.5

2.3

-0.1

22.9

11

62.5

69.0

65.8

1.0

1.7

1.4

-0.8

26.1

14

63.2

78.5

70.8

0.3

0.8

0.5

0.1

28.7

18

86.0

91.7

88.8

1.0

1.4

1.2

0.1

37.6

23

80.5

87.6

84.0

2.4

4.3

3.4

0.2

37.7

29

83.9

75.7

79.8

3.4

5.0

4.2

0.6

35.9

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
Ukanol FR 70 is not readily biodegradable following OECD 301B/EU C.4-C.
Executive summary:

The test item Ukanol FR 70 was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 34.1 mg Ukanol FR 70/L) in test medium following OECD 301B and EU-Method C.4-C. Aniline was chosen as positive control. Activated sludge was used as inoculum (concentration in the test 25 mg dry matter/L). The test was left running for 28 days. All validity criteria were met. Degradation of the positive control was 66 % after eleven days. The following data were determined for the test item Ukanol FR 70: 10-day-window: not detected

degradation at the end of 10-day-window: none

degradation at the end of the test: 4 %

pass level following guideline: 60% at the end of 10-day-window

Therefore, regardless of the 10-day-window, Ukanol FR 70 is not readily biodegradable following OECD 301B/EU C.4-C.