6,6'-(Ethane-1,2-diylbis(azanediyl))bis(dibenzo[c,e][1,2]oxaphosphinine-6-oxide)“

Biodegradation in water: screening tests

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:

2016-09-22 - 2017-03-29

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Specification
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: 28. Oct. 2016, batch no: 20161028.
Pre-Treatment
The sludge was filtrated, washed with tap water (2x), then washed with and re-suspended in test medium. It was then aerated until use. The dry matter was determined as 3700 mg suspended solids/L.

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance:

aniline

Key result

Parameter:

% degradation (CO2 evolution)

Value:

1.2

Sampling time:

28 d

Degradation Values

In the following table, the percentage biodegradation is presented:

Degradation values in %

Day	Positive Control 1	Positive Control 2	Positive Control Mean	Test 1	Test 2	Test Mean	Abiotic Control	Toxicity Control
2	0.1	-1.9	-0.9	-0.2	-0.9	-0.5	1.0	-0.3
4	33.9	15.9	24.9	0.4	-0.1	0.2	1.1	16.9
7	66.1	42.6	54.3	-0.1	0.8	0.3	1.2	33.0
9	76.0	64.0	70.0	0.8	1.6	1.2	0.7	38.8
11	83.8	78.3	81.1	1.8	2.1	2.0	0.4	42.6
14	87.0	82.8	84.9	1.4	1.7	1.6	0.3	42.8
18	88.0	85.9	86.9	1.3	2.3	1.8	-0.2	43.6
23	88.0	85.0	86.5	1.0	1.3	1.2	-0.7	43.6
29	87.4	85.9	86.6	0.3	2.4	1.3	-0.7	43.2

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The test item EDA-DOPO was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 29.3 mg EDA-DOPO/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 25.0 mg dry matter/L). The test was left running for 28 days.
All validity criteria were met. Degradation of the positive control was 70 % after 9 days.

The following data were determined for the test item EDA-DOPO:
10-day-window: not detected
degradation at the end of the test 1 %
pass level following guideline: 60% at the end of 10-day-window for pure substances respective 60 % at the end of the test for mixtures

Therefore, the test item EDA-DOPO is not readily biodegradable following OECD 301B/EU C.4-C.

Executive summary:

The test item EDA-DOPO was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 29.3 mg EDA-DOPO/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 25.0 mg dry matter/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 70 % after 9 days.

The following data were determined for the test item EDA-DOPO:

10-day-window:       not detected

degradation at the end of the test       1 %

pass level following guideline:        60% at the end of 10-day-window for pure substances respective 60 % at the end of the test for mixtures

Therefore, the test item EDA-DOPO is not readily biodegradable following OECD 301B/EU C.4-C.

Description of key information

The test item EDA-DOPO was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 29.3 mg EDA-DOPO/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 25.0 mg dry matter/L). The test was left running for 28 days.

All validity criteria were met. Degradation of the positive control was 70 % after 9 days.

The following data were determined for the test item EDA-DOPO:

10-day-window:       not detected

degradation at the end of the test       1 %

pass level following guideline:        60% at the end of 10-day-window for pure substances respective 60 % at the end of the test for mixtures

Therefore, the test item EDA-DOPO is not readily biodegradable following OECD 301B/EU C.4-C.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed