N,N-bis(9,9-dimethylfluoren-2-yl)-4-phenyl-9,9'-spirobi[fluorene]-4'-amine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Justification for type of information:

For this endpoint a one-to-one read across was performed to a chemical similar compound of the same chemical class with a comparable phys. chem. profile and similar response in biological assays. The relevant study was performed according to GLP and the methods applied are fully compliant with OECD TG 301F .
Regarding a full documentation we kindly refer to the pdf document provided in Chapter 13 of this dossier.

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (O2 consumption)

Value:

> 0 - < 10

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

For this endpoint a one-to-one read across was performed to a chemical similar compound of the same chemical class with a comparable phys. chem. profile and similar response in biological assays. The relevant study was performed according to GLP and the methods applied are fully compliant with OECD TG 301F. The result obtained for the read across from the source compound was not readily biodegradable.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-03-02 to 2012-07-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Version / remarks:

July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch: OS11008922
Appearance: pale yellow powder without visible impurities
Released until: August 15, 2016

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Municipal sewage treatment plant, D-31137 Hildesheim

- Pretreatment:
The activated sludge was washed twice with autoclaved tap water. After the second washing the settled sludge was filled up with mineral salts medium and was maintained in an aerobic condition by aeration for 2-4 hours. Thereafter the sludge was homogenized with a blender. The supernatant was decanted and maintained in an aerobic condition by aeration with C02-free air for 5 days. 10 mL/L were used to initiate inoculation.

- Concentration of sludge: 10 mL/L
- Initial cell/biomass concentration: 10^7 - 10^8 CFU/L
- Water: demineralized

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

test mat.

Initial conc.:

57.2 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Preparation of Test Flasks:
All test solutions were prepared in measuring flasks in demineralised water with the required amounts of mineral medium stock solutions and 10 mL/L inoculum. The test item was weighed out and demineralised water was added. After ultrasonic treatment it was transferred into the measuring flasks.

The reference item was weighed out and transferred into the measuring flasks with demineralised water.

250 mL measuring flasks were used to place 250 mL of the test solutions in the brown glass bottles.

A rubber sleeve with soda lime was hung into the opening of the bottles to absorb evolved CO2. The bottles were closed with Oxi-Top® measuring heads and the measuring system was activated.


Measurements:
The temperature in the incubator was documented continuously throughout the test by a hygrothermograph.
At test start the pH-values of the test solutions in the measuring flasks (before dividing) and at test end the pH-values of the test solutions in the brown glass bottles were determined.
The oxygen consumption was determined continuously from the pressure in the incubation vessels by OxiTop® measuring system at 360 measuring points (every 112 minutes) during the 28 d incubation period.

Reference substance:

benzoic acid, sodium salt

Test performance:

Results of the Functional Control
The pass level of a biodegradation > 60 % was reached after 6 days. The validity criterion that the degradation should be > 60 % after 14 d was fulfilled

Results of the Toxicity Control
In the toxicity control the biodegradation achieved 46 % after 14 days. After 28 days the biodegradation came to 54 %. The validity criterion that the test item should not inhibit the biodegradation of the reference item was fulfilled.

Key result

Parameter:

% degradation (O2 consumption)

Value:

> 0 - < 10

Sampling time:

28 d

Details on results:

no biodegradation was observed

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test item is classified as not readily biodegradable in the 10-d-window and after 28 days.

Executive summary:

Objective

The purpose of this assay was to provide information on the biodegradability of the test item in aqueous environment and thus serve as a rational basis for risk assessment for environmental fate in aqueous compartments.

 

Study Design

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 301F

 

Results

The mean oxygen depletion in the inoculum control was 7 .1 mg O₂/L on day 28.In order to check the activity of the test system aniline was used as functional control. The pass level > 60 % was reached after 6 days. The biodegradation rate reached a maximum of 89 % degradation on day 24.

In the toxicity control containing both test and reference item 46 % degradation occurred within 14 days. After 28 days the biodegradation came to 54 %. The degradation of the reference item was not inhibited by the test item.

The biodegradation of the test item in both replicates did not reach the 10 % level (beginning of biodegradation); no biodegradation was determined.

The validity criteria of the guideline are fulfilled.

 

Conclusion

After a test period of 28 days, the test item is classified as not readily biodegradable within the  10-day window.

Description of key information

The substance is not biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

For this endpoint a one-to-one read across was performed to a chemical similar compound of the same chemical class with a comparable phys. chem. profile and similar response in biological assays. The relevant study was performed according to GLP and the methods applied are fully compliant with OECD TG 301F. The result obtained for the read across from the source compound was not readily biodegradable.